Other Comprehensive Loss - Changes in AOCI, Net of Tax (Details) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2019	Sep. 30, 2018	Sep. 30, 2019	Sep. 30, 2018
Changes in accumulated other comprehensive income (loss), net of tax
Beginning balance	$ 512.3	$ 448.6	$ 481.4	$ 492.0
Total other comprehensive loss	(14.8)	(8.9)	(15.5)	(27.6)
Ending balance	516.1	464.7	516.1	464.7
Defined Benefit Pension and Other Postretirement Plans
Changes in accumulated other comprehensive income (loss), net of tax
Beginning balance			(2.2)	0.4
Other comprehensive (loss) income before reclassifications			0.0	(0.4)
Amounts reclassified from accumulated other comprehensive (loss) income			0.0	0.0
Total other comprehensive loss		0.2	0.0	(0.4)
Ending balance	(2.2)	0.0	(2.2)	0.0
Currency Translation Adjustments
Changes in accumulated other comprehensive income (loss), net of tax
Beginning balance			(117.8)	(86.0)
Other comprehensive (loss) income before reclassifications			(15.5)	(27.3)
Amounts reclassified from accumulated other comprehensive (loss) income			0.0	0.0
Total other comprehensive loss			(15.5)	(27.3)
Ending balance	(133.3)	(113.3)	(133.3)	(113.3)
Hedging Activities
Changes in accumulated other comprehensive income (loss), net of tax
Beginning balance			0.0	(0.1)
Other comprehensive (loss) income before reclassifications			(0.1)	0.2
Amounts reclassified from accumulated other comprehensive (loss) income			0.1	(0.1)
Total other comprehensive loss			0.0	0.1
Ending balance	0.0	0.0	0.0	0.0
Total
Changes in accumulated other comprehensive income (loss), net of tax
Beginning balance	(120.7)	(104.4)	(120.0)	(85.7)
Other comprehensive (loss) income before reclassifications			(15.6)	(27.5)
Amounts reclassified from accumulated other comprehensive (loss) income			0.1	(0.1)
Total other comprehensive loss	(14.8)	(8.9)	(15.5)	(27.6)
Ending balance	$ (135.5)	$ (113.3)	$ (135.5)	$ (113.3)