Goodwill and Other Intangible Assets (Details) (USD $) In Millions, unless otherwise specified	3 Months Ended
Nov. 30, 2014	Nov. 30, 2013	Aug. 31, 2014
Business Acquisition [Line Items]
Amortization expense for intangible assets	$ 69us-gaap_AmortizationOfIntangibleAssets	$ 70us-gaap_AmortizationOfIntangibleAssets
Purchase price, net of assumed cash	13
Goodwill	2,356us-gaap_Goodwill	2,491us-gaap_Goodwill	2,359us-gaap_Goodwill
Kerr Drug [Member]
Business Acquisition [Line Items]
Purchase price, net of assumed cash		170
Goodwill		42
Intangible assets		$ 54

The aggregate expense charged against earnings to allocate the cost of intangible assets (nonphysical assets not used in production) in a systematic and rational manner to the periods expected to benefit from such assets. As a noncash expense, this element is added back to net income when calculating cash provided by or used in operations using the indirect method.

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Amount of consideration transferred, consisting of acquisition-date fair value of assets transferred by the acquirer, liabilities incurred by the acquirer, and equity interest issued by the acquirer.

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The amount of identifiable intangible assets recognized as of the acquisition date.

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Amount after accumulated impairment loss of an asset representing future economic benefits arising from other assets acquired in a business combination that are not individually identified and separately recognized.

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