Consolidated Statements of Comprehensive Income - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Statement of Comprehensive Income [Abstract]
Net income	$ 2,748.8	$ 527.8	$ 350.0
Other comprehensive income (loss), net of tax:
Foreign currency translation adjustments	289.1	(196.2)	(123.9)
Unrecognized pension and postretirement costs	14.5	22.3	89.4
Derivative financial instruments	(21.9)	(37.1)	(4.9)
Total other comprehensive income (loss), net of tax	281.7	(211.0)	(39.4)
Comprehensive income	$ 3,030.5	$ 316.8	$ 310.6