Property, Plant and Equipment	3 Months Ended
	Mar. 31, 2023
Property, Plant and Equipment [Line Items]
Property, Plant and Equipment	PROPERTY, PLANT AND EQUIPMENTIn March 2023, Madison Gas and Electric Company acquired a partial ownership interest in West Riverside, and the related proceeds are included in “Proceeds from sale of partial ownership interest in West Riverside” in investing activities in Alliant Energy’s and WPL’s cash flow statements for the three months ended March 31, 2023. As a result of this transaction, WPL’s undivided current ownership interest in West Riverside is 87.6%.
IPL [Member]
Property, Plant and Equipment [Line Items]
Property, Plant and Equipment	PROPERTY, PLANT AND EQUIPMENTIn March 2023, Madison Gas and Electric Company acquired a partial ownership interest in West Riverside, and the related proceeds are included in “Proceeds from sale of partial ownership interest in West Riverside” in investing activities in Alliant Energy’s and WPL’s cash flow statements for the three months ended March 31, 2023. As a result of this transaction, WPL’s undivided current ownership interest in West Riverside is 87.6%.
WPL [Member]
Property, Plant and Equipment [Line Items]
Property, Plant and Equipment	PROPERTY, PLANT AND EQUIPMENTIn March 2023, Madison Gas and Electric Company acquired a partial ownership interest in West Riverside, and the related proceeds are included in “Proceeds from sale of partial ownership interest in West Riverside” in investing activities in Alliant Energy’s and WPL’s cash flow statements for the three months ended March 31, 2023. As a result of this transaction, WPL’s undivided current ownership interest in West Riverside is 87.6%.