Components of Comprehensive Income, Net of Related Tax (Detail) (USD $) In Millions, unless otherwise specified	3 Months Ended		9 Months Ended
	Sep. 30, 2014	Sep. 30, 2013	Sep. 30, 2014	Sep. 30, 2013
Equity [Abstract]
Net income	$ 371.4	$ 309.4	$ 964.5	$ 837.1
Other comprehensive income (loss)
Unrealized gains (losses) on derivative contracts, before tax	7.5	(3.5)	7.9	9.8
Unrealized (losses) gains on derivative contracts, tax	(2.6)	0.8	(2.4)	(3.3)
Unrealized (losses) gains on derivative contracts, net of tax	4.9	(2.7)	5.5	6.5
Unrealized gains (losses) on marketable debt securities, before tax	1.0	0.1	4.7	(5.7)
Unrealized gains (losses) on marketable debt securities, tax	(0.1)		(1.1)	1.6
Unrealized gains (losses) on marketable debt securities, net of tax	0.9	0.1	3.6	(4.1)
Pension plans, before tax	14.5	2.5	22.0	36.8
Pension plans, tax	(4.4)	(1.5)	(7.0)	(12.6)
Pension plans, net of tax	10.1	1.0	15.0	24.2
Foreign currency translation (losses) gains	(278.0)	120.4	(231.4)	(58.2)
Net other comprehensive income (loss)	(262.1)	118.8	(207.3)	(31.6)
Comprehensive income	$ 109.3	$ 428.2	$ 757.2	$ 805.5