Revenue Recognition - Contract Liabilities (Details) - USD ($) $ in Millions	3 Months Ended			9 Months Ended
	Sep. 30, 2018	Jul. 01, 2018	Apr. 01, 2018	Sep. 30, 2018	Jan. 01, 2018
Contract with Customer, Asset
Contract Assets	$ 1.8	$ 1.4	$ 1.7	$ 1.8	$ 0.6
Change in period	0.4	(0.3)	1.1
Contract Liabilities
Contract Liabilities - Current	11.2	11.6	11.5	11.2	11.3
Increase - Current Liabilities	(0.4)	0.1	0.2
Current Liabilities - Noncurrent	2.7	2.7	2.4	2.7	$ 2.1
Increase (decrease) - Noncurrent Liabilities		$ 0.3	$ 0.3
Revenue recognized, contract liability	$ 5.4			11.5
Impairment loss related to Contract Assets				$ 0.0