New Accounting Pronouncements New Accounting Pronouncements (Details) - USD ($) $ in Millions		12 Months Ended
	Jan. 01, 2018	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016	Jan. 01, 2019
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Reclassification from accumulated other comprehensive loss		$ 0.0	$ (2.6)	$ (4.3)
Expected reclassification of pension expense (income)		12.4	9.6	5.1
Accumulated deficit	$ (159.7)	(211.4)	(162.9)
Prepaid expenses and other current assets	47.4	47.8	45.1
Other long-term assets	121.3	93.9	119.3	$ 84.3
Deferred income taxes	43.0	32.1	$ 41.9
Accounting Standards Update 2018-02
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Reclassification from accumulated other comprehensive loss	$ 2.9	$ 2.9
Minimum | Pro Forma | Accounting Standards Update 2016-02
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Lease liability					$ 130.0
Right of use asset					130.0
Maximum | Pro Forma | Accounting Standards Update 2016-02
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Lease liability					140.0
Right of use asset					$ 140.0