Segment Information - Reportable Segments and Reconciliation to Consolidated Net Income (Details) $ in Millions	3 Months Ended		9 Months Ended		12 Months Ended
	Sep. 30, 2021 USD ($)	Sep. 30, 2020 USD ($)	Sep. 30, 2021 USD ($) segment	Sep. 30, 2020 USD ($)	Sep. 30, 2021 USD ($)	Sep. 30, 2020 USD ($)
Segment Reporting [Abstract]
Number of operating segments | segment			3
Segment Reporting Disclosure [Line Items]
Net sales	$ 110,812	$ 96,145	$ 332,410	$ 260,509
Operating expenses	105,960	89,951	310,991	244,483
Operating income	4,852	6,194	21,419	16,026
Total non-operating income (expense)	(537)	615	1,798	387
Provision for income taxes	(1,155)	(569)	(4,179)	(2,298)
Equity-method investment activity, net of tax	(4)	91	3	(6)
Net income	3,156	6,331	19,041	14,109	$ 26,263	$ 17,377
North America
Segment Reporting Disclosure [Line Items]
Net sales	65,557	59,373	197,473	160,936
Operating expenses	64,677	57,121	189,996	155,232
Operating income	880	2,252	7,477	5,704
International
Segment Reporting Disclosure [Line Items]
Net sales	29,145	25,171	90,515	66,945
Operating expenses	30,056	24,764	89,812	66,590
Operating income	(911)	407	703	355
AWS
Segment Reporting Disclosure [Line Items]
Net sales	16,110	11,601	44,422	32,628
Operating expenses	11,227	8,066	31,183	22,661
Operating income	$ 4,883	$ 3,535	$ 13,239	$ 9,967