Common Equity (Tables)

12 Months Ended

Dec. 31, 2020

Schedule of Common Equity [Line Items]

Common Stock Activity

A summary of Alliant Energy’s common stock activity was as follows:

	2020	2019	2018
Shares outstanding, January 1	245,022,800	236,063,279	231,348,646
Equity forward agreements	4,275,127	8,358,973	—
At-the-market offering programs	—	—	4,171,013
Shareowner Direct Plan	472,283	501,808	576,965
Equity-based compensation plans	98,205	101,478	5,078
Other	—	(2,738)	(38,423)
Shares outstanding, December 31	249,868,415	245,022,800	236,063,279