Income Taxes - Components of Income Tax Expense (Details 5) - USD ($) $ in Millions		3 Months Ended	12 Months Ended
	Jan. 01, 2018	Mar. 31, 2018	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Components of Income Tax Expense (Benefit), Continuing Operations [Abstract]
Remeasurement of deferred taxes for U.S. tax legislation			$ 0.0	$ (4.3)	$ 0.0
Effective Income Tax Rate Reconciliation, at Federal Statutory Income Tax Rate, Percent	21.00%
Transition tax on foreign earnings				24.3
Undistributed Earnings of Foreign Subsidiaries			7.3
Valuation Allowance, Deferred Tax Asset, Increase (Decrease), Amount		$ (5.3)
Current:
Federal			(0.5)	(4.5)	(3.7)
State			(0.3)	0.3	0.2
Foreign			2.1	2.4	1.7
Deferred:
Federal			(5.3)	0.7	15.1
State			0.0	0.1	1.4
Deferred Foreign Income Tax Expense (Benefit)			(2.2)	(0.4)	0.0
Benefit Of Operating Loss Carryforwards			0.0	0.0	(16.1)
Amount allocated to other comprehensive income			0.0	0.0	(15.5)
Change in valuation allowance on beginning-of-the-year deferred tax assets			0.0	(0.8)	0.0
Income tax expense (benefit)			$ (6.2)	$ (2.2)	$ (16.9)