Segment Information - Reportable Segments and Reconciliation to Consolidated Net Income (Detail) (USD $) In Millions, unless otherwise specified	3 Months Ended				9 Months Ended				12 Months Ended
	Sep. 30, 2013		Sep. 30, 2012		Sep. 30, 2013		Sep. 30, 2012		Sep. 30, 2013	Sep. 30, 2012
Segment Reporting Disclosure [Line Items]
Net sales	$ 17,092		$ 13,806		$ 48,865		$ 39,825
Segment operating expenses	17,117		13,834		48,630		39,554
Income (loss) from operations	(25)		(28)		235		271
Stock-based compensation	(281)		(217)		(808)		(597)		(1,043)	(756)
Other operating income (expense), net	(11)		(43)		(74)		(121)
Total non-operating income (expense)	(18)		6		(181)		(64)
Benefit (provision) for income taxes	12		(83)		18		(234)
Equity-method investment activity, net of tax	(10)		(169)		(38)		(110)
Net income (loss)	(41)		(274)		34		(137)		132	40
Operating Segments
Segment Reporting Disclosure [Line Items]
Net sales	17,092		13,806		48,865		39,825
Segment operating expenses	16,825	[1]	13,574	[1]	47,748	[1]	38,836	[1]
Income (loss) from operations	267		232		1,117		989
Operating Segments | North America
Segment Reporting Disclosure [Line Items]
Net sales	10,301		7,884		29,186		22,638
Segment operating expenses	10,006	[1]	7,593	[1]	28,024	[1]	21,655	[1]
Income (loss) from operations	295		291		1,162		983
Operating Segments | International
Segment Reporting Disclosure [Line Items]
Net sales	6,791		5,922		19,679		17,187
Segment operating expenses	6,819	[1]	5,981	[1]	19,724	[1]	17,181	[1]
Income (loss) from operations	$ (28)		$ (59)		$ (45)		$ 6

[1] Represents operating expenses, excluding stock-based compensation and “Other operating expense (income), net,” which are not allocated to segments.