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Derivative Instruments (Notional Amounts Of Derivative Instruments) (Details) - Commodity Contracts [Member] gal in Thousands | 9 Months Ended
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Sep. 30, 2025 Dekatherms MWh gal
Electricity (MWhs) [Member] |
Notional Amount of Derivatives [Line Items] |
Notional unit amount of derivatives (in MWhs) | 1,689
Electricity (MWhs) [Member] | IPL [Member] |
Notional Amount of Derivatives [Line Items] |
Notional unit amount of derivatives (in MWhs) | 563
Electricity (MWhs) [Member] | WPL [Member] |
Notional Amount of Derivatives [Line Items] |
Notional unit amount of derivatives (in MWhs) | 1,126
FTRs (MWhs) [Member] |
Notional Amount of Derivatives [Line Items] |
Notional unit amount of derivatives (in MWhs) | 17,992
FTRs (MWhs) [Member] | IPL [Member] |
Notional Amount of Derivatives [Line Items] |
Notional unit amount of derivatives (in MWhs) | 7,143
FTRs (MWhs) [Member] | WPL [Member] |
Notional Amount of Derivatives [Line Items] |
Notional unit amount of derivatives (in MWhs) | 10,849
Natural Gas (Dths) [Member] |
Notional Amount of Derivatives [Line Items] |
Notional unit amount of derivatives (in Dths) | Dekatherms | 136,910
Natural Gas (Dths) [Member] | IPL [Member] |
Notional Amount of Derivatives [Line Items] |
Notional unit amount of derivatives (in Dths) | Dekatherms | 56,355
Natural Gas (Dths) [Member] | WPL [Member] |
Notional Amount of Derivatives [Line Items] |
Notional unit amount of derivatives (in Dths) | Dekatherms | 80,555
Diesel Fuel (Gallons) [Member] |
Notional Amount of Derivatives [Line Items] |
Notional unit amount of derivatives (in Gallons) | gal | 630
Diesel Fuel (Gallons) [Member] | IPL [Member] |
Notional Amount of Derivatives [Line Items] |
Notional unit amount of derivatives (in Gallons) | gal | 0
Diesel Fuel (Gallons) [Member] | WPL [Member] |
Notional Amount of Derivatives [Line Items] |
Notional unit amount of derivatives (in Gallons) | gal | 630

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