0000052485 2026-08-21 2026-08-21 0000052485 lnt:AlliantEnergyCorpMember 2026-08-21 2026-08-21 0000052485 0000352541 false false 8-K 2026-08-21 ALLIANT ENERGY CORP WI 4902 N. Biltmore Lane Madison WI 53718 608 458-3311 1-9894 39-1380265 INTERSTATE POWER & LIGHT CO IA Alliant Energy Tower Cedar Rapids IA 52401 319 786-4411 1-4117 42-0331370 false false false false Common Stock, $0.01 Par Value LNT NASDAQ false false