Segment Information - Disaggregation of Revenue (Details) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2019	Mar. 31, 2018
Disaggregation of Revenue [Line Items]
Total net sales	$ 59,700	$ 51,042
Online stores
Disaggregation of Revenue [Line Items]
Total net sales	29,498	26,939
Physical stores
Disaggregation of Revenue [Line Items]
Total net sales	4,307	4,263
Third-party seller services
Disaggregation of Revenue [Line Items]
Total net sales	11,141	9,265
Subscription services
Disaggregation of Revenue [Line Items]
Total net sales	4,342	3,102
AWS
Disaggregation of Revenue [Line Items]
Total net sales	7,696	5,442
Other
Disaggregation of Revenue [Line Items]
Total net sales	$ 2,716	$ 2,031