Derivative Instruments (Notional Amounts Of Derivative Instruments) (Details) - Commodity Contracts [Member] gal in Thousands	6 Months Ended
	Jun. 30, 2025 Dekatherms MWh gal
Electricity (MWhs) [Member]
Notional Amount of Derivatives [Line Items]
Notional unit amount of derivatives (in MWhs)	1,911
Electricity (MWhs) [Member] \| IPL [Member]
Notional Amount of Derivatives [Line Items]
Notional unit amount of derivatives (in MWhs)	523
Electricity (MWhs) [Member] \| WPL [Member]
Notional Amount of Derivatives [Line Items]
Notional unit amount of derivatives (in MWhs)	1,388
FTRs (MWhs) [Member]
Notional Amount of Derivatives [Line Items]
Notional unit amount of derivatives (in MWhs)	24,310
FTRs (MWhs) [Member] \| IPL [Member]
Notional Amount of Derivatives [Line Items]
Notional unit amount of derivatives (in MWhs)	9,555
FTRs (MWhs) [Member] \| WPL [Member]
Notional Amount of Derivatives [Line Items]
Notional unit amount of derivatives (in MWhs)	14,755
Natural Gas (Dths) [Member]
Notional Amount of Derivatives [Line Items]
Notional unit amount of derivatives (in Dths) \| Dekatherms	153,204
Natural Gas (Dths) [Member] \| IPL [Member]
Notional Amount of Derivatives [Line Items]
Notional unit amount of derivatives (in Dths) \| Dekatherms	66,568
Natural Gas (Dths) [Member] \| WPL [Member]
Notional Amount of Derivatives [Line Items]
Notional unit amount of derivatives (in Dths) \| Dekatherms	86,636
Diesel Fuel (Gallons) [Member]
Notional Amount of Derivatives [Line Items]
Notional unit amount of derivatives (in Gallons) \| gal	1,260
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	1,260