Property, Plant and Equipment (Details) - USD ($) $ in Millions	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Property, plant and equipment
Property, plant and equipment, at cost	$ 525.8	$ 498.1
Accumulated depreciation	(327.3)	(308.4)
Property, plant and equipment, net	198.5	189.7	$ 184.4
Land
Property, plant and equipment
Property, plant and equipment, at cost	14.5	13.7
Buildings and improvements
Property, plant and equipment
Property, plant and equipment, at cost	164.6	146.9
Machinery and equipment
Property, plant and equipment
Property, plant and equipment, at cost	336.9	323.4
Construction in progress
Property, plant and equipment
Property, plant and equipment, at cost	$ 9.8	$ 14.1