Debt (Details Textuals) (USD $)	9 Months Ended
Sep. 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	731,000,000
Funds available under revolving credit facility	1,269,000,000
Outstanding letters of credit under various bilateral committed letter of credit facilities	1,773,000,000
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]
Senior notes interest rate	7.25%
Repayment of Senior Notes	200,000,000
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]
Senior notes interest rate	6.50%
Repayment of Senior Notes	150,000,000
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		2,000,000,000
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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Amount borrowed under the credit facility as of the balance sheet date.

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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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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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