Segment Information (Sales and PPE by Geographic Location) (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Revenues from External Customers and Long-Lived Assets [Line Items]
Net sales	$ 1,599.1	$ 1,509.1	$ 1,399.8
Property, plant and equipment, net	855.0	778.3	721.0
United States [Member]
Revenues from External Customers and Long-Lived Assets [Line Items]
Net sales	734.6	738.3	667.4
Property, plant and equipment, net	323.8	329.3	332.3
Germany [Member]
Revenues from External Customers and Long-Lived Assets [Line Items]
Net sales	226.4	200.6	194.0
Property, plant and equipment, net	108.8	96.8	102.9
France [Member]
Revenues from External Customers and Long-Lived Assets [Line Items]
Net sales	125.6	116.3	107.6
Property, plant and equipment, net	43.1	37.1	38.6
Other European countries [Member]
Revenues from External Customers and Long-Lived Assets [Line Items]
Net sales	318.5	268.3	252.0
Property, plant and equipment, net	244.9	192.3	117.6
Other [Member]
Revenues from External Customers and Long-Lived Assets [Line Items]
Net sales	194.0	185.6	178.8
Property, plant and equipment, net	$ 134.4	$ 122.8	$ 129.6