XML 74 R37.htm IDEA: XBRL DOCUMENT
v3.25.0.1

Summary of Significant Accounting Policies (Tables) | 12 Months Ended
--- | ---
Dec. 31, 2024
Accounting Policies [Abstract] |
Summary of Ratio of Depreciation to Average Depreciable Property and Average Service Lives for Utility Plan in Service | For utility operations, the ratio of depreciation provisions to average depreciable property was as follows for the years ended December 31:
|  | 2024 |  |  | 2023 |  |  | 2022 |
Avista Utilities |  |  | 3.45 | % |  |  | 3.52 | % |  |  | 3.50 | %
Alaska Electric Light and Power Company |  |  | 2.80 | % |  |  | 2.78 | % |  |  | 2.78 | %
The average service lives for the following broad categories of utility plant in service are (in years):
|  | Avista Utilities |  |  | Alaska Electric Light and Power Company |
Electric thermal/other production |  |  | 27 |  |  |  | 41 |
Hydroelectric production |  |  | 81 |  |  |  | 42 |
Electric transmission |  |  | 44 |  |  |  | 43 |
Electric distribution |  |  | 42 |  |  |  | 39 |
Natural gas distribution property |  |  | 44 |  |  | N/A |
Other shorter-lived general plant |  |  | 8 |  |  |  | 18 |
The gross balances of the major classifications of property, plant and equipment are detailed in the following table as of December 31 (dollars in millions):
|  | 2024 |  |  | 2023 |
Avista Utilities: |  |  |  |  |  |
Electric production |  | $ | 1,523 |  |  | $ | 1,498 |
Electric transmission |  |  | 1,105 |  |  |  | 1,059 |
Electric distribution |  |  | 2,580 |  |  |  | 2,383 |
Electric construction work-in-progress (CWIP) and other |  |  | 452 |  |  |  | 395 |
Electric total |  |  | 5,660 |  |  |  | 5,335 |
Natural gas underground storage |  |  | 63 |  |  |  | 60 |
Natural gas distribution |  |  | 1,624 |  |  |  | 1,539 |
Natural gas CWIP and other |  |  | 95 |  |  |  | 92 |
Natural gas total |  |  | 1,782 |  |  |  | 1,691 |
Common plant (including CWIP) |  |  | 760 |  |  |  | 760 |
Total Avista Utilities |  |  | 8,202 |  |  |  | 7,786 |
AEL&P: |  |  |  |  |  |
Electric production |  |  | 120 |  |  |  | 119 |
Electric transmission |  |  | 23 |  |  |  | 23 |
Electric distribution |  |  | 36 |  |  |  | 32 |
Electric CWIP and other |  |  | 26 |  |  |  | 9 |
Electric total |  |  | 205 |  |  |  | 183 |
Common plant |  |  | 11 |  |  |  | 10 |
Total AEL&P |  |  | 216 |  |  |  | 193 |
Total gross utility property |  |  | 8,418 |  |  |  | 7,979 |
Other (1) |  |  | 6 |  |  |  | 6 |
Total |  | $ | 8,424 |  |  | $ | 7,985 |
(1) Included in other property and investments-net and other non-current assets on the Consolidated Balance Sheets.
Summary of Effective AFUDC Rate | The effective AFUDC rate was the following for the years ended December 31:
|  | 2024 |  |  | 2023 |  |  | 2022 |
Avista Utilities |  |  | 7.03 | % |  |  | 7.03 | % |  |  | 7.12 | %
Alaska Electric Light and Power Company |  |  | 8.47 | % |  |  | 8.61 | % |  |  | 8.08 | %
Stock-Based Compensation | The Company recorded stock-based compensation expense (included in other operating expenses) and income tax benefits in the Consolidated Statements of Income of the following amounts for the years ended December 31 (dollars in millions):
|  | 2024 |  |  | 2023 |  |  | 2022 |
Stock-based compensation expense |  | $ | 8 |  |  | $ | 7 |  |  | $ | 8 |
Income tax benefits |  |  | 2 |  |  |  | 2 |  |  |  | 2 |
The following table summarizes the number of grants, vested and unvested shares, earned shares (based on market metrics), and other pertinent information related to the Company's stock compensation awards for the years ended December 31:
|  | 2024 |  |  | 2023 |  |  | 2022 |
Restricted Shares |  |  |  |  |  |  |  |  |
Shares granted during the year |  |  | 82,433 |  |  |  | 76,806 |  |  |  | 115,746 |
Shares vested during the year |  |  | 75,107 |  |  |  | 75,007 |  |  |  | 44,829 |
Unvested shares at end of year |  |  | 158,464 |  |  |  | 152,140 |  |  |  | 157,860 |
Unrecognized compensation expense at end of year (in millions) |  | $ | 3 |  |  | $ | 3 |  |  | $ | 4 |
TSR Awards |  |  |  |  |  |  |  |  |
TSR shares granted during the year |  |  | 45,739 |  |  |  | 34,912 |  |  |  | 69,814 |
TSR shares vested during the year |  |  | 64,640 |  |  |  | 61,456 |  |  |  | 43,730 |
TSR shares earned based on market metrics |  |  | 35,552 |  |  |  | 44,863 |  |  |  | 48,890 |
Unvested TSR shares at end of year |  |  | 77,530 |  |  |  | 96,915 |  |  |  | 130,567 |
Unrecognized compensation expense at end of year (in millions) |  | $ | 2 |  |  | $ | 2 |  |  | $ | 4 |
CEPS Awards |  |  |  |  |  |  |  |  |
CEPS shares granted during the year |  |  | 137,161 |  |  |  | 104,685 |  |  |  | 69,814 |
CEPS shares vested during the year |  |  | 64,640 |  |  |  | 61,456 |  |  |  | 43,730 |
CEPS shares earned based on performance metrics |  |  | 29,088 |  |  |  | 33,801 |  |  |  | — |
Unvested CEPS shares at end of year |  |  | 232,486 |  |  |  | 161,235 |  |  |  | 130,567 |
Unrecognized compensation expense at end of year (in millions) |  | $ | 3 |  |  | $ | 2 |  |  | $ | 2 |
Other Expense (Income) - Net | Other income - net consisted of the following items for the years ended December 31 (dollars in millions):
|  | 2024 |  |  | 2023 |  |  | 2022 |
Interest income |  | $ | 5 |  |  | $ | 6 |  |  | $ | 2 |
Interest on regulatory deferrals |  |  | 9 |  |  |  | 9 |  |  |  | 2 |
Equity-related AFUDC |  |  | 9 |  |  |  | 7 |  |  |  | 7 |
Non-service portion of pension and other postretirement benefit expenses |  |  | 2 |  |  |  | — |  |  |  | 3 |
Earnings (losses) on investments |  |  | (7 | ) |  |  | (3 | ) |  |  | 48 |
Other income |  |  | 4 |  |  |  | — |  |  |  | 1 |
Total |  | $ | 22 |  |  | $ | 19 |  |  | $ | 63 |
Allowance for Doubtful Accounts | The following table presents the activity in the allowance for doubtful accounts during the years ended December 31 (dollars in millions):
|  | 2024 |  |  | 2023 |  |  | 2022 |
Allowance as of the beginning of the year |  | $ | 5 |  |  | $ | 6 |  |  | $ | 10 |
Additions expensed during the year |  |  | 7 |  |  |  | 7 |  |  |  | — |
Net deductions |  |  | (7 | ) |  |  | (8 | ) |  |  | (4 | )
Allowance as of the end of the year |  | $ | 5 |  |  | $ | 5 |  |  | $ | 6 |
The Company has received grants from various government agencies to assist customers with their energy bills. The Company received these grant funds and applied them to customer accounts, reducing accounts receivable balances. These grants totaled $10 million in 2024, $2 million in 2023 and $6 million in 2022.
Estimated Retirement Costs Collected from Customers | The Company records the amount of estimated retirement costs collected from customers (that do not represent legal or contractual obligations) and includes them as a non-current regulatory liability on the Consolidated Balance Sheets in the following amounts as of December 31 (dollars in millions):
|  | 2024 |  |  | 2023 |
Regulatory liability for utility plant retirement costs |  | $ | 448 |  |  | $ | 417 |
Summary of Appropriated Retained Earnings Amount Included in Retained Earnings | The appropriated retained earnings amounts included in retained earnings were as follows as of December 31 (dollars in millions):
|  | 2024 |  |  | 2023 |
Appropriated retained earnings |  | $ | 62 |  |  | $ | 59 |

X
- Definition Appropriated Retained Earnings [Table Text Block] + References No definition available. + Details
Name: | ava_AppropriatedRetainedEarningsTableTextBlock
Namespace Prefix: | ava_
Data Type: | dtr-types:textBlockItemType
Balance Type: | na
Period Type: | duration

X
- Definition Effective Rate On Allowance For Funds Used During Construction [Table Text Block] + References No definition available. + Details
Name: | ava_EffectiveRateOnAllowanceForFundsUsedDuringConstructionTableTextBlock
Namespace Prefix: | ava_
Data Type: | dtr-types:textBlockItemType
Balance Type: | na
Period Type: | duration

X
- Definition Estimated retirement costs collected from customers + References No definition available. + Details
Name: | ava_EstimatedRetirementCostsCollectedFromCustomersTableTextBlock
Namespace Prefix: | ava_
Data Type: | dtr-types:textBlockItemType
Balance Type: | na
Period Type: | duration

X
- References No definition available. + Details
Name: | us-gaap_AccountingPoliciesAbstract
Namespace Prefix: | us-gaap_
Data Type: | xbrli:stringItemType
Balance Type: | na
Period Type: | duration

X
- Definition Tabular disclosure of allowance for credit loss on financing receivable. + References Reference 1: http://fasb.org/us-gaap/role/ref/otherTransitionRef -Topic 310 -SubTopic 10 -Name Accounting Standards Codification -Section 50 -Paragraph 11B -Publisher FASB -URI https://asc.fasb.org/1943274/2147481962/310-10-50-11B Reference 2: http://www.xbrl.org/2009/role/commonPracticeRef -Topic 326 -SubTopic 20 -Name Accounting Standards Codification -Section 50 -Paragraph 13 -Publisher FASB -URI https://asc.fasb.org/1943274/2147479319/326-20-50-13 + Details
Name: | us-gaap_AllowanceForCreditLossesOnFinancingReceivablesTableTextBlock
Namespace Prefix: | us-gaap_
Data Type: | dtr-types:textBlockItemType
Balance Type: | na
Period Type: | duration

X
- Definition Tabular disclosure of the components of non-operating income or non-operating expense that may include amounts earned from dividends, interest on securities, gains (losses) on securities sold, equity earnings of unconsolidated affiliates, net gain (loss) on sales of business, interest expense and other miscellaneous income or expense items. + References No definition available. + Details
Name: | us-gaap_ScheduleOfOtherNonoperatingIncomeExpenseTableTextBlock
Namespace Prefix: | us-gaap_
Data Type: | dtr-types:textBlockItemType
Balance Type: | na
Period Type: | duration

X
- Definition Tabular disclosure of public utility physical assets used in the normal conduct of business and not intended for resale. Includes, but is not limited to, balances by class of assets, depreciation expense and method used, including composite depreciation, and accumulated depreciation. + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Name Accounting Standards Codification -Topic 980 -SubTopic 20 -Section 45 -Paragraph 1 -Publisher FASB -URI https://asc.fasb.org/1943274/2147481834/980-20-45-1 + Details
Name: | us-gaap_ScheduleOfPublicUtilityPropertyPlantAndEquipmentTextBlock
Namespace Prefix: | us-gaap_
Data Type: | dtr-types:textBlockItemType
Balance Type: | na
Period Type: | duration

X
- Definition Tabular disclosure of activity for award under share-based payment arrangement. Includes, but is not limited to, outstanding award at beginning and end of year, granted, exercised, forfeited, and weighted-average grant date fair value. + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Topic 718 -SubTopic 10 -Name Accounting Standards Codification -Section 50 -Paragraph 2 -Subparagraph (c)(2) -Publisher FASB -URI https://asc.fasb.org/1943274/2147480429/718-10-50-2 Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef -Name Accounting Standards Codification -Section 50 -Paragraph 2 -Subparagraph (d) -SubTopic 10 -Topic 718 -Publisher FASB -URI https://asc.fasb.org/1943274/2147480429/718-10-50-2 Reference 3: http://fasb.org/us-gaap/role/ref/legacyRef -Name Accounting Standards Codification -Section 50 -Paragraph 2 -Subparagraph (e) -SubTopic 10 -Topic 718 -Publisher FASB -URI https://asc.fasb.org/1943274/2147480429/718-10-50-2 + Details
Name: | us-gaap_ScheduleOfShareBasedCompensationActivityTableTextBlock
Namespace Prefix: | us-gaap_
Data Type: | dtr-types:textBlockItemType
Balance Type: | na
Period Type: | duration