Financing Activities (Details) - USD ($) shares in Millions, $ in Millions	9 Months Ended
Oct. 31, 2015	Nov. 01, 2014
Stock Repurchased During Period, Shares	30.6
Stock Repurchased During Period, Value	$ 1,837
Stock Repurchase Program, Remaining Authorized Repurchase Amount	695
Commercial Paper Facility Maximum Borrowing Capacity	1,500
Commercial Paper	$ 791
Commercial Paper, Weighted Average Interest Rate	0.42%
Seven Point Five Percent Senior Debentures Due Two Thousand Fifteen [Member]
Extinguishment of debt	$ 69	$ 0
Debt Instrument, Interest Rate, Stated Percentage	7.50%
Five Point Seven Five Percent Senior Notes Due Two Thousand Fourteen [Member]
Extinguishment of debt		$ 453
Debt Instrument, Interest Rate, Stated Percentage		5.75%
Eight Point One Two Five Percent Senior Debentures Due Two Thousand Thirty Five [Member]
Extinguishment of debt	$ 76	$ 0
Debt Instrument, Interest Rate, Stated Percentage	8.125%
Three point six two five percent senior notes due two thousand twenty four[Member]
Debt Instrument, Interest Rate, Stated Percentage		3.625%
Proceeds from Issuance of Debt		$ 500

Commercial Paper Facility Maximum Borrowing Capacity

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- Definition

Carrying value as of the balance sheet date of short-term borrowings using unsecured obligations issued by banks, corporations and other borrowers to investors. The maturities of these money market securities generally do not exceed 270 days.

+ 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 210.5-02.19(a)(3))

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-Publisher FASB

-Name Accounting Standards Codification

-Topic 942

-SubTopic 210

-Section S99

-Paragraph 1

-Subparagraph (SX 210.9-03.13(2))

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-Publisher SEC

-Name Regulation S-X (SX)

-Number 210

-Section 03

-Paragraph 16

-Article 7

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- Definition

Contractual interest rate for funds borrowed, under the debt agreement.

+ References

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- Definition

Gross amount of debt extinguished.

+ References

No definition available.

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- Definition

The cash inflow during the period from additional borrowings in aggregate debt. Includes proceeds from short-term and long-term debt.

+ References

No definition available.

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- Definition

Weighted average interest rate of short-term debt outstanding.

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- Definition

Amount remaining of a stock repurchase plan authorized.

+ References

No definition available.

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- Definition

Number of shares that have been repurchased during the period and have not been retired and are not held in treasury. Some state laws may govern the circumstances under which an entity may acquire its own stock and prescribe the accounting treatment therefore. This element is used when state law does not recognize treasury stock.

+ References

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

-Publisher FASB

-Name Accounting Standards Codification

-Topic 505

-SubTopic 10

-Section 50

-Paragraph 2

-URI http://asc.fasb.org/extlink&oid=6928386&loc=d3e21463-112644

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-Number 210

-Section 02

-Paragraph 29, 30

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- Definition

Equity impact of the value of stock that has been repurchased during the period and has not been retired and is not held in treasury. Some state laws may mandate the circumstances under which an entity may acquire its own stock and prescribe the accounting treatment therefore. This element is used when state law does not recognize treasury stock.

+ References

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

-Publisher FASB

-Name Accounting Standards Codification

-Topic 505

-SubTopic 10

-Section 50

-Paragraph 2

-URI http://asc.fasb.org/extlink&oid=6928386&loc=d3e21463-112644

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-Section 02

-Paragraph 29, 30, 31

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-Publisher SEC

-Name Regulation S-X (SX)

-Number 210

-Section 04

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