Income Taxes (Details) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2016	Mar. 31, 2015	Dec. 31, 2015
Effective Income Tax Rate Reconciliation, Percent	18.50%	17.10%
Liability for unrecognized tax benefits	$ 32.2		$ 31.6
Unrecognized tax benefits that would affect income tax expense	29.2
Interest and penalties share in unrecognized tax benefits	10.1
Minimum [Member]
Expected change in unrecognized tax benefits, lower	3.0
Maximum [Member]
Expected change in unrecognized tax benefits, lower	$ 24.0