Changes in Accumulated Other Comprehensive Income (Loss) by Component (Detail) - USD ($) $ in Millions		3 Months Ended		9 Months Ended
		Sep. 30, 2021	Sep. 30, 2020	Sep. 30, 2021	Sep. 30, 2020
Accumulated Other Comprehensive Income (Loss) [Line Items]
Beginning balance	[1]			$ 10,390.0
Reclassified out of AOCI		$ (17.7)	$ 41.2	12.0	$ 18.7
Net other comprehensive (loss) income		(115.6)	100.9	(94.9)	(88.9)
Ending balance		11,330.4	10,184.4	11,330.4	10,184.4
Derivative Contracts
Accumulated Other Comprehensive Income (Loss) [Line Items]
Beginning balance		(14.0)	1.1	(29.2)	(15.3)
Recorded into AOCI		35.3	(46.9)	42.8	14.5
Reclassified out of AOCI		(28.7)	32.4	(21.0)	(12.6)
Net other comprehensive (loss) income		6.6	(14.5)	21.8	1.9
Ending balance		(7.4)	(13.4)	(7.4)	(13.4)
Marketable Debt Securities
Accumulated Other Comprehensive Income (Loss) [Line Items]
Beginning balance		8.0	15.5	14.6	6.1
Recorded into AOCI		(2.5)	0.4	(8.2)	10.6
Reclassified out of AOCI		(0.2)	(0.4)	(1.1)	(1.2)
Net other comprehensive (loss) income		(2.7)		(9.3)	9.4
Ending balance		5.3	15.5	5.3	15.5
Pension Plans
Accumulated Other Comprehensive Income (Loss) [Line Items]
Beginning balance		(558.0)	(485.6)	(578.1)	(517.7)
Recorded into AOCI		6.1	(6.4)	3.3	2.4
Reclassified out of AOCI		11.2	9.2	34.1	32.5
Net other comprehensive (loss) income		17.3	2.8	37.4	34.9
Ending balance		(540.7)	(482.8)	(540.7)	(482.8)
Foreign Currency Translation
Accumulated Other Comprehensive Income (Loss) [Line Items]
Beginning balance		(465.6)	(820.9)	(457.6)	(573.2)
Recorded into AOCI		(136.8)	112.6	(144.8)	(135.1)
Net other comprehensive (loss) income		(136.8)	112.6	(144.8)	(135.1)
Ending balance		(602.4)	(708.3)	(602.4)	(708.3)
Accumulated Other Comprehensive Income (Loss)
Accumulated Other Comprehensive Income (Loss) [Line Items]
Beginning balance		(1,029.6)	(1,289.9)	(1,050.3)	(1,100.1)
Recorded into AOCI		(97.9)	59.7	(106.9)	(107.6)
Reclassified out of AOCI		(17.7)	41.2	12.0	18.7
Net other comprehensive (loss) income		(115.6)	100.9	(94.9)	(88.9)
Ending balance		$ (1,145.2)	$ (1,189.0)	$ (1,145.2)	$ (1,189.0)

[1] The December 31, 2020 consolidated balance sheet has been derived from audited financial statements.