Property, Plant and Equipment - Net (Details) - USD ($) $ in Millions	Dec. 31, 2017	Dec. 31, 2016
Property, Plant and Equipment
Total cost	$ 402.5	$ 383.6
Less accumulated depreciation	(290.3)	(274.5)
Property, plant and equipment — net	112.2	109.1
Land
Property, Plant and Equipment
Total cost	9.5	7.3
Building and improvements
Property, Plant and Equipment
Total cost	88.9	91.3
Machinery, equipment and tooling
Property, Plant and Equipment
Total cost	227.3	215.1
Furniture and fixtures
Property, Plant and Equipment
Total cost	6.0	5.8
Computer hardware and software
Property, Plant and Equipment
Total cost	55.1	52.9
Construction in progress
Property, Plant and Equipment
Total cost	$ 15.7	$ 11.2