Revenue (Disaggregation of Revenue by Geographical Area) (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Disaggregation of Revenue [Line Items]
Revenue	$ 24,539.8	$ 22,319.5	$ 21,493.3
U.S.
Disaggregation of Revenue [Line Items]
Revenue	14,229.3	12,722.6	12,391.9
Europe
Disaggregation of Revenue [Line Items]
Revenue	4,187.7	3,765.0	3,663.1
Japan
Disaggregation of Revenue [Line Items]
Revenue	2,583.1	2,547.6	2,407.4
China
Disaggregation of Revenue [Line Items]
Revenue	1,116.9	939.4	750.8
Other foreign countries
Disaggregation of Revenue [Line Items]
Revenue	$ 2,422.7	$ 2,344.9	$ 2,280.1