Stockholders Equity - Additional Information (Detail) - USD ($) $ / shares in Units, $ in Millions	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014	Feb. 29, 2016	Jan. 31, 2010
Stockholders Equity Note [Line Items]
Preferred stock, authorized shares	500,000,000	500,000,000
Preferred stock, par value (in usd per share)	$ 0.01	$ 0.01
Common shares outstanding plus shares underlying outstanding stock awards, including all stock-based awards outstanding, including estimated forfeiture	497,000,000	490,000,000	483,000,000
Stock Repurchase Program, Number of Shares Authorized to be Repurchased				5,000,000,000	2,000,000,000
Stock options outstanding	100,000	200,000	400,000
Allocated Share-based Compensation Expense	$ 2,975	$ 2,119	$ 1,497
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 2 months
Fair value of vested restricted stock units	$ 4,300	$ 2,700	1,700
Shares of common stock granted under the 401(k) savings plan	100,000	200,000
Common stock available for future issuance to employees	123,000,000
Minimum
Stockholders Equity Note [Line Items]
Restricted stock unit awards and stock options, vesting period	2 years
Maximum
Stockholders Equity Note [Line Items]
Restricted stock unit awards and stock options, vesting period	5 years
Cost of Sales [Member]
Stockholders Equity Note [Line Items]
Allocated Share-based Compensation Expense	$ 16	$ 0	0
Fulfillment Expense [Member]
Stockholders Equity Note [Line Items]
Allocated Share-based Compensation Expense	657	482	375
Selling and Marketing Expense [Member]
Stockholders Equity Note [Line Items]
Allocated Share-based Compensation Expense	323	190	125
Technology And Content Expense [Member]
Stockholders Equity Note [Line Items]
Allocated Share-based Compensation Expense	1,664	1,224	804
General and Administrative Expense [Member]
Stockholders Equity Note [Line Items]
Allocated Share-based Compensation Expense	$ 315	$ 223	$ 193