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Common Equity (Tables) | 9 Months Ended
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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.

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