Basis of Presentation (Policies)	9 Months Ended
Sep. 30, 2011
Basis of Presentation [Abstract]
Recently Issued Accounting Standards	The preparation of financial statements in conformity with generally accepted accounting principles (“GAAP”) in the United States requires management to make estimates and assumptions that affect reported and contingent amounts of assets and liabilities as of the date of the financial statements and reported amounts of revenues and expenses during the reporting period. Actual results could differ from those estimates. The accompanying unaudited consolidated financial statements of National Oilwell Varco, Inc. (the “Company”) present information in accordance with GAAP in the United States for interim financial information and the instructions to Form 10-Q and applicable rules of Regulation S-X. They do not include all information or footnotes required by GAAP in the United States for complete consolidated financial statements and should be read in conjunction with our 2010 Annual Report on Form 10-K.
Contingencies	The Company provides service and warranty policies on certain of its products. The Company accrues liabilities under service and warranty policies based upon specific claims and a review of historical warranty and service claim experience in accordance with Accounting Standards Codification (“ASC”) Topic 450 “Contingencies” (“ASC Topic 450”). Adjustments are made to accruals as claim data and historical experience change. In addition, the Company incurs discretionary costs to service its products in connection with product performance issues and accrues for them when they are encountered.
Foreign Currency Matters	The Company’s reporting currency is the U.S. dollar. A majority of the Company’s international entities in which there is a substantial investment have the local currency as their functional currency. As a result, translation adjustments resulting from the process of translating the entities’ financial statements into the reporting currency are reported in Other Comprehensive Income in accordance with ASC Topic 830 “Foreign Currency Matters” (“ASC Topic 830”). For the three months ended September 30, 2011, a majority of these local currencies weakened against the U.S. dollar resulting in a net decrease to Other Comprehensive Income of $117 million upon the translation of their financial statements from their local currency to the U.S. dollar. For the nine months ended September 30, 2011, foreign exchange movements have been insignificant with the majority of the local currencies strengthening slightly, offset by a slightly weaker Canadian dollar, resulting in a net decrease to Other Comprehensive Income of $25 million.
Income Taxes	The Company is subject to taxation in the U.S., various states and foreign jurisdictions. The Company has significant operations in the U.S., Canada, the U.K., the Netherlands and Norway. Tax years that remain subject to examination by major tax jurisdiction vary by legal entity, but are generally open in the U.S. for the tax years after 2007 and outside the U.S. for tax years ending after 2004. The Company does not anticipate that its total unrecognized tax benefits will significantly change due to the settlement of audits or the expiration of statutes of limitation within 12 months of this reporting date. To the extent penalties and interest would be assessed on any underpayment of income tax, such accrued amounts have been classified as a component of income tax expense in the financial statements.
Derivatives and Hedging	ASC Topic 815, “Derivatives and Hedging” (“ASC Topic 815”) requires companies to recognize all of its derivative instruments as either assets or liabilities in the Consolidated Balance Sheet at fair value. The accounting for changes in the fair value (i.e., gains or losses) of a derivative instrument depends on whether it has been designated and qualifies as part of a hedging relationship and further, on the type of hedging relationship. For those derivative instruments that are designated and qualify as hedging instruments, a company must designate the hedging instrument, based upon the exposure being hedged, as a fair value hedge, cash flow hedge, or a hedge of a net investment in a foreign operation.
Non-designated Hedging Strategy	For derivative instruments that are non-designated, the gain or loss on the derivative instrument subject to the hedged risk (i.e. nonfunctional currency monetary accounts) are recognized in other income (expense), net in current earnings. The Company enters into forward exchange contracts to hedge certain nonfunctional currency monetary accounts. The purpose of the Company’s foreign currency hedging activities is to protect the Company from risk that the eventual U.S. dollar-equivalent cash flows from the nonfunctional currency monetary accounts will be adversely affected by changes in the exchange rates.
Fair Value of Financial Instruments	In May 2011, the Financial Accounting Standards Board (“FASB”) issued Accounting Standards Update (“ASU”) No. 2011-04, “Amendments to Achieve Common Fair Value Measurement and Disclosure Requirements in U.S. GAAP and IFRSs” (“ASU No. 2011-04”), which provides guidance about how fair value should be applied where it is already required or permitted under U.S. GAAP. The ASU does not extend the use of fair value or require additional fair value measurements, but rather provides explanations about how to measure fair value. ASU No. 2011-04 requires prospective application and will be effective for interim and annual reporting periods beginning after December 15, 2011. The Company is currently assessing the impact ASU No. 2011-04 will have on its financial statements, but does not expect a significant impact from adoption of the pronouncement.
Presentation of Comprehensive Income	In June 2011, the FASB issued ASU No. 2011-05 “Presentation of Comprehensive Income” (“ASU No. 2011-05”), which eliminates the option to present components of other comprehensive income as part of the statement of changes in equity and requires that all nonowner changes in equity be presented either in a single continuous statement of comprehensive income or in two separate but consecutive statements. ASU No. 2011-05 requires retrospective application and will be effective for interim and annual reporting periods beginning after December 15, 2011. The Company is currently assessing the impact ASU No. 2011-05 will have on its financial statements, but does not expect a significant impact from adoption of the pronouncement.
Intangibles-Goodwill and Other	In September 2011, the FASB issued ASU No. 2011-8 “Intangibles-Goodwill and Other” (“ASU No. 2011-08”), which amends its guidance on the testing of goodwill for impairment allowing entities to perform a qualitative assessment on goodwill impairment to determine whether it is more likely than not (defined as having a likelihood of more than 50 percent) that the fair value of a reporting unit is less than its carrying amount as a basis for determining whether it is necessary to perform the two-step goodwill impairment test. This guidance is effective for goodwill impairment tests performed in interim and annual periods for fiscal years beginning after December 15, 2011, with early adoption permitted. The Company is currently assessing the impact ASU No. 2011-08 will have on its financial statements, but does not expect a significant impact from adoption of the pronouncement.

Basis of Presentation (Policies)

9 Months Ended

Sep. 30, 2011

The preparation of financial statements in conformity with generally accepted accounting principles (“GAAP”) in the United States requires management to make estimates and assumptions that affect reported and contingent amounts of assets and liabilities as of the date of the financial statements and reported amounts of revenues and expenses during the reporting period. Actual results could differ from those estimates.

The accompanying unaudited consolidated financial statements of National Oilwell Varco, Inc. (the “Company”) present information in accordance with GAAP in the United States for interim financial information and the instructions to Form 10-Q and applicable rules of Regulation S-X. They do not include all information or footnotes required by GAAP in the United States for complete consolidated financial statements and should be read in conjunction with our 2010 Annual Report on Form 10-K.

Contingencies

The Company provides service and warranty policies on certain of its products. The Company accrues liabilities under service and warranty policies based upon specific claims and a review of historical warranty and service claim experience in accordance with Accounting Standards Codification (“ASC”) Topic 450 “Contingencies” (“ASC Topic 450”). Adjustments are made to accruals as claim data and historical experience change. In addition, the Company incurs discretionary costs to service its products in connection with product performance issues and accrues for them when they are encountered.

Foreign Currency Matters

The Company’s reporting currency is the U.S. dollar. A majority of the Company’s international entities in which there is a substantial investment have the local currency as their functional currency. As a result, translation adjustments resulting from the process of translating the entities’ financial statements into the reporting currency are reported in Other Comprehensive Income in accordance with ASC Topic 830 “Foreign Currency Matters” (“ASC Topic 830”). For the three months ended September 30, 2011, a majority of these local currencies weakened against the U.S. dollar resulting in a net decrease to Other Comprehensive Income of $117 million upon the translation of their financial statements from their local currency to the U.S. dollar. For the nine months ended September 30, 2011, foreign exchange movements have been insignificant with the majority of the local currencies strengthening slightly, offset by a slightly weaker Canadian dollar, resulting in a net decrease to Other Comprehensive Income of $25 million.

Income Taxes

The Company is subject to taxation in the U.S., various states and foreign jurisdictions. The Company has significant operations in the U.S., Canada, the U.K., the Netherlands and Norway. Tax years that remain subject to examination by major tax jurisdiction vary by legal entity, but are generally open in the U.S. for the tax years after 2007 and outside the U.S. for tax years ending after 2004.

The Company does not anticipate that its total unrecognized tax benefits will significantly change due to the settlement of audits or the expiration of statutes of limitation within 12 months of this reporting date.

To the extent penalties and interest would be assessed on any underpayment of income tax, such accrued amounts have been classified as a component of income tax expense in the financial statements.

Derivatives and Hedging

ASC Topic 815, “Derivatives and Hedging” (“ASC Topic 815”) requires companies to recognize all of its derivative instruments as either assets or liabilities in the Consolidated Balance Sheet at fair value. The accounting for changes in the fair value (i.e., gains or losses) of a derivative instrument depends on whether it has been designated and qualifies as part of a hedging relationship and further, on the type of hedging relationship. For those derivative instruments that are designated and qualify as hedging instruments, a company must designate the hedging instrument, based upon the exposure being hedged, as a fair value hedge, cash flow hedge, or a hedge of a net investment in a foreign operation.

Non-designated Hedging Strategy

For derivative instruments that are non-designated, the gain or loss on the derivative instrument subject to the hedged risk (i.e. nonfunctional currency monetary accounts) are recognized in other income (expense), net in current earnings.

The Company enters into forward exchange contracts to hedge certain nonfunctional currency monetary accounts. The purpose of the Company’s foreign currency hedging activities is to protect the Company from risk that the eventual U.S. dollar-equivalent cash flows from the nonfunctional currency monetary accounts will be adversely affected by changes in the exchange rates.

Fair Value of Financial Instruments

In May 2011, the Financial Accounting Standards Board (“FASB”) issued Accounting Standards Update (“ASU”) No. 2011-04, “Amendments to Achieve Common Fair Value Measurement and Disclosure Requirements in U.S. GAAP and IFRSs” (“ASU No. 2011-04”), which provides guidance about how fair value should be applied where it is already required or permitted under U.S. GAAP. The ASU does not extend the use of fair value or require additional fair value measurements, but rather provides explanations about how to measure fair value. ASU No. 2011-04 requires prospective application and will be effective for interim and annual reporting periods beginning after December 15, 2011. The Company is currently assessing the impact ASU No. 2011-04 will have on its financial statements, but does not expect a significant impact from adoption of the pronouncement.

Presentation of Comprehensive Income

In June 2011, the FASB issued ASU No. 2011-05 “Presentation of Comprehensive Income” (“ASU No. 2011-05”), which eliminates the option to present components of other comprehensive income as part of the statement of changes in equity and requires that all nonowner changes in equity be presented either in a single continuous statement of comprehensive income or in two separate but consecutive statements. ASU No. 2011-05 requires retrospective application and will be effective for interim and annual reporting periods beginning after December 15, 2011. The Company is currently assessing the impact ASU No. 2011-05 will have on its financial statements, but does not expect a significant impact from adoption of the pronouncement.

Intangibles-Goodwill and Other

In September 2011, the FASB issued ASU No. 2011-8 “Intangibles-Goodwill and Other” (“ASU No. 2011-08”), which amends its guidance on the testing of goodwill for impairment allowing entities to perform a qualitative assessment on goodwill impairment to determine whether it is more likely than not (defined as having a likelihood of more than 50 percent) that the fair value of a reporting unit is less than its carrying amount as a basis for determining whether it is necessary to perform the two-step goodwill impairment test. This guidance is effective for goodwill impairment tests performed in interim and annual periods for fiscal years beginning after December 15, 2011, with early adoption permitted. The Company is currently assessing the impact ASU No. 2011-08 will have on its financial statements, but does not expect a significant impact from adoption of the pronouncement.