XML 30 R10.htm IDEA: XBRL DOCUMENT v3.24.1.u1
Investments
 3 Months Ended
Mar. 31, 2024
Schedule of Equity Method Investments [Line Items]  
Investments INVESTMENTS
Unconsolidated Equity Investments - Alliant Energy’s equity (income) loss from unconsolidated investments accounted for under the equity method of accounting for the three months ended March 31 was as follows (in millions):
20242023
ATC Holdings($12)($13)
Other(3)(4)
($15)($17)