Basis of Presentation (Details) - USD ($) $ in Millions		3 Months Ended
	Jan. 01, 2019	Mar. 31, 2019	Mar. 31, 2018
Leases
Decrease to retained earnings		$ (5.1)
Right-of-use assets	$ 8.2	$ 7.1
Other non-current assets		us-gaap:OtherAssetsNoncurrent
Current lease liabilities	4.1	$ 3.4
Other current liabilities		us-gaap:OtherLiabilitiesCurrent
Non-current lease liabilities	4.1	$ 3.7
Other non-current liabilities		us-gaap:OtherLiabilitiesNoncurrent
Total operating lease liabilities	8.2	$ 7.1
Operating lease expense		$ 1.4	$ 1.2
ASU 2016-02
Leases
Decrease to retained earnings	$ (5.1)
Weighted-average remaining lease term	3 years
Weighted-average discount rate	4.90%