Including the current and noncurrent portions, carrying value of Notes as of the date of issuance with the highest claim on the assets of the issuer in case of bankruptcy or liquidation (with maturities initially due after one year or beyond the operating cycle if longer). Senior note holders are paid off in full before any payments are made to junior note holders.

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- Definition

The carrying amount of the equity component of convertible debt which may be settled in cash upon conversion.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name FASB Staff Position (FSP)
-Number APB14-1
-Paragraph 31
-Subparagraph a

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- Definition

The stated principal amount of the debt instrument at time of issuance, which may vary from the carrying amount because of unamortized premium or discount.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher AICPA
-Name Accounting Principles Board Opinion (APB)
-Number 21
-Paragraph 16, 20

+ Details

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- Definition

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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- Definition

Amount of outstanding principal due under the debt instrument at the end of the reporting period.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher SEC
-Name Regulation S-X (SX)
-Number 210
-Section 02
-Paragraph 22
-Article 5

Reference 2: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name FASB Staff Position (FSP)
-Number APB14-1
-Paragraph 31
-Subparagraph b

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- Definition

The amount of debt discount that was originally recognized at the issuance of the instrument that has yet to be amortized.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name FASB Staff Position (FSP)
-Number APB14-1
-Paragraph 31
-Subparagraph b

Reference 2: http://www.xbrl.org/2003/role/presentationRef
-Publisher AICPA
-Name Accounting Principles Board Opinion (APB)
-Number 21
-Paragraph 16, 20

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- Definition

Including the current and noncurrent portions, carrying value as of the balance sheet date of Notes with the highest claim on the assets of the issuer in case of bankruptcy or liquidation (with maturities initially due after one year or beyond the operating cycle if longer). Senior note holders are paid off in full before any payments are made to junior note holders.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher SEC
-Name Regulation S-X (SX)
-Number 210
-Section 03
-Paragraph 16
-Article 9

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Initial Allocations Between Debt and Equity Components of the Debentures (Detail) (USD $) In Millions	Dec. 31, 2010	Dec. 31, 2009	Dec. 22, 2009
Debt Instrument [Line Items]
Debt Carrying Value	$ 4,249	$ 4,534
Exchangeable Debentures
Debt Instrument [Line Items]
Initial Face Amount	1,500
Initial Liability Value	1,231
Initial Equity Value	247
Outstanding principal amount	1,251
Debt Carrying Value	1,156
Unamortized Discount	95
Exchangeable Debentures \| Exchangeable 2004 Senior Debentures 3.25 Percent Due April 2024
Debt Instrument [Line Items]
Initial Face Amount	500
Initial Liability Value	413
Initial Equity Value	76
Outstanding principal amount	325
Debt Carrying Value	325
Exchangeable Debentures \| Exchangeable 2007 Senior Debentures 2.625 Percent Due April 2027
Debt Instrument [Line Items]
Initial Face Amount	600
Initial Liability Value	502
Initial Equity Value	89
Outstanding principal amount	526
Debt Carrying Value	502
Unamortized Discount	24
Exchangeable Debentures \| Exchangeable 2009 Senior Debentures 2.5 Percent Due October 2029
Debt Instrument [Line Items]
Initial Face Amount	400
Initial Liability Value	316
Initial Equity Value	82
Outstanding principal amount	400
Debt Carrying Value	329
Unamortized Discount	71
Exchangeable 2009 Senior Debentures 2.5 Percent Due October 2029
Debt Instrument [Line Items]
Initial Face Amount			400
Outstanding principal amount	400
Debt Carrying Value	329	316
Exchangeable 2007 Senior Debentures 2.625 Percent Due April 2027
Debt Instrument [Line Items]
Outstanding principal amount	526
Debt Carrying Value	502	484
Exchangeable 2004 Senior Debentures 3.25 Percent Due April 2024
Debt Instrument [Line Items]
Outstanding principal amount	325
Debt Carrying Value	$ 325	$ 323