v2.4.0.6

Consolidated Balance Sheets (Parenthetical) (USD $) In Millions, except Share data, unless otherwise specified | Dec. 31, 2012 | Dec. 31, 2011
--- | --- | ---
Other, accum depr. | $ 5.6 | $ 5.3
Non-regulated Generation, accum. depr. | 31.0 | 26.4
Alliant Energy Corporate Services, Inc. and other, accum. depr. | 200.2 | 177.4
Common stock, par value | $ 0.01 | $ 0.01
Common stock, shares authorized (in shares) | 240,000,000 | 240,000,000
Common stock, shares outstanding (in shares) | 110,987,400 | 111,018,821
Shares in deferred compensation trust (in shares) | 216,030 | 262,735
Shares in deferred compensation trust, weighted average cost per share (in dollars per share) | $ 33.61 | $ 31.68
IPL [Member] |  |
Other, accum depr. | 4.1 | 4.0
Common stock, par value | $ 2.50 | $ 2.50
Common stock, shares authorized (in shares) | 24,000,000 | 24,000,000
Common stock, shares outstanding (in shares) | 13,370,788 | 13,370,788
WPL [Member] |  |
Leased Sheboygan Falls Energy Facility, accum. depr. | 46.7 | 40.6
Other, accum depr. | $ 1.5 | $ 1.3
Common stock, par value | $ 5 | $ 5
Common stock, shares authorized (in shares) | 18,000,000 | 18,000,000
Common stock, shares outstanding (in shares) | 13,236,601 | 13,236,601

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