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Revenue - Disaggregation of Revenue (Details) - USD ($) $ in Thousands | 12 Months Ended
--- | ---
Dec. 31, 2023 | Dec. 31, 2022 | Dec. 31, 2021
Disaggregation of Revenue [Line Items] |  |  |
Alternative revenue programs | $ 4,899 | $ (33,357) | $ (6,635)
Total utility revenues | 1,750,996 | 1,709,519 | 1,438,365
Non-utility revenues | 558 | 688 | 571
Total operating revenues | 1,751,554 | 1,710,207 | 1,438,936
Residential Electric [Member] |  |  |
Disaggregation of Revenue [Line Items] |  |  |
Revenue from contract with customer including assessed tax | 445,490 | 434,490 | 413,657
Commercial and Governmental Electric [Member] |  |  |
Disaggregation of Revenue [Line Items] |  |  |
Revenue from contract with customer including assessed tax | 370,549 | 364,438 | 352,034
Industrial Electric [Member] |  |  |
Disaggregation of Revenue [Line Items] |  |  |
Revenue from contract with customer including assessed tax | 109,689 | 107,740 | 106,756
Public Street and Highway Lighting Electric [Member] |  |  |
Disaggregation of Revenue [Line Items] |  |  |
Revenue from contract with customer including assessed tax | 8,243 | 7,737 | 7,722
Retail Electric [Member] |  |  |
Disaggregation of Revenue [Line Items] |  |  |
Revenue from contract with customer including assessed tax | 933,971 | 914,405 | 880,169
Transmission Electric [Member] |  |  |
Disaggregation of Revenue [Line Items] |  |  |
Revenue from contract with customer including assessed tax | 32,941 | 32,307 | 21,005
Other Electric Revenues from Contracts With Customers [Member] |  |  |
Disaggregation of Revenue [Line Items] |  |  |
Revenue from contract with customer including assessed tax | 45,332 | 49,920 | 33,870
Electric [Member] |  |  |
Disaggregation of Revenue [Line Items] |  |  |
Revenue from contract with customer including assessed tax | 1,012,244 | 996,632 | 935,044
Avista Utilities [Member] |  |  |
Disaggregation of Revenue [Line Items] |  |  |
Revenue from contract with customer including assessed tax | 1,485,510 | 1,400,027 | 1,233,904
Derivative revenues | 199,133 | 286,309 | 152,590
Alternative revenue programs | 4,899 | (33,357) | (6,635)
Deferrals and amortizations for rate refunds to customers | 1,026 | 207 | 2,984
Other utility revenues | 12,289 | 10,629 | 10,156
Total utility revenues | 1,702,857 | 1,663,815 | 1,392,999
Avista Utilities [Member] | Residential Electric [Member] |  |  |
Disaggregation of Revenue [Line Items] |  |  |
Revenue from contract with customer including assessed tax | 425,258 | 414,823 | 394,717
Avista Utilities [Member] | Commercial and Governmental Electric [Member] |  |  |
Disaggregation of Revenue [Line Items] |  |  |
Revenue from contract with customer including assessed tax | 343,523 | 338,656 | 326,173
Avista Utilities [Member] | Industrial Electric [Member] |  |  |
Disaggregation of Revenue [Line Items] |  |  |
Revenue from contract with customer including assessed tax | 109,689 | 107,740 | 106,756
Avista Utilities [Member] | Public Street and Highway Lighting Electric [Member] |  |  |
Disaggregation of Revenue [Line Items] |  |  |
Revenue from contract with customer including assessed tax | 7,976 | 7,483 | 7,472
Avista Utilities [Member] | Retail Electric [Member] |  |  |
Disaggregation of Revenue [Line Items] |  |  |
Revenue from contract with customer including assessed tax | 886,446 | 868,702 | 835,118
Avista Utilities [Member] | Transmission Electric [Member] |  |  |
Disaggregation of Revenue [Line Items] |  |  |
Revenue from contract with customer including assessed tax | 32,941 | 32,307 | 21,005
Avista Utilities [Member] | Other Electric Revenues from Contracts With Customers [Member] |  |  |
Disaggregation of Revenue [Line Items] |  |  |
Revenue from contract with customer including assessed tax | 45,332 | 49,920 | 33,870
Avista Utilities [Member] | Electric [Member] |  |  |
Disaggregation of Revenue [Line Items] |  |  |
Revenue from contract with customer including assessed tax | 964,719 | 950,929 | 889,993
Avista Utilities [Member] | Residential Natural Gas [Member] |  |  |
Disaggregation of Revenue [Line Items] |  |  |
Revenue from contract with customer including assessed tax | 325,631 | 284,452 | 221,405
Avista Utilities [Member] | Commercial Natural Gas [Member] |  |  |
Disaggregation of Revenue [Line Items] |  |  |
Revenue from contract with customer including assessed tax | 164,048 | 139,923 | 100,819
Avista Utilities [Member] | Industrial and Interruptible Natural Gas [Member] |  |  |
Disaggregation of Revenue [Line Items] |  |  |
Revenue from contract with customer including assessed tax | 17,315 | 10,471 | 7,796
Avista Utilities [Member] | Retail Natural Gas [Member] |  |  |
Disaggregation of Revenue [Line Items] |  |  |
Revenue from contract with customer including assessed tax | 506,994 | 434,846 | 330,020
Avista Utilities [Member] | Transportation Natural Gas [Member] |  |  |
Disaggregation of Revenue [Line Items] |  |  |
Revenue from contract with customer including assessed tax | 8,172 | 8,627 | 8,547
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 | 5,625 | 5,625 | 5,344
Avista Utilities [Member] | Natural Gas [Member] |  |  |
Disaggregation of Revenue [Line Items] |  |  |
Revenue from contract with customer including assessed tax | 520,791 | 449,098 | 343,911
Alaska Electric Light & Power [Member] |  |  |
Disaggregation of Revenue [Line Items] |  |  |
Revenue from contracts with customers | 47,525 | 45,703 | 45,051
Deferrals and amortizations for rate refunds to customers |  | (614) | (190)
Other utility revenues | 614 | 615 | 505
Total utility revenues | 48,139 | 45,704 | 45,366
Alaska Electric Light & Power [Member] | Residential Electric [Member] |  |  |
Disaggregation of Revenue [Line Items] |  |  |
Revenue from contracts with customers | 20,232 | 19,667 | 18,940
Alaska Electric Light & Power [Member] | Commercial and Governmental Electric [Member] |  |  |
Disaggregation of Revenue [Line Items] |  |  |
Revenue from contracts with customers | 27,026 | 25,782 | 25,861
Alaska Electric Light & Power [Member] | Public Street and Highway Lighting Electric [Member] |  |  |
Disaggregation of Revenue [Line Items] |  |  |
Revenue from contracts with customers | 267 | 254 | 250
Alaska Electric Light & Power [Member] | Retail Electric [Member] |  |  |
Disaggregation of Revenue [Line Items] |  |  |
Revenue from contracts with customers | 47,525 | 45,703 | 45,051
Alaska Electric Light & Power [Member] | Electric [Member] |  |  |
Disaggregation of Revenue [Line Items] |  |  |
Revenue from contracts with customers | 47,525 | 45,703 | 45,051
Corporate and Other [Member] |  |  |
Disaggregation of Revenue [Line Items] |  |  |
Revenue from contract with customer including assessed tax |  |  | 2
Non-utility revenues | 558 | 688 | 571
Corporate and Other [Member] | Other Revenues |  |  |
Disaggregation of Revenue [Line Items] |  |  |
Non-utility revenues | $ 558 | $ 688 | $ 569

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