Segment Information - Net Sales of Similar Products and Services (Details) - USD ($) $ in Millions	3 Months Ended								12 Months Ended
	Dec. 31, 2017	Sep. 30, 2017	Jun. 30, 2017	Mar. 31, 2017	Dec. 31, 2016	Sep. 30, 2016	Jun. 30, 2016	Mar. 31, 2016	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Revenue from External Customer [Line Items]
Net sales	$ 60,453	$ 43,744	$ 37,955	$ 35,714	$ 43,741	$ 32,714	$ 30,404	$ 29,128	$ 177,866	$ 135,987	$ 107,006
Online stores
Revenue from External Customer [Line Items]
Net sales									108,354	91,431	76,863
Physical stores
Revenue from External Customer [Line Items]
Net sales									5,798	0	0
Third-party seller services
Revenue from External Customer [Line Items]
Net sales									31,881	22,993	16,086
Subscription services
Revenue from External Customer [Line Items]
Net sales									9,721	6,394	4,467
AWS
Revenue from External Customer [Line Items]
Net sales									17,459	12,219	7,880
Other
Revenue from External Customer [Line Items]
Net sales									$ 4,653	$ 2,950	$ 1,710