Stockholders Equity - Additional Information (Detail) - USD ($) shares in Millions, $ in Millions		3 Months Ended
		Mar. 31, 2017	Mar. 31, 2016	Dec. 31, 2016	Feb. 29, 2016	Jan. 31, 2010
Stockholders Equity Note [Line Items]
Stock-based compensation		$ 792	$ 544
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		497		497
Net unrecognized compensation cost related to unvested stock-based compensation arrangements		$ 4,500
Net unrecognized compensation cost related to unvested stock-based compensation arrangements, weighted average recognition period (in years)		1 year 1 month
Cost of Sales [Member]
Stockholders Equity Note [Line Items]
Stock-based compensation	[1]	$ 8	0
Fulfillment
Stockholders Equity Note [Line Items]
Stock-based compensation		163	116
Marketing
Stockholders Equity Note [Line Items]
Stock-based compensation		94	56
Technology and content
Stockholders Equity Note [Line Items]
Stock-based compensation		441	317
General and administrative
Stockholders Equity Note [Line Items]
Stock-based compensation		$ 86	$ 55

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