Available-for-Sale Investments (Details) - USD ($) $ in Millions	12 Months Ended
Aug. 31, 2015	Aug. 31, 2014	Aug. 31, 2013
Summary of cost and fair value of available-for-sale securities [Abstract]
Amortized cost basis	$ 754	$ 717
Gross unrealized gains	430	170
Gross unrealized losses	(1)	0
Fair value	1,183	887
Available for sale securities, current	$ 36	0
AmerisourceBergen Common Stock [Member]
Schedule of Available-for-sale Securities [Line Items]
Maximum number of shares in minority equity position (in shares)	19,859,795
Percentage of rights to acquire common share	7.00%
Price of shares acquired through open market transaction	$ 0	493
Number of shares held (in shares)	11,500,000
Percentage of Outstanding Common Stock	5.20%
Sale of acquired available-for-sale securities	$ 52	0	$ 0
Summary of cost and fair value of available-for-sale securities [Abstract]
Amortized cost basis	717	717
Gross unrealized gains	430	170
Gross unrealized losses	0	0
Fair value	1,147	$ 887
Other Investments [Member]
Summary of cost and fair value of available-for-sale securities [Abstract]
Amortized cost basis	37
Gross unrealized gains	0
Gross unrealized losses	(1)
Fair value	$ 36

Amount before tax of unrealized gain in accumulated other comprehensive income (AOCI) on investments in equity securities classified as available-for-sale.

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

-Publisher FASB

-Name Accounting Standards Codification

-Topic 320

-SubTopic 10

-Section 50

-Paragraph 2

-Subparagraph (b)

-URI http://asc.fasb.org/extlink&oid=27724398&loc=d3e27161-111563

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Amount before tax of unrealized loss in accumulated other comprehensive income (AOCI) on investments in equity securities classified as available-for-sale.

+ References

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

-Publisher FASB

-Name Accounting Standards Codification

-Topic 320

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This item represents the cost of equity securities, which are categorized neither as held-to-maturity nor trading, net of adjustments for other-than-temporary impairments recognized in earnings (less any cumulative-effect adjustments recognized, as defined), and fair value hedge accounting adjustments, if any.

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Amount of investment in debt and equity securities categorized neither as trading securities nor held-to-maturity securities and intended be sold or mature one year or operating cycle, if longer.

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Amount of equity securities categorized neither as held-to-maturity nor as trading.

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

-Publisher FASB

-Name Accounting Standards Codification

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-SubTopic 10

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-URI http://asc.fasb.org/extlink&oid=51813488&loc=d3e22054-111558

Reference 2: http://www.xbrl.org/2003/role/presentationRef

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Reference 3: http://www.xbrl.org/2003/role/presentationRef

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Number of securities into which the class of warrant or right may be converted. For example, but not limited to, 500,000 warrants may be converted into 1,000,000 shares.

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-Publisher FASB

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Number of shares of affiliates held for management investment companies.

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-Publisher FASB

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Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table.

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The aggregate value of securities held, which were categorized neither as trading nor held-to-maturity, for which the interest rate reset through an auction process, that failed to be liquidated through auction, and which were sold during the period.

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Percentage of outstanding common shares of affiliates held for management investment companies.

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Refers to the company's right to acquire common shares of subsidiary through open market transactions during the period.

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Value of shares acquired by the entity through open market transactions.

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