Goodwill and Other Intangible Assets, Schedule of Finite-Lived Intangible Assets by Major Class (Details) - USD ($) $ in Millions	May 31, 2016	Aug. 31, 2015
Finite-Lived Intangible Assets [Line Items]
Gross Amortizable Intangible Assets	$ 4,346	$ 4,387
Accumulated amortization	1,403	1,090
Total amortizable intangible assets, net	2,943	3,297
Total indefinite lived intangible assets	8,613	9,054
Total intangible assets, net	11,556	12,351
Customer Relationships [Member]
Finite-Lived Intangible Assets [Line Items]
Gross Amortizable Intangible Assets	1,368	1,409
Accumulated amortization	223	132
Purchased Prescription Files [Member]
Finite-Lived Intangible Assets [Line Items]
Gross Amortizable Intangible Assets	925	885
Accumulated amortization	569	470
Trade Names and Trademarks [Member]
Finite-Lived Intangible Assets [Line Items]
Gross Amortizable Intangible Assets	681	675
Accumulated amortization	129	83
Total indefinite lived intangible assets	6,271	6,590
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	456	440
Accumulated amortization	258	207
Non-compete Agreements [Member]
Finite-Lived Intangible Assets [Line Items]
Gross Amortizable Intangible Assets	161	154
Accumulated amortization	113	92
Purchasing and Payer Contracts [Member]
Finite-Lived Intangible Assets [Line Items]
Gross Amortizable Intangible Assets	94	94
Accumulated amortization	70	65
Pharmacy Licenses [Member]
Finite-Lived Intangible Assets [Line Items]
Total indefinite lived intangible assets	$ 2,342	$ 2,464