v3.25.2
Investments
 6 Months Ended
Jun. 30, 2025
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 and six months ended June 30 was as follows (in millions):
Three MonthsSix Months
2025202420252024
ATC Holdings($14)($13)($28)($25)
Non-utility wind farm in Oklahoma(3)(2)(4)(3)
Corporate venture investments7—11(1)
Other——(2)(2)
($10)($15)($23)($31)