Revenue (Disaggregation of Revenue by Geographical Area) (Details) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2019	Sep. 30, 2018	Sep. 30, 2019	Sep. 30, 2018
Disaggregation of Revenue [Line Items]
Revenue	$ 5,476.6	$ 5,306.9	$ 16,205.5	$ 15,855.7
United States
Disaggregation of Revenue [Line Items]
Revenue	3,060.2	3,070.5	9,203.5	9,108.5
Europe
Disaggregation of Revenue [Line Items]
Revenue	923.4	890.3	2,752.0	2,725.1
Japan
Disaggregation of Revenue [Line Items]
Revenue	641.5	589.0	1,838.4	1,766.2
Other foreign countries
Disaggregation of Revenue [Line Items]
Revenue	$ 851.4	$ 757.1	$ 2,411.7	$ 2,255.9