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Common Equity (Capital Transactions With Subsidiaries) (Details) - USD ($) $ in Millions | 12 Months Ended
--- | ---
Dec. 31, 2015 | Dec. 31, 2014 | Dec. 31, 2013
Common stock dividends | $ 247.3 | $ 225.8 | $ 208.3
IPL [Member] |  |  |
Common stock dividends | 140.0 | 140.0 | 128.1
Repayments of capital | 0.0 | 0.0 | 0.0
Total distributions from common equity | 140.0 | 140.0 | 128.1
WPL [Member] |  |  |
Common stock dividends | 126.9 | 118.7 | 116.3
Repayments of capital | 0.0 | 0.0 | 0.0
Total distributions from common equity | 126.9 | 118.7 | 116.3
Resources [Member] |  |  |
Common stock dividends | 0.0 | 0.0 | 0.0
Repayments of capital | 0.0 | 50.0 | 95.0
Total distributions from common equity | $ 0.0 | $ 50.0 | $ 95.0

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