Segment Information - Net Sales of Similar Products and Services (Detail) (USD $) In Millions, unless otherwise specified	3 Months Ended
	Mar. 31, 2015		Mar. 31, 2014
Revenue from External Customer [Line Items]
Net sales	$ 22,717		$ 19,741
Media
Revenue from External Customer [Line Items]
Net sales	5,289		5,467
Electronics and other general merchandise
Revenue from External Customer [Line Items]
Net sales	15,628		13,017
AWS
Revenue from External Customer [Line Items]
Net sales	1,566		1,050
Other
Revenue from External Customer [Line Items]
Net sales	$ 234	[1]	$ 207	[1]

[1] Includes sales from non-retail activities, such as certain advertising services and our co-branded credit card agreements.