Goodwill and Intangible Assets - Changes in Carrying Amount of Goodwill (Detail) $ in Millions	3 Months Ended
	Mar. 31, 2021 USD ($)
Goodwill [Line Items]
Goodwill, Beginning Balance	$ 11,527.4
Accumulated impairment losses, Beginning Balance	(2,265.6)
Goodwill, net of accumulated impairment losses, Beginning Balance	9,261.8
Purchase accounting adjustments	28.0
Currency translation	(56.6)
Goodwill, Ending Balance	11,498.8
Accumulated impairment losses, Ending Balance	(2,265.6)
Goodwill, net of accumulated impairment losses, Ending Balance	9,233.2
Americas [Member]
Goodwill [Line Items]
Goodwill, Beginning Balance	9,583.7
Accumulated impairment losses, Beginning Balance	(1,228.6)
Goodwill, net of accumulated impairment losses, Beginning Balance	8,355.1
Purchase accounting adjustments	20.6
Currency translation	(37.8)
Goodwill, Ending Balance	9,566.5
Accumulated impairment losses, Ending Balance	(1,228.6)
Goodwill, net of accumulated impairment losses, Ending Balance	8,337.9
EMEA [Member]
Goodwill [Line Items]
Goodwill, Beginning Balance	1,362.9
Accumulated impairment losses, Beginning Balance	(1,037.0)
Goodwill, net of accumulated impairment losses, Beginning Balance	325.9
Purchase accounting adjustments	5.1
Currency translation	(10.0)
Goodwill, Ending Balance	1,358.0
Accumulated impairment losses, Ending Balance	(1,037.0)
Goodwill, net of accumulated impairment losses, Ending Balance	321.0
Asia Pacific [Member]
Goodwill [Line Items]
Goodwill, Beginning Balance	580.8
Goodwill, net of accumulated impairment losses, Beginning Balance	580.8
Purchase accounting adjustments	2.3
Currency translation	(8.8)
Goodwill, Ending Balance	574.3
Goodwill, net of accumulated impairment losses, Ending Balance	$ 574.3