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	$ 241.7	$ 206.9	$ 150.7
Other comprehensive income (loss), net of tax:
Foreign currency translation adjustments	4.9	(39.2)	68.8
Prior service cost arising during period, net of tax of $0	0.0	(0.3)	0.0
Net actuarial (loss) gain arising during period, net of tax of $(0.3), $(0.2) and $1.3	(1.9)	(0.7)	6.3
Settlement effects arising during period, net of tax of $0.8	2.7	0.0	0.0
Less: amortization of actuarial (gain) loss, net of tax of $0, $0.3 and $0.5	(0.2)	1.1	3.6
Less: amortization of prior service credit, net of tax of $(0.1), $(0.5) and $(0.5)	(0.5)	(1.5)	(3.5)
Net loss on investment securities, net of tax of $0, $(0.1) and $(2.5)	0.0	(0.1)	(4.7)
Net (loss) gain on derivatives, net of tax of $(0.2), $1.5 and $(0.1)	(0.4)	3.8	(1.0)
Other comprehensive income (loss), net of tax	4.6	(36.9)	69.5
Comprehensive income	$ 246.3	$ 170.0	$ 220.2