Avista (AVA) 10-Q 5 Nov 24 2024 Q3 Quarterly report Financial data

Document and Entity Information

Document and Entity Information - shares	9 Months Ended
	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

CONDENSED CONSOLIDATED STATEMEN

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

CONDENSED CONSOLIDATED STATEM_2

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

CONDENSED CONSOLIDATED STATEM_3

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)

CONDENSED CONSOLIDATED BALANCE

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

CONDENSED CONSOLIDATED BALANC_2

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

CONDENSED CONSOLIDATED STATEM_4

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

CONDENSED CONSOLIDATED STATEM_5

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

Pay vs Performance Disclosure

Pay vs Performance Disclosure - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	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

Insider Trading Arrangements

Insider Trading Arrangements	3 Months Ended
	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

Summary of Significant Accounti

Summary of Significant Accounting Policies	9 Months Ended
	Sep. 30, 2024
Accounting Policies [Abstract]
Summary of Significant Accounting Policies	NOTE 1. SUMMARY OF SIGNIF ICANT 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 b usiness 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.

New Accounting Standards

New Accounting Standards	9 Months Ended
	Sep. 30, 2024
Accounting Standards Update and Change in Accounting Principle [Abstract]
New Accounting Standards	NOTE 2. NEW ACCO UNTING 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.

Balance Sheet Components

Balance Sheet Components	9 Months Ended
	Sep. 30, 2024
Balance Sheet Related Disclosures [Abstract]
Balance Sheet Components	NOTE 3. BALANCE SHEET COMPONENTS 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 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 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, December 31, 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, December 31, 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

Revenue

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 AEL&P Total Utility Avista 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 8,062 — 8,062 9,353 — 9,353 Total electric revenue from contracts $ 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 32,457 — 32,457 33,580 — 33,580 Total electric revenue from contracts $ 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

Derivatives and Risk Management

Derivatives and Risk Management	9 Months Ended
	Sep. 30, 2024
Derivative Instruments and Hedges, Assets [Abstract]
Derivatives and Risk Management	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 Financial Physical Financial Physical Financial Physical Financial 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 2 0 27. 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 Financial Physical Financial Physical Financial Physical Financial 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 2 0 26. (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 Notional Mandatory 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 Gross Collateral Net Asset 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 Gross Collateral Net Asset 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 a s 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.

Pension Plans and Other Postret

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 OTHE R 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 no t expect further contributions in 2024. 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 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 of fset 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.

Income Taxes

Income Taxes	9 Months Ended
	Sep. 30, 2024
Income Tax Disclosure [Abstract]
Income Taxes	NOTE 7. IN COME 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. 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 ( 2,445 ) ( 13.6 ) ( 3,744 ) ( 34.3 ) ( 14,128 ) ( 12.3 ) ( 22,956 ) ( 32.4 ) Tax effect of regulatory treatment of utility ( 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.

Short-Term Borrowings

Short-Term Borrowings	9 Months Ended
	Sep. 30, 2024
Short-Term Debt [Abstract]
Short-Term Borrowings	NOTE 8. S HORT-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 a greement 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.

Long-Term Debt

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.

Long-Term Debt to Affiliated Tr

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 DEB T 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. T he 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.

Fair Value

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 Estimated Carrying Estimated 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 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 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 0.53 x to 4.71 x Revenue 2.21 x 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.

Common Stock

Common Stock	9 Months Ended
	Sep. 30, 2024
Stockholders' Equity Note [Abstract]
Common Stock	NOTE 12. COMM ON 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.

Accumulated Other Comprehensive

Accumulated Other Comprehensive Loss	9 Months Ended
	Sep. 30, 2024
Accumulated Other Comprehensive Loss [Abstract]
Accumulated Other Comprehensive Loss	NOTE 13. ACCUMULATED OT HER 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, December 31, Unfunded benefit obligation for pensions and other postretirement benefit plans - 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 Three months ended September 30, Nine months ended September 30, Details about Accumulated Other Comprehensive Loss Components 2024 2023 2024 2023 Amortization of defined benefit pension and 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.

Earnings Per Common Share

Earnings Per Common Share	9 Months Ended
	Sep. 30, 2024
Earnings Per Share [Abstract]
Earnings Per Common Share	NOTE 14. EARNINGS PER COMMON SHAR E 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.

Commitments and Contingencies

Commitments and Contingencies	9 Months Ended
	Sep. 30, 2024
Commitments and Contingencies Disclosure [Abstract]
Commitments and Contingencies	NOTE 15. COMMITMENT S 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. doe s 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 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 % — 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.

Information by Business Segment

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 Alaska Total Utility Other Intersegment 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.

Summary of Significant Accoun_2

Summary of Significant Accounting Policies (Policies)	9 Months Ended
	Sep. 30, 2024
Accounting Policies [Abstract]
Nature of Business	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 b usiness segment information.
Basis of Reporting	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	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	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 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	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

Balance Sheet Components (Table

Balance Sheet Components (Tables)	9 Months Ended
	Sep. 30, 2024
Balance Sheet Related Disclosures [Abstract]
Schedule of 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
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 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, December 31, 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, December 31, 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

Revenue (Tables)

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 AEL&P Total Utility Avista 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 8,062 — 8,062 9,353 — 9,353 Total electric revenue from contracts $ 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 32,457 — 32,457 33,580 — 33,580 Total electric revenue from contracts $ 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

Derivatives and Risk Manageme_2

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 Financial Physical Financial Physical Financial Physical Financial 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 2 0 27. 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 Financial Physical Financial Physical Financial Physical Financial 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 2 0 26. (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.
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 Notional Mandatory 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 Gross Collateral Net Asset 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 Gross Collateral Net Asset 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 a s 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.

Pension Plans and Other Postr_2

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

Income Taxes (Tables)

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 ( 2,445 ) ( 13.6 ) ( 3,744 ) ( 34.3 ) ( 14,128 ) ( 12.3 ) ( 22,956 ) ( 32.4 ) Tax effect of regulatory treatment of utility ( 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.

Short-Term Borrowings (Tables)

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	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 %

Long-Term Debt to Affiliated _2

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 (Tables)

Fair Value (Tables)	9 Months Ended
	Sep. 30, 2024
Fair Value Disclosures [Abstract]
Schedule of Carrying Value and Estimated Fair Value of Financial Instruments	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 Estimated Carrying Estimated 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	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 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.
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 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 0.53 x to 4.71 x Revenue 2.21 x 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)	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.

Accumulated Other Comprehensi_2

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, December 31, Unfunded benefit obligation for pensions and other postretirement benefit plans - 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 Three months ended September 30, Nine months ended September 30, Details about Accumulated Other Comprehensive Loss Components 2024 2023 2024 2023 Amortization of defined benefit pension and 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.

Earnings Per Common Share (Tabl

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

Commitments and Contingencies (

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 % —

Information by Business Segme_2

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 Alaska Total Utility Other Intersegment 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 - Addi

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

Balance Sheet Components - Sche

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

Balance Sheet Components - Sc_2

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 - Sc_3

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

Balance Sheet Components - Othe

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

Balance Sheet Components - Ot_2

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

Balance Sheet Components - Sc_4

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 - Sc_5

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

Revenue - Schedule of Utilities

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

Revenue - Additional Informatio

Revenue - Additional Information (Details) $ in Millions	Sep. 30, 2024 USD ($)
Revenue from Contract with Customer [Abstract]
Revenue, Remaining Performance Obligation, Amount	$ 3

Revenue - Disaggregation of Rev

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

Derivatives and Risk Manageme_3

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 MWh MMBTU
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

Derivatives and Risk Manageme_4

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

Derivatives and Risk Manageme_5

Derivatives and Risk Management - Summary of Foreign Currency Exchange Derivatives (Details) $ in Thousands, $ in Thousands	Sep. 30, 2024 USD ($) DerivativeContracts	Sep. 30, 2024 CAD ($) DerivativeContracts	Dec. 31, 2023 USD ($) DerivativeContracts	Dec. 31, 2023 CAD ($) 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 Manageme_6

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

Derivatives and Risk Manageme_7

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)

Derivatives and Risk Manageme_8

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

Pension Plans and Other Postr_3

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%
Percentage of service related net periodic benefit costs recorded to operating expenses				60%
Percentage of non-service related net periodic benefit costs capitalized to regulatory assets				40%
Percentage of non-service related net periodic benefit costs recorded to other expense				60%
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

Pension Plans and Other Postr_4

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

Income Taxes - Summary of Signi

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%	21%	21%	21%
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%	(22.90%)

Short-Term Borrowings - Additio

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%
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

Short-Term Borrowings - Schedul

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%

Long-Term Debt - Additional Inf

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

Long-Term Debt to Affiliated _3

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
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%
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
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

Long-Term Debt to Affiliated _4

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%

Fair Value - Schedule of Carryi

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

Fair Value - Additional Informa

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

Fair Value - Schedule of Fair V

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		75	$ 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	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		75	182
Fair Value, Recurring [Member] | Level 2 [Member] | Foreign Exchange Contract [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Gross Asset		7	2
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. Included in other property and investments-net and other non-current assets on the Condensed Consolidated Balance Sheets. The Level 3 energy commodity derivative balances are associated with a natural gas exchange agreement.

Fair Value - Schedule of Quanti

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]

Fair Value - Schedule of Activi

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)	Other Nonoperating Income (Expense)	Other Nonoperating Income (Expense)	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)	Other Nonoperating Income (Expense)	Other Nonoperating Income (Expense)	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.

Common Stock - Additional Infor

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
Proceeds from issuance of common stock	$ 18,100	$ 35,743	$ 88,165

Accumulated Other Comprehensi_3

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

Accumulated Other Comprehensi_4

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

Accumulated Other Comprehensi_5

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)

Earnings Per Common Share - Sch

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

Earnings Per Common Share - Add

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

Commitments and Contingencies -

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 ($) Plaintiff Lawsuit	Dec. 31, 2024 USD ($)	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%
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%
Collective Bargaining Agreements Avista Utilities Bargaining Unit Employees [Member] | IBEW [Member]
Loss Contingencies [Line Items]
Percentage of largest group of employees represented						90%
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%
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%		25%
Colstrip [Member] | NorthWestern [Member] | Unit 4 [Member]
Loss Contingencies [Line Items]
Owners percentage interest						30%				15%

Commitments and Contingencies_2

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%
Avista [Member] | Unit 4 [Member]
Loss Contingencies [Line Items]
Owners percentage interest	15%
PacifiCorp [Member] | Unit 3 [Member]
Loss Contingencies [Line Items]
Owners percentage interest	10%
PacifiCorp [Member] | Unit 4 [Member]
Loss Contingencies [Line Items]
Owners percentage interest	10%
PGE [Member] | Unit 3 [Member]
Loss Contingencies [Line Items]
Owners percentage interest	20%
PGE [Member] | Unit 4 [Member]
Loss Contingencies [Line Items]
Owners percentage interest	20%
PSE [Member] | Unit 3 [Member]
Loss Contingencies [Line Items]
Owners percentage interest	25%
PSE [Member] | Unit 4 [Member]
Loss Contingencies [Line Items]
Owners percentage interest	25%	25%
NorthWestern [Member] | Unit 4 [Member]
Loss Contingencies [Line Items]
Owners percentage interest	30%		15%
Talen [Member] | Unit 3 [Member]
Loss Contingencies [Line Items]
Owners percentage interest	30%

Information by Business Segme_3

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

Information by Business Segme_4

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)