Segment Information - Data by geographic area (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Revenue from external customers and Long-lived assets, net
Revenues	$ 23,179.4	$ 22,785.1	$ 21,386.9
Long-lived assets, net	3,784.9	3,571.1
U.S.
Revenue from external customers and Long-lived assets, net
Revenues	13,511.8	12,607.8	12,487.2
Long-lived assets, net	2,481.1	2,365.5
Foreign
Revenue from external customers and Long-lived assets, net
Revenues	9,667.6	10,177.3	$ 8,899.7
Long-lived assets, net	$ 1,303.8	$ 1,205.6