Goodwill and Intangible Assets (Changes in Carrying Amount of Goodwill) (Details) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2019	Mar. 31, 2019
Goodwill [Line Items]
Goodwill, gross, beginning balance	$ 10,132.8
Accumulated impairment losses, beginning balance	(385.0)
Foreign currency translation	(139.9)
Goodwill, net, beginning balance	9,747.8
Accumulated impairment losses, ending balance	(385.0)
Goodwill, gross, ending balance	9,992.9
Goodwill, net, ending balance	9,747.8	$ 9,607.9
North America Segment
Goodwill [Line Items]
Goodwill, gross, beginning balance	3,892.9
Accumulated impairment losses, beginning balance	(385.0)
Foreign currency translation	4.8
Goodwill, net, beginning balance	3,507.9
Accumulated impairment losses, ending balance	(385.0)
Goodwill, gross, ending balance	3,897.7
Goodwill, net, ending balance	3,507.9	3,512.7
Europe Segment
Goodwill [Line Items]
Goodwill, gross, beginning balance	4,657.4
Accumulated impairment losses, beginning balance	0.0
Foreign currency translation	(149.8)
Goodwill, net, beginning balance	4,657.4
Accumulated impairment losses, ending balance	0.0
Goodwill, gross, ending balance	4,507.6
Goodwill, net, ending balance	4,657.4	4,507.6
Rest of World Segment
Goodwill [Line Items]
Goodwill, gross, beginning balance	1,582.5
Accumulated impairment losses, beginning balance	0.0
Foreign currency translation	5.1
Goodwill, net, beginning balance	1,582.5
Accumulated impairment losses, ending balance	0.0
Goodwill, gross, ending balance	1,587.6
Goodwill, net, ending balance	$ 1,582.5	$ 1,587.6