Segment Information - Disaggregation of Revenue (Details) - USD ($) $ in Millions	3 Months Ended								12 Months Ended
	Dec. 31, 2018	Sep. 30, 2018	Jun. 30, 2018	Mar. 31, 2018	Dec. 31, 2017	Sep. 30, 2017	Jun. 30, 2017	Mar. 31, 2017	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Disaggregation of Revenue [Line Items]
Total net sales	$ 72,383	$ 56,576	$ 52,886	$ 51,042	$ 60,453	$ 43,744	$ 37,955	$ 35,714	$ 232,887	$ 177,866	$ 135,987
Online stores
Disaggregation of Revenue [Line Items]
Total net sales									122,987	108,354	91,431
Physical stores
Disaggregation of Revenue [Line Items]
Total net sales									17,224	5,798	0
Third-party seller services
Disaggregation of Revenue [Line Items]
Total net sales									42,745	31,881	22,993
Subscription services
Disaggregation of Revenue [Line Items]
Total net sales									14,168	9,721	6,394
AWS
Disaggregation of Revenue [Line Items]
Total net sales									25,655	17,459	12,219
Other
Disaggregation of Revenue [Line Items]
Total net sales									$ 10,108	$ 4,653	$ 2,950