Property, Plant and Equipment, net (Details) - USD ($)
$ in Millions
3 Months Ended
Mar. 31, 2018
Mar. 31, 2017
Dec. 31, 2017
Property, Plant and Equipment      
Cost $ 592.5   $ 552.0
Less accumulated depreciation (389.1)   (369.0)
Total 203.4   183.0
Depreciation 11.9 $ 11.7  
Land      
Property, Plant and Equipment      
Cost 7.5   7.7
Buildings and improvements      
Property, Plant and Equipment      
Cost 105.0   103.2
Machinery, equipment, and other      
Property, Plant and Equipment      
Cost $ 480.0   $ 441.1