Property, Plant, and Equipment (Details) - USD ($) $ in Millions	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Property, Plant, and Equipment [Abstract]
Land and land improvements	$ 34.7	$ 34.4
Buildings	137.4	122.7
Machinery and equipment	261.8	217.3
Tooling, dies, patterns, etc.	55.9	42.9
Office furniture and equipment	37.3	26.6
Other	16.9	9.8
Construction in progress	23.0	50.8
Property, plant and equipment, gross	567.0	504.5
Accumulated depreciation	(203.8)	(146.1)
Property, plant and equipment, net	$ 363.2	$ 358.4	$ 340.8