Segment Information - Net Sales of Similar Products and Services (Detail) (USD $) In Millions, unless otherwise specified	3 Months Ended
	Mar. 31, 2014		Mar. 31, 2013
Revenue from External Customer [Line Items]
Net sales	$ 19,741		$ 16,070
Media
Revenue from External Customer [Line Items]
Net sales	5,467		5,058
Electronics and other general merchandise
Revenue from External Customer [Line Items]
Net sales	13,017		10,214
Other
Revenue from External Customer [Line Items]
Net sales	$ 1,257	[1]	$ 798	[1]

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