Other Comprehensive Loss - OCI (Details) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2021	Jun. 30, 2020	Jun. 30, 2021	Jun. 30, 2020
Foreign currency translation adjustments [Abstract]
Foreign currency translation	$ 0.9	$ 3.4	$ (2.7)	$ (4.1)
Foreign currency translation, tax	0.0	0.0	0.0	0.0
Foreign currency translation, net of tax	0.9	3.4	(2.7)	(4.1)
Other Comprehensive (Income) Loss, Defined Benefit Plan, after Reclassification Adjustment, Tax, Attributable to Parent [Abstract]
Other Comprehensive (Income) Loss, Defined Benefit Plan, before Tax, after Reclassification Adjustment, Attributable to Parent	0.2	0.1	0.4	0.3
Other Comprehensive (Income) Loss, Defined Benefit Plan, after Reclassification Adjustment, Tax, Attributable to Parent	0.2	0.2	0.2	(0.1)
Net change in employee benefit plans	0.4	0.3	0.6	0.2
Changes in fair value of cash flow hedges:
Changes in fair value of cash flow hedges, before tax	0.1	0.6	(1.8)	(0.6)
Changes in fair value of cash flow hedges, tax	(0.1)	0.0	0.0	0.1
Changes in fair value of cash flow hedges, net of tax	0.0	0.6	(1.8)	(0.5)
Total other comprehensive earnings [Abstract]
Other comprehensive loss, before tax	1.2	4.1	(4.1)	(4.4)
Other comprehensive loss, tax	0.1	0.2	0.2	0.0
Other comprehensive earnings (loss), net of tax	$ 1.3	$ 4.3	$ (3.9)	$ (4.4)