Other Comprehensive Income (Loss) - Changes in AOCI, Net of Tax (Details) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2020	Jun. 30, 2019	Jun. 30, 2020	Jun. 30, 2019
Changes in accumulated other comprehensive income (loss), net of tax
Beginning balance	$ 509.4	$ 508.0	$ 541.1	$ 481.4
Current period other comprehensive loss	4.8	(3.9)	(28.7)	(0.7)
Ending balance	515.2	512.3	515.2	512.3
Defined Benefit Pension and Other Postretirement Plans
Changes in accumulated other comprehensive income (loss), net of tax
Beginning balance			(2.7)	(2.2)
Current period other comprehensive loss			0.1	0.0
Ending balance	(2.6)	(2.2)	(2.6)	(2.2)
Currency Translation Adjustments
Changes in accumulated other comprehensive income (loss), net of tax
Beginning balance			(114.2)	(117.8)
Current period other comprehensive loss			(28.9)	(0.6)
Ending balance	(143.1)	(118.4)	(143.1)	(118.4)
Hedging Activities
Changes in accumulated other comprehensive income (loss), net of tax
Beginning balance			(0.1)	0.0
Current period other comprehensive loss			0.1	(0.1)
Ending balance	0.0	(0.1)	0.0	(0.1)
Total
Changes in accumulated other comprehensive income (loss), net of tax
Beginning balance	(150.5)	(116.8)	(117.0)	(120.0)
Current period other comprehensive loss	4.8	(3.9)	(28.7)	(0.7)
Ending balance	$ (145.7)	$ (120.7)	$ (145.7)	$ (120.7)