Income Taxes (Details) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2017	Sep. 30, 2016	Sep. 30, 2017	Sep. 30, 2016	Dec. 31, 2016
Effective Income Tax Rate Reconciliation, Percent	17.10%	15.80%	15.40%	17.80%
Foreign Earnings Repatriated	$ 1.3		$ 1.3
Unrecognized Tax Benefits	21.4		21.4		$ 20.8
Unrecognized Tax Benefits that Would Impact Effective Tax Rate	18.7		18.7
Unrecognized Tax Benefits, Income Tax Penalties and Interest Expense			9.6
Minimum [Member]
Significant Change in Unrecognized Tax Benefits is Reasonably Possible, Amount of Unrecorded Benefit	2.1		2.1
Maximum [Member]
Significant Change in Unrecognized Tax Benefits is Reasonably Possible, Amount of Unrecorded Benefit	$ 17.0		$ 17.0