Accumulated Other Comprehensive Loss (Details) - USD ($) $ in Millions	3 Months Ended	6 Months Ended
Jun. 30, 2018	Jun. 30, 2017	Jun. 30, 2018	Jun. 30, 2017
Accumulated Other Comprehensive Loss
Beginning balance			$ 802.2
Other comprehensive (loss) income	$ (21.5)	$ 11.4	(9.4)	$ 13.9
Amounts reclassified from accumulated other comprehensive loss, net of income taxes	0.1	0.2	0.4	0.4
Net current-period other comprehensive (loss) income, net of taxes	(21.4)	11.6	(9.0)	14.3
Ending balance	816.3		816.3
Accumulated other comprehensive loss
Accumulated Other Comprehensive Loss
Beginning balance	4.3	(32.5)	(8.1)	(35.2)
Ending balance	(17.1)	(20.9)	(17.1)	(20.9)
Foreign currency translation adjustments
Accumulated Other Comprehensive Loss
Beginning balance	14.3	(22.2)	2.2	(24.7)
Other comprehensive (loss) income	(21.5)	11.4	(9.4)	13.9
Amounts reclassified from accumulated other comprehensive loss, net of income taxes	0.0	0.0	0.0	0.0
Net current-period other comprehensive (loss) income, net of taxes	(21.5)	11.4	(9.4)	13.9
Ending balance	(7.2)	(10.8)	(7.2)	(10.8)
Pension liability adjustments, net of taxes
Accumulated Other Comprehensive Loss
Beginning balance	(10.0)	(10.3)	(10.3)	(10.5)
Other comprehensive (loss) income	0.0	0.0	0.0	0.0
Amounts reclassified from accumulated other comprehensive loss, net of income taxes	0.1	0.2	0.4	0.4
Net current-period other comprehensive (loss) income, net of taxes	0.1	0.2	0.4	0.4
Ending balance	$ (9.9)	$ (10.1)	$ (9.9)	$ (10.1)

A roll forward is a reconciliation of a concept from the beginning of a period to the end of a period.

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Amount after tax, before reclassification adjustments, of other comprehensive income (loss), attributable to parent.

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Amount after tax of other comprehensive income (loss) attributable to parent entity.

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Amount after tax of reclassification adjustments of other comprehensive income (loss) attributable to parent.

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Total of all stockholders' equity (deficit) items, net of receivables from officers, directors, owners, and affiliates of the entity which are attributable to the parent. The amount of the economic entity's stockholders' equity attributable to the parent excludes the amount of stockholders' equity which is allocable to that ownership interest in subsidiary equity which is not attributable to the parent (noncontrolling interest, minority interest). This excludes temporary equity and is sometimes called permanent equity.

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