Common Equity (Tables)

12 Months Ended

Dec. 31, 2016

Schedule of Common Equity [Line Items]

Common Stock Activity

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

	2016	2015		2014
Shares outstanding, January 1	226,918,432	221,871,360		221,887,338
At-the-market offering program	—	4,373,234		—
Shareowner Direct Plan issuances	732,814	606,010		—
Equity-based compensation plans (Note 12(b))	22,408	112,756		71,094
Other	—	(44,928	)	(87,072	)
Shares outstanding, December 31	227,673,654	226,918,432		221,871,360