Goodwill and Other Intangible Assets, Schedule of Goodwill (Details) $ in Millions	3 Months Ended
	Nov. 30, 2016 USD ($)
Goodwill [Roll Forward]
Net book value - Beginning Period	$ 15,527
Currency translation adjustments	(324)
Net book value - Ending Period	15,203
Retail Pharmacy USA [Member]
Goodwill [Roll Forward]
Net book value - Beginning Period	9,036
Currency translation adjustments	0
Net book value - Ending Period	9,036
Retail Pharmacy International [Member]
Goodwill [Roll Forward]
Net book value - Beginning Period	3,369
Currency translation adjustments	(160)
Net book value - Ending Period	3,209
Pharmaceutical Wholesale [Member]
Goodwill [Roll Forward]
Net book value - Beginning Period	3,122
Currency translation adjustments	(164)
Net book value - Ending Period	$ 2,958