Goodwill and Other Intangible Assets - Changes in Carrying Amount of Goodwill (Detail) - USD ($) $ in Millions	3 Months Ended	12 Months Ended
	Mar. 31, 2020	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Goodwill [Line Items]
Goodwill, Beginning Balance	$ 11,253.3	$ 11,253.3	$ 11,248.0
Accumulated impairment losses, Beginning Balance	(1,653.6)	(1,653.6)	(1,653.6)
Goodwill, net of accumulated impairment losses, Beginning Balance	9,599.7	9,599.7	9,594.4
Other acquisitions		162.2	25.0
Currency translation		111.9	(19.7)
Impairment	(612.0)	(612.0)
Goodwill, Ending Balance		11,527.4	11,253.3	$ 11,248.0
Accumulated impairment losses, Ending Balance		(2,265.6)	(1,653.6)	(1,653.6)
Goodwill, net of accumulated impairment losses, Ending Balance		9,261.8	9,599.7	9,594.4
Americas [Member]
Goodwill [Line Items]
Goodwill, Beginning Balance	7,699.8	7,699.8	7,712.4
Goodwill, net of accumulated impairment losses, Beginning Balance	7,699.8	7,699.8	7,712.4
Goodwill reportable segment change		1,661.3
Accumulated impairment losses reportable segment change		(1,086.6)
Other acquisitions		142.4
Currency translation		80.2	(12.6)
Impairment		(142.0)
Goodwill, Ending Balance		9,583.7	7,699.8	7,712.4
Accumulated impairment losses, Ending Balance		(1,228.6)
Goodwill, net of accumulated impairment losses, Ending Balance		8,355.1	7,699.8	7,712.4
EMEA [Member]
Goodwill [Line Items]
Goodwill, Beginning Balance	1,316.8	1,316.8	1,322.2
Accumulated impairment losses, Beginning Balance	(567.0)	(567.0)	(567.0)
Goodwill, net of accumulated impairment losses, Beginning Balance	749.8	749.8	755.2
Goodwill reportable segment change		17.0
Other acquisitions		10.9
Currency translation		18.2	(5.4)
Impairment	(470.0)	(470.0)		(567.0)
Goodwill, Ending Balance		1,362.9	1,316.8	1,322.2
Accumulated impairment losses, Ending Balance		(1,037.0)	(567.0)	(567.0)
Goodwill, net of accumulated impairment losses, Ending Balance		325.9	749.8	755.2
Asia Pacific [Member]
Goodwill [Line Items]
Goodwill, Beginning Balance	507.4	507.4	507.2
Goodwill, net of accumulated impairment losses, Beginning Balance	507.4	507.4	507.2
Goodwill reportable segment change		51.0
Other acquisitions		8.9
Currency translation		13.5	0.2
Goodwill, Ending Balance		580.8	507.4	507.2
Goodwill, net of accumulated impairment losses, Ending Balance		580.8	507.4	507.2
Immaterial Product Category Operating Segments [Member]
Goodwill [Line Items]
Goodwill, Beginning Balance	1,729.3	1,729.3	1,706.2
Accumulated impairment losses, Beginning Balance	(1,086.6)	(1,086.6)	(1,086.6)
Goodwill, net of accumulated impairment losses, Beginning Balance	$ 642.7	642.7	619.6
Goodwill reportable segment change		(1,729.3)
Accumulated impairment losses reportable segment change		$ 1,086.6
Other acquisitions			25.0
Currency translation			(1.9)
Goodwill, Ending Balance			1,729.3	1,706.2
Accumulated impairment losses, Ending Balance			(1,086.6)	(1,086.6)
Goodwill, net of accumulated impairment losses, Ending Balance			$ 642.7	$ 619.6