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	$ 305.7	$ 277.8	$ 186.6
Other comprehensive income (loss):
Foreign currency translation adjustments	33.9	(11.6)	(58.7)
Net change in pension and post-retirement benefit liabilities	(5.3)	10.4	5.7
Change in fair value of available-for-sale marketable equity securities	(0.5)	(2.1)	1.2
Net change in fair value of cash flow hedges	16.1	9.8	(18.4)
Reclassification of pension and post-retirement benefit losses into earnings	7.3	6.3	9.7
Reclassification of cash flow hedge losses into earnings	(13.7)	12.3	12.5
Other comprehensive income (loss) before taxes	37.8	25.1	(48.0)
Tax expense	(0.1)	(15.5)	(3.2)
Other comprehensive income (loss), net of tax	37.7	9.6	(51.2)
Comprehensive income	$ 343.4	$ 287.4	$ 135.4