Supplementary Financial Statement Information (Details5) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2018	Mar. 31, 2017
Schedule of Equity Method Investments [Line Items]
Revenue	$ 74.8	$ 72.5
Gross profit	21.1	25.5
Net income	4.2	8.9
Cost of Sales [Member]
Schedule of Equity Method Investments [Line Items]
Income from equity method investments	$ 1.3	$ 3.4