Investments - Available for Sale and Held to Maturity Investments (Detail) (USD $) In Millions, unless otherwise specified	Feb. 15, 2015	Aug. 31, 2014
Available For Sale And Held To Maturity [Line Items]
Available-For-Sale, Cost Basis	$ 1,557
Available-for-sale, Recorded Basis, Total	1,560us-gaap_AvailableForSaleSecurities
Held-to-maturity, Cost Basis	27us-gaap_HeldToMaturitySecurities
Total investments, Recorded Basis	1,587us-gaap_ShortTermInvestments	1,577us-gaap_ShortTermInvestments
Short-term Investments
Available For Sale And Held To Maturity [Line Items]
Unrealized gains	3	1
Total investments, Cost Basis	1,584	1,576
Total investments, Recorded Basis	1,587	1,577
Short-term Investments \| Available-for-sale Securities
Available For Sale And Held To Maturity [Line Items]
Available-For-Sale, Cost Basis	1,557	1,408
Unrealized gains	3	1
Available-for-sale, Recorded Basis, Total	1,560	1,409
Short-term Investments \| Available-for-sale Securities \| Government and agency securities
Available For Sale And Held To Maturity [Line Items]
Available-For-Sale, Cost Basis	1,553	1,404
Unrealized gains	3	1
Available-for-sale, Recorded Basis, Total	1,556	1,405
Short-term Investments \| Available-for-sale Securities \| Asset and mortgage backed securities
Available For Sale And Held To Maturity [Line Items]
Available-For-Sale, Cost Basis	4	4
Unrealized gains	0	0
Available-for-sale, Recorded Basis, Total	4	4
Short-term Investments \| Held-to-maturity Securities
Available For Sale And Held To Maturity [Line Items]
Held-to-maturity, Cost Basis		168
Held-to-maturity, Recorded Basis, Total		168
Short-term Investments \| Held-to-maturity Securities \| Certificates of Deposit [Member]
Available For Sale And Held To Maturity [Line Items]
Held-to-maturity, Cost Basis	27	155
Held-to-maturity, Recorded Basis, Total	27	155
Short-term Investments \| Held-to-maturity Securities \| Bankers' Acceptances
Available For Sale And Held To Maturity [Line Items]
Held-to-maturity, Cost Basis		13
Held-to-maturity, Recorded Basis, Total		$ 13

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The total cost of investments classified as Available for Sale and Held to Maturity.

+ References

No definition available.

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- Definition

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

+ References

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

-Publisher FASB

-Name Accounting Standards Codification

-Topic 210

-SubTopic 10

-Section S99

-Paragraph 1

-Subparagraph (SX 210.5-02.2)

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-Publisher FASB

-Name Accounting Standards Codification

-Topic 320

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-Section 50

-Paragraph 2

-Subparagraph (aa)

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- Definition

Amount of investment in debt and equity securities categorized neither as held-to-maturity nor trading.

+ References

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

-Publisher FASB

-Name Accounting Standards Codification

-Topic 320

-SubTopic 10

-Section 25

-Paragraph 1

-Subparagraph (b)

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- Definition

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

+ References

No definition available.

+ Details

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- Definition

Amount after other than temporary impairment (OTTI) accretion, of investments in debt securities classified as held-to-maturity.

+ References

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

-Publisher FASB

-Name Accounting Standards Codification

-Topic 320

-SubTopic 10

-Section 50

-Paragraph 5

-Subparagraph (f)

-URI http://asc.fasb.org/extlink&oid=27724398&loc=d3e27232-111563

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-Publisher FASB

-Name Accounting Standards Codification

-Topic 944

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-Paragraph 1

-Subparagraph (SX 210.7-03.1)

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-Publisher FASB

-Name Accounting Standards Codification

-Topic 942

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-Section S99

-Paragraph 1

-Subparagraph (SX 210.9-03.6)

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- Definition

Fair value of investments in debt securities classified as held-to-maturity.

+ References

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- Definition

Investments which are intended to be sold in the short term (usually less than one year or the normal operating cycle, whichever is longer) including trading securities, available-for-sale securities, held-to-maturity securities, and other short-term investments not otherwise listed in the existing taxonomy.

+ References

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

-Publisher FASB

-Name Accounting Standards Codification

-Topic 210

-SubTopic 10

-Section S99

-Paragraph 1

-Subparagraph (SX 210.5-02.2)

-URI http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682

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

-Publisher SEC

-Name Regulation S-X (SX)

-Number 210

-Section 03

-Paragraph 1

-Subparagraph g

-Article 7

+ Details

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