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Derivatives, Hedging Programs and Other Financial Instruments - Summary of Derivative Positions (Parenthetical) (Details) - Scenario, Forecast | Dec. 31, 2026 | Dec. 31, 2025 | Dec. 31, 2024 | Dec. 31, 2023 | Dec. 31, 2022 | Dec. 31, 2021 | Dec. 31, 2020
--- | --- | --- | --- | --- | --- | --- | ---
Electricity |  |  |  |  |  |  |
Derivative [Line Items] |  |  |  |  |  |  |
Derivative, Nonmonetary Notional Amount, Percent of Required Need, Coverage |  |  |  |  | 49.00% | 58.00% | 59.00%
Natural Gas |  |  |  |  |  |  |
Derivative [Line Items] |  |  |  |  |  |  |
Derivative, Nonmonetary Notional Amount, Percent of Required Need, Coverage | 25.00% | 25.00% | 85.00% | 93.00% | 95.00% | 91.00% | 83.00%

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- Definition The percentage of expected requirements covered by the aggregate notional amount of derivative contracts expressed in nonmonetary units. For example, the number of barrels specified in a fuel oil forward purchase contract as a percentage of expected need. + References No definition available. + Details
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