Segment Information - Disaggregation of Revenue (Details) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2018	Sep. 30, 2017	Sep. 30, 2018	Sep. 30, 2017
Disaggregation of Revenue [Line Items]
Total net sales	$ 56,576	$ 43,744	$ 160,504	$ 117,413
Online stores (1)
Disaggregation of Revenue [Line Items]
Total net sales	29,061	26,392	83,165	72,971
Physical stores (2)
Disaggregation of Revenue [Line Items]
Total net sales	4,248	1,276	12,824	1,276
Third-party seller services (3)
Disaggregation of Revenue [Line Items]
Total net sales	10,395	7,928	29,361	21,357
Subscription services (4)
Disaggregation of Revenue [Line Items]
Total net sales	3,698	2,441	10,209	6,544
AWS
Disaggregation of Revenue [Line Items]
Total net sales	6,679	4,584	18,225	12,346
Other (5)
Disaggregation of Revenue [Line Items]
Total net sales	$ 2,495	$ 1,123	$ 6,720	$ 2,919