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Benefit Plans (Recognized Compensation Expense And Income Tax Benefits) (Details) - USD ($) $ in Millions | 12 Months Ended
--- | ---
Dec. 31, 2019 | Dec. 31, 2018 | Dec. 31, 2017
Compensation expense | $ 26.0 | $ 17.0 | $ 15.1
Income tax benefits | 7.3 | 4.9 | 6.2
IPL [Member] |  |  |
Compensation expense | 14.5 | 9.4 | 8.3
Income tax benefits | 4.2 | 2.8 | 3.4
WPL [Member] |  |  |
Compensation expense | 10.3 | 6.9 | 6.4
Income tax benefits | $ 2.8 | $ 1.9 | $ 2.6

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