Goodwill and Other Intangible Assets, Schedule of Finite-Lived Intangible Assets by Major Class (Details) - USD ($) $ in Millions	Feb. 29, 2016	Aug. 31, 2015
Finite-Lived Intangible Assets [Line Items]
Gross Amortizable Intangible Assets	$ 4,246	$ 4,387
Accumulated amortization	1,293	1,090
Total amortizable intangible assets, net	2,953	3,297
Total indefinite lived intangible assets	8,169	9,054
Total intangible assets, net	11,122	12,351
Customer Relationships [Member]
Finite-Lived Intangible Assets [Line Items]
Gross Amortizable Intangible Assets	1,293	1,409
Accumulated amortization	182	132
Purchased Prescription Files [Member]
Finite-Lived Intangible Assets [Line Items]
Gross Amortizable Intangible Assets	904	885
Accumulated amortization	536	470
Loyalty Card Holders [Member]
Finite-Lived Intangible Assets [Line Items]
Gross Amortizable Intangible Assets	661	730
Accumulated amortization	41	41
Favorable Lease Interests [Member]
Finite-Lived Intangible Assets [Line Items]
Gross Amortizable Intangible Assets	457	440
Accumulated amortization	246	207
Non-compete Agreements [Member]
Finite-Lived Intangible Assets [Line Items]
Gross Amortizable Intangible Assets	158	154
Accumulated amortization	106	92
Purchasing and Payer Contracts [Member]
Finite-Lived Intangible Assets [Line Items]
Gross Amortizable Intangible Assets	95	94
Accumulated amortization	68	65
Trade Names and Trademarks [Member]
Finite-Lived Intangible Assets [Line Items]
Gross Amortizable Intangible Assets	678	675
Accumulated amortization	114	83
Total indefinite lived intangible assets	5,947	6,590
Pharmacy Licenses [Member]
Finite-Lived Intangible Assets [Line Items]
Total indefinite lived intangible assets	$ 2,222	$ 2,464