Property, Plant and Equipment - Components of Company's Property, Plant and Equipment (Details) - USD ($) $ in Millions	Mar. 31, 2019	Dec. 31, 2018
Property Plant And Equipment [Line Items]
Property, plant and equipment, gross	$ 160.0	$ 152.5
Less: Accumulated depreciation	(121.9)	(120.3)
Total	38.1	32.2
Land
Property Plant And Equipment [Line Items]
Property, plant and equipment, gross	10.0	10.0
Buildings
Property Plant And Equipment [Line Items]
Property, plant and equipment, gross	36.9	36.2
Machinery and Equipment
Property Plant And Equipment [Line Items]
Property, plant and equipment, gross	$ 113.1	$ 106.3