Goodwill and Other Intangible Assets, Schedule of Finite-Lived Intangible Assets by Major Class (Details) (USD $) In Millions, unless otherwise specified	Nov. 30, 2014	Aug. 31, 2014	Nov. 30, 2013
Finite-Lived Intangible Assets [Line Items]
Gross intangible assets	$ 2,126	$ 2,116	$ 2,185
Accumulated amortization	(1,005)	(936)	(877)
Intangible assets, Net	1,121us-gaap_FiniteLivedIntangibleAssetsNet	1,180us-gaap_FiniteLivedIntangibleAssetsNet	1,308us-gaap_FiniteLivedIntangibleAssetsNet
Purchased Prescription File [Member]
Finite-Lived Intangible Assets [Line Items]
Gross intangible assets	1,086	1,079	1,103
Accumulated amortization	(515)	(474)	(447)
Favorable lease interests [Member]
Finite-Lived Intangible Assets [Line Items]
Gross intangible assets	382	382	381
Accumulated amortization	(183)	(174)	(152)
Purchasing and Payer Contract [Member]
Finite-Lived Intangible Assets [Line Items]
Gross intangible assets	301	301	348
Accumulated amortization	(151)	(145)	(154)
Non-compete Agreements [Member]
Finite-Lived Intangible Assets [Line Items]
Gross intangible assets	154	151	150
Accumulated amortization	(78)	(70)	(67)
Trade Names [Member]
Finite-Lived Intangible Assets [Line Items]
Gross intangible assets	199	199	199
Accumulated amortization	(74)	(69)	(54)
Other Amortizable Intangible Assets [Member]
Finite-Lived Intangible Assets [Line Items]
Gross intangible assets	4	4	4
Accumulated amortization	$ (4)	$ (4)	$ (3)

Accumulated amount of amortization of assets, excluding financial assets and goodwill, lacking physical substance with a finite life.

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 350

-SubTopic 30

-Section 50

-Paragraph 2

-Subparagraph (a)(1)

-URI http://asc.fasb.org/extlink&oid=26713463&loc=d3e16323-109275

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