Components of Comprehensive Income, Net of Related Tax (Detail) (USD $) In Millions, unless otherwise specified	3 Months Ended		9 Months Ended
	Sep. 30, 2013	Sep. 30, 2012	Sep. 30, 2013	Sep. 30, 2012
Comprehensive Income (Loss) [Line Items]
Net income	$ 309.4	$ 233.6	$ 837.1	$ 858.1
Other comprehensive income (loss)
Unrealized (losses) gains on derivative contracts, before tax	(3.5)	(3.3)	9.8	(9.5)
Unrealized (losses) gains on derivative contracts, tax	0.8	0.9	(3.3)	2.6
Net current period OCI, gains and losses on cash flow hedges	(2.7)	(2.4)	6.5	(6.9)
Unrealized gains (losses) on marketable debt securities, before tax	0.1	1.1	(5.7)	3.8
Unrealized gains (losses)on marketable debt securities, tax		(0.3)	1.6	(1.1)
Net current period OCI, unrealized gains and losses on available-for-sales securities	0.1	0.8	(4.1)	2.7
Employee benefit plans, before tax	2.5	5.0	36.8	24.1
Employee benefit plans, tax	(1.5)	(2.0)	(12.6)	(8.1)
Employee benefit plans, net of tax	1.0	3.0	24.2	16.0
Currency translation gains (losses)	120.4	73.9	(58.2)	46.6
Net other comprehensive income (loss)	118.8	75.3	(31.6)	58.4
Comprehensive income	$ 428.2	$ 308.9	$ 805.5	$ 916.5