Segment Information - Reportable Segments and Reconciliation to Consolidated Net Income (Details) $ in Millions	3 Months Ended		6 Months Ended		12 Months Ended
	Jun. 30, 2017 USD ($)	Jun. 30, 2016 USD ($)	Jun. 30, 2017 USD ($) segment	Jun. 30, 2016 USD ($)	Jun. 30, 2017 USD ($)	Jun. 30, 2016 USD ($)
Segment Reporting [Abstract]
Number of operating segments | segment			3
Segment Reporting Disclosure [Line Items]
Net sales	$ 37,955	$ 30,404	$ 73,669	$ 59,532
Operating expenses	37,327	29,119	72,037	57,176
Operating income (loss)	628	1,285	1,632	2,356
Total non-operating income (expense)	38	(106)	(14)	(122)
Provision for income taxes	(467)	(307)	(695)	(782)
Equity-method investment activity, net of tax	(2)	(15)	(2)	(82)
Net income	197	857	921	1,370	$ 1,922	$ 1,931
North America
Segment Reporting Disclosure [Line Items]
Net sales	22,370	17,674	43,362	34,670
Operating expenses	21,934	16,972	42,330	33,380
Operating income (loss)	436	702	1,032	1,290
International
Segment Reporting Disclosure [Line Items]
Net sales	11,485	9,844	22,546	19,410
Operating expenses	12,209	9,979	23,752	19,665
Operating income (loss)	(724)	(135)	(1,206)	(255)
AWS
Segment Reporting Disclosure [Line Items]
Net sales	4,100	2,886	7,761	5,452
Operating expenses	3,184	2,168	5,955	4,131
Operating income (loss)	$ 916	$ 718	$ 1,806	$ 1,321