Segment Information - Net Sales of Similar Products and Services (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
Revenue from External Customer [Line Items]
Net sales	$ 17,092		$ 13,806		$ 48,865		$ 39,825
Media
Revenue from External Customer [Line Items]
Net sales	5,033		4,600		14,488		13,427
Electronics and other general merchandise
Revenue from External Customer [Line Items]
Net sales	11,048		8,558		31,677		24,695
Other
Revenue from External Customer [Line Items]
Net sales	$ 1,011	[1]	$ 648	[1]	$ 2,700	[1]	$ 1,703	[1]

[1] Includes sales from non-retail activities, such as Amazon Web Services (“AWS”), advertising services, and our co-branded credit card agreements.