Supplementary Financial Statement Information (Details5) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2018	Jun. 30, 2017	Jun. 30, 2018	Jun. 30, 2017
Schedule of Equity Method Investments [Line Items]
Revenue	$ 83.5	$ 76.8	$ 158.3	$ 149.3
Gross profit	23.6	23.6	44.7	49.1
Net income	5.1	6.5	9.3	15.4
Cost of Sales [Member]
Schedule of Equity Method Investments [Line Items]
Income from equity method investments	$ 1.7	$ 2.2	$ 3.0	$ 5.6