Other Comprehensive Loss - AOCI (Details) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2021	Sep. 30, 2020	Sep. 30, 2021	Sep. 30, 2020
Reclassification Adjustment out of Accumulated Other Comprehensive Income on Derivatives [Line Items]
Amortization or settlement of actuarial losses and prior service costs	$ 0.2	$ 0.2	$ 0.6	$ 0.5
Other Comprehensive (Income) Loss, Defined Benefit Plan, Reclassification Adjustment from AOCI, Tax	0.1	(0.1)	(0.1)	0.0
Other Comprehensive (Income) Loss, Defined Benefit Plan, Reclassification Adjustment from AOCI, after Tax	0.1	0.3	0.7	0.5
Other Comprehensive Income (Loss), Cash Flow Hedge, Gain (Loss), Reclassification, before Tax	0.0	(0.6)	(1.9)	(0.2)
Other Comprehensive Income (Loss), Cash Flow Hedge, Gain (Loss), Reclassification, Tax	0.1	0.1	0.5	0.1
Net losses (gains) reclassified into earnings	0.1	(0.5)	(1.4)	(0.1)
Accumulated Other Comprehensive Income (Loss), Net of Tax [Abstract]
Beginning balance			(100.5)	(112.0)
Other comprehensive (loss) earnings, net of tax	(3.7)	10.4	(7.6)	6.0
Ending balance	(108.1)	(106.0)	(108.1)	(106.0)
Accumulated Net Gain (Loss) from Cash Flow Hedges Attributable to Parent
Accumulated Other Comprehensive Income (Loss), Net of Tax [Abstract]
Beginning balance			1.6	0.5
Other comprehensive (loss) earnings, net of tax			(1.9)	0.4
Ending balance	(0.3)	0.9	(0.3)	0.9
Employee benefit plans
Accumulated Other Comprehensive Income (Loss), Net of Tax [Abstract]
Beginning balance			(22.1)	(18.7)
Other comprehensive (loss) earnings, net of tax			0.7	0.5
Ending balance	(21.4)	(18.2)	(21.4)	(18.2)
Cumulative foreign currency translation adjustments
Accumulated Other Comprehensive Income (Loss), Net of Tax [Abstract]
Beginning balance			(80.0)	(93.8)
Other comprehensive (loss) earnings, net of tax			(6.4)	5.1
Ending balance	$ (86.4)	$ (88.7)	$ (86.4)	$ (88.7)