Income Taxes - Narrative (Details) - USD ($) $ in Millions		3 Months Ended	12 Months Ended
	Jan. 01, 2018	Dec. 31, 2017	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Income Tax Contingency [Line Items]
Impact of Tax Cuts and Jobs Act		$ 166.9	$ (0.6)	$ (166.9)	$ 0.0
Adjustment to provisional amount			0.6
Reclassification for stranded tax effects resulting from the the Tax Reform Act	$ 1.6
Deferred tax liabilities		(199.9)	(210.2)	(199.9)
Valuation allowance		21.2	58.5	21.2
Retained earnings		767.8	981.8	767.8
Increase in valuation allowance			37.3	13.9
Unrecognized tax benefit that would impact effective tax rate		$ 4.6	7.4	4.6
Unrecognized tax benefits, interest			2.9	$ 0.5
State and Local Jurisdiction
Income Tax Contingency [Line Items]
Operating loss carryforwards			668.4
State tax credit carryforward			$ 3.5
Accounting Standards Update 2016-16 | Adjustment
Income Tax Contingency [Line Items]
Prepaid income taxes	59.4
Income tax payable	3.0
Deferred tax liabilities	18.0
Valuation allowance	17.2
Retained earnings	$ (44.4)