Consolidated Statements of Comprehensive Income - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Statement of Comprehensive Income [Abstract]
Net income	$ 408.7	$ 359.0	$ 305.7
Other comprehensive income (loss):
Foreign currency translation adjustments	3.7	(16.9)	33.9
Reclassification of foreign currency translation adjustments into earnings	(2.1)	(27.9)	0.0
Net change in pension and post-retirement benefit liabilities	(7.1)	(14.2)	(5.3)
Change in fair value of available-for-sale marketable equity securities	0.0	(1.8)	(0.5)
Net change in fair value of cash flow hedges	1.3	(13.6)	16.1
Reclassification of pension and post-retirement benefit losses into earnings	5.7	9.3	7.3
non-cash pension settlement loss	99.2	0.4	0.0
Reclassification of cash flow hedge losses into earnings	6.9	(6.1)	(13.7)
Other comprehensive income (loss) before taxes	111.8	(15.0)	37.8
Tax expense	(26.8)	(16.4)	(0.1)
Other comprehensive income (loss), net of tax	85.0	(31.4)	37.7
Comprehensive income	$ 493.7	$ 327.6	$ 343.4