Slicers (applies to each fact value in each table cell)

Reporting Entity [Axis]

0001018724 (http://www.sec.gov/CIK)

Equity [Abstract]	Period [Axis]
	2016-01-01 - 2016-12-31
Equity [Abstract]
Stock-Based Compensation Expense	Stock-based compensation expense is as follows (in millions):   Year Ended December 31,   2014   2015   2016 Cost of sales (1) $ —   $ —   $ 16 Fulfillment 375   482   657 Marketing 125   190   323 Technology and content 804   1,224   1,664 General and administrative 193   223   315 Total stock-based compensation expense $ 1,497   $ 2,119   $ 2,975
Nonvested Restricted Stock Units Activity	The following table summarizes our restricted stock unit activity (in millions):   Number of Units   Weighted Average Grant-Date Fair Value Outstanding as of January 1, 2014 16.3   $ 233 Units granted 8.5   328 Units vested (5.1 )   202 Units forfeited (2.3 )   264 Outstanding as of December 31, 2014 17.4   285 Units granted 9.8   426 Units vested (5.6 )   253 Units forfeited (2.7 )   321 Outstanding as of December 31, 2015 18.9   362 Units granted 9.3   660 Units vested (6.1 )   321 Units forfeited (2.3 )   440 Outstanding as of December 31, 2016 19.8   $ 506
Nonvested Share Activity	Scheduled vesting for outstanding restricted stock units as of December 31, 2016, is as follows (in millions):     Year Ended December 31,           2017   2018   2019   2020   2021   Thereafter   Total Scheduled vesting—restricted stock units 7.0   7.2   3.5   1.6   0.2   0.3   19.8