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Benefit Plans (Recognized Compensation Expense And Income Tax Benefits) (Details) - USD ($) $ in Millions | 3 Months Ended | 9 Months Ended
--- | --- | ---
Sep. 30, 2019 | Sep. 30, 2018 | Sep. 30, 2019 | Sep. 30, 2018
Compensation expense | $ 7.5 | $ 4.2 | $ 15.6 | $ 12.6
Income tax benefits | 2.1 | 1.2 | 4.4 | 3.6
IPL [Member] |  |  |  |
Compensation expense | 4.2 | 2.4 | 8.7 | 7.0
Income tax benefits | 1.2 | 0.7 | 2.5 | 2.1
WPL [Member] |  |  |  |
Compensation expense | 3.0 | 1.7 | 6.2 | 5.1
Income tax benefits | $ 0.8 | $ 0.5 | $ 1.7 | $ 1.4

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