Income Taxes (Textuals) (Details) - USD ($) $ in Millions	3 Months Ended	6 Months Ended
Jun. 30, 2018	Jun. 30, 2017	Jun. 30, 2018	Jun. 30, 2017	Dec. 31, 2017
Income Taxes (Textual) [Abstract]
Income tax provision	$ 35.0	$ 21.0	$ 51.0	$ 35.0
Effective tax rate	23.20%	16.80%	20.80%	18.10%
Unrecognized tax benefits	$ 126.0		$ 126.0		$ 130.0
Interest accrued for unrecognized tax benefits	$ 5.0		$ 5.0

Percentage of current income tax expense (benefit) and deferred income tax expense (benefit) pertaining to continuing operations.

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Amount of current income tax expense (benefit) and deferred income tax expense (benefit) pertaining to continuing operations.

+ References

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Amount of interest expense accrued for an underpayment of income taxes.

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The total amount of unrecognized tax benefits that, if recognized, would affect the effective tax rate.

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Income taxes.

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