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v3.24.3

Commitments and Contingencies (Details) $ in Thousands | 1 Months Ended | 3 Months Ended | 6 Months Ended | 9 Months Ended
--- | --- | --- | --- | ---
Mar. 31, 2024 plan | Sep. 30, 2024 USD ($) | Sep. 30, 2023 USD ($) | Dec. 31, 2025 USD ($) | Sep. 30, 2024 USD ($) | Sep. 30, 2023 USD ($)
Other Commitments [Line Items] |  |  |  |  |  |
Payments to acquire productive assets |  |  |  |  | $ 259,750 | $ 229,849
Pre-tax benefit |  | $ 104,156 | $ 116,701 |  | 303,889 | $ 294,517
Federal Energy Regulatory Commission | Otter Tail Power Company |  |  |  |  |  |
Other Commitments [Line Items] |  |  |  |  |  |
Estimated liability of refund obligation |  | 500 |  |  | 500 |
Pre-tax benefit |  | $ 2,500 |  |  | $ 2,500 |
Environmental Protection Agency | Otter Tail Power Company |  |  |  |  |  |
Other Commitments [Line Items] |  |  |  |  |  |
Number of outstanding state implementation plans, timeline provided by regulatory agency | plan | 34 |  |  |  |  |
Forecast | Solar |  |  |  |  |  |
Other Commitments [Line Items] |  |  |  |  |  |
Payments to acquire productive assets |  |  |  | $ 23,600 |  |
Commitments, termination fee |  |  |  | $ 5,000 |  |

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