Segment Information - Net Sales of Similar Products and Services (Detail) (USD $) In Millions, unless otherwise specified	3 Months Ended				6 Months Ended
	Jun. 30, 2014		Jun. 30, 2013		Jun. 30, 2014		Jun. 30, 2013
Revenue from External Customer [Line Items]
Net sales	$ 19,340		$ 15,704		$ 39,081		$ 31,774
Media
Revenue from External Customer [Line Items]
Net sales	4,844		4,397		10,311		9,455
Electronics and other general merchandise
Revenue from External Customer [Line Items]
Net sales	13,278		10,415		26,296		20,629
Other
Revenue from External Customer [Line Items]
Net sales	$ 1,218	[1]	$ 892	[1]	$ 2,474	[1]	$ 1,690	[1]

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