v2.4.0.6

Common Equity (Capital Transactions With Subsidiaries) (Details) (USD $) In Millions, unless otherwise specified | 12 Months Ended
--- | ---
Dec. 31, 2012 | Dec. 31, 2011 | Dec. 31, 2010
Common stock dividends | $ 199.3 | $ 188.1 | $ 174.6
IPL [Member] |  |  |
Common stock dividends | 122.9 | 73.4 | 0
Repayments of capital | 0 | (100.7) | (118.2)
Total distributions from common equity | 122.9 | 174.1 | 118.2
WPL [Member] |  |  |
Common stock dividends | 112.0 | 112.1 | 109.5
Repayments of capital | 0 | 0 | 0
Total distributions from common equity | 112.0 | 112.1 | 109.5
Resources [Member] |  |  |
Common stock dividends | 0 | 0 | 0
Repayments of capital | 0 | 0 | (65.0)
Total distributions from common equity | $ 0 | $ 0 | $ 65.0

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