Condensed Consolidated Statements of Comprehensive Income (Unaudited) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2017	Mar. 31, 2016
Statement of Comprehensive Income [Abstract]
Net income	$ 108.8	$ 92.6
Other comprehensive income (loss), net of tax:
Foreign currency translation adjustment	33.1	(75.3)
Unrealized holding gain on available-for-sale securities	0.1	0.1
Pension and postretirement liability adjustment	0.7	0.5
Total other comprehensive income (loss)	33.9	(74.7)
Comprehensive income	$ 142.7	$ 17.9