Revenue Recognition - Contract Liabilities (Details) - USD ($) $ in Millions	3 Months Ended				6 Months Ended
	Jun. 30, 2019	Mar. 31, 2019	Jul. 01, 2018	Apr. 01, 2018	Jun. 30, 2019	Jul. 01, 2018	Jan. 01, 2019	Jan. 01, 2018
Contract with Customer, Asset
Contract Assets	$ 0.1	$ 0.3	$ 1.4	$ 1.7	$ 0.1	$ 1.4	$ 1.0	$ 0.6
Change in period	(0.2)	(0.7)	(0.3)	1.1
Contract Liabilities
Contract Liabilities - Current	12.1	11.4	11.6	11.5	12.1	11.6	11.3	11.3
Increase (decrease) - Current Liabilities	0.7	0.1	0.1	0.2
Current Liabilities - Noncurrent	2.8	$ 2.7	2.7	2.4	2.8	2.7	$ 2.7	$ 2.1
Increase (decrease) - Noncurrent Liabilities	0.1		0.3	$ 0.3
Revenue recognized, contract liability	$ 2.8		$ 3.2		6.1	$ 6.1
Impairment loss related to Contract Assets					$ 0.0