Business Segment Information - Information by Geographical Area (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Revenue and property, plant and equipment by geographical area
Total revenue	$ 1,987.5	$ 2,072.6	$ 1,895.6
Long-lived assets	463.0	371.7	270.6
United States
Revenue and property, plant and equipment by geographical area
Total revenue	455.9	529.8	489.4
Long-lived assets	61.3	53.2	44.1
Germany
Revenue and property, plant and equipment by geographical area
Total revenue	244.9	213.6	201.1
Long-lived assets	227.8	175.1	137.0
Rest of Europe
Revenue and property, plant and equipment by geographical area
Total revenue	519.8	505.2	500.2
Long-lived assets	144.7	118.3	78.7
Asia Pacific
Revenue and property, plant and equipment by geographical area
Total revenue	629.1	651.0	549.2
Long-lived assets	22.1	16.4	6.3
Other
Revenue and property, plant and equipment by geographical area
Total revenue	137.8	173.0	155.7
Long-lived assets	$ 7.1	$ 8.7	$ 4.5