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Property, Plant, and Equipment (Narrative) (Details) - USD ($) $ in Millions | 3 Months Ended | 9 Months Ended
--- | --- | ---
Sep. 30, 2021 | Sep. 30, 2020 | Sep. 30, 2021 | Sep. 30, 2020
Property, Plant and Equipment [Line Items] |  |  |  |
Charges associated with Schahfer Generating Station Retirement | $ 3.6 | $ 0.0 | $ 12.2 | $ 4.6
Plant and Equipment associated with Schahfer Generating Station Retirement | $ 831.8 |  | $ 831.8 |

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- Definition Charges associated with Schahfer Generating Station Retirement + References No definition available. + Details
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- Definition Plant and Equipment Associated with Schahfer Generating Station Retirement + References No definition available. + Details
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- Definition Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table. + References No definition available. + Details
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