Common Equity (Tables)

9 Months Ended

Sep. 30, 2012

Stockholders' Equity Note [Abstract]

Common Share Activity

A summary of Alliant Energy’s common stock activity during the nine months ended September 30, 2012 was as follows:

Shares outstanding, January 1	111,018,821
Equity incentive plans (Note 5(b))	20,195
Other (a)	(51,616	)
Shares outstanding, September 30	110,987,400

(a) Includes shares transferred from employees to Alliant Energy to satisfy tax withholding requirements in connection with the vesting of certain restricted stock under the equity incentive plans.