Segment Information - Operations in Geographical Areas (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Revenues from External Customers and Long-Lived Assets [Line Items]
Sales	$ 6,452.7	$ 5,756.1	$ 5,378.2
Long-lived assets	9,734.4	6,896.6	5,049.9
United States
Revenues from External Customers and Long-Lived Assets [Line Items]
Sales	3,539.6	3,148.7	3,028.8
Long-lived assets	8,152.0	5,374.1	3,922.6
China
Revenues from External Customers and Long-Lived Assets [Line Items]
Sales	569.0	498.4	458.9
United Kingdom
Revenues from External Customers and Long-Lived Assets [Line Items]
Long-lived assets	358.7	405.8	353.4
Germany
Revenues from External Customers and Long-Lived Assets [Line Items]
Sales	234.7	217.2	180.5
Long-lived assets	261.3	274.8	241.6
All other (each country individually less than 5% of total sales)
Revenues from External Customers and Long-Lived Assets [Line Items]
Sales	2,109.4	1,891.8	1,710.0
All other (each country individually less than 5% of total assets)
Revenues from External Customers and Long-Lived Assets [Line Items]
Long-lived assets	$ 962.4	$ 841.9	$ 532.3