Segment Information - Disaggregation of Revenue (Details) - USD ($) $ in Millions	3 Months Ended								12 Months Ended
	Dec. 31, 2020	Sep. 30, 2020	Jun. 30, 2020	Mar. 31, 2020	Dec. 31, 2019	Sep. 30, 2019	Jun. 30, 2019	Mar. 31, 2019	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Disaggregation of Revenue [Line Items]
Total net sales	$ 125,555	$ 96,145	$ 88,912	$ 75,452	$ 87,437	$ 69,981	$ 63,404	$ 59,700	$ 386,064	$ 280,522	$ 232,887
Online stores
Disaggregation of Revenue [Line Items]
Total net sales									197,346	141,247	122,987
Physical stores
Disaggregation of Revenue [Line Items]
Total net sales									16,227	17,192	17,224
Third-party seller services
Disaggregation of Revenue [Line Items]
Total net sales									80,461	53,762	42,745
Subscription services
Disaggregation of Revenue [Line Items]
Total net sales									25,207	19,210	14,168
AWS
Disaggregation of Revenue [Line Items]
Total net sales									45,370	35,026	25,655
Other
Disaggregation of Revenue [Line Items]
Total net sales									$ 21,453	$ 14,085	$ 10,108