0000950170-24-121737 | 10-Q | XBRL Viewer

Derivatives and Risk Management

9 Months Ended

Sep. 30, 2024

Derivative Instruments and Hedges, Assets [Abstract]

NOTE 5. DERIVATIVES AND RISK MANAGEMENT

Energy Commodity Derivatives

Avista Corp. is exposed to market risks relating to changes in electricity and natural gas commodity prices and certain other fuel prices. Market risk is, in general, the risk of fluctuation in the market price of the commodity being traded and is influenced primarily by supply and demand. Market risk includes the fluctuation in the market price of associated derivative commodity instruments. Avista Corp. utilizes derivative instruments, such as forwards, futures, swap derivatives and options, to manage the various risks relating to these commodity price exposures. Avista Corp. has an energy resources risk policy and control procedures to manage these risks.

As part of Avista Corp.'s resource procurement and management operations in the electric business, Avista Corp. engages in an ongoing process of resource optimization, which involves the economic selection from available energy resources to serve Avista Corp.'s load obligations and the use of these resources to capture available economic value through wholesale market transactions. These include sales and purchases of electric capacity and energy, fuel for electric generation, and derivative contracts related to capacity, energy and fuel. Such transactions are part of the process of matching resources with load obligations and hedging a portion of the related financial risks. These transactions range from terms of intra-hour up to multiple years.

As part of its resource procurement and management of its natural gas business, Avista Corp. makes continuing projections of its natural gas loads and assesses available natural gas resources including natural gas storage availability. Natural gas resource planning typically includes peak requirements, low and average monthly requirements and delivery constraints from natural gas supply locations to Avista Corp.’s distribution system. However, daily variations in natural gas demand can be significantly different than monthly demand projections. Based on these projections, Avista Corp. plans and executes a series of transactions to hedge a portion of its projected natural gas requirements through forward market transactions and derivative instruments. These transactions may extend as much as three natural gas operating years (November through October) into the future. Avista Corp. also leaves a significant portion of its natural gas supply requirements unhedged for purchase in short-term and spot markets.

Avista Corp. plans for sufficient natural gas delivery capacity to serve its retail customers for a theoretical peak day event. Avista Corp. generally has more pipeline and storage capacity than what is needed during periods other than a peak-day. Avista Corp. optimizes its natural gas resources by using market opportunities to generate economic value that mitigates the fixed costs. Avista Corp. also optimizes its natural gas storage capacity by purchasing and storing natural gas when prices are traditionally lower, typically in the summer, and withdrawing during higher priced months, typically during the winter. However, if market conditions and prices indicate that Avista Corp. should buy or sell natural gas at other times during the year, Avista Corp. engages in optimization transactions to capture value in the marketplace. Natural gas optimization activities include, but are not limited to, wholesale market sales of surplus natural gas supplies, purchases and sales of natural gas to optimize use of pipeline and storage capacity, and participation in the transportation capacity release market.

The following table presents the underlying energy commodity derivative volumes as of September 30, 2024 expected to be delivered in each respective year (in thousands of MWhs and mmBTUs):


	Purchases								Sales
	Electric Derivatives				Gas Derivatives				Electric Derivatives				Gas Derivatives
Year	Physical (1) MWh		Financial (1) MWh		Physical (1) mmBTUs		Financial (1) mmBTUs		Physical (1) MWh		Financial (1) MWh		Physical (1) mmBTUs		Financial (1) mmBTUs
Remainder 2024		6		—		12,866		19,734		194		408		581		2,690
2025		—		—		24,248		29,315		348		175		1,115		1,125
2026		—		—		14,663		10,765		—		—		—		—
2027		—		—		3,910		1,350		—		—		—		—

As of September 30, 2024, there were no expected deliveries of energy commodity derivatives after 2027.

The following table presents the underlying energy commodity derivative volumes as of December 31, 2023 expected to be delivered in each respective year (in thousands of MWhs and mmBTUs):


	Purchases								Sales
	Electric Derivatives				Gas Derivatives				Electric Derivatives				Gas Derivatives
Year	Physical (1) MWh		Financial (1) MWh		Physical (1) mmBTUs		Financial (1) mmBTUs		Physical (1) MWh		Financial (1) MWh		Physical (1) mmBTUs		Financial (1) mmBTUs
2024		9		—		22,747		74,596		472		510		1,723		12,038
2025		—		—		12,505		19,590		11		96		1,115		1,125
2026		—		—		5,570		3,940		—		—		—		—

As of December 31, 2023, there were no expected deliveries of energy commodity derivatives after 2026.

(1)

Physical transactions represent commodity transactions in which Avista Corp. will take or make delivery of either electricity or natural gas; financial transactions represent derivative instruments with delivery of cash in the amount of the benefit or cost but with no physical delivery of the commodity, such as futures, swap derivatives, options, or forward contracts.

The electric and natural gas derivative contracts above will be included in either power supply costs or natural gas supply costs during the period they are scheduled to be delivered and will be included in the various deferral and recovery mechanisms (ERM, PCA and PGAs), or in the general rate case process, and are expected to be recovered through retail rates from customers.

Foreign Currency Exchange Derivatives

A significant portion of Avista Corp.’s natural gas supply (including fuel for power generation) is obtained from Canadian sources. Most of those transactions are executed in U.S. dollars, which avoids foreign currency risk. A portion of Avista Corp.’s short-term natural gas transactions and long-term Canadian transportation contracts are committed based on Canadian currency prices. The short-term natural gas transactions are settled within 60 days with U.S. dollars. Avista Corp. hedges a portion of the foreign currency risk by purchasing Canadian currency exchange derivatives when such commodity transactions are initiated. The foreign currency exchange derivatives and the unhedged foreign currency risk have not had a material effect on Avista Corp.’s financial condition, results of operations or cash flows and these differences in cost related to currency fluctuations are included with natural gas supply costs for ratemaking.

The following table summarizes the foreign currency exchange derivatives outstanding as of September 30, 2024 and December 31, 2023 (dollars in thousands):


	September 30,		December 31,
	2024		2023
Number of contracts		27		5
Notional amount (in United States dollars)	$	1,660	$	81
Notional amount (in Canadian dollars)		2,251		109

Interest Rate Swap Derivatives

Avista Corp. is affected by fluctuating interest rates related to a portion of its existing debt, and future borrowing requirements. Avista Corp. may hedge a portion of its interest rate risk with financial derivative instruments, including interest rate swap derivatives. These interest rate swap derivatives are considered economic hedges against fluctuations in future cash flows associated with anticipated debt issuances.

The following table summarizes the unsettled interest rate swap derivatives outstanding as of September 30, 2024 and December 31, 2023 (dollars in thousands):


Balance Sheet Date	Number of Contracts		Notional Amount		Mandatory Cash Settlement Date
September 30, 2024		1	$	10,000	2025
December 31, 2023		2	$	20,000	2024
		1		10,000	2025

See Note 9 for discussion of the remarketed bonds and the related settlement of interest rate swaps in connection with the pricing of the bonds in March 2024.

Summary of Outstanding Derivative Instruments

The amounts recorded on the Condensed Consolidated Balance Sheet as of September 30, 2024 and December 31, 2023 reflect the offsetting of derivative assets and liabilities where a legal right of offset exists.

The following table presents the fair values and locations of derivative instruments recorded on the Condensed Consolidated Balance Sheet as of September 30, 2024 (in thousands):


	Fair Value
Derivative and Balance Sheet Location	Gross Asset		Gross Liability			Collateral Netted		Net Asset (Liability) on Balance Sheet
Foreign currency exchange derivatives
Other current assets	$	7	$	—		$	—	$	7
Interest rate swap derivatives
Other non-current liabilities and deferred credits		—		(75	)		—		(75	)
Energy commodity derivatives
Other current assets		7,612		(834	)		—		6,778
Other property and investments-net and other non-current assets		1,594		—			—		1,594
Other current liabilities		10,161		(54,972	)		17,199		(27,612	)
Other non-current liabilities and deferred credits		2,028		(16,330	)		2,716		(11,586	)
Total derivative instruments recorded on the balance sheet	$	21,402	$	(72,211	)	$	19,915	$	(30,894	)

The following table presents the fair values and locations of derivative instruments recorded on the Condensed Consolidated Balance Sheet as of December 31, 2023 (in thousands):


	Fair Value
Derivative and Balance Sheet Location	Gross Asset		Gross Liability			Collateral Netted		Net Asset (Liability) on Balance Sheet
Foreign currency exchange derivatives
Other current assets	$	2	$	—		$	—	$	2
Interest rate swap derivatives
Other current assets		3,667		—			—		3,667
Other non-current liabilities and deferred credits		—		(182	)		—		(182	)
Energy commodity derivatives
Other current assets		8,531		(379	)		—		8,152
Other current liabilities		19,510		(79,082	)		42,355		(17,217	)
Other non-current liabilities and deferred credits		2,913		(20,633	)		—		(17,720	)
Total derivative instruments recorded on the balance sheet	$	34,623	$	(100,276	)	$	42,355	$	(23,298	)

Exposure to Demands for Collateral

Avista Corp.'s derivative contracts often require collateral (in the form of cash or letters of credit) or other credit enhancements, or reductions or terminations of a portion of the contract through cash settlement. In the event of changes in market prices or a downgrade in Avista Corp.'s credit ratings or other established credit criteria, additional collateral may be required. In periods of price volatility, the level of exposure can change significantly. As a result, sudden and significant demands may be made against Avista Corp.'s credit facilities and cash. Avista Corp. actively monitors the exposure to possible collateral calls and takes steps to mitigate capital requirements.

The following table presents collateral outstanding related to its derivative instruments as of September 30, 2024 and December 31, 2023 (in thousands):


	September 30,		December 31,
	2024		2023
Energy commodity derivatives
Cash collateral posted	$	24,773	$	43,095
Letters of credit outstanding		7,000		20,000

No letters of credit were outstanding, and no cash collateral was on deposit, related to interest rate swap derivatives as of September 30, 2024 and December 31, 2023.

Certain of Avista Corp.’s derivative instruments contain provisions that require Avista Corp. to maintain an "investment grade" credit rating from the major credit rating agencies. If Avista Corp.’s credit ratings were to fall below "investment grade," it would be in violation of these provisions, and the counterparties to the derivative instruments could request immediate payment or demand immediate and ongoing collateralization on derivative instruments in net liability positions.

The following table presents the aggregate fair value of energy commodity derivative instruments with credit-risk-related contingent features in a liability position and the amount of additional collateral Avista Corp. could be required to post as of September 30, 2024 (in thousands):


	September 30,
	2024
Energy commodity derivatives
Liabilities with credit-risk-related contingent features	$	32,051
Additional collateral to post		31,799

As of September 30, 2024, there are no material interest rate swap derivative instruments with credit-risk-related contingent features in a liability position.

Earnings Per Common Share

9 Months Ended

Sep. 30, 2024

Earnings Per Share [Abstract]

Earnings Per Common Share

NOTE 14. EARNINGS PER COMMON SHARE

The following table presents the computation of basic and diluted earnings per common share for the three and nine months ended September 30 (in thousands, except per share amounts):


	Three months ended September 30,				Nine months ended September 30,
	2024		2023		2024		2023
Numerator:
Net income	$	18,487	$	14,716	$	112,840	$	87,045
Denominator:
Weighted-average number of common shares outstanding-basic		78,836		76,734		78,463		75,962
Effect of dilutive securities:
Performance and restricted stock awards		132		27		82		94
Weighted-average number of common shares outstanding-diluted		78,968		76,761		78,545		76,056
Earnings per common share:
Basic	$	0.23	$	0.19	$	1.44	$	1.15
Diluted	$	0.23	$	0.19	$	1.44	$	1.14

There were no shares excluded from the calculation because they were antidilutive.

Derivatives and Risk Management - Summary of Unsettled Interest Rate Swap Derivatives (Details) - Interest Rate Swap [Member] $ in Thousands	9 Months Ended	12 Months Ended
	Sep. 30, 2024 USD ($) Contract	Dec. 31, 2023 USD ($) Contract
2024 [Member]
Derivatives, Fair Value [Line Items]
Number of Contracts \| Contract		2
Notional Amount \| $		$ 20,000
Mandatory Cash Settlement Date		2024
2025 [Member]
Derivatives, Fair Value [Line Items]
Number of Contracts \| Contract	1	1
Notional Amount \| $	$ 10,000	$ 10,000
Mandatory Cash Settlement Date	2025	2025

Short-Term Borrowings - Additional Information (Details) - USD ($)	9 Months Ended
	Sep. 30, 2024	Dec. 31, 2023
Avista Utilities [Member]
Short-term Debt [Line Items]
Line of credit facility, maximum borrowing capacity	$ 500,000,000
Line of credit facility, expiration date	2028-06
Line of credit facility additional expiration period	2 years
Line of credit facility, covenant terms, maximum debt to equity ratio	65.00%
Average interest rate on borrowings	6.13%	6.46%
Letters of credit outstanding	$ 4,700,000	$ 4,700,000
Avista Utilities [Member] \| Letter of Credit [Member]
Short-term Debt [Line Items]
Principal amount	50,000,000
Letters of credit outstanding	7,000,000	20,000,000
Alaska Electric Light & Power [Member]
Short-term Debt [Line Items]
Line of credit facility, maximum borrowing capacity	$ 25,000,000
Line of credit facility, expiration date	2028-06
Line of credit facility, covenant terms, maximum debt to equity ratio	67.50%
Average interest rate on borrowings	7.30%
Letters of credit outstanding	$ 4,300,000	$ 0

Information by Business Segments - Schedule of Business Segments (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2024	Sep. 30, 2023	Sep. 30, 2024	Sep. 30, 2023	Dec. 31, 2023
Segment Reporting Information [Line Items]
Operating revenues	$ 393,742	$ 379,626	$ 1,405,230	$ 1,234,194
Resource costs	142,033	148,282	579,476	482,454
Other operating expenses	107,614	103,072	329,128	312,881
Depreciation and amortization	67,889	66,905	203,650	198,272
Income (loss) from operations	48,768	38,087	204,140	158,496
Interest expense	37,326	35,484	111,467	106,765
Income tax expense (benefit)	(478)	(3,786)	2,323	(16,224)
Net income (loss)	18,487	14,716	112,840	87,045
Capital expenditures	154,221	132,531	405,428	359,277
Total Assets	7,780,883		7,780,883		$ 7,702,477
Operating Segments [Member] \| Utility Revenue [Member]
Segment Reporting Information [Line Items]
Operating revenues	393,565	379,524	1,404,991	1,233,827
Resource costs	142,033	148,282	579,476	482,454
Other operating expenses	107,298	102,469	328,138	310,518
Depreciation and amortization	67,886	66,860	203,642	198,196
Income (loss) from operations	48,910	38,633	204,899	160,568
Interest expense	37,195	35,352	111,076	106,374
Income tax expense (benefit)	(101)	(3,809)	3,274	(15,301)
Net income (loss)	19,844	13,786	116,307	89,624
Capital expenditures	154,221	132,531	405,428	359,277
Total Assets	7,612,787		7,612,787		7,532,387
Operating Segments [Member] \| Avista Utilities [Member] \| Utility Revenue [Member]
Segment Reporting Information [Line Items]
Operating revenues	383,746	369,673	1,369,496	1,198,419
Resource costs	140,669	146,793	576,302	478,947
Other operating expenses	103,106	98,609	315,953	299,274
Depreciation and amortization	65,024	64,125	195,082	190,008
Income (loss) from operations	47,738	37,081	194,127	148,897
Interest expense	35,762	33,896	106,828	102,014
Income tax expense (benefit)	(39)	(3,845)	1,475	(17,349)
Net income (loss)	19,803	13,498	111,246	83,935
Capital expenditures	143,938	127,666	389,098	347,264
Total Assets	7,336,820		7,336,820		7,262,704
Operating Segments [Member] \| Alaska Electric Light & Power [Member] \| Utility Revenue [Member]
Segment Reporting Information [Line Items]
Operating revenues	9,819	9,851	35,495	35,408
Resource costs	1,364	1,489	3,174	3,507
Other operating expenses	4,192	3,860	12,185	11,244
Depreciation and amortization	2,862	2,735	8,560	8,188
Income (loss) from operations	1,172	1,552	10,772	11,671
Interest expense	1,433	1,456	4,248	4,360
Income tax expense (benefit)	(62)	36	1,799	2,048
Net income (loss)	41	288	5,061	5,689
Capital expenditures	10,283	4,865	16,330	12,013
Total Assets	275,967		275,967		269,683
Other [Member] \| Non-Utility Revenue [Member]
Segment Reporting Information [Line Items]
Operating revenues	177	102	239	367
Resource costs	0	0	0	0
Other operating expenses	316	603	990	2,363
Depreciation and amortization	3	45	8	76
Income (loss) from operations	(142)	(546)	(759)	(2,072)
Interest expense	674	538	1,886	1,333
Income tax expense (benefit)	(377)	23	(951)	(923)
Net income (loss)	(1,357)	930	(3,467)	(2,579)
Capital expenditures	0	0	0	0
Total Assets	194,801		194,801		191,665
Intersegment Eliminations [Member]
Segment Reporting Information [Line Items]
Operating revenues	0	0	0	0
Resource costs	0	0	0	0
Other operating expenses	0	0	0	0
Depreciation and amortization	0	0	0	0
Income (loss) from operations	0	0	0	0
Interest expense	(543)	(406)	(1,495)	(942)
Income tax expense (benefit)	0	0	0	0
Net income (loss)	0	0	0	0
Capital expenditures	0	$ 0	0	$ 0
Total Assets	$ (26,705)		$ (26,705)		$ (21,575)

CONDENSED CONSOLIDATED BALANCE SHEETS (Parenthetical) - USD ($) $ in Thousands	Sep. 30, 2024	Dec. 31, 2023
Statement of Financial Position [Abstract]
Accounts and notes receivable, allowances	$ 3,124	$ 4,987
Common stock, par value	$ 0	$ 0
Common stock, shares authorized	200,000,000	200,000,000
Common stock, shares, issued	79,180,956	78,074,587
Common stock, shares outstanding	79,180,956	78,074,587

Fair Value

9 Months Ended

Sep. 30, 2024

Fair Value Disclosures [Abstract]

Fair Value

NOTE 11. FAIR VALUE

The carrying values of cash and cash equivalents, accounts and notes receivable, accounts payable, and short-term borrowings as shown on the Condensed Consolidated Balance Sheets are reasonable estimates of their fair values. The carrying values of long-term debt (including current portion and material finance leases) and long-term debt to affiliated trusts as shown on the Condensed Consolidated Balance Sheets may be different from the estimated fair value. See below for the estimated fair value of long-term debt and long-term debt to affiliated trusts.

The fair value hierarchy prioritizes the inputs used to measure fair value. The hierarchy gives the highest priority to unadjusted quoted prices in active markets for identical assets or liabilities (Level 1 measurements) and the lowest priority to fair values derived from unobservable inputs (Level 3 measurements).

The three levels of the fair value hierarchy are defined as follows:

Level 1 – Quoted prices are available in active markets for identical assets or liabilities. Active markets are those in which transactions for the asset or liability occur with sufficient frequency and volume to provide pricing information on an ongoing basis.

Level 2 – Pricing inputs are other than quoted prices in active markets included in Level 1, but which are either directly or indirectly observable as of the reporting date. Level 2 includes financial instruments valued using models or other valuation methodologies. These models are primarily industry-standard models that consider various assumptions, including quoted forward prices for commodities, time value, volatility factors, and current market and contractual prices for the underlying instruments, as well as other relevant economic measures. Substantially all of these assumptions are observable in the marketplace throughout the full term of the instrument, can be derived from observable data or are supported by observable levels at which transactions are executed in the marketplace.

Level 3 – Pricing inputs include significant inputs generally unobservable from objective sources. These inputs may be used with internally developed methodologies that result in management’s best estimate of fair value.

Financial assets and liabilities are classified in their entirety based on the lowest level of input that is significant to the fair value measurement. The Company’s assessment of the significance of a particular input to the fair value measurement requires judgment, and may affect the valuation of fair value assets and liabilities and their placement within the fair value hierarchy levels. The determination of the fair values incorporates various factors including the credit standing of the counterparties involved and the impact

of credit enhancements (such as cash deposits and letters of credit), and the impact of Avista Corp.’s nonperformance risk on its liabilities.

The following table sets forth the carrying value and estimated fair value of the Company’s financial instruments not reported at estimated fair value on the Condensed Consolidated Balance Sheets as of September 30, 2024 and December 31, 2023 (dollars in thousands):


	September 30, 2024				December 31, 2023
	Carrying Value		Estimated Fair Value		Carrying Value		Estimated Fair Value
Long-term debt (Level 2)	$	1,100,000	$	999,103	$	1,100,000	$	968,893
Long-term debt (Level 3)		1,533,700		1,268,561		1,450,000		1,166,512
Snettisham finance lease obligation (Level 3)		39,945		37,500		42,495		39,600
Long-term debt to affiliated trusts (Level 3)		51,547		46,990		51,547		46,098

These estimates of fair value of long-term debt and long-term debt to affiliated trusts were primarily based on available market information, which generally consists of estimated market prices from third party brokers for debt with similar risk and terms. The price ranges obtained from the third party brokers consisted of market prices of 63.9 percent to 110.08 percent of the principal amount, where 100.0 percent of the principal amount (adjusted for unamortized discount or premium) represents the carrying value recorded on the Condensed Consolidated Balance Sheets. Level 2 long-term debt represents publicly issued bonds with quoted market prices; however, due to their limited trading activity, they are classified as Level 2 because brokers must generate quotes and make estimates if there is no trading activity near a period end. Level 3 long-term debt consists of private placement bonds and debt to affiliated trusts, which typically have no secondary trading activity. Fair values in Level 3 are estimated based on market prices from third party brokers using secondary market quotes for debt with similar risk and terms to generate quotes for Avista Corp. bonds. Due to the unique nature of the Snettisham finance lease obligation, the estimated fair value of these items was determined based on a discounted cash flow model using available market information. The Snettisham finance lease obligation fair value is determined using the Morgan Markets A Ex-Fin discount rate as published on September 30, 2024 and December 31, 2023.

The following table discloses by level within the fair value hierarchy the Company’s assets and liabilities measured and reported on the Condensed Consolidated Balance Sheets as of September 30, 2024 and December 31, 2023 at fair value on a recurring basis (dollars in thousands):


	Level 1		Level 2		Level 3		Counterparty and Cash Collateral Netting (1)			Total
September 30, 2024
Assets:
Energy commodity derivatives	$	—	$	21,395	$	—	$	(13,023	)	$	8,372
Foreign currency exchange derivatives		—		7		—		—			7
Equity Investments		—		—		52,819		—			52,819
Deferred compensation assets
Mutual Funds:
Fixed income securities (3)		1,026		—		—		—			1,026
Equity securities (3)		7,727		—		—		—			7,727
Total	$	8,753	$	21,402	$	52,819	$	(13,023	)	$	69,951
Liabilities:
Energy commodity derivatives (2)	$	—	$	65,159	$	6,977	$	(32,938	)	$	39,198
Interest rate swap derivatives		—		75		—		—			75
Total	$	—	$	65,234	$	6,977	$	(32,938	)	$	39,273
December 31, 2023
Assets:
Energy commodity derivatives (2)	$	—	$	30,954	$	—	$	(22,802	)	$	8,152
Foreign currency exchange derivatives		—		2		—		—			2
Interest rate swap derivatives		—		3,667		—		—			3,667
Equity Investments		—		—		50,254		—			50,254
Deferred compensation assets
Mutual Funds:
Fixed income securities (3)		1,117		—		—		—			1,117
Equity securities (3)		6,524		—		—		—			6,524
Total	$	7,641	$	34,623	$	50,254	$	(22,802	)	$	69,716
Liabilities:
Energy commodity derivatives (2)	$	—	$	91,844	$	8,250	$	(65,157	)	$	34,937
Interest rate swap derivatives		—		182		—		—			182
Total	$	—	$	92,026	$	8,250	$	(65,157	)	$	35,119

(1)

The Company is permitted to net derivative assets and derivative liabilities with the same counterparty when a legally enforceable master netting agreement exists. In addition, the Company nets derivative assets and derivative liabilities against any payables and receivables for cash collateral held or placed with these same counterparties.

(2)

The Level 3 energy commodity derivative balances are associated with a natural gas exchange agreement.

(3)

Included in other property and investments-net and other non-current assets on the Condensed Consolidated Balance Sheets.

The difference between the amount of derivative assets and liabilities disclosed in respective levels in the table above and the amount of derivative assets and liabilities disclosed on the Condensed Consolidated Balance Sheets is due to netting arrangements with certain counterparties. See Note 5 for additional discussion of derivative netting.

To establish fair value for energy commodity derivatives, the Company uses quoted market prices and forward price curves to estimate the fair value of energy commodity derivative instruments included in Level 2. Electric derivative valuations are performed using market quotes, adjusted for periods in between quotable periods. Natural gas derivative valuations are estimated using New York Mercantile Exchange pricing for similar instruments, adjusted for basin differences, using market quotes. Where observable inputs are available for substantially the full term of the contract, the derivative asset or liability is included in Level 2.

To establish fair values for interest rate swap derivatives, the Company uses forward market curves for interest rates for the term of the swaps and discounts the cash flows back to present value using an appropriate discount rate. The discount rate is calculated by third party brokers according to the terms of the swap derivatives and evaluated by the Company for reasonableness, with consideration given to the potential non-performance risk by the Company. Future cash flows of the interest rate swap derivatives are equal to the fixed interest rate in the swap compared to the floating market interest rate multiplied by the notional amount for each period.

Deferred compensation assets and liabilities represent funds held by the Company in a Rabbi Trust for an executive deferral plan. These funds consist of actively traded equity and bond funds with quoted prices in active markets.

Level 3 Fair Value

Natural Gas Exchange Agreement

For the natural gas commodity exchange agreement, the Company uses the same Level 2 market quotes described above; however, the Company also estimates the purchase and sales volumes (within contractual limits) as well as the timing of those transactions. Changing the timing of volume estimates changes the timing of purchases and sales, impacting which brokered quote is used. Because the brokered quotes can vary significantly from period to period, the unobservable estimates of the timing and volume of transactions can have a significant impact on the calculated fair value. The Company currently estimates volumes and timing of transactions based on a most likely scenario using historical data. Historically, the timing and volume of transactions are not highly correlated with market prices and market volatility.

The natural gas commodity exchange agreement expires in April 2025. The Company expects remaining transactions under the agreement will be sales.

The following table presents the quantitative information which was used to estimate the fair values of the Level 3 assets and liabilities above as of September 30, 2024 (dollars in thousands):


	Fair Value (Net) at			Valuation	Unobservable	Range and Weighted
	September 30, 2024			Technique	Input	Average Price
Natural gas exchange agreement	$	(6,977	)	Internally derived weighted average cost of gas	Forward sales prices	$2.57 - $8.08/mmBTU $5.86 Weighted Average
					Sales volumes	75,000 - 310,000 mmBTUs

The valuation methods, significant inputs and resulting fair values described above were developed by the Company and are reviewed on at least a quarterly basis to ensure they provide a reasonable estimate of fair value each reporting period.

Equity Investments

The Company has two equity investments measured at fair value on a recurring basis. For one investment, fair value is determined using a market approach, starting with enterprise values from recent market transaction data for comparable companies with similar equity instruments. The market transaction data was used to estimate an enterprise value of the underlying investment and that value was allocated to the various classes of equity via an option pricing model and a waterfall approach. The selection of appropriate comparable companies and the expected time to a liquidation event requires management judgment. The significant assumptions in the analysis include the comparable market transactions and related enterprise values, time to liquidity event and the market discount for lack of liquidity. In the event there are relevant market transactions for the same or similar securities of the subject company or there is the reasonable possibility of a transaction occurring, those transactions are utilized as an input to the valuation with a probability weight applied to the valuation.

For the second investment, the fair value is determined using an income approach utilizing a discounted cash flow model. The model is based on income statement forecasts from the underlying company to determine cash flows for the period of ownership. The model then utilizes market multiples from publicly traded comparable companies in similar industries and projects to estimate the terminal

fair value. The market multiples are reduced to reflect the difference in the life cycle between the publicly traded comparable companies and the start-up nature of the investment company. The selection of appropriate comparable companies, market multiples and the reduction to those market multiples requires management judgment. The significant assumptions in the model include the discount rate representing the risk associated with the investment, market multiples and the related reduction to those multiples, revenue forecasts, and the estimated terminal date for the investment. In the event there are relevant market transactions for the same or similar securities of the subject company or there is the reasonable possibility of a transaction occurring, those transactions are used to determine the fair value of Avista Corp.’s investment under a market approach instead of utilizing a discounted cash flow model. The market transactions are considered Level 3 inputs because they are not publicly available observable transactions.

The following table presents the quantitative information which was used to estimate the fair values of the Level 3 equity investments as of September 30, 2024 (dollars in thousands):


	Fair Value at
	September 30, 2024		Valuation Technique	Unobservable Input	Range
Equity investments	$	52,819	Market approach	Comparable enterprise values	$130,000-$388,600 $246,000 Average
				Time to liquidity event	1.50 years
			Discounted cash flows	Revenue market multiples	0.53x to 4.71x Revenue 2.21x Average
				Market multiple exit reduction	50%
				Discount rate	25%
				Annual revenues	$5,000 - $138,000
				Terminal date	2029

The following table presents activity for assets and liabilities measured at fair value using significant unobservable inputs (Level 3) for the three and nine months ended September 30 (dollars in thousands):


	Natural Gas Exchange Agreement (1)			Equity Investments			Total
Three Months Ended September 30, 2024:
Beginning balance	$	(7,981	)	$	50,357		$	42,376
Total gains or (losses) (realized/unrealized):
Included in regulatory assets/liabilities		1,005			—			1,005
Recognized in net income		—			1,478			1,478
Purchases and debt conversions		—			984			984
Settlements		(1	)		—			(1	)
Ending balance as of September 30, 2024	$	(6,977	)	$	52,819		$	45,842
Three Months Ended September 30, 2023:
Beginning balance	$	(11,721	)	$	48,453		$	36,732
Total gains or (losses) (realized/unrealized):
Included in regulatory assets/liabilities		(3,652	)		—			(3,652	)
Recognized in net income		—			2,024			2,024
Ending balance as of September 30, 2023	$	(15,373	)	$	50,477		$	35,104
Nine Months Ended September 30, 2024:
Beginning balance	$	(8,250	)	$	50,254		$	42,004
Total gains or (losses) (realized/unrealized):
Included in regulatory assets/liabilities		986			—			986
Recognized in net income		—			636			636
Purchases and debt conversions		—			1,929			1,929
Settlements		287			—			287
Ending balance as of September 30, 2024	$	(6,977	)	$	52,819		$	45,842
Nine Months Ended September 30, 2023:
Beginning balance	$	(17,734	)	$	54,284		$	36,550
Total gains or (losses) (realized/unrealized):
Included in regulatory assets/liabilities		2,115			—			2,115
Recognized in net income		—			(3,174	)		(3,174	)
Purchases and debt conversions		—			2,367			2,367
Settlements		246			—			246
Other		—			(3,000	)		(3,000	)
Ending balance as of September 30, 2023	$	(15,373	)	$	50,477		$	35,104

(1)

There were no purchases, issuances or transfers from other categories during the periods presented in the table above.

- Definition

The entire disclosure for the fair value of financial instruments (as defined), including financial assets and financial liabilities (collectively, as defined), and the measurements of those instruments as well as disclosures related to the fair value of non-financial assets and liabilities. Such disclosures about the financial instruments, assets, and liabilities would include: (1) the fair value of the required items together with their carrying amounts (as appropriate); (2) for items for which it is not practicable to estimate fair value, disclosure would include: (a) information pertinent to estimating fair value (including, carrying amount, effective interest rate, and maturity, and (b) the reasons why it is not practicable to estimate fair value; (3) significant concentrations of credit risk including: (a) information about the activity, region, or economic characteristics identifying a concentration, (b) the maximum amount of loss the entity is exposed to based on the gross fair value of the related item, (c) policy for requiring collateral or other security and information as to accessing such collateral or security, and (d) the nature and brief description of such collateral or security; (4) quantitative information about market risks and how such risks are managed; (5) for items measured on both a recurring and nonrecurring basis information regarding the inputs used to develop the fair value measurement; and (6) for items presented in the financial statement for which fair value measurement is elected: (a) information necessary to understand the reasons for the election, (b) discussion of the effect of fair value changes on earnings, (c) a description of [similar groups] items for which the election is made and the relation thereof to the balance sheet, the aggregate carrying value of items included in the balance sheet that are not eligible for the election; (7) all other required (as defined) and desired information.

+ References

Reference 1: http://www.xbrl.org/2003/role/exampleRef
-Topic 820
-SubTopic 10
-Name Accounting Standards Codification
-Section 55
-Paragraph 107
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147482078/820-10-55-107

Reference 2: http://www.xbrl.org/2003/role/exampleRef
-Topic 820
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-URI https://asc.fasb.org/1943274/2147482078/820-10-55-100

Reference 3: http://www.xbrl.org/2003/role/disclosureRef
-Topic 820
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-Paragraph 2
-Subparagraph (c)(3)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147482106/820-10-50-2

Reference 4: http://www.xbrl.org/2003/role/disclosureRef
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-Name Accounting Standards Codification
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-Paragraph 6A
-Subparagraph (a)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147482106/820-10-50-6A

Reference 5: http://www.xbrl.org/2003/role/disclosureRef
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-Name Accounting Standards Codification
-Section 50
-Paragraph 2E
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147482106/820-10-50-2E

Reference 6: http://www.xbrl.org/2003/role/disclosureRef
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-Topic 820
-SubTopic 10
-Name Accounting Standards Codification
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Reference 9: http://www.xbrl.org/2003/role/disclosureRef
-Topic 820
-SubTopic 10
-Name Accounting Standards Codification
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Reference 10: http://www.xbrl.org/2003/role/disclosureRef
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+ Details

Derivatives and Risk Management - Schedules of Fair Values and Locations of Derivative Instruments (Details) - USD ($) $ in Thousands	Sep. 30, 2024	Dec. 31, 2023
Derivatives, Fair Value [Line Items]
Gross Asset	$ 21,402	$ 34,623
Gross Liability	(72,211)	(100,276)
Collateral Netted	19,915	42,355
Net Asset (Liability) on Balance Sheet	(30,894)	(23,298)
Other Current Liabilities [Member] \| Commodity Contracts [Member]
Derivatives, Fair Value [Line Items]
Gross Asset	10,161	19,510
Gross Liability	(54,972)	(79,082)
Collateral Netted	17,199	42,355
Net Asset (Liability) on Balance Sheet	(27,612)	(17,217)
Other Current Assets [Member] \| Foreign Exchange Contract [Member]
Derivatives, Fair Value [Line Items]
Gross Asset	7	2
Net Asset (Liability) on Balance Sheet	7	2
Other Current Assets [Member] \| Interest Rate Swap [Member]
Derivatives, Fair Value [Line Items]
Gross Asset		3,667
Net Asset (Liability) on Balance Sheet		3,667
Other Current Assets [Member] \| Commodity Contracts [Member]
Derivatives, Fair Value [Line Items]
Gross Asset	7,612	8,531
Gross Liability	(834)	(379)
Net Asset (Liability) on Balance Sheet	6,778	8,152
Other Property and Investments-Net and Other Non-current Assets [Member] \| Commodity Contracts [Member]
Derivatives, Fair Value [Line Items]
Gross Asset	1,594
Net Asset (Liability) on Balance Sheet	1,594
Other Noncurrent Liabilities [Member] \| Interest Rate Swap [Member]
Derivatives, Fair Value [Line Items]
Gross Liability	75	(182)
Net Asset (Liability) on Balance Sheet	(75)	(182)
Other Noncurrent Liabilities [Member] \| Commodity Contracts [Member]
Derivatives, Fair Value [Line Items]
Gross Asset	2,028	2,913
Gross Liability	(16,330)	(20,633)
Collateral Netted	2,716
Net Asset (Liability) on Balance Sheet	$ (11,586)	$ (17,720)

Long-Term Debt to Affiliated Trusts (Tables)

9 Months Ended

Sep. 30, 2024

Long Term Debt To Affiliated Trust [Abstract]

Schedule of Distribution Rates

The distribution rates were as follows during the nine months ended September 30, 2024 and the year ended December 31, 2023:


	September 30,			December 31,
	2024			2023
Low distribution rate		6.15	%		5.64	%
High distribution rate		6.51	%		6.55	%
Distribution rate at the end of the period		6.15	%		6.51	%

Fair Value - Schedule of Quantitative Information (Details) $ in Thousands	9 Months Ended
	Sep. 30, 2024 USD ($) MMBTU $ / MMBTU
Fair Value, Recurring [Member] \| Level 3 [Member]
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis Valuation Techniques [Line Items]
Equity investments	$ 52,819
Investment, Type [Extensible Enumeration]	Equity Funds [Member]
Fair Value, Recurring [Member] \| Natural Gas Exchange Agreements [Member]
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis Valuation Techniques [Line Items]
Derivative Liability	$ (6,977)
Internally Derived Weighted Average Cost Of Gas [Member] \| Sales [Member] \| Minimum [Member] \| Natural Gas Exchange Agreements [Member]
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis Valuation Techniques [Line Items]
Derivative, Forward Price \| $ / MMBTU	2.57
Transaction/Delivery Volumes \| MMBTU	75,000
Internally Derived Weighted Average Cost Of Gas [Member] \| Sales [Member] \| Maximum [Member] \| Natural Gas Exchange Agreements [Member]
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis Valuation Techniques [Line Items]
Derivative, Forward Price \| $ / MMBTU	8.08
Transaction/Delivery Volumes \| MMBTU	310,000
Internally Derived Weighted Average Cost Of Gas [Member] \| Sales [Member] \| Weighted Average [Member] \| Natural Gas Exchange Agreements [Member]
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis Valuation Techniques [Line Items]
Derivative, Forward Price \| $ / MMBTU	5.86
Market Approach [Member] \| Minimum [Member] \| Fair Value, Recurring [Member]
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis Valuation Techniques [Line Items]
Equity investments, comparable enterprise values	$ 130,000
Equity investments, time to liquidity event	1 year 6 months
Investment, Type [Extensible Enumeration]	Equity Funds [Member]
Market Approach [Member] \| Maximum [Member] \| Fair Value, Recurring [Member]
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis Valuation Techniques [Line Items]
Equity investments, comparable enterprise values	$ 388,600
Investment, Type [Extensible Enumeration]	Equity Funds [Member]
Market Approach [Member] \| Weighted Average [Member] \| Fair Value, Recurring [Member]
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis Valuation Techniques [Line Items]
Equity investments, comparable enterprise values	$ 246,000
Investment, Type [Extensible Enumeration]	Equity Funds [Member]
Discounted Cash Flows [Member] \| Fair Value, Recurring [Member]
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis Valuation Techniques [Line Items]
Equity investments, terminal date	2029
Investment, Type [Extensible Enumeration]	Equity Funds [Member]
Discounted Cash Flows [Member] \| Discount Rate [Member] \| Fair Value, Recurring [Member]
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis Valuation Techniques [Line Items]
Equity investments, measurement input	25
Investment, Type [Extensible Enumeration]	Equity Funds [Member]
Discounted Cash Flows [Member] \| Market Multiple Exit Reduction [Member] \| Fair Value, Recurring [Member]
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis Valuation Techniques [Line Items]
Equity investments, measurement input	50
Investment, Type [Extensible Enumeration]	Equity Funds [Member]
Discounted Cash Flows [Member] \| Revenue Market Multiples [Member] \| Minimum [Member] \| Fair Value, Recurring [Member]
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis Valuation Techniques [Line Items]
Equity investments, measurement input	0.53
Investment, Type [Extensible Enumeration]	Equity Funds [Member]
Discounted Cash Flows [Member] \| Revenue Market Multiples [Member] \| Maximum [Member] \| Fair Value, Recurring [Member]
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis Valuation Techniques [Line Items]
Equity investments, measurement input	4.71
Investment, Type [Extensible Enumeration]	Equity Funds [Member]
Discounted Cash Flows [Member] \| Revenue Market Multiples [Member] \| Weighted Average [Member] \| Fair Value, Recurring [Member]
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis Valuation Techniques [Line Items]
Equity investments, measurement input	2.21
Investment, Type [Extensible Enumeration]	Equity Funds [Member]
Discounted Cash Flows [Member] \| Annual Revenues [Member] \| Minimum [Member] \| Fair Value, Recurring [Member]
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis Valuation Techniques [Line Items]
Equity investments, annual revenues	$ 5,000
Investment, Type [Extensible Enumeration]	Equity Funds [Member]
Discounted Cash Flows [Member] \| Annual Revenues [Member] \| Maximum [Member] \| Fair Value, Recurring [Member]
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis Valuation Techniques [Line Items]
Equity investments, annual revenues	$ 138,000
Investment, Type [Extensible Enumeration]	Equity Funds [Member]

Long-Term Debt to Affiliated Trusts - Schedule of Distribution Rates Paid (Details) - Trust Preferred Securities Subject to Mandatory Redemption [Member]	Sep. 30, 2024	Dec. 31, 2023
Debt Instrument [Line Items]
Interest rate	6.15%	6.51%
Minimum [Member]
Debt Instrument [Line Items]
Interest rate	6.15%	5.64%
Maximum [Member]
Debt Instrument [Line Items]
Interest rate	6.51%	6.55%

- Definition

Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table.

+ References

Reference 1: http://www.xbrl.org/2003/role/exampleRef
-Topic 835
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-Section 55
-Paragraph 8
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+ Details

Short-Term Borrowings

9 Months Ended

Sep. 30, 2024

Short-Term Debt [Abstract]

Short-Term Borrowings

NOTE 8. SHORT-TERM BORROWINGS

Avista Corp.

Lines of Credit

Avista Corp. has a committed line of credit in the total amount of $500 million, with an expiration date of June 2028. The Company has the option to extend for two additional one year periods (subject to customary conditions). The committed line of credit is secured by non-transferable first mortgage bonds of Avista Corp. issued to the agent bank that are payable only to the extent that Avista Corp. defaults on its obligations under the committed line of credit.

Balances outstanding and interest rates on borrowings (excluding letters of credit) under Avista Corp.’s revolving committed line of credit were as follows as of September 30, 2024 and December 31, 2023 (dollars in thousands):


	September 30,			December 31,
	2024			2023
Borrowings outstanding at end of period	$	283,000		$	349,000
Letters of credit outstanding at end of period		4,700			4,700
Average interest rate on borrowings at end of period		6.13	%		6.46	%

Letter of Credit Facility

Avista Corp. has a letter of credit agreement in the aggregate amount of $50 million. Either party may terminate the agreement at any time.

Avista Corp. had $7.0 million and $20.0 million in letters of credit outstanding under this agreement as of September 30, 2024 and December 31, 2023, respectively. Letters of credit are not reflected on the Condensed Consolidated Balance Sheets. If a letter of credit were drawn upon by the holder, Avista Corp. would have an immediate obligation to reimburse the bank that issued the letter of credit.

Covenants and Default Provisions

The short-term borrowing agreements contain customary covenants and default provisions, including a change in control (as defined in the agreements). The events of default under each of the credit facilities also include a cross default from other indebtedness (as defined) and, in the case of the letter of credit agreement, other obligations. The committed line of credit agreement also includes a covenant which does not permit the ratio of “consolidated total debt” to “consolidated total capitalization” of Avista Corp. to be greater than 65 percent at any time. As of September 30, 2024, the Company complied with this covenant.

AEL&P

AEL&P has a committed line of credit in the amount of $25.0 million that expires in June 2028. There was $4.3 million outstanding under this agreement as of September 30, 2024 with an average interest rate of 7.3 percent, and no balance outstanding as of December 31, 2023. The committed line of credit is secured by non-transferable first mortgage bonds of AEL&P issued to the agent bank that would only become due and payable in the event, and then only to the extent, that AEL&P defaults on its obligations under the committed line of credit.

The committed line of credit agreement contains customary covenants and default provisions. The credit agreement has a covenant which does not permit the ratio of "consolidated total debt at AEL&P" to "consolidated total capitalization at AEL&P," including the impact of the Snettisham bonds to be greater than 67.5 percent at any time. As of September 30, 2024, AEL&P complied with this covenant.

Balance Sheet Components - Schedule of Inventory (Details) - USD ($) $ in Thousands	Sep. 30, 2024	Dec. 31, 2023
Balance Sheet Related Disclosures [Abstract]
Materials and supplies	$ 97,398	$ 81,651
Emission allowances	69,885	56,097
Stored natural gas	11,239	16,272
Fuel stock	7,418	5,964
Total	$ 185,940	$ 159,984

Fair Value - Schedule of Carrying Value and Estimated Fair Value of Financial Instruments (Details) - USD ($) $ in Thousands	Sep. 30, 2024	Dec. 31, 2023
Level 2 [Member] \| Reported Value Measurement [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Long-term Debt, Fair Value	$ 1,100,000	$ 1,100,000
Level 2 [Member] \| Estimate of Fair Value Measurement [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Long-term Debt, Fair Value	999,103	968,893
Level 3 [Member] \| Reported Value Measurement [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Long-term Debt, Fair Value	1,533,700	1,450,000
Level 3 [Member] \| Reported Value Measurement [Member] \| Alaska Electric Light & Power [Member] \| Finance Lease [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Finance Lease Obligation	39,945	42,495
Level 3 [Member] \| Estimate of Fair Value Measurement [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Long-term Debt, Fair Value	1,268,561	1,166,512
Level 3 [Member] \| Estimate of Fair Value Measurement [Member] \| Alaska Electric Light & Power [Member] \| Finance Lease [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Finance Lease Obligation	37,500	39,600
Affiliated Entity [Member] \| Level 3 [Member] \| Reported Value Measurement [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Long-term Debt, Fair Value	51,547	51,547
Affiliated Entity [Member] \| Level 3 [Member] \| Estimate of Fair Value Measurement [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Long-term Debt, Fair Value	$ 46,990	$ 46,098

Revenue

9 Months Ended

Sep. 30, 2024

Revenue from Contract with Customer [Abstract]

Revenue

NOTE 4. REVENUE

The core principle of the revenue recognition model is that an entity should identify the various performance obligations in a contract, allocate the transaction price among the performance obligations and recognize revenue when (or as) the entity satisfies each performance obligation.

Utility Revenues

Revenue from Contracts with Customers

General

The majority of Avista Corp.’s revenue is from rate-regulated sales of electricity and natural gas to retail customers, which has two performance obligations, (1) having service available for a specified period (typically a month at a time) and (2) the delivery of energy to customers. The total energy price generally has a fixed component (basic charge) related to having service available and a usage-based component, related to the delivery and consumption of energy. The commodity is sold and/or delivered to and consumed by the customer simultaneously, and the provisions of the relevant utility commission authorization determine the charges the Company may bill the customer. Since all revenue recognition criteria are met upon the delivery of energy to customers, revenue is recognized immediately.

Revenues from contracts with customers are presented in the Condensed Consolidated Statements of Income in the line item "Utility revenues, exclusive of alternative revenue programs."

Non-Derivative Wholesale Contracts

The Company has certain wholesale contracts that are not accounted for as derivatives and are considered revenue from contracts with customers. Revenue is recognized as energy is delivered to the customer or the service is available for a specified period of time, consistent with the discussion of rate-regulated sales above.

Alternative Revenue Programs (Decoupling)

Alternative revenue programs are contracts between an entity and a regulator of utilities, not a contract between an entity and a customer. GAAP requires the presentation of revenue arising from alternative revenue programs separately from revenues arising from contracts with customers on the Condensed Consolidated Statements of Income. The Company's decoupling mechanisms (also known as a FCA in Idaho) qualify as alternative revenue programs. Decoupling revenue deferrals are recognized in the Condensed Consolidated Statements of Income during the period they occur (i.e. during the period of revenue shortfall or excess due to fluctuations in customer usage), subject to certain limitations, and a regulatory asset or liability is established which will be surcharged or rebated to customers in future periods. GAAP requires that for an alternative revenue program, like decoupling, the revenue must be expected to be collected from customers within 24 months of the deferral to qualify for recognition in the Condensed Consolidated Statements of Income. Amounts included in the Company's decoupling program that are not expected to be collected from customers within 24 months are not recorded in the financial statements until the period in which revenue recognition criteria are met. The amounts expected to be collected from customers within 24 months represents an estimate made by the Company on an ongoing basis due to it being based on the volumes of electric and natural gas sold to customers on a go-forward basis.

The Company records alternative program revenues under the gross method, which is to amortize the decoupling regulatory asset/liability to the alternative revenue program line item on the Condensed Consolidated Statements of Income as it is collected from or refunded to customers. The cash passing between the Company and the customers is presented in revenue from contracts with customers since it is a portion of the overall tariff paid by customers. This method results in a gross-up to both revenue from contracts with customers and revenue from alternative revenue programs, but has a net zero impact on total revenue. Depending on whether the previous deferral balance being amortized was a regulatory asset or regulatory liability, and depending on the size and direction of the current year deferral of surcharges and/or rebates to customers, it could result in negative alternative revenue program revenue during the year.

Derivative Revenue

Most wholesale electric and natural gas transactions (including both physical and financial transactions), and the sale of fuel are considered derivatives, which are disclosed separately from revenue from contracts with customers. Revenue is recognized for these items upon the settlement/expiration of the derivative contract. Derivative revenue includes transactions entered into and settled within the same month.

Other Utility Revenue

Other utility revenue includes rent, sales of materials, late fees and other charges that do not represent contracts with customers. This revenue is excluded from revenue from contracts with customers, as this revenue does not represent items where a customer contracted with the Company to obtain goods or services that are an output of the Company’s ordinary activities in exchange for consideration. As such, these revenues are presented separately from revenue from contracts with customers.

Other Considerations for Utility Revenues

Gross Versus Net Presentation

Revenues and resource costs from Avista Utilities’ settled energy contracts “booked out” (not physically delivered) are reported on a net basis as part of derivative revenues.

Utility-related taxes collected from customers (primarily state excise taxes and city utility taxes) are imposed on Avista Utilities as opposed to being imposed on customers; therefore, Avista Utilities is the taxpayer and records these transactions on a gross basis in revenue from contracts with customers and operating expense (taxes other than income taxes). The utility-related taxes collected from customers at AEL&P are imposed on the customers rather than AEL&P; therefore, the customers are the taxpayers and AEL&P is acting as their agent. As such, these transactions at AEL&P are presented on a net basis within revenue from contracts with customers.

Utility-related taxes included in revenue from contracts with customers were as follows for the three and nine months ended September 30 (dollars in thousands):


	Three months ended September 30,				Nine months ended September 30,
	2024		2023		2024		2023
Utility-related taxes	$	16,775	$	14,484	$	60,442	$	56,356

Significant Judgments and Unsatisfied Performance Obligations

The only significant judgments involving revenue recognition are estimates surrounding unbilled revenue and receivables from contracts with customers and estimates surrounding the amount of decoupling revenues that will be collected from customers within 24 months (discussed above).

The Company has certain capacity arrangements, where the Company has a contractual obligation to provide either electric or natural gas capacity to its customers for a fixed fee. Most of these arrangements are paid for in arrears by the customers and do not result in deferred revenue and only result in receivables from the customers. The Company has one capacity agreement where the customer makes payments throughout the year. As of September 30, 2024, the Company estimates it had unsatisfied capacity performance obligations of $3.0 million, which will be recognized as revenue in future periods as the capacity is provided to the customers. These performance obligations are not reflected in the financial statements, as the Company has not received payment for these services.

Disaggregation of Total Operating Revenue

The following table disaggregates total operating revenue by segment and source for the three and nine months ended September 30 (dollars in thousands):


	Three months ended September 30,					Nine months ended September 30,
	2024			2023		2024			2023
Avista Utilities
Revenue from contracts with customers	$	318,171		$	285,821	$	1,136,926		$	1,058,725
Derivative revenues		56,462			77,562		194,647			141,080
Alternative revenue programs		3,978			3,578		23,032			(9,947	)
Other utility revenues		5,135			2,712		14,891			8,561
Total Avista Utilities		383,746			369,673		1,369,496			1,198,419
AEL&P
Revenue from contracts with customers		9,826			9,700		35,163			34,934
Deferrals and amortizations for rate refunds to customers		(183	)		—		(183	)		—
Other utility revenues		176			151		515			474
Total AEL&P		9,819			9,851		35,495			35,408

Other non-utility revenues		177			102		239			367
Total operating revenues	$	393,742		$	379,626	$	1,405,230		$	1,234,194

Utility Revenue from Contracts with Customers by Type and Service

The following table disaggregates revenue from contracts with customers associated with the Company's electric operations for the three and nine months ended September 30 (dollars in thousands):


	2024						2023
	Avista Utilities		AEL&P		Total Utility		Avista Utilities		AEL&P		Total Utility
Three months ended September 30:
ELECTRIC OPERATIONS
Revenue from contracts with customers
Residential	$	110,328	$	3,444	$	113,772	$	95,881	$	3,186	$	99,067
Commercial		97,389		6,313		103,702		89,772		6,447		96,219
Industrial		36,910		—		36,910		29,584		—		29,584
Public street and highway lighting		2,186		69		2,255		2,005		67		2,072
Total retail revenue		246,813		9,826		256,639		217,242		9,700		226,942
Transmission		9,250		—		9,250		7,721		—		7,721
Other revenue from contracts with customers		8,062		—		8,062		9,353		—		9,353
Total electric revenue from contracts with customers	$	264,125	$	9,826	$	273,951	$	234,316	$	9,700	$	244,016
Nine months ended September 30:
ELECTRIC OPERATIONS
Revenue from contracts with customers
Residential	$	345,166	$	15,146	$	360,312	$	305,203	$	14,485	$	319,688
Commercial		275,525		19,819		295,344		252,344		20,257		272,601
Industrial		95,014		—		95,014		82,707		—		82,707
Public street and highway lighting		6,604		198		6,802		5,940		192		6,132
Total retail revenue		722,309		35,163		757,472		646,194		34,934		681,128
Transmission		28,380		—		28,380		24,143		—		24,143
Other revenue from contracts with customers		32,457		—		32,457		33,580		—		33,580
Total electric revenue from contracts with customers	$	783,146	$	35,163	$	818,309	$	703,917	$	34,934	$	738,851

The following table disaggregates revenue from contracts with customers associated with the Company's natural gas operations for the three and nine months ended September 30 (dollars in thousands):


	Three months ended September 30,				Nine months ended September 30,
	2024		2023		2024		2023
	Avista Utilities		Avista Utilities		Avista Utilities		Avista Utilities
NATURAL GAS OPERATIONS
Revenue from contracts with customers
Residential	$	30,285	$	29,372	$	217,682	$	218,212
Commercial		17,203		15,381		114,495		113,183
Industrial and interruptible		2,720		3,480		9,880		13,136
Total retail revenue		50,208		48,233		342,057		344,531
Transportation		2,432		1,866		7,504		6,058
Other revenue from contracts with customers		1,406		1,406		4,219		4,219
Total natural gas revenue from contracts with customers	$	54,046	$	51,505	$	353,780	$	354,808

- Definition

The entire disclosure of revenue from contract with customer to transfer good or service and to transfer nonfinancial asset. Includes, but is not limited to, disaggregation of revenue, credit loss recognized from contract with customer, judgment and change in judgment related to contract with customer, and asset recognized from cost incurred to obtain or fulfill contract with customer. Excludes insurance and lease contracts.

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Topic 606
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 9
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147479806/606-10-50-9

Reference 2: http://www.xbrl.org/2003/role/disclosureRef
-Topic 606
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 10
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147479806/606-10-50-10

Reference 3: http://www.xbrl.org/2003/role/disclosureRef
-Topic 606
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 15
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147479806/606-10-50-15

Reference 4: http://www.xbrl.org/2003/role/disclosureRef
-Topic 606
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 12
-Subparagraph (a)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147479806/606-10-50-12

Reference 5: http://www.xbrl.org/2003/role/disclosureRef
-Topic 606
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 12
-Subparagraph (b)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147479806/606-10-50-12

Reference 6: http://www.xbrl.org/2003/role/disclosureRef
-Topic 606
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 12
-Subparagraph (c)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147479806/606-10-50-12

Reference 7: http://www.xbrl.org/2003/role/disclosureRef
-Topic 606
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 12
-Subparagraph (d)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147479806/606-10-50-12

Reference 8: http://www.xbrl.org/2003/role/disclosureRef
-Topic 606
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 12
-Subparagraph (e)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147479806/606-10-50-12

Reference 9: http://www.xbrl.org/2003/role/disclosureRef
-Topic 606
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 13
-Subparagraph (b)(2)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147479806/606-10-50-13

Reference 10: http://www.xbrl.org/2003/role/disclosureRef
-Name Accounting Standards Codification
-Topic 606
-Publisher FASB
-URI https://asc.fasb.org/606/tableOfContent

+ Details

Derivatives and Risk Management - Summary of Foreign Currency Exchange Derivatives (Details) $ in Thousands, $ in Thousands	Sep. 30, 2024 CAD ($) DerivativeContracts	Sep. 30, 2024 USD ($) DerivativeContracts	Dec. 31, 2023 CAD ($) DerivativeContracts	Dec. 31, 2023 USD ($) DerivativeContracts
Foreign Currency Fair Value Hedge Derivative [Line Items]
Number of contracts \| DerivativeContracts	27	27	5	5
United States of America, Dollars [Member] \| Foreign Exchange Contract [Member]
Foreign Currency Fair Value Hedge Derivative [Line Items]
Notional amount		$ 1,660		$ 81
Canada, Dollars [Member] \| Foreign Exchange Contract [Member]
Foreign Currency Fair Value Hedge Derivative [Line Items]
Notional amount	$ 2,251		$ 109

Derivatives and Risk Management (Tables)

9 Months Ended

Sep. 30, 2024

Derivative Instruments and Hedges, Assets [Abstract]

Schedule of Energy Commodity Derivative Volumes

The following table presents the underlying energy commodity derivative volumes as of September 30, 2024 expected to be delivered in each respective year (in thousands of MWhs and mmBTUs):


	Purchases								Sales
	Electric Derivatives				Gas Derivatives				Electric Derivatives				Gas Derivatives
Year	Physical (1) MWh		Financial (1) MWh		Physical (1) mmBTUs		Financial (1) mmBTUs		Physical (1) MWh		Financial (1) MWh		Physical (1) mmBTUs		Financial (1) mmBTUs
Remainder 2024		6		—		12,866		19,734		194		408		581		2,690
2025		—		—		24,248		29,315		348		175		1,115		1,125
2026		—		—		14,663		10,765		—		—		—		—
2027		—		—		3,910		1,350		—		—		—		—

As of September 30, 2024, there were no expected deliveries of energy commodity derivatives after 2027.

The following table presents the underlying energy commodity derivative volumes as of December 31, 2023 expected to be delivered in each respective year (in thousands of MWhs and mmBTUs):


	Purchases								Sales
	Electric Derivatives				Gas Derivatives				Electric Derivatives				Gas Derivatives
Year	Physical (1) MWh		Financial (1) MWh		Physical (1) mmBTUs		Financial (1) mmBTUs		Physical (1) MWh		Financial (1) MWh		Physical (1) mmBTUs		Financial (1) mmBTUs
2024		9		—		22,747		74,596		472		510		1,723		12,038
2025		—		—		12,505		19,590		11		96		1,115		1,125
2026		—		—		5,570		3,940		—		—		—		—

As of December 31, 2023, there were no expected deliveries of energy commodity derivatives after 2026.

(1)

Summary of Foreign Currency Exchange Derivatives

The following table summarizes the foreign currency exchange derivatives outstanding as of September 30, 2024 and December 31, 2023 (dollars in thousands):


	September 30,		December 31,
	2024		2023
Number of contracts		27		5
Notional amount (in United States dollars)	$	1,660	$	81
Notional amount (in Canadian dollars)		2,251		109

Summary of Unsettled Interest Rate Swap Derivatives

The following table summarizes the unsettled interest rate swap derivatives outstanding as of September 30, 2024 and December 31, 2023 (dollars in thousands):


Balance Sheet Date	Number of Contracts		Notional Amount		Mandatory Cash Settlement Date
September 30, 2024		1	$	10,000	2025
December 31, 2023		2	$	20,000	2024
		1		10,000	2025

Schedules of Fair Values and Locations of Derivative Instruments

The following table presents the fair values and locations of derivative instruments recorded on the Condensed Consolidated Balance Sheet as of September 30, 2024 (in thousands):


	Fair Value
Derivative and Balance Sheet Location	Gross Asset		Gross Liability			Collateral Netted		Net Asset (Liability) on Balance Sheet
Foreign currency exchange derivatives
Other current assets	$	7	$	—		$	—	$	7
Interest rate swap derivatives
Other non-current liabilities and deferred credits		—		(75	)		—		(75	)
Energy commodity derivatives
Other current assets		7,612		(834	)		—		6,778
Other property and investments-net and other non-current assets		1,594		—			—		1,594
Other current liabilities		10,161		(54,972	)		17,199		(27,612	)
Other non-current liabilities and deferred credits		2,028		(16,330	)		2,716		(11,586	)
Total derivative instruments recorded on the balance sheet	$	21,402	$	(72,211	)	$	19,915	$	(30,894	)

The following table presents the fair values and locations of derivative instruments recorded on the Condensed Consolidated Balance Sheet as of December 31, 2023 (in thousands):


	Fair Value
Derivative and Balance Sheet Location	Gross Asset		Gross Liability			Collateral Netted		Net Asset (Liability) on Balance Sheet
Foreign currency exchange derivatives
Other current assets	$	2	$	—		$	—	$	2
Interest rate swap derivatives
Other current assets		3,667		—			—		3,667
Other non-current liabilities and deferred credits		—		(182	)		—		(182	)
Energy commodity derivatives
Other current assets		8,531		(379	)		—		8,152
Other current liabilities		19,510		(79,082	)		42,355		(17,217	)
Other non-current liabilities and deferred credits		2,913		(20,633	)		—		(17,720	)
Total derivative instruments recorded on the balance sheet	$	34,623	$	(100,276	)	$	42,355	$	(23,298	)

Schedule of Collateral Outstanding Related to Derivative Instruments

The following table presents collateral outstanding related to its derivative instruments as of September 30, 2024 and December 31, 2023 (in thousands):


	September 30,		December 31,
	2024		2023
Energy commodity derivatives
Cash collateral posted	$	24,773	$	43,095
Letters of credit outstanding		7,000		20,000

No letters of credit were outstanding, and no cash collateral was on deposit, related to interest rate swap derivatives as of September 30, 2024 and December 31, 2023.


	September 30,
	2024
Energy commodity derivatives
Liabilities with credit-risk-related contingent features	$	32,051
Additional collateral to post		31,799

As of September 30, 2024, there are no material interest rate swap derivative instruments with credit-risk-related contingent features in a liability position.

Summary of Significant Accounting Policies (Policies)

9 Months Ended

Sep. 30, 2024

Accounting Policies [Abstract]

Nature of Business

Avista Corp. is primarily an electric and natural gas utility with certain other business ventures. Avista Utilities is an operating division of Avista Corp., comprising its regulated utility operations in the Pacific Northwest. Avista Utilities provides electric distribution and transmission, and natural gas distribution services in parts of eastern Washington and northern Idaho. Avista Utilities also provides natural gas distribution service in parts of northeastern and southwestern Oregon. Avista Utilities has electric generating facilities in Washington, Idaho, Oregon and Montana. Avista Utilities also supplies electricity to a small number of customers in Montana.

AERC is a wholly-owned subsidiary of Avista Corp. The primary subsidiary of AERC is AEL&P, which comprises Avista Corp.'s regulated utility operations in Alaska.

Avista Capital, a wholly owned non-regulated subsidiary of Avista Corp., is the parent company of the subsidiary companies in the non-utility businesses, except AJT Mining Properties, Inc., which is a subsidiary of AERC. See Note 16 for business segment information.

Basis of Reporting

The condensed consolidated financial statements include the assets, liabilities, revenues and expenses of the Company and its subsidiaries and other majority owned subsidiaries and variable interest entities for which the Company or its subsidiaries are the primary beneficiaries. Intercompany balances were eliminated in consolidation. The accompanying condensed consolidated financial statements include the Company’s proportionate share of utility plant and related operations associated with its interests in jointly owned plants.

Regulation

The Company is subject to state regulation in Washington, Idaho, Montana, Oregon and Alaska. The Company is subject to federal regulation primarily by the FERC, as well as various other federal agencies with regulatory oversight of particular aspects of its operations.

Derivative Assets and Liabilities

Derivatives are recorded as either assets or liabilities on the Condensed Consolidated Balance Sheets measured at estimated fair value.

The WUTC and the IPUC issued accounting orders authorizing Avista Corp. to offset energy commodity derivative assets or liabilities with a regulatory asset or liability. This accounting treatment is intended to defer the recognition of mark-to-market gains and losses on energy commodity transactions until the period of delivery. Realized benefits and costs result in adjustments to retail rates through PGAs, the ERM in Washington, the PCA mechanism in Idaho, and periodic general rate cases. The resulting regulatory assets associated with energy commodity derivative instruments are probable of recovery through future rates.

Substantially all forward contracts to purchase or sell power and natural gas are recorded as derivative assets or liabilities at estimated fair value with an offsetting regulatory asset or liability. Contracts not considered derivatives are accounted for on the accrual basis until they are settled or realized unless there is a decline in the fair value of the contract determined to be other-than-temporary.

For interest rate swap derivatives, Avista Corp. records all mark-to-market gains and losses in each accounting period as assets and liabilities, as well as offsetting regulatory assets and liabilities, such that there is no income statement impact. The interest rate swap derivatives are risk management tools similar to energy commodity derivatives. Upon settlement of interest rate swap derivatives, the regulatory asset or liability is amortized as a component of interest expense over the term of the associated debt. The Company records an offset of interest rate swap derivative assets and liabilities with regulatory assets and liabilities, based on the prior practice of the commissions to provide recovery through the ratemaking process.

The Company has multiple master netting agreements with a variety of entities allowing for cross-commodity netting of derivative agreements with the same counterparty (i.e. power derivatives can be netted with natural gas derivatives). In addition, some master netting agreements allow for the netting of commodity derivatives and interest rate swap derivatives for the same counterparty. The Company does not have agreements which allow for cross-affiliate netting among multiple affiliated legal entities. The Company nets all derivative instruments when allowed by the agreement for presentation in the Condensed Consolidated Balance Sheets.

Fair Value Measurements

Fair value represents the price that would be received when selling an asset or paid to transfer a liability (an exit price) in an orderly transaction between market participants at the measurement date. Energy commodity derivative assets and liabilities, deferred compensation assets, some equity investments, as well as derivatives related to interest rate swaps and foreign currency exchange contracts, are reported at estimated fair value on the Condensed Consolidated Balance Sheets. See Note 11 for the Company’s fair value disclosures.

Contingencies

The Company has unresolved regulatory, legal and tax issues which have inherently uncertain outcomes. The Company accrues a loss contingency if it is probable that a liability has been incurred and the amount of the loss or impairment can be reasonably estimated. The Company also discloses loss contingencies that do not meet these conditions for accrual if there is a reasonable possibility that a material loss may be incurred. See Note 15 for further discussion of the Company's commitments and contingencies.

Inventory

Inventories of materials and supplies, emission allowances, fuel stock and stored natural gas are recorded at average cost and consisted of the following as of September 30, 2024 and December 31, 2023 (dollars in thousands):


	September 30,		December 31,
	2024		2023
Materials and supplies	$	97,398	$	81,651
Emission allowances		69,885		56,097
Stored natural gas		11,239		16,272
Fuel stock		7,418		5,964
Total	$	185,940	$	159,984

- Definition

Disclosure of inventory accounting policy for inventory classes, including, but not limited to, basis for determining inventory amounts, methods by which amounts are added and removed from inventory classes, loss recognition on impairment of inventories, and situations in which inventories are stated above cost.

+ References + Details

Pay vs Performance Disclosure - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
Pay vs Performance Disclosure - USD ($) $ in Thousands	Sep. 30, 2024	Sep. 30, 2023	Sep. 30, 2024	Sep. 30, 2023
Pay vs Performance Disclosure
Net Income (Loss)	$ 18,487	$ 14,716	$ 112,840	$ 87,045

- Definition

The portion of profit or loss for the period, net of income taxes, which is attributable to the parent.

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Topic 250
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 6
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147483443/250-10-50-6

Reference 2: http://www.xbrl.org/2003/role/disclosureRef
-Topic 250
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-Name Accounting Standards Codification
-Section 50
-Paragraph 9
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147483443/250-10-50-9

Reference 3: http://www.xbrl.org/2003/role/disclosureRef
-Topic 805
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-Name Accounting Standards Codification
-Section 65
-Paragraph 1
-Subparagraph (g)
-Publisher FASB
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Reference 4: http://www.xbrl.org/2003/role/disclosureRef
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-Section 65
-Paragraph 2
-Subparagraph (g)(3)
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-URI https://asc.fasb.org/1943274/2147478666/740-323-65-2

Reference 5: http://fasb.org/us-gaap/role/ref/legacyRef
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Reference 6: http://www.xbrl.org/2003/role/disclosureRef
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Reference 7: http://www.xbrl.org/2003/role/disclosureRef
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Reference 8: http://www.xbrl.org/2003/role/disclosureRef
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Reference 9: http://www.xbrl.org/2003/role/disclosureRef
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Reference 10: http://www.xbrl.org/2003/role/disclosureRef
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Reference 11: http://www.xbrl.org/2003/role/disclosureRef
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Reference 12: http://www.xbrl.org/2003/role/disclosureRef
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Reference 13: http://www.xbrl.org/2003/role/disclosureRef
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Reference 14: http://www.xbrl.org/2003/role/disclosureRef
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Reference 15: http://www.xbrl.org/2003/role/disclosureRef
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Reference 26: http://www.xbrl.org/2003/role/disclosureRef
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Reference 29: http://www.xbrl.org/2003/role/disclosureRef
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Reference 30: http://www.xbrl.org/2003/role/disclosureRef
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Reference 36: http://www.xbrl.org/2003/role/disclosureRef
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Reference 37: http://fasb.org/us-gaap/role/ref/legacyRef
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+ Details

Balance Sheet Components - Other Property and Investments-Net and Other Non-current Assets (Details) - USD ($) $ in Thousands	Sep. 30, 2024	Dec. 31, 2023
Balance Sheet Related Disclosures [Abstract]
Equity investments	$ 159,227	$ 153,350
Operating lease ROU assets	$ 66,334	$ 67,585
Operating Lease, Right-of-Use Asset, Statement of Financial Position [Extensible Enumeration]	Total	Total
Finance lease ROU assets	$ 33,683	$ 36,414
Finance Lease, Right-of-Use Asset, Statement of Financial Position [Extensible Enumeration]	Total	Total
Non-utility property	$ 33,504	$ 33,813
Notes receivable	15,295	15,287
Long-term prepaid license fees	19,314	19,448
Pension asset	44,278	32,997
Investment in affiliated trust	11,547	11,547
Deferred compensation assets	8,962	7,794
Other	19,607	15,750
Total	$ 411,751	$ 393,985

Short-Term Borrowings - Schedule of Balances Outstanding and Interest Rates of Borrowings (Details) - Avista Utilities [Member] - USD ($) $ in Thousands	Sep. 30, 2024	Dec. 31, 2023
Short-term Debt [Line Items]
Borrowings outstanding at end of period	$ 283,000	$ 349,000
Letters of credit outstanding at end of period	$ 4,700	$ 4,700
Average interest rate on borrowings at end of period	6.13%	6.46%

- Definition

The carrying value as of the balance sheet date of the current and noncurrent portions of long-term obligations drawn from a line of credit, which is a bank's commitment to make loans up to a specific amount. Examples of items that might be included in the application of this element may consist of letters of credit, standby letters of credit, and revolving credit arrangements, under which borrowings can be made up to a maximum amount as of any point in time conditional on satisfaction of specified terms before, as of and after the date of drawdowns on the line. Includes short-term obligations that would normally be classified as current liabilities but for which (a) postbalance sheet date issuance of a long term obligation to refinance the short term obligation on a long term basis, or (b) the enterprise has entered into a financing agreement that clearly permits the enterprise to refinance the short-term obligation on a long term basis and the following conditions are met (1) the agreement does not expire within 1 year and is not cancelable by the lender except for violation of an objectively determinable provision, (2) no violation exists at the BS date, and (3) the lender has entered into the financing agreement is expected to be financially capable of honoring the agreement.

+ References + Details

Fair Value (Tables)

9 Months Ended

Sep. 30, 2024

Fair Value Disclosures [Abstract]

Schedule of Carrying Value and Estimated Fair Value of Financial Instruments


	September 30, 2024				December 31, 2023
	Carrying Value		Estimated Fair Value		Carrying Value		Estimated Fair Value
Long-term debt (Level 2)	$	1,100,000	$	999,103	$	1,100,000	$	968,893
Long-term debt (Level 3)		1,533,700		1,268,561		1,450,000		1,166,512
Snettisham finance lease obligation (Level 3)		39,945		37,500		42,495		39,600
Long-term debt to affiliated trusts (Level 3)		51,547		46,990		51,547		46,098

Schedule of Fair Value of Assets and Liabilities Measured on Recurring Basis


	Level 1		Level 2		Level 3		Counterparty and Cash Collateral Netting (1)			Total
September 30, 2024
Assets:
Energy commodity derivatives	$	—	$	21,395	$	—	$	(13,023	)	$	8,372
Foreign currency exchange derivatives		—		7		—		—			7
Equity Investments		—		—		52,819		—			52,819
Deferred compensation assets
Mutual Funds:
Fixed income securities (3)		1,026		—		—		—			1,026
Equity securities (3)		7,727		—		—		—			7,727
Total	$	8,753	$	21,402	$	52,819	$	(13,023	)	$	69,951
Liabilities:
Energy commodity derivatives (2)	$	—	$	65,159	$	6,977	$	(32,938	)	$	39,198
Interest rate swap derivatives		—		75		—		—			75
Total	$	—	$	65,234	$	6,977	$	(32,938	)	$	39,273
December 31, 2023
Assets:
Energy commodity derivatives (2)	$	—	$	30,954	$	—	$	(22,802	)	$	8,152
Foreign currency exchange derivatives		—		2		—		—			2
Interest rate swap derivatives		—		3,667		—		—			3,667
Equity Investments		—		—		50,254		—			50,254
Deferred compensation assets
Mutual Funds:
Fixed income securities (3)		1,117		—		—		—			1,117
Equity securities (3)		6,524		—		—		—			6,524
Total	$	7,641	$	34,623	$	50,254	$	(22,802	)	$	69,716
Liabilities:
Energy commodity derivatives (2)	$	—	$	91,844	$	8,250	$	(65,157	)	$	34,937
Interest rate swap derivatives		—		182		—		—			182
Total	$	—	$	92,026	$	8,250	$	(65,157	)	$	35,119

(1)

(2)

The Level 3 energy commodity derivative balances are associated with a natural gas exchange agreement.

(3)

Included in other property and investments-net and other non-current assets on the Condensed Consolidated Balance Sheets.

Schedule of Quantitative Information

The following table presents the quantitative information which was used to estimate the fair values of the Level 3 assets and liabilities above as of September 30, 2024 (dollars in thousands):


	Fair Value (Net) at			Valuation	Unobservable	Range and Weighted
	September 30, 2024			Technique	Input	Average Price
Natural gas exchange agreement	$	(6,977	)	Internally derived weighted average cost of gas	Forward sales prices	$2.57 - $8.08/mmBTU $5.86 Weighted Average
					Sales volumes	75,000 - 310,000 mmBTUs

The following table presents the quantitative information which was used to estimate the fair values of the Level 3 equity investments as of September 30, 2024 (dollars in thousands):


	Fair Value at
	September 30, 2024		Valuation Technique	Unobservable Input	Range
Equity investments	$	52,819	Market approach	Comparable enterprise values	$130,000-$388,600 $246,000 Average
				Time to liquidity event	1.50 years
			Discounted cash flows	Revenue market multiples	0.53x to 4.71x Revenue 2.21x Average
				Market multiple exit reduction	50%
				Discount rate	25%
				Annual revenues	$5,000 - $138,000
				Terminal date	2029

Schedule of Activity For Energy Commodity Derivative Assets (Liabilities) Measured At Fair Value and Equity Investments Using Significant Unobservable Inputs (Level 3)


	Natural Gas Exchange Agreement (1)			Equity Investments			Total
Three Months Ended September 30, 2024:
Beginning balance	$	(7,981	)	$	50,357		$	42,376
Total gains or (losses) (realized/unrealized):
Included in regulatory assets/liabilities		1,005			—			1,005
Recognized in net income		—			1,478			1,478
Purchases and debt conversions		—			984			984
Settlements		(1	)		—			(1	)
Ending balance as of September 30, 2024	$	(6,977	)	$	52,819		$	45,842
Three Months Ended September 30, 2023:
Beginning balance	$	(11,721	)	$	48,453		$	36,732
Total gains or (losses) (realized/unrealized):
Included in regulatory assets/liabilities		(3,652	)		—			(3,652	)
Recognized in net income		—			2,024			2,024
Ending balance as of September 30, 2023	$	(15,373	)	$	50,477		$	35,104
Nine Months Ended September 30, 2024:
Beginning balance	$	(8,250	)	$	50,254		$	42,004
Total gains or (losses) (realized/unrealized):
Included in regulatory assets/liabilities		986			—			986
Recognized in net income		—			636			636
Purchases and debt conversions		—			1,929			1,929
Settlements		287			—			287
Ending balance as of September 30, 2024	$	(6,977	)	$	52,819		$	45,842
Nine Months Ended September 30, 2023:
Beginning balance	$	(17,734	)	$	54,284		$	36,550
Total gains or (losses) (realized/unrealized):
Included in regulatory assets/liabilities		2,115			—			2,115
Recognized in net income		—			(3,174	)		(3,174	)
Purchases and debt conversions		—			2,367			2,367
Settlements		246			—			246
Other		—			(3,000	)		(3,000	)
Ending balance as of September 30, 2023	$	(15,373	)	$	50,477		$	35,104

(1)

There were no purchases, issuances or transfers from other categories during the periods presented in the table above.

Balance Sheet Components - Schedule of Other Current Assets (Details) - USD ($) $ in Thousands	Sep. 30, 2024	Dec. 31, 2023
Balance Sheet Related Disclosures [Abstract]
Prepayments	$ 40,074	$ 52,752
Income taxes receivable	9,102	29,234
Derivative assets net of collateral	6,785	11,821
Collateral posted for derivative instruments after netting with outstanding derivative	4,858	0
Other	10,288	9,977
Total	$ 71,107	$ 103,784

Balance Sheet Components (Tables)

9 Months Ended

Sep. 30, 2024

Balance Sheet Related Disclosures [Abstract]

Schedule of Inventory


	September 30,		December 31,
	2024		2023
Materials and supplies	$	97,398	$	81,651
Emission allowances		69,885		56,097
Stored natural gas		11,239		16,272
Fuel stock		7,418		5,964
Total	$	185,940	$	159,984

Schedule of Other Current Assets

Other current assets consisted of the following as of September 30, 2024 and December 31, 2023 (dollars in thousands):


	September 30,		December 31,
	2024		2023
Prepayments	$	40,074	$	52,752
Income taxes receivable		9,102		29,234
Derivative assets net of collateral		6,785		11,821
Collateral posted for derivative instruments after netting with outstanding derivatives		4,858		—
Other		10,288		9,977
Total	$	71,107	$	103,784

Schedule of Net Utility Property Recorded at Original Cost Net of Accumulated Depreciation

Net utility property, which is recorded at original cost, net of accumulated depreciation, consisted of the following as of September 30, 2024 and December 31, 2023 (dollars in thousands):


	September 30,		December 31,
	2024		2023
Utility plant in service	$	8,067,517	$	7,799,481
Construction work in progress		246,490		179,527
Total		8,314,007		7,979,008
Less: Accumulated depreciation and amortization		2,389,617		2,278,952
Total	$	5,924,390	$	5,700,056

Other Property and Investments-Net and Other Non-Current Assets

Other property and investments-net and other non-current assets consisted of the following as of September 30, 2024 and December 31, 2023 (dollars in thousands):


	September 30,		December 31,
	2024		2023
Equity investments	$	159,227	$	153,350
Operating lease ROU assets		66,334		67,585
Finance lease ROU assets		33,683		36,414
Non-utility property		33,504		33,813
Notes receivable		15,295		15,287
Long-term prepaid license fees		19,314		19,448
Pension asset		44,278		32,997
Investment in affiliated trust		11,547		11,547
Deferred compensation assets		8,962		7,794
Other		19,607		15,750
Total	$	411,751	$	393,985

Other Current Liabilities

Other current liabilities consisted of the following as of September 30, 2024 and December 31, 2023 (dollars in thousands):


	September 30, 2024		December 31, 2023
Accrued taxes other than income taxes	$	29,160	$	31,928
Derivative liabilities net of collateral		27,612		17,217
Employee paid time off accruals		33,222		32,072
Accrued interest		41,863		23,539
Climate Commitment Act obligations		—		19,081
Pensions and other postretirement benefits		14,852		14,082
Other		54,489		54,017
Total	$	201,198	$	191,936

Schedule of Other Non-Current Liabilities and Deferred Credits

Other non-current liabilities and deferred credits consisted of the following as of September 30, 2024 and December 31, 2023 (dollars in thousands):


	September 30, 2024		December 31, 2023
Operating lease liabilities	$	65,386	$	63,559
Finance lease liabilities		36,421		39,095
Deferred investment tax credits		28,303		28,233
Climate Commitment Act obligations		66,375		26,026
Asset retirement obligations		18,207		18,058
Derivative liabilities net of collateral		11,661		17,902
Other		21,253		17,357
Total	$	247,606	$	210,230

Schedule of Regulatory Assets and Liabilities

Regulatory assets and liabilities consisted of the following as of September 30, 2024 and December 31, 2023 (dollars in thousands):


	September 30, 2024				December 31, 2023
	Current		Non-Current		Current		Non-Current
Regulatory Assets
Energy commodity derivatives	$	38,033	$	12,708	$	51,419	$	17,720
Deferred Climate Commitment Act costs		36,102		21,834		—		46,022
Deferred power costs		13,410		22,724		29,190		20,654
Wildfire resiliency		8,277		14,312		—		23,737
Decoupling surcharge		10,476		8,123		4,638		5,469
Deferred natural gas costs		3,376		—		60,667		—
Income tax related assets		—		246,863		—		244,303
Pension and other postretirement benefit plans		—		111,844		—		117,658
Interest rate swaps		—		174,151		—		179,489
AFUDC above FERC allowed rate		—		48,232		—		49,985
Settlement with Coeur d'Alene Tribe		—		35,855		—		36,692
Advanced meter infrastructure		—		27,069		—		29,345
Utility plant abandoned		—		31,610		—		38,274
Colstrip excess depreciation		—		23,824		—		19,429
COVID-19 deferrals		—		11,846		—		12,142
Demand side management programs		—		27,496		—		10,033
Other regulatory assets		5,523		48,751		413		43,216
Total regulatory assets	$	115,197	$	867,242	$	146,327	$	894,168
Regulatory Liabilities
Other income tax related liabilities	$	8,918	$	53,859	$	25,129	$	56,582
Excess deferred income taxes		14,223		282,629		14,510		293,029
Deferred Climate Commitment Act revenues		32,947		14,296		—		37,231
Deferred power costs		7,172		5,312		—		4,000
Deferred natural gas costs		13,213		—		9,296		—
Decoupling rebate		7,495		3,150		18,680		6,344
Utility plant retirement costs		—		439,874		—		417,027
Interest rate swaps		—		23,580		—		23,752
COVID-19 deferrals		—		10,443		—		10,172
Other regulatory liabilities		8,227		6,904		8,392		8,529
Total regulatory liabilities	$	92,195	$	840,047	$	76,007	$	856,666

New Accounting Standards

9 Months Ended

Sep. 30, 2024

Accounting Standards Update and Change in Accounting Principle [Abstract]

New Accounting Standards

NOTE 2. NEW ACCOUNTING STANDARDS

ASU 2022-03 "Fair Value Measurement of Equity Securities Subject to Contractual Sale Restrictions"

In June 2022, the FASB issued ASU 2022-03, Fair Value Measurement (Topic 820): Fair Value Measurement of Equity Securities Subject to Contractual Sale Restrictions. The purpose of this guidance is to clarify that a contractual restriction on the ability to sell an equity security is not considered part of the unit of account of the equity security, and therefore should not be considered when measuring the equity security's fair value. Additionally, an entity cannot separately recognize and measure a contractual sale restriction. This guidance also adds specific disclosures related to equity securities subject to contractual sale restrictions, including (i) the fair value of equity securities subject to contractual sale restrictions reflected in the balance sheet, (ii) the nature and remaining duration of the restrictions and (iii) the circumstances that could cause a lapse in the restrictions. The Company adopted the amendments effective January 1, 2024, with no material impacts to the Company's financial statements resulting upon adoption.

ASU 2023-06 "Disclosure Improvements - Codification Amendments in Response to the SEC's Disclosure Update and Simplification Initiative"

In October 2023, the FASB issued ASU 2023-06, which incorporates a variety of SEC required disclosures into the FASB Accounting Standards Codification (ASC). For entities subject to SEC's existing disclosure requirements, the effective date for each amendment will be the date on which the SEC removes the related disclosure from Regulation S-X or Regulation S-K, with early adoption permitted. If the SEC has not removed the applicable requirement from Regulation S-X or Regulation S-K by June 30, 2027, the

disclosure requirements will be removed from the Codification. The requirements of the ASU will not have a material impact on the Company's financial statements.

ASU 2023-07 "Segment Reporting (Topic 280) - Improvements to Reportable Segment Disclosures"

In November 2023, the FASB issued ASU 2023-07, requiring additional disclosures around reportable segment information. The additional required disclosures include significant segment expenses, an amount for other segment activity not included in the disaggregated segment amounts and a description of the activity, and the title and position of the chief operating decision maker and an explanation of how they use the reported measures of segment profit or loss in assessing segment performance and allocating resources. The ASU is effective for fiscal years beginning after December 15, 2023 and interim periods beginning after December 15, 2024, and early adoption is permitted. The Company expects the implementation of the ASU to result in expanded segment reporting disclosures.

ASU 2023-09 "Income Taxes (Topic 740) - Improvements to Income Tax Disclosures"

In December 2023, the FASB issued ASU 2023-09, requiring additional income tax disclosures. The additional disclosures include prescribed items presented in the income tax rate reconciliation, and further disaggregation of income taxes paid amounts between federal, state and foreign taxes. The ASU is effective for fiscal years beginning after December 15, 2024 and early adoption is permitted. The Company expects the implementation of the ASU to result in expanded income tax disclosures.

- Definition

The entire disclosure for change in accounting principle. Includes, but is not limited to, nature, reason, and method of adopting amendment to accounting standards or other change in accounting principle.

+ References

+ Details

Pension Plans and Other Postretirement Benefit Plans (Tables)

9 Months Ended

Sep. 30, 2024

Retirement Benefits, Description [Abstract]

Components of Net Periodic Benefit Cost

The Company uses a December 31 measurement date for its defined benefit pension and other postretirement benefit plans. The following table sets forth the components of net periodic benefit costs for the three and nine months ended September 30 (dollars in thousands):


	Pension Benefits						Other Postretirement Benefits
	2024			2023			2024			2023
Three months ended September 30:
Service cost	$	4,030		$	3,098		$	719		$	559
Interest cost		8,430			8,524			1,706			1,872
Expected return on plan assets		(11,356	)		(10,922	)		(974	)		(891	)
Amortization of prior service cost (credit)		126			123			(263	)		(263	)
Net loss recognition		684			1,184			96			(54	)
Net periodic benefit cost	$	1,914		$	2,007		$	1,284		$	1,223
Nine months ended September 30:
Service cost	$	11,739		$	11,092		$	2,000		$	1,909
Interest cost		25,012			24,277			5,178			4,825
Expected return on plan assets		(33,940	)		(32,766	)		(2,922	)		(2,673	)
Curtailment loss		169			—			—			—
Amortization of prior service cost (credit)		375			369			(789	)		(789	)
Net loss recognition		2,043			3,208			275			471
Net periodic benefit cost	$	5,398		$	6,180		$	3,742		$	3,743

Revenue - Schedule of Utilities Operating Revenue Expense Taxes (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2024	Sep. 30, 2023	Sep. 30, 2024	Sep. 30, 2023
Revenue from Contract with Customer [Abstract]
Utility-related taxes	$ 16,775	$ 14,484	$ 60,442	$ 56,356

Income Taxes - Summary of Significant Factors Impact on Difference Between Effective Tax Rate and Federal Statutory Rate (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2024	Sep. 30, 2023	Sep. 30, 2024	Sep. 30, 2023
Income Tax Disclosure [Abstract]
Federal income taxes at statutory rates	$ 3,782	$ 2,294	$ 24,184	$ 14,872
Flow through related to deduction of meters and mixed service costs	(2,445)	(3,744)	(14,128)	(22,956)
Tax effect of regulatory treatment of utility plant differences	(1,317)	(828)	(7,291)	(6,040)
State income tax expense	160	151	878	949
Tax credits	(86)	(862)	(486)	(1,997)
Other	(572)	(797)	(834)	(1,052)
Total income tax expense (benefit)	$ (478)	$ (3,786)	$ 2,323	$ (16,224)
Federal income taxes at statutory rates	21.00%	21.00%	21.00%	21.00%
Flow through related to deduction of meters and mixed service costs	(13.60%)	(34.30%)	(12.30%)	(32.40%)
Tax effect of regulatory treatment of utility plant differences	(7.30%)	(7.60%)	(6.40%)	(8.50%)
State income tax expense	0.90%	1.40%	0.80%	1.30%
Tax credits	(0.50%)	(7.90%)	(0.40%)	(2.80%)
Other	(3.20%)	(7.20%)	(0.70%)	(1.50%)
Total income tax benefit	(2.70%)	(34.60%)	2.00%	(22.90%)

Common Stock

9 Months Ended

Sep. 30, 2024

Stockholders' Equity Note [Abstract]

Common Stock

NOTE 12. COMMON STOCK

The Company issued shares of common stock for total net proceeds of $18.1 million and $35.7 million during the three and nine months ended September 30, 2024, respectively. Most of these shares were issued in at-the-market transactions pursuant to the Company's sales agency agreements under which the Company may offer and sell new shares of common stock through its sales agents from time to time. Under these sales agency agreements, the Company issued 0.5 million and 1.0 million shares during the three and nine months ended September 30, 2024, respectively.

- Definition

The entire disclosure for equity.

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Topic 505
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 13
-Subparagraph (b)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147481112/505-10-50-13

Reference 2: http://www.xbrl.org/2003/role/disclosureRef
-Topic 505
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 13
-Subparagraph (h)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147481112/505-10-50-13

Reference 3: http://www.xbrl.org/2003/role/disclosureRef
-Topic 505
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 14
-Subparagraph (b)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147481112/505-10-50-14

Reference 4: http://www.xbrl.org/2003/role/disclosureRef
-Topic 946
-SubTopic 235
-Name Accounting Standards Codification
-Section 50
-Paragraph 2
-Subparagraph (a)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147477968/946-235-50-2

Reference 5: http://www.xbrl.org/2003/role/disclosureRef
-Topic 946
-SubTopic 235
-Name Accounting Standards Codification
-Section 50
-Paragraph 2
-Subparagraph (d)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147477968/946-235-50-2

Reference 6: http://www.xbrl.org/2003/role/disclosureRef
-Topic 946
-SubTopic 505
-Name Accounting Standards Codification
-Section 50
-Paragraph 6
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147478448/946-505-50-6

Reference 7: http://www.xbrl.org/2003/role/disclosureRef
-Topic 815
-SubTopic 40
-Name Accounting Standards Codification
-Section 50
-Paragraph 6
-Subparagraph (a)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147480237/815-40-50-6

Reference 8: http://www.xbrl.org/2003/role/disclosureRef
-Topic 505
-SubTopic 10
-Name Accounting Standards Codification
-Section S99
-Paragraph 1
-Subparagraph (SX 210.3-04)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147480008/505-10-S99-1

Reference 9: http://www.xbrl.org/2003/role/disclosureRef
-Topic 235
-SubTopic 10
-Name Accounting Standards Codification
-Section S99
-Paragraph 1
-Subparagraph (SX 210.4-08(e)(1))
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147480678/235-10-S99-1

Reference 10: http://fasb.org/us-gaap/role/ref/legacyRef
-Topic 505
-Name Accounting Standards Codification
-Publisher FASB
-URI https://asc.fasb.org/505/tableOfContent

Reference 11: http://www.xbrl.org/2003/role/disclosureRef
-Topic 505
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 13
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147481112/505-10-50-13

Reference 12: http://www.xbrl.org/2003/role/disclosureRef
-Topic 505
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 13
-Subparagraph (g)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147481112/505-10-50-13

Reference 13: http://www.xbrl.org/2003/role/disclosureRef
-Topic 505
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 13
-Subparagraph (i)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147481112/505-10-50-13

Reference 14: http://www.xbrl.org/2003/role/disclosureRef
-Topic 505
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 14
-Subparagraph (a)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147481112/505-10-50-14

Reference 15: http://www.xbrl.org/2003/role/disclosureRef
-Topic 505
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 14
-Subparagraph (c)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147481112/505-10-50-14

Reference 16: http://www.xbrl.org/2003/role/disclosureRef
-Topic 505
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 16
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-Publisher FASB
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Reference 17: http://www.xbrl.org/2003/role/disclosureRef
-Topic 505
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 18
-Subparagraph (a)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147481112/505-10-50-18

Reference 18: http://www.xbrl.org/2003/role/disclosureRef
-Topic 505
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 18
-Subparagraph (b)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147481112/505-10-50-18

Reference 19: http://www.xbrl.org/2003/role/disclosureRef
-Topic 505
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 18
-Subparagraph (d)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147481112/505-10-50-18

+ Details

CONDENSED CONSOLIDATED STATEMENTS OF COMPREHENSIVE INCOME - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2024	Sep. 30, 2023	Sep. 30, 2024	Sep. 30, 2023
Statement of Comprehensive Income [Abstract]
Net income	$ 18,487	$ 14,716	$ 112,840	$ 87,045
Change in unfunded benefit obligation for pension and other postretirement benefit plans - net of taxes of ($3), ($5) ($5) and ($15), respectively	(9)	(19)	(18)	(56)
Comprehensive income	$ 18,478	$ 14,697	$ 112,822	$ 86,989

- Definition

Amount after tax of increase (decrease) in equity from transactions and other events and circumstances from net income and other comprehensive income. Excludes changes in equity resulting from investments by owners and distributions to owners.

+ References + Details

- Definition

The portion of profit or loss for the period, net of income taxes, which is attributable to the parent.

+ References

+ Details

Derivatives and Risk Management - Schedule of Energy Commodity Derivative Volumes (Details) MWh in Thousands, MMBTU in Thousands	9 Months Ended	12 Months Ended
	Sep. 30, 2024 MMBTU MWh	Dec. 31, 2023 MMBTU MWh
Purchase [Member] \| Physical [Member] \| Electric Derivative [Member]
Energy Commodity Derivative Volumes [Line Items]
Year one \| MWh	6	9
Year two \| MWh	0	0
Year three \| MWh	0	0
Year four \| MWh	0
Purchase [Member] \| Physical [Member] \| Gas Derivative [Member]
Energy Commodity Derivative Volumes [Line Items]
Year one \| MMBTU	12,866	22,747
Year two \| MMBTU	24,248	12,505
Year three \| MMBTU	14,663	5,570
Year four \| MMBTU	3,910
Purchase [Member] \| Financial [Member] \| Electric Derivative [Member]
Energy Commodity Derivative Volumes [Line Items]
Year one \| MWh	0	0
Year two \| MWh	0	0
Year three \| MWh	0	0
Year four \| MWh	0
Purchase [Member] \| Financial [Member] \| Gas Derivative [Member]
Energy Commodity Derivative Volumes [Line Items]
Year one \| MMBTU	19,734	74,596
Year two \| MMBTU	29,315	19,590
Year three \| MMBTU	10,765	3,940
Year four \| MMBTU	1,350
Sales [Member] \| Physical [Member] \| Electric Derivative [Member]
Energy Commodity Derivative Volumes [Line Items]
Year one \| MWh	194	472
Year two \| MWh	348	11
Year three \| MWh	0	0
Year four \| MWh	0
Sales [Member] \| Physical [Member] \| Gas Derivative [Member]
Energy Commodity Derivative Volumes [Line Items]
Year one \| MMBTU	581	1,723
Year two \| MMBTU	1,115	1,115
Year three \| MMBTU	0	0
Year four \| MMBTU	0
Sales [Member] \| Financial [Member] \| Electric Derivative [Member]
Energy Commodity Derivative Volumes [Line Items]
Year one \| MWh	408	510
Year two \| MWh	175	96
Year three \| MWh	0	0
Year four \| MWh	0
Sales [Member] \| Financial [Member] \| Gas Derivative [Member]
Energy Commodity Derivative Volumes [Line Items]
Year one \| MMBTU	2,690	12,038
Year two \| MMBTU	1,125	1,125
Year three \| MMBTU	0	0
Year four \| MMBTU	0

CONDENSED CONSOLIDATED STATEMENTS OF COMPREHENSIVE INCOME (LOSS) (Parenthetical) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2024	Sep. 30, 2023	Sep. 30, 2024	Sep. 30, 2023
Statement of Comprehensive Income [Abstract]
Other Comprehensive Income (Loss), Defined Benefit Plan, after Reclassification Adjustment, Tax	$ (3)	$ (5)	$ (5)	$ (15)

Balance Sheet Components - Schedule of Regulatory Assets and Liabilities (Details) - USD ($) $ in Thousands	Sep. 30, 2024	Dec. 31, 2023
Regulated Asset Liability [Line Items]
Regulatory Assets, Current	$ 115,197	$ 146,327
Regulatory Assets, Non-Current	867,242	894,168
Regulatory Liabilities, Current	92,195	76,007
Regulatory Liabilities, Non-Current	840,047	856,666
Other Income Tax Related Liabilities [Member]
Regulated Asset Liability [Line Items]
Regulatory Liabilities, Current	8,918	25,129
Regulatory Liabilities, Non-Current	53,859	56,582
Excess Deferred Income Taxes [Member]
Regulated Asset Liability [Line Items]
Regulatory Liabilities, Current	14,223	14,510
Regulatory Liabilities, Non-Current	282,629	293,029
Deferred Climate Commitment Act Revenues [Member]
Regulated Asset Liability [Line Items]
Regulatory Liabilities, Current	32,947	0
Regulatory Liabilities, Non-Current	14,296	37,231
Deferred Power Costs [Member]
Regulated Asset Liability [Line Items]
Regulatory Liabilities, Current	7,172	0
Regulatory Liabilities, Non-Current	5,312	4,000
Deferred Natural Gas Costs [Member]
Regulated Asset Liability [Line Items]
Regulatory Liabilities, Current	13,213	9,296
Regulatory Liabilities, Non-Current	0	0
Decoupling Rebate [Member]
Regulated Asset Liability [Line Items]
Regulatory Liabilities, Current	7,495	18,680
Regulatory Liabilities, Non-Current	3,150	6,344
Utility Plant Retirement Costs [Member]
Regulated Asset Liability [Line Items]
Regulatory Liabilities, Current	0	0
Regulatory Liabilities, Non-Current	439,874	417,027
Interest Rate Swaps [Member]
Regulated Asset Liability [Line Items]
Regulatory Liabilities, Current	0	0
Regulatory Liabilities, Non-Current	23,580	23,752
COVID-19 Deferrals [Member]
Regulated Asset Liability [Line Items]
Regulatory Liabilities, Current	0	0
Regulatory Liabilities, Non-Current	10,443	10,172
Other Regulatory Liabilities [Member]
Regulated Asset Liability [Line Items]
Regulatory Liabilities, Current	8,227	8,392
Regulatory Liabilities, Non-Current	6,904	8,529
Energy Commodity Derivatives [Member]
Regulated Asset Liability [Line Items]
Regulatory Assets, Current	38,033	51,419
Regulatory Assets, Non-Current	12,708	17,720
Deferred Climate Commitment Act Costs [Member]
Regulated Asset Liability [Line Items]
Regulatory Assets, Current	36,102	0
Regulatory Assets, Non-Current	21,834	46,022
Deferred Power Costs [Member]
Regulated Asset Liability [Line Items]
Regulatory Assets, Current	13,410	29,190
Regulatory Assets, Non-Current	22,724	20,654
Wildfire Resiliency [Member]
Regulated Asset Liability [Line Items]
Regulatory Assets, Current	8,277	0
Regulatory Assets, Non-Current	14,312	23,737
Decoupling Surcharge [Member]
Regulated Asset Liability [Line Items]
Regulatory Assets, Current	10,476	4,638
Regulatory Assets, Non-Current	8,123	5,469
Deferred Natural Gas Costs [Member]
Regulated Asset Liability [Line Items]
Regulatory Assets, Current	3,376	60,667
Regulatory Assets, Non-Current	0	0
Income Tax Related Assets [Member]
Regulated Asset Liability [Line Items]
Regulatory Assets, Current	0	0
Regulatory Assets, Non-Current	246,863	244,303
Pension and Other Postretirement Benefit Plans [Member]
Regulated Asset Liability [Line Items]
Regulatory Assets, Current	0	0
Regulatory Assets, Non-Current	111,844	117,658
Interest Rate Swaps [Member]
Regulated Asset Liability [Line Items]
Regulatory Assets, Current	0	0
Regulatory Assets, Non-Current	174,151	179,489
AFUDC Above FERC Allowed Rate [Member]
Regulated Asset Liability [Line Items]
Regulatory Assets, Current	0	0
Regulatory Assets, Non-Current	48,232	49,985
Settlement with Coeur d'Alene Tribe [Member]
Regulated Asset Liability [Line Items]
Regulatory Assets, Current	0	0
Regulatory Assets, Non-Current	35,855	36,692
Advanced Meter Infrastructure [Member]
Regulated Asset Liability [Line Items]
Regulatory Assets, Current	0	0
Regulatory Assets, Non-Current	27,069	29,345
Utility Plant Abandoned [Member]
Regulated Asset Liability [Line Items]
Regulatory Assets, Current	0	0
Regulatory Assets, Non-Current	31,610	38,274
Colstrip Excess Depreciation [Member]
Regulated Asset Liability [Line Items]
Regulatory Assets, Current	0	0
Regulatory Assets, Non-Current	23,824	19,429
COVID-19 Deferrals [Member]
Regulated Asset Liability [Line Items]
Regulatory Assets, Current	0	0
Regulatory Assets, Non-Current	11,846	12,142
Demand Side Management Programs [Member]
Regulated Asset Liability [Line Items]
Regulatory Assets, Current	0	0
Regulatory Assets, Non-Current	27,496	10,033
Other Regulatory Assets [Member]
Regulated Asset Liability [Line Items]
Regulatory Assets, Current	5,523	413
Regulatory Assets, Non-Current	$ 48,751	$ 43,216

Income Taxes (Tables)

9 Months Ended

Sep. 30, 2024

Income Tax Disclosure [Abstract]

Summary of Significant Factors Impact on Difference Between Effective Tax Rate and Federal Statutory Rate

The following table summarizes the significant factors impacting the difference between the Company's effective tax rate and the federal statutory rate for the three and nine months ended September 30 (dollars in thousands):


	Three months ended September 30,										Nine months ended September 30,
	2024					2023					2024					2023
Federal income taxes at statutory rates	$	3,782		21.0	%	$	2,294		21.0	%	$	24,184		21.0	%	$	14,872		21.0	%
Increase (decrease) in tax resulting from:
Flow through related to deduction of meters and mixed service costs (1)		(2,445	)	(13.6	)		(3,744	)	(34.3	)		(14,128	)	(12.3	)		(22,956	)	(32.4	)
Tax effect of regulatory treatment of utility plant differences		(1,317	)	(7.3	)		(828	)	(7.6	)		(7,291	)	(6.4	)		(6,040	)	(8.5	)
State income tax expense		160		0.9			151		1.4			878		0.8			949		1.3
Tax credits		(86	)	(0.5	)		(862	)	(7.9	)		(486	)	(0.4	)		(1,997	)	(2.8	)
Other		(572	)	(3.2	)		(797	)	(7.2	)		(834	)	(0.7	)		(1,052	)	(1.5	)
Total income tax expense (benefit)	$	(478	)	(2.7	)%	$	(3,786	)	(34.6	)%	$	2,323		2.0	%	$	(16,224	)	(22.9	)%

(1)

The Company's general rate cases included approval of base rate increases, offset by tax customer credits. As the tax customer credits are returned to customers, this results in a decrease to income tax expense as a result of flowing through the benefits related to meters and mixed service costs.

Long-Term Debt to Affiliated Trusts - Additional Information (Details) - USD ($) $ in Millions	1 Months Ended	9 Months Ended	12 Months Ended
	Jul. 31, 2023	Sep. 30, 2024	Dec. 31, 2000
Debt Instrument [Line Items]
Payments for repurchase of trust preferred securities			$ 10.0
1997 Floating Rate Junior Subordinated Deferrable Interest Debentures, Series B [Member] \| Avista Capital II [Member]
Debt Instrument [Line Items]
Junior subordinated debenture issuance date		1997
Principal amount		$ 51.5
Avista Corp [Member]
Debt Instrument [Line Items]
Noncontrolling interest, ownership percentage by parent		100.00%
Trust Preferred Securities Subject to Mandatory Redemption [Member] \| 1997 Floating Rate Junior Subordinated Deferrable Interest Debentures, Series B [Member] \| Avista Capital II [Member]
Debt Instrument [Line Items]
Principal amount		$ 50.0
Trust Preferred Securities Subject to Mandatory Redemption [Member] \| 1997 Floating Rate Junior Subordinated Deferrable Interest Debentures, Series B [Member] \| SOFR [Member] \| Avista Capital II [Member]
Debt Instrument [Line Items]
Debt instrument, basis spread on variable rate	1.137%
Common Trust Securities [Member] \| 1997 Floating Rate Junior Subordinated Deferrable Interest Debentures, Series B [Member] \| Avista Capital II [Member]
Debt Instrument [Line Items]
Principal amount		$ 1.5

Earnings Per Common Share (Tables)

9 Months Ended

Sep. 30, 2024

Earnings Per Share [Abstract]

Schedule of Computation of Basic and Diluted Earnings Per Common Share

The following table presents the computation of basic and diluted earnings per common share for the three and nine months ended September 30 (in thousands, except per share amounts):


	Three months ended September 30,				Nine months ended September 30,
	2024		2023		2024		2023
Numerator:
Net income	$	18,487	$	14,716	$	112,840	$	87,045
Denominator:
Weighted-average number of common shares outstanding-basic		78,836		76,734		78,463		75,962
Effect of dilutive securities:
Performance and restricted stock awards		132		27		82		94
Weighted-average number of common shares outstanding-diluted		78,968		76,761		78,545		76,056
Earnings per common share:
Basic	$	0.23	$	0.19	$	1.44	$	1.15
Diluted	$	0.23	$	0.19	$	1.44	$	1.14

Common Stock - Additional Information (Details) - USD ($) $ in Thousands, shares in Millions	3 Months Ended	9 Months Ended
	Sep. 30, 2024	Sep. 30, 2024	Sep. 30, 2023
Class Of Stock [Line Items]
Shares issued under sales agency agreements	0.5	1.0
Proceeds from issuance of common stock	$ 18,100	$ 35,743	$ 88,165

- Definition

Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table.

+ References

Reference 1: http://www.xbrl.org/2003/role/exampleRef
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Reference 13: http://www.xbrl.org/2003/role/disclosureRef
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Reference 14: http://www.xbrl.org/2003/role/disclosureRef
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Reference 15: http://www.xbrl.org/2003/role/disclosureRef
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+ Details

Earnings Per Common Share - Schedule of Computation of Basic and Diluted Earnings Per Common Share (Details) - USD ($) $ / shares in Units, shares in Thousands, $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2024	Sep. 30, 2023	Sep. 30, 2024	Sep. 30, 2023
Numerator:
Net income	$ 18,487	$ 14,716	$ 112,840	$ 87,045
Denominator:
Weighted-average number of common shares outstanding-basic	78,836	76,734	78,463	75,962
Effect of dilutive securities:
Performance and restricted stock awards	132	27	82	94
Weighted-average number of common shares outstanding-diluted	78,968	76,761	78,545	76,056
Earnings per common share:
Basic	$ 0.23	$ 0.19	$ 1.44	$ 1.15
Diluted	$ 0.23	$ 0.19	$ 1.44	$ 1.14

Revenue - Disaggregation of Revenue (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2024	Sep. 30, 2023	Sep. 30, 2024	Sep. 30, 2023
Disaggregation of Revenue [Line Items]
Alternative revenue programs	$ 3,978	$ 3,578	$ 23,032	$ (9,947)
Total utility revenues	393,565	379,524	1,404,991	1,233,827
Non-utility revenues	177	102	239	367
Total operating revenues	393,742	379,626	1,405,230	1,234,194
Residential Electric [Member]
Disaggregation of Revenue [Line Items]
Revenue from contract with customer including assessed tax	113,772	99,067	360,312	319,688
Commercial Electric [Member]
Disaggregation of Revenue [Line Items]
Revenue from contract with customer including assessed tax	103,702	96,219	295,344	272,601
Industrial Electric [Member]
Disaggregation of Revenue [Line Items]
Revenue from contract with customer including assessed tax	36,910	29,584	95,014	82,707
Public Street and Highway Lighting Electric [Member]
Disaggregation of Revenue [Line Items]
Revenue from contract with customer including assessed tax	2,255	2,072	6,802	6,132
Retail Electric [Member]
Disaggregation of Revenue [Line Items]
Revenue from contract with customer including assessed tax	256,639	226,942	757,472	681,128
Transmission Electric [Member]
Disaggregation of Revenue [Line Items]
Revenue from contract with customer including assessed tax	9,250	7,721	28,380	24,143
Other Electric Revenues from Contracts With Customers [Member]
Disaggregation of Revenue [Line Items]
Revenue from contract with customer including assessed tax	8,062	9,353	32,457	33,580
Electric [Member]
Disaggregation of Revenue [Line Items]
Revenue from contract with customer including assessed tax	273,951	244,016	818,309	738,851
Avista Utilities [Member]
Disaggregation of Revenue [Line Items]
Revenue from contract with customer including assessed tax	318,171	285,821	1,136,926	1,058,725
Derivative revenues	56,462	77,562	194,647	141,080
Alternative revenue programs	3,978	3,578	23,032	(9,947)
Other utility revenues	5,135	2,712	14,891	8,561
Total utility revenues	383,746	369,673	1,369,496	1,198,419
Avista Utilities [Member] \| Residential Electric [Member]
Disaggregation of Revenue [Line Items]
Revenue from contract with customer including assessed tax	110,328	95,881	345,166	305,203
Avista Utilities [Member] \| Commercial Electric [Member]
Disaggregation of Revenue [Line Items]
Revenue from contract with customer including assessed tax	97,389	89,772	275,525	252,344
Avista Utilities [Member] \| Industrial Electric [Member]
Disaggregation of Revenue [Line Items]
Revenue from contract with customer including assessed tax	36,910	29,584	95,014	82,707
Avista Utilities [Member] \| Public Street and Highway Lighting Electric [Member]
Disaggregation of Revenue [Line Items]
Revenue from contract with customer including assessed tax	2,186	2,005	6,604	5,940
Avista Utilities [Member] \| Retail Electric [Member]
Disaggregation of Revenue [Line Items]
Revenue from contract with customer including assessed tax	246,813	217,242	722,309	646,194
Avista Utilities [Member] \| Transmission Electric [Member]
Disaggregation of Revenue [Line Items]
Revenue from contract with customer including assessed tax	9,250	7,721	28,380	24,143
Avista Utilities [Member] \| Other Electric Revenues from Contracts With Customers [Member]
Disaggregation of Revenue [Line Items]
Revenue from contract with customer including assessed tax	8,062	9,353	32,457	33,580
Avista Utilities [Member] \| Electric [Member]
Disaggregation of Revenue [Line Items]
Revenue from contract with customer including assessed tax	264,125	234,316	783,146	703,917
Avista Utilities [Member] \| Residential Natural Gas [Member]
Disaggregation of Revenue [Line Items]
Revenue from contract with customer including assessed tax	30,285	29,372	217,682	218,212
Avista Utilities [Member] \| Commercial Natural Gas [Member]
Disaggregation of Revenue [Line Items]
Revenue from contract with customer including assessed tax	17,203	15,381	114,495	113,183
Avista Utilities [Member] \| Industrial and Interruptible Natural Gas [Member]
Disaggregation of Revenue [Line Items]
Revenue from contract with customer including assessed tax	2,720	3,480	9,880	13,136
Avista Utilities [Member] \| Retail Natural Gas [Member]
Disaggregation of Revenue [Line Items]
Revenue from contract with customer including assessed tax	50,208	48,233	342,057	344,531
Avista Utilities [Member] \| Transportation Natural Gas [Member]
Disaggregation of Revenue [Line Items]
Revenue from contract with customer including assessed tax	2,432	1,866	7,504	6,058
Avista Utilities [Member] \| Other Natural Gas Revenues from Contracts With Customers [Member]
Disaggregation of Revenue [Line Items]
Revenue from contract with customer including assessed tax	1,406	1,406	4,219	4,219
Avista Utilities [Member] \| Natural Gas [Member]
Disaggregation of Revenue [Line Items]
Revenue from contract with customer including assessed tax	54,046	51,505	353,780	354,808
Alaska Electric Light & Power [Member]
Disaggregation of Revenue [Line Items]
Revenue from contracts with customers	9,826	9,700	35,163	34,934
Deferrals and amortizations for rate refunds to customers	(183)		(183)
Other utility revenues	176	151	515	474
Total utility revenues	9,819	9,851	35,495	35,408
Alaska Electric Light & Power [Member] \| Residential Electric [Member]
Disaggregation of Revenue [Line Items]
Revenue from contracts with customers	3,444	3,186	15,146	14,485
Alaska Electric Light & Power [Member] \| Commercial Electric [Member]
Disaggregation of Revenue [Line Items]
Revenue from contracts with customers	6,313	6,447	19,819	20,257
Alaska Electric Light & Power [Member] \| Public Street and Highway Lighting Electric [Member]
Disaggregation of Revenue [Line Items]
Revenue from contracts with customers	69	67	198	192
Alaska Electric Light & Power [Member] \| Retail Electric [Member]
Disaggregation of Revenue [Line Items]
Revenue from contracts with customers	9,826	9,700	35,163	34,934
Alaska Electric Light & Power [Member] \| Electric [Member]
Disaggregation of Revenue [Line Items]
Revenue from contracts with customers	9,826	9,700	35,163	34,934
Corporate and Other [Member]
Disaggregation of Revenue [Line Items]
Non-utility revenues	$ 177	$ 102	$ 239	$ 367

Document and Entity Information - shares	9 Months Ended
Document and Entity Information - shares	Sep. 30, 2024	Oct. 31, 2024
Cover [Abstract]
Entity Registrant Name	AVISTA CORPORATION
Amendment Flag	false
Entity Filer Category	Large Accelerated Filer
Entity Small Business	false
Entity Information, Former Legal or Registered Name	None
City Area Code	509
Entity Incorporation, State or Country Code	WA
Document Transition Report	false
Document Quarterly Report	true
Document Type	10-Q
Document Period End Date	Sep. 30, 2024
Entity File Number	1-3701
Entity Tax Identification Number	91-0462470
Entity Address, Address Line One	1411 East Mission Avenue
Entity Address, City or Town	Spokane
Entity Address, State or Province	WA
Entity Address, Postal Zip Code	99202-2600
Local Phone Number	489-0500
Entity Current Reporting Status	Yes
Entity Interactive Data Current	Yes
Entity Emerging Growth Company	false
Entity Shell Company	false
Document Fiscal Year Focus	2024
Document Fiscal Period Focus	Q3
Entity Central Index Key	0000104918
Current Fiscal Year End Date	--12-31
Entity Common Stock, Shares Outstanding		79,182,817
Title of 12(b) Security	Common Stock
Trading Symbol	AVA
Security Exchange Name	NYSE

Long-Term Debt to Affiliated Trusts

9 Months Ended

Sep. 30, 2024

Long Term Debt To Affiliated Trust [Abstract]

Long- Term Debt To Affiliated Trusts

NOTE 10. LONG-TERM DEBT TO AFFILIATED TRUSTS

In 1997, the Company issued Floating Rate Junior Subordinated Deferrable Interest Debentures, Series B, with a principal amount of $51.5 million to Avista Capital II, an affiliated business trust formed by the Company. Avista Capital II issued $50.0 million of Preferred Trust Securities. The distribution rate on the Preferred Trust Securities is three-month CME Term SOFR plus 1.137 percent.

The distribution rates were as follows during the nine months ended September 30, 2024 and the year ended December 31, 2023:


	September 30,			December 31,
	2024			2023
Low distribution rate		6.15	%		5.64	%
High distribution rate		6.51	%		6.55	%
Distribution rate at the end of the period		6.15	%		6.51	%

Concurrent with the issuance of the Preferred Trust Securities, Avista Capital II issued $1.5 million of Common Trust Securities to the Company. The Preferred Trust Securities may be redeemed at the option of Avista Capital II at any time and mature on June 1, 2037. In December 2000, the Company purchased $10.0 million of these Preferred Trust Securities.

The Company owns 100 percent of Avista Capital II and has solely and unconditionally guaranteed the payment of distributions on, and redemption price and liquidation amount for, the Preferred Trust Securities to the extent Avista Capital II has funds available for such payments from the respective debt securities. Upon maturity or prior redemption of such debt securities, the Preferred Trust Securities will be mandatorily redeemed. The Company does not include these capital trusts in its condensed consolidated financial statements as Avista Corp. is not the primary beneficiary. As such, the sole assets of the capital trusts are $51.5 million of junior subordinated deferrable interest debentures of Avista Corp., which are reflected on the Condensed Consolidated Balance Sheets. Interest expense to affiliated trusts in the Condensed Consolidated Statements of Income represents interest expense on these debentures.

Accumulated Other Comprehensive Loss - Schedule of Accumulated Other Comprehensive Loss, Net of Tax (Details) - USD ($) $ in Thousands	Sep. 30, 2024	Dec. 31, 2023
Accumulated Other Comprehensive Loss [Abstract]
Unfunded benefit obligation for pensions and other postretirement benefit plans - net of taxes of $100 and $95, respectively	$ 375	$ 357

Pension Plans and Other Postretirement Benefit Plans

9 Months Ended

Sep. 30, 2024

Retirement Benefits, Description [Abstract]

Pension Plans and Other Postretirement Benefit Plans

NOTE 6. PENSION PLANS AND OTHER POSTRETIREMENT BENEFIT PLANS

Avista Utilities

The Company contributed $10.0 million in cash to the pension plan for the nine months ended September 30, 2024, and does not expect further contributions in 2024.


	Pension Benefits						Other Postretirement Benefits
	2024			2023			2024			2023
Three months ended September 30:
Service cost	$	4,030		$	3,098		$	719		$	559
Interest cost		8,430			8,524			1,706			1,872
Expected return on plan assets		(11,356	)		(10,922	)		(974	)		(891	)
Amortization of prior service cost (credit)		126			123			(263	)		(263	)
Net loss recognition		684			1,184			96			(54	)
Net periodic benefit cost	$	1,914		$	2,007		$	1,284		$	1,223
Nine months ended September 30:
Service cost	$	11,739		$	11,092		$	2,000		$	1,909
Interest cost		25,012			24,277			5,178			4,825
Expected return on plan assets		(33,940	)		(32,766	)		(2,922	)		(2,673	)
Curtailment loss		169			—			—			—
Amortization of prior service cost (credit)		375			369			(789	)		(789	)
Net loss recognition		2,043			3,208			275			471
Net periodic benefit cost	$	5,398		$	6,180		$	3,742		$	3,743

Total service costs in the table above are recorded to the same accounts as labor expense. Labor and benefits expense is recorded to various projects based on whether the work is a capital project or an operating expense. Approximately 40 percent of all labor and benefits is capitalized to utility property and 60 percent is expensed to utility other operating expenses.

The non-service portion of costs in the table above are recorded to other expense below income from operations in the Condensed Consolidated Statements of Income or capitalized as a regulatory asset. Approximately 40 percent of the costs are capitalized to regulatory assets and 60 percent is expensed to the income statement.

In 2024, the Company offered pension participants an election to leave the pension plan for an alternative defined contribution 401(k) plan. In April 2024, it was determined that due to the number of participants electing to leave the pension plan, as well as the resulting decrease in expected future service, this event resulted in a curtailment of the pension plan, and an associated gain of $1.4 million for the reduction in the benefit obligation. This gain was offset against the unrecognized net actuarial loss (and recorded within a regulatory asset). There was also a $0.2 million loss recognized for the acceleration of unrecognized prior service costs. The curtailment triggered a remeasurement of pension plan. The impact of the remeasurement was not material to the Company's condensed consolidated financial statements.

- Definition

The entire disclosure for retirement benefits.

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
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-Name Accounting Standards Codification
-Section 50
-Paragraph 1
-Subparagraph (r)(1)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147480506/715-20-50-1

Reference 12: http://www.xbrl.org/2003/role/disclosureRef
-Topic 715
-SubTopic 20
-Name Accounting Standards Codification
-Section 50
-Paragraph 1
-Subparagraph (r)(2)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147480506/715-20-50-1

Reference 13: http://www.xbrl.org/2003/role/disclosureRef
-Topic 715
-SubTopic 20
-Name Accounting Standards Codification
-Section S99
-Paragraph 2
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147480126/715-20-S99-2

Reference 14: http://www.xbrl.org/2003/role/disclosureRef
-Topic 715
-SubTopic 60
-Name Accounting Standards Codification
-Section 50
-Paragraph 3
-Subparagraph (c)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147480266/715-60-50-3

+ Details

Accumulated Other Comprehensive Loss

9 Months Ended

Sep. 30, 2024

Accumulated Other Comprehensive Loss [Abstract]

Accumulated Other Comprehensive Loss

NOTE 13. ACCUMULATED OTHER COMPREHENSIVE LOSS

Accumulated other comprehensive loss, net of tax, consisted of the following as of September 30, 2024 and December 31, 2023 (dollars in thousands):


	September 30, 2024		December 31, 2023
Unfunded benefit obligation for pensions and other postretirement benefit plans - net of taxes of $100 and $95, respectively	$	375	$	357

The following table details the reclassifications out of accumulated other comprehensive loss by component for the three and nine months ended September 30 (dollars in thousands):


	Amounts Reclassified from Accumulated Other Comprehensive Loss
	Three months ended September 30,						Nine months ended September 30,
Details about Accumulated Other Comprehensive Loss Components (Affected Line Item in Statement of Income)	2024			2023			2024			2023
Amortization of defined benefit pension and postretirement benefit items
Amortization of net prior service cost (1)	$	(137	)	$	(140	)	$	(414	)	$	(420	)
Amortization of net loss (1)		780			1,130			2,318			3,679
Adjustment due to effects of regulation (1)		(655	)		(1,014	)		(1,927	)		(3,330	)
Total before tax (2)		(12	)		(24	)		(23	)		(71	)
Tax expense (2)		3			5			5			15
Net of tax (2)	$	(9	)	$	(19	)	$	(18	)	$	(56	)

(1)

These accumulated other comprehensive loss components are included in the computation of net periodic pension cost (see Note 6 for additional details).

(2)

Description is also the affected line item on the Condensed Consolidated Statements of Income.

Information by Business Segments - Additional Information (Details)	9 Months Ended
	Sep. 30, 2024 ReportableSegments
Segment Reporting [Abstract]
Number of reportable segments	1

Derivatives and Risk Management - Schedule of Collateral Outstanding Related to Derivative Instruments (Details) - USD ($) $ in Thousands	Sep. 30, 2024	Dec. 31, 2023
Derivative [Line Items]
Balance sheet offsetting	$ 19,915	$ 42,355
Commodity Contracts [Member]
Derivative [Line Items]
Cash collateral posted	24,773	43,095
Letters of credit outstanding	7,000	$ 20,000
Liabilities with credit-risk-related contingent features	32,051
Additional collateral to post	$ 31,799

Fair Value - Additional Information (Details)	Sep. 30, 2024 Investment
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Number of equity investments measured at fair value on recurring basic	2
Measurement Input, Quoted Price [Member] \| Secured and Unsecured Debt [Member] \| Estimate of Fair Value Measurement [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Long-term debt, measurement input	1
Measurement Input, Quoted Price [Member] \| Minimum [Member] \| Secured and Unsecured Debt [Member] \| Estimate of Fair Value Measurement [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Long-term debt, measurement input	0.639
Measurement Input, Quoted Price [Member] \| Maximum [Member] \| Secured and Unsecured Debt [Member] \| Estimate of Fair Value Measurement [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Long-term debt, measurement input	1.1008

CONDENSED CONSOLIDATED STATEMENTS OF CASH FLOWS - USD ($) $ in Thousands	9 Months Ended
	Sep. 30, 2024	Sep. 30, 2023
Operating Activities:
Net income	$ 112,840	$ 87,045
Non-cash items included in net income:
Depreciation and amortization	203,650	198,272
Deferred income tax provision	(24,853)	(15,958)
Power and natural gas cost deferrals, net	86,408	(25,046)
Amortization of debt expense	1,578	2,431
Stock-based compensation expense	8,291	7,098
Equity-related AFUDC	(6,174)	(4,921)
Pension and other postretirement benefit expense	9,140	9,923
Other regulatory assets and liabilities	(20,973)	(12,582)
Other deferred debits and credits	25,811	31,058
Change in decoupling regulatory deferral	(22,872)	11,231
Realized and unrealized losses on assets	873	966
Other	(1,513)	(2,525)
Contributions to defined benefit pension plan	(10,000)	(10,000)
Cash paid for settlement of interest rate swap agreements		(409)
Cash received for settlement of interest rate swap agreements	4,397	7,869
Changes in certain current assets and liabilities:
Accounts and notes receivable	67,697	119,908
Inventory	(25,956)	(37,500)
Collateral for derivative instruments	17,581	144,163
Income taxes receivable	20,132	(1,417)
Other current assets	13,601	(22,941)
Accounts payable	(33,269)	(96,794)
Other current liabilities	17,818	3,435
Net cash provided by operating activities	444,207	393,306
Investing Activities:
Utility property capital expenditures (excluding equity-related AFUDC)	(405,428)	(359,277)
Investments made in equity and property	(7,574)	(12,000)
Proceeds from sale of investments		3,200
Other	2,990	(503)
Net cash used in investing activities	(410,012)	(368,580)
Financing Activities:
Net decrease in short-term borrowings	(61,750)	(241,500)
Proceeds from issuance of long-term debt	83,700	250,000
Maturity of long-term debt and finance leases	(2,550)	(15,926)
Issuance of common stock, net of issuance costs	35,743	88,165
Cash dividends paid	(112,475)	(105,163)
Other	(2,742)	(5,100)
Net cash used in financing activities	(60,074)	(29,524)
Net decrease in cash and cash equivalents	(25,879)	(4,798)
Cash and cash equivalents at beginning of period	35,003	13,428
Cash and cash equivalents at end of period	$ 9,124	$ 8,630

Commitments and Contingencies - Additional Information (Details)		1 Months Ended				9 Months Ended
	Oct. 31, 2024	Apr. 30, 2024 USD ($)	Apr. 30, 2022 USD ($) a	Jul. 31, 2021 USD ($)	Aug. 31, 2019 USD ($)	Sep. 30, 2024 USD ($) Lawsuit Plaintiff	Dec. 31, 2024 USD ($)	Jul. 31, 2024	Aug. 31, 2023 a	Jan. 16, 2023	Sep. 30, 2020 a Structures
Subsequent Event [Member]
Loss Contingencies [Line Items]
Revision period for emissions report	45 days
Forecast [Member]
Loss Contingencies [Line Items]
Additions emissions liability							$ 200,000
Additional costs allocated percentage							10.00%
Forecast [Member] \| Idaho [Member]
Loss Contingencies [Line Items]
Estimated additional liability							$ 12,000,000
Forecast [Member] \| Washington [Member]
Loss Contingencies [Line Items]
Estimated additional liability							20,000,000
Collective Bargaining Agreements Avista Utilities Employees [Member] \| IBEW [Member]
Loss Contingencies [Line Items]
Percentage of employees represented						36.00%
Collective Bargaining Agreements Avista Utilities Bargaining Unit Employees [Member] \| IBEW [Member]
Loss Contingencies [Line Items]
Percentage of largest group of employees represented						90.00%
Collective Bargaining Agreements [Member] \| IBEW [Member]
Loss Contingencies [Line Items]
Agreement term						4 years
Agreement expiration month and year						2025-03
Maximum [Member] \| Forecast [Member]
Loss Contingencies [Line Items]
Estimated additional liability							$ 32,000,000
Customers [Member] \| Forecast [Member]
Loss Contingencies [Line Items]
Additional costs allocated percentage							90.00%
Natural and Cultural Damage Claim [Member]
Loss Contingencies [Line Items]
Loss contingency, damages sought, value				$ 2,000,000
Amout of settle all claims and allegations		$ 900,000
Unspecified Damages [Member]
Loss Contingencies [Line Items]
Number Of Plaintiffs \| Plaintiff						128
Economic Damage [Member]
Loss Contingencies [Line Items]
Number Of Plaintiffs \| Plaintiff						40
Boyds Fire [Member] \| Damage from Fire [Member] \| Maximum [Member]
Loss Contingencies [Line Items]
Loss contingency, damages sought, value					$ 4,400,000
Boyds Fire [Member] \| Property Damages [Member] \| Avista Corp [Member]
Loss Contingencies [Line Items]
Loss contingency, damages sought, value					800,000
Boyds Fire [Member] \| Insurance proceeds paid to their insureds [Member] \| Avista Corp [Member]
Loss Contingencies [Line Items]
Loss contingency, damages sought, value					$ 1,800,000
Road 11 Fire [Member] \| Damage from Fire [Member] \| Avista Corp [Member]
Loss Contingencies [Line Items]
Loss contingency, damages sought, value			$ 5,000,000
Road fire covered area \| a			10,000
Settlement Amount			$ 100,000
Babb Road Fire [Member] \| Damage from Fire [Member]
Loss Contingencies [Line Items]
Loss contingency, damages sought, value						$ 23,000,000
Number of residential, commercial and other structures impacted \| Structures											220
Road fire covered area \| a											15,000
Number of subrogation actions filed \| Lawsuit						6
Number of actions on behalf of individual plaintiffs \| Plaintiff						5
Economic Losses Of Plaintiffs						$ 8,200,000
Insurance Settlements Receivable						$ 3,500,000
Number of class action lawsuit \| Lawsuit						1
Orofino Fire [Member] \| Damage from Fire [Member]
Loss Contingencies [Line Items]
Road fire covered area \| a									53
System Unit Resource Protection Act [Member] \| Natural and Cultural Damage Claim [Member]
Loss Contingencies [Line Items]
Increased potential claim				$ 6,000,000
Colstrip [Member]
Loss Contingencies [Line Items]
Agreement voting requirement						NorthWestern has initiated arbitration pursuant to the O&O Agreement to resolve these business disagreements, and two actions have been initiated to compel arbitration of those disputes: one by Talen in the Montana Thirteenth Judicial District Court for Yellowstone County, and one by the Western Co-Owners, which is pending in Montana Federal District Court. In light of the ownership transfer agreements, the Colstrip owners agreed to stay both the litigation and the arbitration through March 2024. On April 1, 2024, the agreement to stay lapsed and the parties are now in the process of reengaging in arbitration discussions. An arbitration date has not yet been scheduled. The Company cannot predict the outcome of the arbitration process.
Colstrip [Member] \| Maximum [Member]
Loss Contingencies [Line Items]
Litigation Settlement						$ 100,000
Colstrip [Member] \| PSE [Member] \| Unit 4 [Member]
Loss Contingencies [Line Items]
Owners percentage interest						25.00%		25.00%
Colstrip [Member] \| NorthWestern [Member] \| Unit 4 [Member]
Loss Contingencies [Line Items]
Owners percentage interest						30.00%				15.00%

Revenue - Additional Information (Details) $ in Millions	Sep. 30, 2024 USD ($)
Revenue from Contract with Customer [Abstract]
Revenue, Remaining Performance Obligation, Amount	$ 3.0

Pension Plans and Other Postretirement Benefit Plans - Additional Information (Details) - USD ($) $ in Thousands	1 Months Ended	3 Months Ended		9 Months Ended
	Apr. 30, 2024	Sep. 30, 2024	Sep. 30, 2023	Sep. 30, 2024	Sep. 30, 2023
Defined Benefit Plan Disclosure [Line Items]
Payment for pension benefits				$ 10,000	$ 10,000
Percentage of service related net periodic benefit costs capitalized to utility property				40.00%
Percentage of service related net periodic benefit costs recorded to operating expenses				60.00%
Percentage of non-service related net periodic benefit costs capitalized to regulatory assets				40.00%
Percentage of non-service related net periodic benefit costs recorded to other expense				60.00%
Curtailment associated gain (loss)	$ 1,400
Pension Plans, Defined Benefit [Member]
Defined Benefit Plan Disclosure [Line Items]
Expected contributions to pension plan		$ 0		$ 0
Curtailment associated gain (loss)				(169)
Loss on acceleration of unrecognized priof service costs		$ 126	$ 123	$ 375	$ 369

Balance Sheet Components - Other Current Liabilities (Details) - USD ($) $ in Thousands	Sep. 30, 2024	Dec. 31, 2023
Balance Sheet Related Disclosures [Abstract]
Accrued taxes other than income taxes	$ 29,160	$ 31,928
Derivative liabilities net of collateral	27,612	17,217
Employee paid time off accruals	33,222	32,072
Accrued interest	41,863	23,539
Climate Commitment Act obligations	0	19,081
Pensions and other postretirement benefits	14,852	14,082
Other	54,489	54,017
Total	$ 201,198	$ 191,936

Accumulated Other Comprehensive Loss (Tables)

9 Months Ended

Sep. 30, 2024

Accumulated Other Comprehensive Loss [Abstract]

Schedule of Accumulated Other Comprehensive Loss, Net of Tax

Accumulated other comprehensive loss, net of tax, consisted of the following as of September 30, 2024 and December 31, 2023 (dollars in thousands):


	September 30, 2024		December 31, 2023
Unfunded benefit obligation for pensions and other postretirement benefit plans - net of taxes of $100 and $95, respectively	$	375	$	357

Reclassification out of Accumulated Other Comprehensive Loss

The following table details the reclassifications out of accumulated other comprehensive loss by component for the three and nine months ended September 30 (dollars in thousands):


	Amounts Reclassified from Accumulated Other Comprehensive Loss
	Three months ended September 30,						Nine months ended September 30,
Details about Accumulated Other Comprehensive Loss Components (Affected Line Item in Statement of Income)	2024			2023			2024			2023
Amortization of defined benefit pension and postretirement benefit items
Amortization of net prior service cost (1)	$	(137	)	$	(140	)	$	(414	)	$	(420	)
Amortization of net loss (1)		780			1,130			2,318			3,679
Adjustment due to effects of regulation (1)		(655	)		(1,014	)		(1,927	)		(3,330	)
Total before tax (2)		(12	)		(24	)		(23	)		(71	)
Tax expense (2)		3			5			5			15
Net of tax (2)	$	(9	)	$	(19	)	$	(18	)	$	(56	)

(1)

These accumulated other comprehensive loss components are included in the computation of net periodic pension cost (see Note 6 for additional details).

(2)

Description is also the affected line item on the Condensed Consolidated Statements of Income.

Short-Term Borrowings (Tables)

9 Months Ended

Sep. 30, 2024

Line of Credit Facility [Line Items]

Schedule of Balances Outstanding and Interest Rates of Borrowings


	September 30,			December 31,
	2024			2023
Borrowings outstanding at end of period	$	283,000		$	349,000
Letters of credit outstanding at end of period		4,700			4,700
Average interest rate on borrowings at end of period		6.13	%		6.46	%

CONDENSED CONSOLIDATED STATEMENTS OF INCOME - USD ($) shares in Thousands, $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2024	Sep. 30, 2023	Sep. 30, 2024	Sep. 30, 2023
Utility revenues:
Utility revenues, exclusive of alternative revenue programs	$ 389,587	$ 375,946	$ 1,381,959	$ 1,243,774
Alternative revenue programs	3,978	3,578	23,032	(9,947)
Total utility revenues	393,565	379,524	1,404,991	1,233,827
Non-utility revenues	177	102	239	367
Total operating revenues	393,742	379,626	1,405,230	1,234,194
Utility operating expenses:
Resource costs	142,033	148,282	579,476	482,454
Other operating expenses	107,298	102,469	328,138	310,518
Depreciation and amortization	67,886	66,860	203,642	198,196
Taxes other than income taxes	27,438	23,280	88,836	82,091
Non-utility operating expenses	319	648	998	2,439
Total operating expenses	344,974	341,539	1,201,090	1,075,698
Income from operations	48,768	38,087	204,140	158,496
Interest expense	36,675	34,827	109,503	104,929
Interest expense to affiliated trust	651	657	1,964	1,836
Capitalized interest	(1,306)	(926)	(3,412)	(2,634)
Other income-net	(5,261)	(7,401)	(19,078)	(16,456)
Income before income taxes	18,009	10,930	115,163	70,821
Income tax expense (benefit)	(478)	(3,786)	2,323	(16,224)
Net income	$ 18,487	$ 14,716	$ 112,840	$ 87,045
Weighted-average common shares outstanding (thousands), basic	78,836	76,734	78,463	75,962
Weighted-average common shares outstanding (thousands), diluted	78,968	76,761	78,545	76,056
Earnings per common share:
Basic	$ 0.23	$ 0.19	$ 1.44	$ 1.15
Diluted	$ 0.23	$ 0.19	$ 1.44	$ 1.14

Balance Sheet Components - Schedule of Net Utility Property Recorded at Original Cost Net of Accumulated Depreciation (Details) - USD ($) $ in Thousands	Sep. 30, 2024	Dec. 31, 2023
Balance Sheet Related Disclosures [Abstract]
Utility plant in service	$ 8,067,517	$ 7,799,481
Construction work in progress	246,490	179,527
Total	8,314,007	7,979,008
Less: Accumulated depreciation and amortization	2,389,617	2,278,952
Total	$ 5,924,390	$ 5,700,056

Commitments and Contingencies (Tables)

9 Months Ended

Sep. 30, 2024

Commitments and Contingencies Disclosure [Abstract]

Ownership and Operating Ownership Interest Percentage

Colstrip Units 3 and 4 are owned by the Company, PacifiCorp, Portland General Electric (PGE), and Puget Sound Energy (PSE) (collectively, the "Western Co-Owners"), as well as NorthWestern and Talen Montana, LLC (Talen), as tenants in common under an Ownership and Operating Agreement, dated May 6, 1981, as amended (O&O Agreement), in the percentages set forth below:


Co-Owner	Unit 3			Unit 4
Avista		15	%		15	%
PacifiCorp		10	%		10	%
PGE		20	%		20	%
PSE		25	%		25	%
NorthWestern		—			30	%
Talen		30	%		—

Fair Value - Schedule of Fair Value of Assets and Liabilities Measured on Recurring Basis (Details) - USD ($)
$ in Thousands

Sep. 30, 2024

Dec. 31, 2023

Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]

Gross Asset

$ 21,402

$ 34,623

Liability

72,211

100,276

Fair Value, Recurring [Member]

Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]

Assets, Fair Value Disclosure

69,951

69,716

Financial Liabilities Fair Value Disclosure

39,273

35,119

Counterparty and Cash Collateral Netting, Assets

^[1]

(13,023)

(22,802)

Counterparty and Cash Collateral Netting, Liabilities

^[1]

(32,938)

(65,157)

Fair Value, Recurring [Member] | Fixed Income Funds [Member]

Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]

Deferred compensation assets:

^[2]

1,026

1,117

Fair Value, Recurring [Member] | Equity Funds [Member]

Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]

Equity investments

52,819

50,254

Deferred compensation assets:

^[2]

7,727

6,524

Fair Value, Recurring [Member] | Energy Commodity Derivatives [Member]

Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]

Counterparty and Cash Collateral Netting, Assets

^[1]

(13,023)

(22,802)

^[3]

Derivative Asset

8,372

8,152

^[3]

Counterparty and Cash Collateral Netting, Liabilities

^[1],[3]

(32,938)

(65,157)

Derivative Liability

^[3]

39,198

34,937

Fair Value, Recurring [Member] | Interest Rate Swap [Member]

Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]

Derivative Asset

3,667

Derivative Liability

$ 182

Fair Value, Recurring [Member] | Natural Gas Exchange Agreements [Member]

Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]

Derivative Liability

$ 6,977

Fair Value, Recurring [Member] | Foreign Exchange Contract [Member]

Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]

Derivative Asset, Statement of Financial Position [Extensible Enumeration]

Investments and Other Noncurrent Assets

Derivative Asset

$ 7

$ 2

Fair Value, Recurring [Member] | Level 1 [Member]

Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]

Assets, Fair Value Disclosure

8,753

7,641

Fair Value, Recurring [Member] | Level 1 [Member] | Fixed Income Funds [Member]

Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]

Deferred compensation assets:

^[2]

1,026

1,117

Fair Value, Recurring [Member] | Level 1 [Member] | Equity Funds [Member]

Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]

Deferred compensation assets:

^[2]

7,727

6,524

Fair Value, Recurring [Member] | Level 2 [Member]

Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]

Assets, Fair Value Disclosure

21,402

34,623

Financial Liabilities Fair Value Disclosure

65,234

92,026

Fair Value, Recurring [Member] | Level 2 [Member] | Energy Commodity Derivatives [Member]

Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]

Gross Asset

21,395

30,954

^[3]

Liability

^[3]

65,159

91,844

Fair Value, Recurring [Member] | Level 2 [Member] | Interest Rate Swap [Member]

Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]

Gross Asset

3,667

Liability

182

Fair Value, Recurring [Member] | Level 2 [Member] | Foreign Exchange Contract [Member]

Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]

Gross Asset

Fair Value, Recurring [Member] | Level 3 [Member]

Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]

Equity investments

52,819

Assets, Fair Value Disclosure

52,819

50,254

Financial Liabilities Fair Value Disclosure

6,977

8,250

Fair Value, Recurring [Member] | Level 3 [Member] | Equity Funds [Member]

Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]

Equity investments

52,819

50,254

Fair Value, Recurring [Member] | Level 3 [Member] | Energy Commodity Derivatives [Member]

Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]

Liability

^[3]

$ 6,977

$ 8,250

[1]	The Company is permitted to net derivative assets and derivative liabilities with the same counterparty when a legally enforceable master netting agreement exists. In addition, the Company nets derivative assets and derivative liabilities against any payables and receivables for cash collateral held or placed with these same counterparties.
[2]	Included in other property and investments-net and other non-current assets on the Condensed Consolidated Balance Sheets.
[3]	The Level 3 energy commodity derivative balances are associated with a natural gas exchange agreement.

Balance Sheet Components - Schedule of Other Non-Current Liabilities and Deferred Credits (Details) - USD ($) $ in Thousands	Sep. 30, 2024	Dec. 31, 2023
Balance Sheet Related Disclosures [Abstract]
Operating lease liabilities	$ 65,386	$ 63,559
Operating Lease, Liability, Noncurrent, Statement of Financial Position [Extensible Enumeration]	Total	Total
Finance lease liabilities	$ 36,421	$ 39,095
Deferred investment tax credits	28,303	28,233
Climate Commitment Act obligations	66,375	26,026
Asset retirement obligations	18,207	18,058
Derivative liabilities net of collateral	11,661	17,902
Other	21,253	17,357
Total	$ 247,606	$ 210,230

Balance Sheet Components

9 Months Ended

Sep. 30, 2024

Balance Sheet Related Disclosures [Abstract]

Balance Sheet Components

NOTE 3. BALANCE SHEET COMPONENTS

Inventory


	September 30,		December 31,
	2024		2023
Materials and supplies	$	97,398	$	81,651
Emission allowances		69,885		56,097
Stored natural gas		11,239		16,272
Fuel stock		7,418		5,964
Total	$	185,940	$	159,984

Other Current Assets

Other current assets consisted of the following as of September 30, 2024 and December 31, 2023 (dollars in thousands):


	September 30,		December 31,
	2024		2023
Prepayments	$	40,074	$	52,752
Income taxes receivable		9,102		29,234
Derivative assets net of collateral		6,785		11,821
Collateral posted for derivative instruments after netting with outstanding derivatives		4,858		—
Other		10,288		9,977
Total	$	71,107	$	103,784

Net Utility Property

Net utility property, which is recorded at original cost, net of accumulated depreciation, consisted of the following as of September 30, 2024 and December 31, 2023 (dollars in thousands):


	September 30,		December 31,
	2024		2023
Utility plant in service	$	8,067,517	$	7,799,481
Construction work in progress		246,490		179,527
Total		8,314,007		7,979,008
Less: Accumulated depreciation and amortization		2,389,617		2,278,952
Total	$	5,924,390	$	5,700,056

Other Property and Investments-Net and Other Non-Current Assets

Other property and investments-net and other non-current assets consisted of the following as of September 30, 2024 and December 31, 2023 (dollars in thousands):


	September 30,		December 31,
	2024		2023
Equity investments	$	159,227	$	153,350
Operating lease ROU assets		66,334		67,585
Finance lease ROU assets		33,683		36,414
Non-utility property		33,504		33,813
Notes receivable		15,295		15,287
Long-term prepaid license fees		19,314		19,448
Pension asset		44,278		32,997
Investment in affiliated trust		11,547		11,547
Deferred compensation assets		8,962		7,794
Other		19,607		15,750
Total	$	411,751	$	393,985

Other Current Liabilities

Other current liabilities consisted of the following as of September 30, 2024 and December 31, 2023 (dollars in thousands):


	September 30, 2024		December 31, 2023
Accrued taxes other than income taxes	$	29,160	$	31,928
Derivative liabilities net of collateral		27,612		17,217
Employee paid time off accruals		33,222		32,072
Accrued interest		41,863		23,539
Climate Commitment Act obligations		—		19,081
Pensions and other postretirement benefits		14,852		14,082
Other		54,489		54,017
Total	$	201,198	$	191,936

Other Non-Current Liabilities and Deferred Credits

Other non-current liabilities and deferred credits consisted of the following as of September 30, 2024 and December 31, 2023 (dollars in thousands):


	September 30, 2024		December 31, 2023
Operating lease liabilities	$	65,386	$	63,559
Finance lease liabilities		36,421		39,095
Deferred investment tax credits		28,303		28,233
Climate Commitment Act obligations		66,375		26,026
Asset retirement obligations		18,207		18,058
Derivative liabilities net of collateral		11,661		17,902
Other		21,253		17,357
Total	$	247,606	$	210,230

Regulatory Assets and Liabilities

Regulatory assets and liabilities consisted of the following as of September 30, 2024 and December 31, 2023 (dollars in thousands):


	September 30, 2024				December 31, 2023
	Current		Non-Current		Current		Non-Current
Regulatory Assets
Energy commodity derivatives	$	38,033	$	12,708	$	51,419	$	17,720
Deferred Climate Commitment Act costs		36,102		21,834		—		46,022
Deferred power costs		13,410		22,724		29,190		20,654
Wildfire resiliency		8,277		14,312		—		23,737
Decoupling surcharge		10,476		8,123		4,638		5,469
Deferred natural gas costs		3,376		—		60,667		—
Income tax related assets		—		246,863		—		244,303
Pension and other postretirement benefit plans		—		111,844		—		117,658
Interest rate swaps		—		174,151		—		179,489
AFUDC above FERC allowed rate		—		48,232		—		49,985
Settlement with Coeur d'Alene Tribe		—		35,855		—		36,692
Advanced meter infrastructure		—		27,069		—		29,345
Utility plant abandoned		—		31,610		—		38,274
Colstrip excess depreciation		—		23,824		—		19,429
COVID-19 deferrals		—		11,846		—		12,142
Demand side management programs		—		27,496		—		10,033
Other regulatory assets		5,523		48,751		413		43,216
Total regulatory assets	$	115,197	$	867,242	$	146,327	$	894,168
Regulatory Liabilities
Other income tax related liabilities	$	8,918	$	53,859	$	25,129	$	56,582
Excess deferred income taxes		14,223		282,629		14,510		293,029
Deferred Climate Commitment Act revenues		32,947		14,296		—		37,231
Deferred power costs		7,172		5,312		—		4,000
Deferred natural gas costs		13,213		—		9,296		—
Decoupling rebate		7,495		3,150		18,680		6,344
Utility plant retirement costs		—		439,874		—		417,027
Interest rate swaps		—		23,580		—		23,752
COVID-19 deferrals		—		10,443		—		10,172
Other regulatory liabilities		8,227		6,904		8,392		8,529
Total regulatory liabilities	$	92,195	$	840,047	$	76,007	$	856,666

Derivatives and Risk Management - Additional Information (Details)	9 Months Ended	12 Months Ended
	Sep. 30, 2024 USD ($) MMBTU MWh	Dec. 31, 2023 USD ($) MMBTU MWh
Canadian [Member]
Derivative [Line Items]
Number of days Canadian currency prices are settled with U.S. dollars	60 days
Interest Rate Swap [Member]
Derivative [Line Items]
Cash collateral posted \| $	$ 0	$ 0
Letters of credit outstanding \| $	$ 0	$ 0
Purchase [Member] \| Physical [Member] \| Electric Derivative [Member]
Derivative [Line Items]
Expected deliveries of energy commodity derivatives after four years \| MWh	0
Expected deliveries of energy commodity derivatives after three years \| MWh		0
Purchase [Member] \| Physical [Member] \| Gas Derivative [Member]
Derivative [Line Items]
Expected deliveries of energy commodity derivatives after four years \| MMBTU	0
Expected deliveries of energy commodity derivatives after three years \| MMBTU		0
Purchase [Member] \| Financial [Member] \| Electric Derivative [Member]
Derivative [Line Items]
Expected deliveries of energy commodity derivatives after four years \| MWh	0
Expected deliveries of energy commodity derivatives after three years \| MWh		0
Purchase [Member] \| Financial [Member] \| Gas Derivative [Member]
Derivative [Line Items]
Expected deliveries of energy commodity derivatives after four years \| MMBTU	0
Expected deliveries of energy commodity derivatives after three years \| MMBTU		0
Sales [Member] \| Physical [Member] \| Electric Derivative [Member]
Derivative [Line Items]
Expected deliveries of energy commodity derivatives after four years \| MWh	0
Expected deliveries of energy commodity derivatives after three years \| MWh		0
Sales [Member] \| Physical [Member] \| Gas Derivative [Member]
Derivative [Line Items]
Expected deliveries of energy commodity derivatives after four years \| MMBTU	0
Expected deliveries of energy commodity derivatives after three years \| MMBTU		0
Sales [Member] \| Financial [Member] \| Electric Derivative [Member]
Derivative [Line Items]
Expected deliveries of energy commodity derivatives after four years \| MWh	0
Expected deliveries of energy commodity derivatives after three years \| MWh		0
Sales [Member] \| Financial [Member] \| Gas Derivative [Member]
Derivative [Line Items]
Expected deliveries of energy commodity derivatives after four years \| MMBTU	0
Expected deliveries of energy commodity derivatives after three years \| MMBTU		0

Pension Plans and Other Postretirement Benefit Plans - Components of Net Periodic Benefit Costs (Details) - USD ($) $ in Thousands	1 Months Ended	3 Months Ended		9 Months Ended
	Apr. 30, 2024	Sep. 30, 2024	Sep. 30, 2023	Sep. 30, 2024	Sep. 30, 2023
Defined Benefit Plan Disclosure [Line Items]
Curtailment loss	$ (1,400)
Pension Benefits [Member]
Defined Benefit Plan Disclosure [Line Items]
Service cost		$ 4,030	$ 3,098	$ 11,739	$ 11,092
Interest cost		8,430	8,524	25,012	24,277
Expected return on plan assets		(11,356)	(10,922)	(33,940)	(32,766)
Curtailment loss				169
Amortization of prior service cost (credit)		126	123	375	369
Net loss recognition		684	1,184	2,043	3,208
Net periodic benefit cost		1,914	2,007	5,398	6,180
Other Postretirement Benefits [Member]
Defined Benefit Plan Disclosure [Line Items]
Service cost		719	559	2,000	1,909
Interest cost		1,706	1,872	5,178	4,825
Expected return on plan assets		(974)	(891)	(2,922)	(2,673)
Amortization of prior service cost (credit)		(263)	(263)	(789)	(789)
Net loss recognition		96	(54)	275	471
Net periodic benefit cost		$ 1,284	$ 1,223	$ 3,742	$ 3,743

Information by Business Segments

9 Months Ended

Sep. 30, 2024

Segment Reporting [Abstract]

Information by Business Segments

NOTE 16. INFORMATION BY BUSINESS SEGMENTS

The business segment presentation reflects the basis used by the Company's management to analyze performance and determine the allocation of resources. The Company's management evaluates performance based on income (loss) from operations before income taxes as well as net income (loss). The accounting policies of the segments are the same as those described in the summary of significant accounting policies. Avista Utilities' business is managed based on the total regulated utility operation; therefore, it is considered one segment. AEL&P is a separate reportable business segment, as it has separate financial reports reviewed in detail by

the Chief Operating Decision Maker and its operations and risks are sufficiently different from Avista Utilities and the other businesses at AERC that it cannot be aggregated with other operating segments. The Other category, which is not a reportable segment, includes other investments and operations of various subsidiaries, as well as certain other operations of Avista Capital.

The following table presents information for each of the Company’s business segments (dollars in thousands):


	Avista Utilities			Alaska Electric Light and Power Company			Total Utility			Other			Intersegment Eliminations (1)			Total
For the three months ended September 30, 2024:
Operating revenues	$	383,746		$	9,819		$	393,565		$	177		$	—		$	393,742
Resource costs		140,669			1,364			142,033			—			—			142,033
Other operating expenses		103,106			4,192			107,298			316			—			107,614
Depreciation and amortization		65,024			2,862			67,886			3			—			67,889
Income (loss) from operations		47,738			1,172			48,910			(142	)		—			48,768
Interest expense (2)		35,762			1,433			37,195			674			(543	)		37,326
Income tax benefit		(39	)		(62	)		(101	)		(377	)		—			(478	)
Net income (loss)		19,803			41			19,844			(1,357	)		—			18,487
Capital expenditures (3)		143,938			10,283			154,221			—			—			154,221
For the three months ended September 30, 2023:
Operating revenues	$	369,673		$	9,851		$	379,524		$	102		$	—		$	379,626
Resource costs		146,793			1,489			148,282			—			—			148,282
Other operating expenses		98,609			3,860			102,469			603			—			103,072
Depreciation and amortization		64,125			2,735			66,860			45			—			66,905
Income (loss) from operations		37,081			1,552			38,633			(546	)		—			38,087
Interest expense (2)		33,896			1,456			35,352			538			(406	)		35,484
Income tax expense (benefit)		(3,845	)		36			(3,809	)		23			—			(3,786	)
Net income		13,498			288			13,786			930			—			14,716
Capital expenditures (3)		127,666			4,865			132,531			—			—			132,531
For the nine months ended September 30, 2024:
Operating revenues	$	1,369,496		$	35,495		$	1,404,991		$	239		$	—		$	1,405,230
Resource costs		576,302			3,174			579,476			—			—			579,476
Other operating expenses		315,953			12,185			328,138			990			—			329,128
Depreciation and amortization		195,082			8,560			203,642			8			—			203,650
Income (loss) from operations		194,127			10,772			204,899			(759	)		—			204,140
Interest expense (2)		106,828			4,248			111,076			1,886			(1,495	)		111,467
Income tax expense (benefit)		1,475			1,799			3,274			(951	)		—			2,323
Net income (loss)		111,246			5,061			116,307			(3,467	)		—			112,840
Capital expenditures (3)		389,098			16,330			405,428			—			—			405,428
For the nine months ended September 30, 2023:
Operating revenues	$	1,198,419		$	35,408		$	1,233,827		$	367		$	—		$	1,234,194
Resource costs		478,947			3,507			482,454			—			—			482,454
Other operating expenses		299,274			11,244			310,518			2,363			—			312,881
Depreciation and amortization		190,008			8,188			198,196			76			—			198,272
Income (loss) from operations		148,897			11,671			160,568			(2,072	)		—			158,496
Interest expense (2)		102,014			4,360			106,374			1,333			(942	)		106,765
Income tax expense (benefit)		(17,349	)		2,048			(15,301	)		(923	)		—			(16,224	)
Net income (loss)		83,935			5,689			89,624			(2,579	)		—			87,045
Capital expenditures (3)		347,264			12,013			359,277			—			—			359,277
Total Assets:
As of September 30, 2024:	$	7,336,820		$	275,967		$	7,612,787		$	194,801		$	(26,705	)	$	7,780,883
As of December 31, 2023:	$	7,262,704		$	269,683		$	7,532,387		$	191,665		$	(21,575	)	$	7,702,477

(1)

Intersegment eliminations reported as interest expense represent intercompany interest.

(2)

Including interest expense to affiliated trusts.

(3)

The capital expenditures for the other businesses are included in other investing activities on the Condensed Consolidated Statements of Cash Flows.

- Definition

The entire disclosure for reporting segments including data and tables. Reportable segments include those that meet any of the following quantitative thresholds a) it's reported revenue, including sales to external customers and intersegment sales or transfers is 10 percent or more of the combined revenue, internal and external, of all operating segments b) the absolute amount of its reported profit or loss is 10 percent or more of the greater, in absolute amount of 1) the combined reported profit of all operating segments that did not report a loss or 2) the combined reported loss of all operating segments that did report a loss c) its assets are 10 percent or more of the combined assets of all operating segments.

+ References

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+ Details

Information by Business Segments (Tables)

9 Months Ended

Sep. 30, 2024

Segment Reporting [Abstract]

Schedule of Business Segments

The following table presents information for each of the Company’s business segments (dollars in thousands):


	Avista Utilities			Alaska Electric Light and Power Company			Total Utility			Other			Intersegment Eliminations (1)			Total
For the three months ended September 30, 2024:
Operating revenues	$	383,746		$	9,819		$	393,565		$	177		$	—		$	393,742
Resource costs		140,669			1,364			142,033			—			—			142,033
Other operating expenses		103,106			4,192			107,298			316			—			107,614
Depreciation and amortization		65,024			2,862			67,886			3			—			67,889
Income (loss) from operations		47,738			1,172			48,910			(142	)		—			48,768
Interest expense (2)		35,762			1,433			37,195			674			(543	)		37,326
Income tax benefit		(39	)		(62	)		(101	)		(377	)		—			(478	)
Net income (loss)		19,803			41			19,844			(1,357	)		—			18,487
Capital expenditures (3)		143,938			10,283			154,221			—			—			154,221
For the three months ended September 30, 2023:
Operating revenues	$	369,673		$	9,851		$	379,524		$	102		$	—		$	379,626
Resource costs		146,793			1,489			148,282			—			—			148,282
Other operating expenses		98,609			3,860			102,469			603			—			103,072
Depreciation and amortization		64,125			2,735			66,860			45			—			66,905
Income (loss) from operations		37,081			1,552			38,633			(546	)		—			38,087
Interest expense (2)		33,896			1,456			35,352			538			(406	)		35,484
Income tax expense (benefit)		(3,845	)		36			(3,809	)		23			—			(3,786	)
Net income		13,498			288			13,786			930			—			14,716
Capital expenditures (3)		127,666			4,865			132,531			—			—			132,531
For the nine months ended September 30, 2024:
Operating revenues	$	1,369,496		$	35,495		$	1,404,991		$	239		$	—		$	1,405,230
Resource costs		576,302			3,174			579,476			—			—			579,476
Other operating expenses		315,953			12,185			328,138			990			—			329,128
Depreciation and amortization		195,082			8,560			203,642			8			—			203,650
Income (loss) from operations		194,127			10,772			204,899			(759	)		—			204,140
Interest expense (2)		106,828			4,248			111,076			1,886			(1,495	)		111,467
Income tax expense (benefit)		1,475			1,799			3,274			(951	)		—			2,323
Net income (loss)		111,246			5,061			116,307			(3,467	)		—			112,840
Capital expenditures (3)		389,098			16,330			405,428			—			—			405,428
For the nine months ended September 30, 2023:
Operating revenues	$	1,198,419		$	35,408		$	1,233,827		$	367		$	—		$	1,234,194
Resource costs		478,947			3,507			482,454			—			—			482,454
Other operating expenses		299,274			11,244			310,518			2,363			—			312,881
Depreciation and amortization		190,008			8,188			198,196			76			—			198,272
Income (loss) from operations		148,897			11,671			160,568			(2,072	)		—			158,496
Interest expense (2)		102,014			4,360			106,374			1,333			(942	)		106,765
Income tax expense (benefit)		(17,349	)		2,048			(15,301	)		(923	)		—			(16,224	)
Net income (loss)		83,935			5,689			89,624			(2,579	)		—			87,045
Capital expenditures (3)		347,264			12,013			359,277			—			—			359,277
Total Assets:
As of September 30, 2024:	$	7,336,820		$	275,967		$	7,612,787		$	194,801		$	(26,705	)	$	7,780,883
As of December 31, 2023:	$	7,262,704		$	269,683		$	7,532,387		$	191,665		$	(21,575	)	$	7,702,477

(1)

Intersegment eliminations reported as interest expense represent intercompany interest.

(2)

Including interest expense to affiliated trusts.

(3)

The capital expenditures for the other businesses are included in other investing activities on the Condensed Consolidated Statements of Cash Flows.

New Accounting Standards - Additional Information (Details) - ASU 2022-03	Sep. 30, 2024
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Change in accounting principle accounting standards update, adopted	true
Change in accounting principle accounting standards update, adoption date	Jan. 01, 2024
Change in accounting principle accounting standards update, immaterial effect	true

- Definition

Indicates (true false) whether accounting standards update was adopted.

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Reference 92: http://www.xbrl.org/2003/role/disclosureRef
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Reference 93: http://www.xbrl.org/2003/role/disclosureRef
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Reference 94: http://www.xbrl.org/2003/role/disclosureRef
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Reference 96: http://www.xbrl.org/2003/role/disclosureRef
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Reference 97: http://www.xbrl.org/2003/role/disclosureRef
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Reference 100: http://www.xbrl.org/2003/role/disclosureRef
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-Section 65
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-Subparagraph (a)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147476166/350-60-65-1

+ Details

CONDENSED CONSOLIDATED STATEMENTS OF EQUITY - USD ($) $ in Thousands	Total	Common Stock [Member]	Accumulated Other Comprehensive Loss [Member]	Retained Earnings [Member]
Beginning Balance (in shares) at Dec. 31, 2022		74,945,948
Shares issued		2,418,177
Ending Balance (in shares) at Sep. 30, 2023		77,364,125
Beginning Balance at Dec. 31, 2022		$ 1,525,185	$ (2,058)	$ 811,541
Equity compensation expense		7,097
Issuance of common stock, net of issuance costs		88,165
Payment of minimum tax withholdings for share-based payment awards		(1,667)
Other comprehensive loss			(56)
Net income	$ 87,045			87,045
Dividends on common stock				(105,365)
Ending Balance at Sep. 30, 2023	$ 2,409,887	$ 1,618,780	(2,114)	793,221
Dividends declared per common share	$ 1.38
Beginning Balance (in shares) at Jun. 30, 2023		76,524,184
Shares issued		839,941
Ending Balance (in shares) at Sep. 30, 2023		77,364,125
Beginning Balance at Jun. 30, 2023		$ 1,588,503	(2,095)	814,013
Equity compensation expense		1,637
Issuance of common stock, net of issuance costs		28,640
Other comprehensive loss			(19)
Net income	$ 14,716			14,716
Dividends on common stock				(35,508)
Ending Balance at Sep. 30, 2023	$ 2,409,887	$ 1,618,780	(2,114)	793,221
Dividends declared per common share	$ 0.46
Beginning Balance (in shares) at Dec. 31, 2023	78,074,587	78,074,587
Shares issued	1,000,000	1,106,369
Ending Balance (in shares) at Sep. 30, 2024	79,180,956	79,180,956
Beginning Balance at Dec. 31, 2023	$ 2,485,323	$ 1,644,327	(357)	841,353
Equity compensation expense		8,291
Issuance of common stock, net of issuance costs		35,743
Payment of minimum tax withholdings for share-based payment awards		(1,585)
Other comprehensive loss			(18)
Net income	112,840			112,840
Dividends on common stock				(112,506)
Ending Balance at Sep. 30, 2024	$ 2,528,088	$ 1,686,776	(375)	841,687
Dividends declared per common share	$ 1.425
Beginning Balance (in shares) at Jun. 30, 2024		78,702,117
Shares issued	500,000	478,839
Ending Balance (in shares) at Sep. 30, 2024	79,180,956	79,180,956
Beginning Balance at Jun. 30, 2024		$ 1,666,692	(366)	860,913
Equity compensation expense		1,941
Issuance of common stock, net of issuance costs		18,143
Other comprehensive loss			(9)
Net income	$ 18,487			18,487
Dividends on common stock				(37,713)
Ending Balance at Sep. 30, 2024	$ 2,528,088	$ 1,686,776	$ (375)	$ 841,687
Dividends declared per common share	$ 0.475

Accumulated Other Comprehensive Loss - Schedule of Accumulated Other Comprehensive Loss, Net of Tax (Parenthetical) (Details) - USD ($) $ in Thousands	Sep. 30, 2024	Dec. 31, 2023
Accumulated Other Comprehensive Loss [Abstract]
Accumulated other comprehensive income (loss), pension and other postretirement benefit plans net unamortized (gain) loss, tax	$ 100	$ 95

Long-Term Debt - Additional Information (Details) $ in Thousands	1 Months Ended	9 Months Ended
	Mar. 31, 2024 USD ($) Contract	Sep. 30, 2024 USD ($)	Sep. 30, 2023 USD ($)	Apr. 30, 2024 USD ($)
Debt Instrument [Line Items]
Proceeds from issuance of long-term debt		$ 83,700	$ 250,000
Secured Debt [Member]
Debt Instrument [Line Items]
Pollution control bonds				$ 83,700
3.875% Due in 2032 and 2034 \| Interest Rate Swap [Member] \| First Mortgage [Member]
Debt Instrument [Line Items]
Number of interest rate swaps settled \| Contract	2
Notional amount	$ 20,000
Net payments from settlement of derivatives	$ 4,400
2032 \| Secured Debt [Member]
Debt Instrument [Line Items]
Debt instrument interest rate percentage				3.875%
Closure of Pollution Control Bonds				$ 66,700
2034 \| Secured Debt [Member]
Debt Instrument [Line Items]
Debt instrument interest rate percentage				3.875%
Closure of Pollution Control Bonds				$ 17,000

Earnings Per Common Share - Additional Information (Details) - shares	3 Months Ended		9 Months Ended
	Sep. 30, 2024	Sep. 30, 2023	Sep. 30, 2024	Sep. 30, 2023
Earnings Per Share [Abstract]
Antidilutive securities excluded from computation of earnings per share, amount	0	0	0	0

Fair Value - Schedule of Activity For Energy Commodity Derivative Assets (Liabilities) Measured At Fair Value and Equity Investments Using Significant Unobservable Inputs (Level 3) (Details) - Level 3 [Member] - USD ($)
$ in Thousands

3 Months Ended

9 Months Ended

Sep. 30, 2024

Sep. 30, 2023

Sep. 30, 2024

Sep. 30, 2023

Fair Value Liabilities Measured On Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]

Beginning Balance

$ 42,376

$ 36,732

$ 42,004

$ 36,550

Included in regulatory assets/liabilities

1,005

(3,652)

986

2,115

Recognized in net income

$ 1,478

$ 2,024

$ 636

$ (3,174)

Fair Value, Net Derivative Asset (Liability), Recurring Basis, Unobservable Input Reconciliation, Gain (Loss), Statement of Income or Comprehensive Income [Extensible Enumeration]

Other Nonoperating Income (Expense)

Purchases and debt conversions

$ 984

$ 1,929

$ 2,367

Settlements

(1)

287

246

Other

(3,000)

Ending Balance

45,842

$ 35,104

45,842

35,104

Equity Investment [Member]

Fair Value Liabilities Measured On Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]

Beginning Balance

50,357

48,453

50,254

54,284

Recognized in net income

$ 1,478

$ 2,024

$ 636

$ (3,174)

Fair Value, Asset, Recurring Basis, Unobservable Input Reconciliation, Gain (Loss), Statement of Income or Comprehensive Income [Extensible Enumeration]

Other Nonoperating Income (Expense)

Purchases and debt conversions

$ 984

$ 1,929

$ 2,367

Other

(3,000)

Ending Balance

52,819

$ 50,477

52,819

50,477

Natural Gas Exchange Agreements [Member]

Fair Value Liabilities Measured On Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]

Beginning Balance

^[1]

(7,981)

(11,721)

(8,250)

(17,734)

Included in regulatory assets/liabilities

^[1]

1,005

(3,652)

986

2,115

Settlements

^[1]

(1)

287

246

Ending Balance

^[1]

$ (6,977)

$ (15,373)

$ (6,977)

$ (15,373)

[1]	There were no purchases, issuances or transfers from other categories during the periods presented in the table above.

Commitments and Contingencies

9 Months Ended

Sep. 30, 2024

Commitments and Contingencies Disclosure [Abstract]

Commitments and Contingencies

NOTE 15. COMMITMENTS AND CONTINGENCIES

In the course of its business, the Company becomes involved in various claims, controversies, disputes and other contingent matters, including the items described in this Note. Some of these claims, controversies, disputes and other contingent matters involve litigation or other contested proceedings. For all such matters, the Company will vigorously protect and defend its interests and pursue its rights. However, no assurance can be given as to the outcome of any matter because litigation and other contested proceedings are subject to numerous uncertainties. For matters affecting Avista Utilities’ or AEL&P's operations, the Company intends to seek, to the extent appropriate, recovery of incurred costs through the ratemaking process.

Climate Commitment Act (CCA)

The CCA requires the Company to submit greenhouse gas emission reports to the Washington State Department of Ecology (Ecology) annually for its electric and natural gas entities. The CCA then requires the Company to contract with a third-party verifier to audit the emissions data in the emissions reports. In August 2024, the Company’s third-party verifier submitted to Ecology its verification report on the Company’s 2023 emissions report. The verification report was issued with an adverse emissions data verification

statement. In September 2024, in the absence of a positive verification statement, Ecology assigned an emission level (AEL) to Avista Corp. based on information submitted by the Company’s third-party verifier.

The Company disagrees with the emissions assigned by Ecology as the amounts do not consider the application of the white paper entitled “Consideration of Electricity Imports and Determination of the Electricity Importer Under the Climate Commitment Act”, which was previously discussed with and agreed to in principle by Ecology. The third-party verifier was unable to apply the white paper as it couldn’t confirm with Ecology that the methodologies applied by the Company were consistent with the white paper before the initial reporting deadline. Ecology, the Company, and the third-party verifier have engaged in discussions regarding the proper application of the calculation methods identified in Ecology’s Greenhouse Gas Reporting Program and the white paper.

The Company has revised and re-submitted its emissions report to the third-party verifier and Ecology. The revised report makes certain adjustments identified by the verifier, but is otherwise consistent with the initial report regarding total emissions. The revised report has been reviewed by the third-party verifier, and the verifier has provided the Company written confirmation that it intends to issue a report with a positive emissions data verification statement in the fourth quarter of 2024. The revised report may result in an additional emissions liability of $0.2 million allocated to Idaho. The Company does not recover CCA emissions obligations from customers in Idaho. The Company believes it has sufficient allowances to cover the additional emissions liability allocated to Washington. Any additional costs allocated to Washington would be deferred and included in the ERM, which, based on Avista Corp.’s current position in the ERM, would be allocated 90 percent to customers and 10 percent to the Company.

On October 31, 2024, Ecology agreed to stay the AEL issued in September 2024 for a period of 45 days to allow the Company to revise its emissions report (see above) and receive a positive verification statement from the third-party verifier. Under Washington law and as provided in an agreement with the Company entered into on October 31, 2024, Ecology has the authority and will adjust the AEL upon receipt of a report with a positive verification statement. Avista Corp. expects to receive a positive verification statement and for Ecology to adjust the AEL in the fourth quarter of 2024. If Avista Corp. does not receive a positive verification statement or if, despite the express agreement between Ecology and the Company, Ecology does not adjust the AEL, Avista Corp. estimates the additional liability could be up to $32 million, of which $12 million would be allocated to Idaho and $20 million allocated to Washington. The Company does not believe such an outcome is probable and the Company would exercise all available legal and administrative remedies to preserve its rights under the law.

Collective Bargaining Agreements

The Company's collective bargaining agreement with the IBEW represents 36 percent of all Avista Utilities' employees. The Company's largest represented group, representing approximately 90 percent of Avista Utilities' bargaining unit employees in Washington and Idaho, are covered under a four year agreement which expires in March 2025.

The current agreement includes a clause to negotiate wages in effect for the last year of the agreement. On July 31, 2024, the IBEW voted to approve new wages for 2024 and 2025, with wages for 2024 effective retroactively to March 26, 2024 and wages for 2025 taking effect on January 1, 2025.

Boyds Fire (State of Washington Department of Natural Resources v. Avista)

In August 2019, the Company was served with a complaint, captioned “State of Washington Department of Natural Resources v. Avista Corporation,” seeking recovery of up to $4.4 million for fire suppression and investigation costs and related expenses incurred in connection with a wildfire that occurred in Ferry County, Washington, in August 2018. Specifically, the complaint alleges the fire, which became known as the “Boyds Fire,” was caused by a dead ponderosa pine tree falling into an overhead distribution line, and that Avista Corp., along with its independent vegetation management contractors Asplundh Tree Company and CN Utility Consulting, were negligent in failing to identify and remove the tree before it came into contact with the line. Avista Corp. disputes that it was negligent in failing to identify and remove the tree in question. Additional lawsuits were subsequently filed by private landowners seeking $0.8 million in property damages as well as potential non-economic damages, and holders of insurance subrogation claims seeking recovery of $1.8 million in insurance proceeds purportedly paid to their insureds.

The lawsuits were filed in the Superior Court of Ferry County, Washington, and is scheduled for trial on July 7, 2025. The Company continues to vigorously defend itself in the litigation. However, at this time the Company is unable to predict the likelihood of an adverse outcome or estimate a range of potential loss in the event of such an outcome.

Road 11 Fire

In April 2022, Avista Corp. received a notice of claim from property owners seeking damages of $5 million in connection with a fire that occurred in Douglas County, Washington, in July 2020. In June 2022, those claimants filed suit in the Superior Court of Douglas County, Washington, seeking unspecified damages. The fire, which was designated as the “Road 11 Fire,” occurred in the vicinity of an Avista Corp. 115kv line, resulting in damage to three overhead transmission structures. The fire occurred during a high wind event and grew to 10,000 acres before being contained. In June 2024, the parties reached an agreement to settle the matter for $0.1 million which will result in dismissal of the lawsuit with prejudice.

Labor Day 2020 Windstorm/ Babb Road Fire

In September 2020, a severe windstorm occurred in eastern Washington and northern Idaho. The extreme weather event resulted in customer outages and multiple wildfires in the region, including the Babb Road Fire, which occurred near the town of Malden, Washington. The Babb Road Fire covered approximately 15,000 acres and destroyed approximately 220 structures. There are no reports of personal injury or death resulting from the fire.

In May 2021 the Company learned the Washington Department of Natural Resources (DNR) had completed its investigation and issued a report on the Babb Road Fire.

The DNR report concluded, among other things, that

•

the fire was ignited when a branch of a multi-dominant Ponderosa Pine tree was broken off by the wind and fell on an Avista Corp. distribution line;

•

the tree was located approximately 30 feet from the center of Avista Corp.’s distribution line and approximately 20 feet beyond Avista Corp.’s right-of-way;

•

the tree showed some evidence of insect damage, a small area of scarring where a lateral branch/leader (LBL) had broken off in the past, and some past signs of Gall Rust disease.

The DNR report concluded that: “because of the unusual configuration of the tree, and its proximity to the powerline, a closer inspection was warranted. A nearer inspection of the tree should have revealed the cut LBL ends and its previous failure, and necessitated determination of the failure potential of the adjacent LBL, implicated in starting the Babb Road Fire.”

The DNR report acknowledged that, other than the multi-dominant nature of the tree, the conditions mentioned above would not have been easily visible without close-up inspection of, or cutting into, the tree. The report also acknowledged that, while the presence of multiple tops would have been visible from the nearby roadway, the tree did not fail at a v-fork due to the presence of multiple tops. The Company contends that applicable inspection standards did not require a closer inspection of the otherwise healthy tree, nor was the Company negligent with respect to its maintenance, inspection or vegetation management practices.

Eleven lawsuits have been filed in connection with the Babb Road fire. Asplundh Tree Company and CN Utility Consulting, which both perform vegetation management services as independent contractors to the Company, are also named as defendants in each of the lawsuits. The lawsuits include six subrogation actions filed by 51 insurance companies seeking to recover approximately $23 million purportedly paid to insureds to date; and five actions on behalf of 128 individual plaintiffs seeking unspecified damages, one of which was originally filed as a class action lawsuit on behalf of three putative individual plaintiffs, but which has since been amended to assert direct claims on behalf of the named plaintiffs. In the course of discovery, 40 individual plaintiffs have provided economic damage estimates, claiming total economic losses of approximately $8.2 million, of which approximately $3.5 million is covered by insurance or other forms of reimbursement. These plaintiffs may also seek as-yet unspecified non-economic damages (pain and suffering and emotional distress). The Company does not believe non-economic damages are applicable in this case and plans to dispute such claims.

All proceedings, except for one action filed on September 1, 2023 on behalf of three individual plaintiffs (the "Widman Action") have been consolidated in the Superior Court of Spokane County Washington under the lead action Blakeley v. Avista Corporation et al., and variously assert causes of action for negligence, private nuisance, and trespass (the "Blakeley Proceeding").

In November 2023, all parties to the Blakeley Proceeding agreed to a stipulated order, which was presented to and entered by the Superior Court of Spokane County, Washington. The order consolidates the Blakeley Proceeding for trial (in addition to discovery and pre-trial proceedings) and bifurcates the trial into liability and damages phases, such that the initial trial in the case will focus solely on whether the defendants are legally responsible for the Babb Road Fire. A trial date on the liability phase has been set for May 5, 2025. The Widman Action is set for trial on October 6, 2025.

In addition, the stipulated order relating to the Blakeley Proceeding memorializes the plaintiffs' agreement to voluntarily dismiss all claims asserting inverse condemnation as a theory of liability, without prejudice to their ability to seek permission from the Court to refile those claims at a later date if they can show good cause to do so. The Widman Action does not include claims for inverse condemnation. The parties to the Blakeley Proceeding agreed to a preliminary mediation no later than 60 days prior to the liability trial, and, if there is a trial following that mediation and if the jury returns a verdict in the plaintiffs' favor in the liability trial, a second mediation within 90 days following the verdict focusing on damages. Finally, the plaintiffs agreed to complete a damages questionnaire identifying all claimed damages being sought in connection with the litigation.

In June 2024, a motion was filed in one of the individual actions (the "VanDyke Action") to add three additional plaintiffs. Although the statute of limitations for new claims has passed, the plaintiffs argued that the addition of new plaintiffs is timely because the lawsuit was initially pled as a class action. The Court subsequently allowed two of the proposed plaintiffs to be added to the action on the grounds that they were minors at the time of the incident, but denied the remainder of the motion.

The Company will vigorously defend itself in the legal proceedings; however, at this time the Company is unable to predict the likelihood of an adverse outcome or estimate a range of potential loss in the event of such an outcome.

Orofino Fire

In August 2023, a fire subsequently referred to as the "Hospital Fire" started in windy conditions near Orofino, Idaho, burning 53 acres and seven primary residences, as well as several outbuildings. The Idaho Department of Lands investigated and has issued a report in which it concluded the fire was caused by an electrical fault igniting three separate spots which then spread uphill. The Company has a distribution line in the area near the ignition point. The Company has to date found no evidence suggesting negligence on its part. Except for two claims for damage to personal property, the Company has not, at this time, received any claims in connection with the fire. The Company will vigorously defend itself in the event any such claims are asserted; however, at this time, it is unable to estimate the likelihood of an adverse outcome nor the amount or range of a potential loss in the event of an adverse outcome.

Colstrip

Colstrip Owners Arbitration and Litigation


Co-Owner	Unit 3			Unit 4
Avista		15	%		15	%
PacifiCorp		10	%		10	%
PGE		20	%		20	%
PSE		25	%		25	%
NorthWestern		—			30	%
Talen		30	%		—

Colstrip Units 1 and 2, owned by PSE and Talen, were shut down in 2020 and are in the process of being decommissioned. The co-owners of Units 3 and 4 also own undivided interests in facilities common to both Units 3 and 4, as well as in certain facilities common to all four Colstrip units.

The Washington Clean Energy Transformation Act (CETA), among other things, imposes deadlines by which each electric utility must eliminate from its electricity rates in Washington the costs and benefits associated with coal-fired resources, such as Colstrip. The practical impact of CETA is electricity from such resources, including Colstrip, may no longer be delivered to Washington retail customers after 2025.

The co-owners of Colstrip Units 3 and 4 have differing needs for the generating capacity of these units. Accordingly, certain business disagreements have arisen among the co-owners, including, disagreements as to the requirements for shutting down these units. NorthWestern has initiated arbitration pursuant to the O&O Agreement to resolve these business disagreements, and two actions have been initiated to compel arbitration of those disputes: one by Talen in the Montana Thirteenth Judicial District Court for Yellowstone County, and one by the Western Co-Owners, which is pending in Montana Federal District Court. In light of the ownership transfer agreements, the Colstrip owners agreed to stay both the litigation and the arbitration through March 2024. On April 1, 2024, the agreement to stay lapsed and the parties are now in the process of reengaging in arbitration discussions. An arbitration date has not yet been scheduled. The Company cannot predict the outcome of the arbitration process.

Agreement Between Avista and NorthWestern

In January 2023, the Company entered into an agreement with NorthWestern under which, subject to the terms and conditions specified in the agreement, the Company will transfer its 15 percent ownership in Colstrip Units 3 and 4 to NorthWestern. There is no monetary exchange included in the transaction. The transaction is scheduled to close on December 31, 2025 or such other date as the parties mutually agree upon.

Under the agreement, the Company will remain obligated through the close of the transaction to pay its share of (i) operating expenses, (ii) capital expenditures, but not in excess of the portion allocable pro rata to the portion of useful life (through 2030) expired through the close of the transaction, and (iii) site remediation expenses except certain costs relating to post closing activities. In addition, the Company would enter into an agreement under which it would retain its voting rights with respect to decisions relating to remediation.

The Company will retain its Colstrip transmission system assets, which are excluded from the transaction.

The transaction is subject to the satisfaction of customary closing conditions including NorthWestern's ability to enter into a new coal supply agreement by December 31, 2024.

The Company does not expect this transaction to have a direct material impact on its financial results.

Agreement Between PSE and NorthWestern

In July 2024, PSE entered into an agreement with NorthWestern under which, PSE will transfer its 25 percent ownership in Colstrip Units 3 and 4 to NorthWestern. There is no monetary exchange included in the transaction. The transaction is scheduled to close on December 31, 2025.

Burnett et al. v. Talen et al.

Multiple property owners initiated a legal proceeding (titled Burnett et al. v. Talen et al.) in the Montana District Court for Rosebud County against Talen, PSE, PacifiCorp, PGE, Avista Corp., NorthWestern, and Westmoreland Rosebud Mining. The plaintiffs allege a failure to contain coal dust in connection with the operation of Colstrip, and seek unspecified damages. The Colstrip owners reached a settlement with one of the litigants, Richard Burnett, for an amount of less than $0.1 million. The settlement does not involve or implicate the claims of any other litigants. The Company will vigorously defend itself in the litigation, but at this time is unable to predict the outcome, nor an amount or range of potential impact in the event of an outcome adverse to the Company’s interests.

Westmoreland Mine Permits

Two lawsuits have been commenced by the Montana Environmental Information Center and others, challenging certain permits relating to the operation of the Westmoreland Rosebud Mine, which provides coal to Colstrip. In the first, the Montana District Court for Rosebud County issued an order vacating a permit for one area of the mine, which decision was subsequently upheld by the Montana Supreme Court. In the second, the Montana Federal District Court vacated a decision by the federal Office of Surface Mining Reclamation and Enforcement, a branch of the United States Department of the Interior, approving expansion of the mine into a new area, pending further analysis of potential environmental impact. An initial appeal of that decision to the Ninth Circuit was dismissed for lack of jurisdiction, pending further proceedings before the Department of the Interior. Avista Corp. is not a party to either of these proceedings, but continues to monitor the progress of both issues and assess the impact, if any, of the proceedings on Westmoreland’s ability to meet its contractual coal supply obligations.

National Park Service (NPS) - Natural and Cultural Damage Claim

In March 2017, the Company accessed property managed by the National Park Service (NPS) to prevent the imminent failure of a power pole surrounded by flood water in the Spokane River. The Company voluntarily reported its actions to the NPS several days later. Thereafter, in March 2018, the NPS notified the Company that it might seek recovery for unspecified costs and damages allegedly caused during the incident pursuant to the System Unit Resource Protection Act (SURPA), 54 U.S.C. 100721 et seq. In January 2021, the United States Department of Justice (DOJ) requested the Company and the DOJ renew discussions relating to the matter. In July 2021, the DOJ communicated that it may seek damages of approximately $2 million in connection with the incident for alleged damage to “natural and cultural resources”. In addition, the DOJ indicated that it may seek treble damages under the SURPA and state law, bringing its total potential claim to approximately $6 million.

In April 2024 the parties reached a settlement in principle, through which the Company has agreed to pay $0.9 million in order to settle all claims and allegations relating to the matter. The settlement in principle is contingent upon execution of a mutually acceptable settlement agreement, as well as a required public notice and comment period to be initiated by NPS and/or the DOJ.

Rathdrum, Idaho Natural Gas Incident

In October 2021, there was an incident in Rathdrum, Idaho involving the Company’s natural gas infrastructure. The incident occurred after a third party damaged those facilities during excavation work. The incident resulted in a fire which destroyed one residence and resulted in minor injuries to the occupants. In January 2023, the Company was served with a lawsuit filed in the District Court of Kootenai County, Idaho by one property owner, seeking unspecified damages. In February 2024, the Company received a second lawsuit filed by the owners of the adjacent property, seeking damages for personal injury and emotional distress from having witnessed the incident. The Company will vigorously defend itself in the legal proceedings; however, at this time the Company is unable to predict the likelihood of an adverse outcome or estimate a range of potential loss in the event of such an outcome.

Other Contingencies

In the normal course of business, the Company has various other legal claims and contingent matters outstanding. The Company believes any liability arising from these actions will not have a material impact on its financial condition, results of operations or cash flows. It is possible a change could occur in the Company’s estimates of the probability or amount of a liability being incurred. Such a change, should it occur, could be significant. See "Note 22 of the Notes to Consolidated Financial Statements" in the 2023 Form 10-K for additional discussion regarding other contingencies.

Accumulated Other Comprehensive Loss - Reclassification out of Accumulated Other Comprehensive Loss (Details) - Accumulated Defined Benefit Plans Adjustment Attributable to Parent [Member] - Reclassification out of Accumulated Other Comprehensive Income [Member] - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2024	Sep. 30, 2023	Sep. 30, 2024	Sep. 30, 2023
Reclassification Adjustment Out Of Accumulated Other Comprehensive Income [Line Items]
Amortization of net prior service cost	$ (137)	$ (140)	$ (414)	$ (420)
Amortization of net loss	780	1,130	2,318	3,679
Adjustment due to effects of regulation	(655)	(1,014)	(1,927)	(3,330)
Other comprehensive (income) loss, defined benefit plan, reclassification adjustment from AOCI, before tax	(12)	(24)	(23)	(71)
Other comprehensive (income) loss, defined benefit plan, reclassification adjustment from AOCI, tax	3	5	5	15
Other comprehensive (income) loss, defined benefit plan, reclassification adjustment from AOCI, after tax	$ (9)	$ (19)	$ (18)	$ (56)

Commitments and Contingencies - Ownership and Operating Interest Percentage (Details) - Colstrip [Member]	Sep. 30, 2024	Jul. 31, 2024	Jan. 16, 2023
Avista [Member] \| Unit 3 [Member]
Loss Contingencies [Line Items]
Owners percentage interest	15.00%
Avista [Member] \| Unit 4 [Member]
Loss Contingencies [Line Items]
Owners percentage interest	15.00%
PacifiCorp [Member] \| Unit 3 [Member]
Loss Contingencies [Line Items]
Owners percentage interest	10.00%
PacifiCorp [Member] \| Unit 4 [Member]
Loss Contingencies [Line Items]
Owners percentage interest	10.00%
PGE [Member] \| Unit 3 [Member]
Loss Contingencies [Line Items]
Owners percentage interest	20.00%
PGE [Member] \| Unit 4 [Member]
Loss Contingencies [Line Items]
Owners percentage interest	20.00%
PSE [Member] \| Unit 3 [Member]
Loss Contingencies [Line Items]
Owners percentage interest	25.00%
PSE [Member] \| Unit 4 [Member]
Loss Contingencies [Line Items]
Owners percentage interest	25.00%	25.00%
NorthWestern [Member] \| Unit 4 [Member]
Loss Contingencies [Line Items]
Owners percentage interest	30.00%		15.00%
Talen [Member] \| Unit 3 [Member]
Loss Contingencies [Line Items]
Owners percentage interest	30.00%

Long-Term Debt

9 Months Ended

Sep. 30, 2024

Debt Disclosure [Abstract]

Long Term Debt

NOTE 9. LONG-TERM DEBT

In April 2024, the Company closed on the remarketing of $66.7 million and $17.0 million of the City of Forsyth, Montana Pollution Control Revenue Refunding Bonds due in 2032 and 2034, respectively. The bonds are not subject to ordinary optional redemption. The bonds are secured by equal principal amounts of non-transferable first mortgage bonds of the Company. The interest rate on both series of bonds is 3.875 percent. Avista Corp. purchased the Forsyth bonds upon original issuance in December 2010, with the intention to hold the bonds until market conditions were favorable for remarketing the bonds to unaffiliated investors. While the Company was the holder of these bonds, the bonds were not reflected as an asset or a liability on the Consolidated Balance Sheets. Upon the remarketing of these bonds, the Company recognized long term debt of $83.7 million.

In connection with the pricing of the Forsyth bonds in March 2024, the Company cash-settled two interest rate swap derivatives (notional aggregate amount of $20.0 million) and received a net amount of $4.4 million, which will be amortized as a component of interest expense over the life of the bonds. See Note 5 for a discussion of interest rate swap derivatives.

The net proceeds from the remarketing of the Forsyth bonds were used to repay a portion of the borrowings outstanding under the Company's committed line of credit.

Revenue (Tables)

9 Months Ended

Sep. 30, 2024

Revenue from Contract with Customer [Abstract]

Schedule of Utilities Operating Revenue Expense Taxes

Utility-related taxes included in revenue from contracts with customers were as follows for the three and nine months ended September 30 (dollars in thousands):


	Three months ended September 30,				Nine months ended September 30,
	2024		2023		2024		2023
Utility-related taxes	$	16,775	$	14,484	$	60,442	$	56,356

Disaggregation of Revenue

Disaggregation of Total Operating Revenue

The following table disaggregates total operating revenue by segment and source for the three and nine months ended September 30 (dollars in thousands):


	Three months ended September 30,					Nine months ended September 30,
	2024			2023		2024			2023
Avista Utilities
Revenue from contracts with customers	$	318,171		$	285,821	$	1,136,926		$	1,058,725
Derivative revenues		56,462			77,562		194,647			141,080
Alternative revenue programs		3,978			3,578		23,032			(9,947	)
Other utility revenues		5,135			2,712		14,891			8,561
Total Avista Utilities		383,746			369,673		1,369,496			1,198,419
AEL&P
Revenue from contracts with customers		9,826			9,700		35,163			34,934
Deferrals and amortizations for rate refunds to customers		(183	)		—		(183	)		—
Other utility revenues		176			151		515			474
Total AEL&P		9,819			9,851		35,495			35,408

Other non-utility revenues		177			102		239			367
Total operating revenues	$	393,742		$	379,626	$	1,405,230		$	1,234,194

Utility Revenue from Contracts with Customers by Type and Service

The following table disaggregates revenue from contracts with customers associated with the Company's electric operations for the three and nine months ended September 30 (dollars in thousands):


	2024						2023
	Avista Utilities		AEL&P		Total Utility		Avista Utilities		AEL&P		Total Utility
Three months ended September 30:
ELECTRIC OPERATIONS
Revenue from contracts with customers
Residential	$	110,328	$	3,444	$	113,772	$	95,881	$	3,186	$	99,067
Commercial		97,389		6,313		103,702		89,772		6,447		96,219
Industrial		36,910		—		36,910		29,584		—		29,584
Public street and highway lighting		2,186		69		2,255		2,005		67		2,072
Total retail revenue		246,813		9,826		256,639		217,242		9,700		226,942
Transmission		9,250		—		9,250		7,721		—		7,721
Other revenue from contracts with customers		8,062		—		8,062		9,353		—		9,353
Total electric revenue from contracts with customers	$	264,125	$	9,826	$	273,951	$	234,316	$	9,700	$	244,016
Nine months ended September 30:
ELECTRIC OPERATIONS
Revenue from contracts with customers
Residential	$	345,166	$	15,146	$	360,312	$	305,203	$	14,485	$	319,688
Commercial		275,525		19,819		295,344		252,344		20,257		272,601
Industrial		95,014		—		95,014		82,707		—		82,707
Public street and highway lighting		6,604		198		6,802		5,940		192		6,132
Total retail revenue		722,309		35,163		757,472		646,194		34,934		681,128
Transmission		28,380		—		28,380		24,143		—		24,143
Other revenue from contracts with customers		32,457		—		32,457		33,580		—		33,580
Total electric revenue from contracts with customers	$	783,146	$	35,163	$	818,309	$	703,917	$	34,934	$	738,851

The following table disaggregates revenue from contracts with customers associated with the Company's natural gas operations for the three and nine months ended September 30 (dollars in thousands):


	Three months ended September 30,				Nine months ended September 30,
	2024		2023		2024		2023
	Avista Utilities		Avista Utilities		Avista Utilities		Avista Utilities
NATURAL GAS OPERATIONS
Revenue from contracts with customers
Residential	$	30,285	$	29,372	$	217,682	$	218,212
Commercial		17,203		15,381		114,495		113,183
Industrial and interruptible		2,720		3,480		9,880		13,136
Total retail revenue		50,208		48,233		342,057		344,531
Transportation		2,432		1,866		7,504		6,058
Other revenue from contracts with customers		1,406		1,406		4,219		4,219
Total natural gas revenue from contracts with customers	$	54,046	$	51,505	$	353,780	$	354,808

CONDENSED CONSOLIDATED BALANCE SHEETS - USD ($) $ in Thousands	Sep. 30, 2024	Dec. 31, 2023
Current Assets:
Cash and cash equivalents	$ 9,124	$ 35,003
Accounts and notes receivable-less allowances of $3,124 and $4,987, respectively	143,706	216,744
Inventory	185,940	159,984
Regulatory assets	115,197	146,327
Other current assets	71,107	103,784
Total current assets	525,074	661,842
Net utility property	5,924,390	5,700,056
Goodwill	52,426	52,426
Non-current regulatory assets	867,242	894,168
Other property and investments-net and other non-current assets	411,751	393,985
Total assets	7,780,883	7,702,477
Current Liabilities:
Accounts payable	104,512	143,262
Current portion of long-term debt	15,000	15,000
Short-term borrowings	287,250	349,000
Regulatory liabilities	92,195	76,007
Other current liabilities	201,198	191,936
Total current liabilities	700,155	775,205
Pensions and other postretirement benefits	88,619	89,830
Deferred income taxes	726,175	718,318
Non-current regulatory liabilities	840,047	856,666
Other non-current liabilities and deferred credits	247,606	210,230
Total liabilities	5,252,795	5,217,154
Commitments and Contingencies (See Notes to Condensed Consolidated Financial Statements)
Shareholders' Equity:
Common stock, no par value; 200,000,000 shares authorized; 79,180,956 and 78,074,587 shares issued and outstanding, respectively	1,686,776	1,644,327
Accumulated other comprehensive loss	(375)	(357)
Retained earnings	841,687	841,353
Total shareholders’ equity	2,528,088	2,485,323
Total liabilities and equity	7,780,883	7,702,477
Non Affiliated Trusts [Member]
Current Liabilities:
Long-term debt	2,598,646	2,515,358
Affiliated Trusts [Member]
Current Liabilities:
Long-term debt	$ 51,547	$ 51,547

Insider Trading Arrangements	3 Months Ended
Insider Trading Arrangements	Sep. 30, 2024
Trading Arrangements, by Individual
Rule 10b5-1 Arrangement Adopted	false
Non-Rule 10b5-1 Arrangement Adopted	false
Rule 10b5-1 Arrangement Terminated	false
Non-Rule 10b5-1 Arrangement Terminated	false

Income Taxes

9 Months Ended

Sep. 30, 2024

Income Tax Disclosure [Abstract]

Income Taxes

NOTE 7. INCOME TAXES

In accordance with interim reporting requirements, the Company uses an estimated annual effective tax rate for computing its provisions for income taxes. An estimate of annual income tax expense (or benefit) is made each interim period using estimates for annual pre-tax income, income tax adjustments and tax credits. The estimated annual effective tax rates do not include discrete events such as tax law changes, examination settlements, accounting method changes or adjustments to tax expense or benefits attributable to prior years. Discrete events are recorded in the interim period in which they occur or become known. The estimated annual tax rate is applied to year-to-date pre-tax income to determine income tax expense (or benefit) for the interim period consistent with the annual estimate. In subsequent interim periods, income tax expense (or benefit) for the period is computed as the difference between the year-to-date amount reported for the previous interim period and the current period’s year-to-date amount.


	Three months ended September 30,										Nine months ended September 30,
	2024					2023					2024					2023
Federal income taxes at statutory rates	$	3,782		21.0	%	$	2,294		21.0	%	$	24,184		21.0	%	$	14,872		21.0	%
Increase (decrease) in tax resulting from:
Flow through related to deduction of meters and mixed service costs (1)		(2,445	)	(13.6	)		(3,744	)	(34.3	)		(14,128	)	(12.3	)		(22,956	)	(32.4	)
Tax effect of regulatory treatment of utility plant differences		(1,317	)	(7.3	)		(828	)	(7.6	)		(7,291	)	(6.4	)		(6,040	)	(8.5	)
State income tax expense		160		0.9			151		1.4			878		0.8			949		1.3
Tax credits		(86	)	(0.5	)		(862	)	(7.9	)		(486	)	(0.4	)		(1,997	)	(2.8	)
Other		(572	)	(3.2	)		(797	)	(7.2	)		(834	)	(0.7	)		(1,052	)	(1.5	)
Total income tax expense (benefit)	$	(478	)	(2.7	)%	$	(3,786	)	(34.6	)%	$	2,323		2.0	%	$	(16,224	)	(22.9	)%

(1)

- Definition

The entire disclosure for income tax.

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
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-URI https://asc.fasb.org/1943274/2147482685/740-10-50-12

Reference 2: http://www.xbrl.org/2003/role/exampleRef
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Reference 3: http://www.xbrl.org/2003/role/disclosureRef
-Topic 740
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Reference 4: http://www.xbrl.org/2003/role/disclosureRef
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-URI https://asc.fasb.org/1943274/2147482685/740-10-50-12B

Reference 5: http://www.xbrl.org/2003/role/disclosureRef
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-URI https://asc.fasb.org/1943274/2147477891/740-270-50-1

Reference 6: http://www.xbrl.org/2003/role/disclosureRef
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Reference 7: http://www.xbrl.org/2003/role/disclosureRef
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Reference 8: http://www.xbrl.org/2003/role/disclosureRef
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Reference 9: http://www.xbrl.org/2003/role/disclosureRef
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Reference 10: http://www.xbrl.org/2003/role/disclosureRef
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-URI https://asc.fasb.org/1943274/2147482685/740-10-50-14

Reference 11: http://www.xbrl.org/2003/role/disclosureRef
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-URI https://asc.fasb.org/1943274/2147482685/740-10-50-21

Reference 12: http://www.xbrl.org/2003/role/disclosureRef
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Reference 13: http://www.xbrl.org/2003/role/disclosureRef
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Reference 14: http://www.xbrl.org/2003/role/disclosureRef
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-URI https://asc.fasb.org/1943274/2147482603/740-30-50-2

+ Details

Summary of Significant Accounting Policies	9 Months Ended
Summary of Significant Accounting Policies	Sep. 30, 2024
Accounting Policies [Abstract]
Summary of Significant Accounting Policies	NOTE 1. SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES Nature of Business Avista Corp. is primarily an electric and natural gas utility with certain other business ventures. Avista Utilities is an operating division of Avista Corp., comprising its regulated utility operations in the Pacific Northwest. Avista Utilities provides electric distribution and transmission, and natural gas distribution services in parts of eastern Washington and northern Idaho. Avista Utilities also provides natural gas distribution service in parts of northeastern and southwestern Oregon. Avista Utilities has electric generating facilities in Washington, Idaho, Oregon and Montana. Avista Utilities also supplies electricity to a small number of customers in Montana. AERC is a wholly-owned subsidiary of Avista Corp. The primary subsidiary of AERC is AEL&P, which comprises Avista Corp.'s regulated utility operations in Alaska. Avista Capital, a wholly owned non-regulated subsidiary of Avista Corp., is the parent company of the subsidiary companies in the non-utility businesses, except AJT Mining Properties, Inc., which is a subsidiary of AERC. See Note 16 for business segment information. Basis of Reporting The condensed consolidated financial statements include the assets, liabilities, revenues and expenses of the Company and its subsidiaries and other majority owned subsidiaries and variable interest entities for which the Company or its subsidiaries are the primary beneficiaries. Intercompany balances were eliminated in consolidation. The accompanying condensed consolidated financial statements include the Company’s proportionate share of utility plant and related operations associated with its interests in jointly owned plants. Regulation The Company is subject to state regulation in Washington, Idaho, Montana, Oregon and Alaska. The Company is subject to federal regulation primarily by the FERC, as well as various other federal agencies with regulatory oversight of particular aspects of its operations. Derivative Assets and Liabilities Derivatives are recorded as either assets or liabilities on the Condensed Consolidated Balance Sheets measured at estimated fair value. The WUTC and the IPUC issued accounting orders authorizing Avista Corp. to offset energy commodity derivative assets or liabilities with a regulatory asset or liability. This accounting treatment is intended to defer the recognition of mark-to-market gains and losses on energy commodity transactions until the period of delivery. Realized benefits and costs result in adjustments to retail rates through PGAs, the ERM in Washington, the PCA mechanism in Idaho, and periodic general rate cases. The resulting regulatory assets associated with energy commodity derivative instruments are probable of recovery through future rates. Substantially all forward contracts to purchase or sell power and natural gas are recorded as derivative assets or liabilities at estimated fair value with an offsetting regulatory asset or liability. Contracts not considered derivatives are accounted for on the accrual basis until they are settled or realized unless there is a decline in the fair value of the contract determined to be other-than-temporary. For interest rate swap derivatives, Avista Corp. records all mark-to-market gains and losses in each accounting period as assets and liabilities, as well as offsetting regulatory assets and liabilities, such that there is no income statement impact. The interest rate swap derivatives are risk management tools similar to energy commodity derivatives. Upon settlement of interest rate swap derivatives, the regulatory asset or liability is amortized as a component of interest expense over the term of the associated debt. The Company records an offset of interest rate swap derivative assets and liabilities with regulatory assets and liabilities, based on the prior practice of the commissions to provide recovery through the ratemaking process. The Company has multiple master netting agreements with a variety of entities allowing for cross-commodity netting of derivative agreements with the same counterparty (i.e. power derivatives can be netted with natural gas derivatives). In addition, some master netting agreements allow for the netting of commodity derivatives and interest rate swap derivatives for the same counterparty. The Company does not have agreements which allow for cross-affiliate netting among multiple affiliated legal entities. The Company nets all derivative instruments when allowed by the agreement for presentation in the Condensed Consolidated Balance Sheets. Fair Value Measurements Fair value represents the price that would be received when selling an asset or paid to transfer a liability (an exit price) in an orderly transaction between market participants at the measurement date. Energy commodity derivative assets and liabilities, deferred compensation assets, some equity investments, as well as derivatives related to interest rate swaps and foreign currency exchange contracts, are reported at estimated fair value on the Condensed Consolidated Balance Sheets. See Note 11 for the Company’s fair value disclosures. Contingencies The Company has unresolved regulatory, legal and tax issues which have inherently uncertain outcomes. The Company accrues a loss contingency if it is probable that a liability has been incurred and the amount of the loss or impairment can be reasonably estimated. The Company also discloses loss contingencies that do not meet these conditions for accrual if there is a reasonable possibility that a material loss may be incurred. See Note 15 for further discussion of the Company's commitments and contingencies.

Derivatives and Risk Management - Additional Information (Details)	9 Months Ended	12 Months Ended
	Sep. 30, 2024 USD ($) MMBTU MWh	Dec. 31, 2023 USD ($) MMBTU MWh
Canadian [Member]
Derivative [Line Items]
Number of days Canadian currency prices are settled with U.S. dollars	60 days
Interest Rate Swap [Member]
Derivative [Line Items]
Cash collateral posted \| $	$ 0	$ 0
Letters of credit outstanding \| $	$ 0	$ 0
Purchase [Member] \| Physical [Member] \| Electric Derivative [Member]
Derivative [Line Items]
Expected deliveries of energy commodity derivatives after four years \| MWh	0
Expected deliveries of energy commodity derivatives after three years \| MWh		0
Purchase [Member] \| Physical [Member] \| Gas Derivative [Member]
Derivative [Line Items]
Expected deliveries of energy commodity derivatives after four years \| MMBTU	0
Expected deliveries of energy commodity derivatives after three years \| MMBTU		0
Purchase [Member] \| Financial [Member] \| Electric Derivative [Member]
Derivative [Line Items]
Expected deliveries of energy commodity derivatives after four years \| MWh	0
Expected deliveries of energy commodity derivatives after three years \| MWh		0
Purchase [Member] \| Financial [Member] \| Gas Derivative [Member]
Derivative [Line Items]
Expected deliveries of energy commodity derivatives after four years \| MMBTU	0
Expected deliveries of energy commodity derivatives after three years \| MMBTU		0
Sales [Member] \| Physical [Member] \| Electric Derivative [Member]
Derivative [Line Items]
Expected deliveries of energy commodity derivatives after four years \| MWh	0
Expected deliveries of energy commodity derivatives after three years \| MWh		0
Sales [Member] \| Physical [Member] \| Gas Derivative [Member]
Derivative [Line Items]
Expected deliveries of energy commodity derivatives after four years \| MMBTU	0
Expected deliveries of energy commodity derivatives after three years \| MMBTU		0
Sales [Member] \| Financial [Member] \| Electric Derivative [Member]
Derivative [Line Items]
Expected deliveries of energy commodity derivatives after four years \| MWh	0
Expected deliveries of energy commodity derivatives after three years \| MWh		0
Sales [Member] \| Financial [Member] \| Gas Derivative [Member]
Derivative [Line Items]
Expected deliveries of energy commodity derivatives after four years \| MMBTU	0
Expected deliveries of energy commodity derivatives after three years \| MMBTU		0