Debt (Details Textuals) (USD $)	6 Months Ended
Jun. 30, 2011	Apr. 21, 2008
Line of Credit Facility [Line Items]
Funds borrowed to finance the cash portion of the Grant Prideco acquisition		$ 2,000,000,000
Outstanding letters of credit	559,000,000
Funds available under revolving credit facility	1,441,000,000
Outstanding letters of credit under various bilateral committed letter of credit facilities	1,716,000,000
Interest rate under multicurrency facility	LIBOR, NIBOR or EURIBOR plus 0.26%
7.25% interest payable semiannually on Senior Notes due on May 1, 2011 [Member]
Debt (Textuals) [Abstract]
Repayment of Senior Notes	200,000,000
Senior notes interest rate	7.25%
5.65% interest payable semiannually on Senior Notes due on November 15, 2012 [Member]
Debt (Textuals) [Abstract]
Senior notes interest rate	5.65%
5.5% interest payable semiannually on Senior Notes due on November 19, 2012 [Member]
Debt (Textuals) [Abstract]
Senior notes interest rate	5.50%
6.5% interest payable semiannually on Senior Notes due on March 15, 2011 [Member]
Debt (Textuals) [Abstract]
Repayment of Senior Notes	150,000,000
Senior notes interest rate	6.50%
6.125% interest payable semiannually on Senior Notes due on August 15, 2015 [Member]
Debt (Textuals) [Abstract]
Senior notes interest rate	6.125%
Existing Unsecured revolving credit facility [Member]
Line of Credit Facility [Line Items]
Unsecured revolving credit facility		500,000,000
New Unsecured revolving credit facility [Member]
Line of Credit Facility [Line Items]
Funds borrowed to finance the cash portion of the Grant Prideco acquisition		3,000,000,000
Five year revolving credit facility [Member]
Line of Credit Facility [Line Items]
Unsecured revolving credit facility		2,000,000,000
Outstanding letters of credit	0
364-day revolving credit facility [Member]
Line of Credit Facility [Line Items]
Unsecured revolving credit facility		$ 1,000,000,000

Debt.

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Interest rate under multicurrency facility.

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Outstanding letters of credit under various bilateral committed letter of credit facilities.

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Interest rate stated in the contractual debt agreement.

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

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-Publisher FASB
-Name Accounting Standards Codification
-Topic 210
-SubTopic 10
-Section S99
-Paragraph 1
-Subparagraph (SX 210.5-02.22(a)(1))
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Amount borrowed under the credit facility as of the balance sheet date.

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Reference 1: http://www.xbrl.org/2003/role/presentationRef
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-Name Regulation S-X (SX)
-Number 210
-Section 02
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Amount of current borrowing capacity under the credit facility considering any current restrictions on the amount that could be borrowed (for example, borrowings may be limited by the amount of current assets), but without considering any amounts currently outstanding under the facility.

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-Name Regulation S-X (SX)
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-Section 02
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Maximum borrowing capacity under the credit facility without consideration of any current restrictions on the amount that could be borrowed or the amounts currently outstanding under the facility.

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Reference 1: http://www.xbrl.org/2003/role/presentationRef
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Amount of borrowing capacity currently available under the credit facility (current borrowing capacity less the amount of borrowings outstanding).

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The cash outflow for a long-term debt where the holder has highest claim on the entity's asset in case of bankruptcy or liquidation during the period.

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Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
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