Property, Plant and Equipment	9 Months Ended
	Sep. 30, 2023
Property, Plant and Equipment [Line Items]
Property, Plant and Equipment	PROPERTY, PLANT AND EQUIPMENTIn March 2023 and June 2023, Madison Gas and Electric Company and WEC Energy Group, Inc., respectively, acquired partial ownership interests in West Riverside. The related proceeds are included in “Proceeds from sales of partial ownership interest in West Riverside” in investing activities in Alliant Energy’s and WPL’s cash flows statements for the nine months ended September 30, 2023. As a result of these transactions, WPL’s undivided current ownership interest in West Riverside is 73.8%.
IPL [Member]
Property, Plant and Equipment [Line Items]
Property, Plant and Equipment	PROPERTY, PLANT AND EQUIPMENTIn March 2023 and June 2023, Madison Gas and Electric Company and WEC Energy Group, Inc., respectively, acquired partial ownership interests in West Riverside. The related proceeds are included in “Proceeds from sales of partial ownership interest in West Riverside” in investing activities in Alliant Energy’s and WPL’s cash flows statements for the nine months ended September 30, 2023. As a result of these transactions, WPL’s undivided current ownership interest in West Riverside is 73.8%.
WPL [Member]
Property, Plant and Equipment [Line Items]
Property, Plant and Equipment	PROPERTY, PLANT AND EQUIPMENTIn March 2023 and June 2023, Madison Gas and Electric Company and WEC Energy Group, Inc., respectively, acquired partial ownership interests in West Riverside. The related proceeds are included in “Proceeds from sales of partial ownership interest in West Riverside” in investing activities in Alliant Energy’s and WPL’s cash flows statements for the nine months ended September 30, 2023. As a result of these transactions, WPL’s undivided current ownership interest in West Riverside is 73.8%.