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Common Equity (Tables) | 3 Months Ended
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Mar. 31, 2013
Stockholders' Equity Note [Abstract] |
Common Share Activity | A summary of Alliant Energy’s common stock activity during the three months ended March 31, 2013 was as follows:
Shares outstanding, January 1 | 110,987,400 |
Equity-based compensation plans (Note 5(b)) | (45,028 | )
Other (a) | (20,357 | )
Shares outstanding, March 31 | 110,922,015 |
(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-based compensation plans.

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