Common Equity (Tables)

3 Months Ended

Mar. 31, 2015

Stockholders' Equity Note [Abstract]

Common Share Activity

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

Shares outstanding, January 1, 2015	110,935,680
At-the-market offering program	1,996,450
Shareowner Direct Plan	11,193
Equity-based compensation plans (Note 9(b))	56,378
Other	(22,463	)
Shares outstanding, March 31, 2015	112,977,238