Stockholders Equity - Additional Information (Detail) - USD ($) shares in Millions, $ in Millions		3 Months Ended		9 Months Ended
		Sep. 30, 2016	Sep. 30, 2015	Sep. 30, 2016	Sep. 30, 2015	Feb. 29, 2016	Dec. 31, 2015	Jan. 31, 2010
Stockholders Equity Note [Line Items]
Stock-based compensation		$ 776	$ 544	$ 2,088	$ 1,513
Stock Repurchase Program, Number of Shares Authorized to be Repurchased						5,000		2,000
Common shares outstanding plus shares underlying outstanding stock awards, including all stock-based awards outstanding, including estimated forfeiture		496		496			490
Net unrecognized compensation cost related to unvested stock-based compensation arrangements		$ 4,600		$ 4,600
Net unrecognized compensation cost related to unvested stock-based compensation arrangements, weighted average recognition period (in years)				1 year 2 months
Cost of Sales [Member]
Stockholders Equity Note [Line Items]
Stock-based compensation	[1]	7	0	$ 7	0
Fulfillment
Stockholders Equity Note [Line Items]
Stock-based compensation		165	122	467	344
Marketing
Stockholders Equity Note [Line Items]
Stock-based compensation		85	48	221	133
Technology and content
Stockholders Equity Note [Line Items]
Stock-based compensation		434	309	1,171	861
General and administrative
Stockholders Equity Note [Line Items]
Stock-based compensation		$ 85	$ 65	$ 222	$ 175

[1] Beginning in Q3 2016, stock-based compensation expense was recorded to cost of sales for eligible employees providing delivery services.