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Commitments and Contingencies - Narrative (Details) $ in Thousands | 12 Months Ended | 24 Months Ended |
--- | --- | --- | ---
Dec. 31, 2024 USD ($) agreement | Dec. 31, 2023 USD ($) | Dec. 31, 2022 USD ($) | Dec. 31, 2026 USD ($) | Jun. 30, 2024 regionalTransmissionOrganization
Other Commitments [Line Items] |  |  |  |  |
Capacity and energy requirement costs | $ 6,000 | $ 5,600 | $ 13,100 |  |
Coal purchase commitment, number of agreements | agreement | 2 |  |  |  |
Coal purchase commitment costs | $ 44,700 | 43,700 | 45,100 |  |
Land easement non-lease payments expense | 1,800 | 1,800 | 1,400 |  |
Payments to acquire productive assets | 358,650 | 287,134 | 171,134 |  |
Pre-tax benefit | 366,892 | $ 363,489 | $ 357,535 |  |
Number of regional transmission organizations with show cause proceedings | regionalTransmissionOrganization |  |  |  |  | 4
Solar | Forecast |  |  |  |  |
Other Commitments [Line Items] |  |  |  |  |
Payments to acquire productive assets |  |  |  | $ 23,600 |
Commitments, termination fee |  |  |  | $ 5,000 |
OTP | Federal Energy Regulatory Commission |  |  |  |  |
Other Commitments [Line Items] |  |  |  |  |
Pre-tax benefit | 2,500 |  |  |  |
Estimated liability of refund obligation | $ 500 |  |  |  |
OTP | OTP Land Easements |  |  |  |  |
Other Commitments [Line Items] |  |  |  |  |
Long-term purchase commitment, period | 99 years |  |  |  |
Long-term purchase commitment, amount | $ 62,000 |  |  |  |
OTP | Other Commitments |  |  |  |  |
Other Commitments [Line Items] |  |  |  |  |
Long-term purchase commitment, amount | $ 10,600 |  |  |  |

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