Goodwill and Other Intangible Assets, Schedule of Goodwill (Details) - USD ($) $ in Millions		12 Months Ended
		Aug. 31, 2016	Aug. 31, 2015
Goodwill [Roll Forward]
Net book value - Beginning Period		$ 16,372	$ 2,359
Acquisitions		23	14,972
Sale of business		(4)	(706)	[1]
Other	[2]	0	(3)
Currency translation adjustments		(864)	(250)
Net book value - Ending Period		15,527	16,372
Retail Pharmacy USA [Member]
Goodwill [Roll Forward]
Net book value - Beginning Period		8,940	2,359
Acquisitions		0	7,290
Sale of business		(4)	(706)	[1]
Other	[2]	100	(3)
Currency translation adjustments		0	0
Net book value - Ending Period		9,036	8,940
Retail Pharmacy International [Member]
Goodwill [Roll Forward]
Net book value - Beginning Period		3,898	0
Acquisitions		23	4,036
Sale of business		0	0	[1]
Other	[2]	(113)	0
Currency translation adjustments		(439)	(138)
Net book value - Ending Period		3,369	3,898
Pharmaceutical Wholesale [Member]
Goodwill [Roll Forward]
Net book value - Beginning Period		3,534	0
Acquisitions		0	3,646
Sale of business		0	0	[1]
Other	[2]	13	0
Currency translation adjustments		(425)	(112)
Net book value - Ending Period		$ 3,122	$ 3,534

[1] Represents goodwill associated with Walgreens Infusion Services business which was sold in April 2015.

[2] Other primarily represents the reallocation of goodwill between reporting units and purchase accounting adjustments for prior year acquisitions.