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Tax - Difference Between Effective Tax Rate (Detail) (USD $) In Millions, unless otherwise specified	3 Months Ended
	Mar. 31, 2015	Mar. 31, 2014
Income Tax Disclosure [Abstract]
Federal income tax at U.S. federal statutory rate	$ 176us-gaap_FederalIncomeTaxExpenseBenefitContinuingOperations	$ 276us-gaap_FederalIncomeTaxExpenseBenefitContinuingOperations
Foreign income tax rate differential	(46)us-gaap_ForeignIncomeTaxExpenseBenefitContinuingOperations	(47)us-gaap_ForeignIncomeTaxExpenseBenefitContinuingOperations
State income tax, net of federal benefit	4us-gaap_StateAndLocalIncomeTaxExpenseBenefitContinuingOperations	6us-gaap_StateAndLocalIncomeTaxExpenseBenefitContinuingOperations
Nondeductible expenses	5us-gaap_IncomeTaxReconciliationNondeductibleExpense	11us-gaap_IncomeTaxReconciliationNondeductibleExpense
Tax benefit of manufacturing deduction	(10)us-gaap_IncomeTaxReconciliationDeductionsQualifiedProductionActivities	(7)us-gaap_IncomeTaxReconciliationDeductionsQualifiedProductionActivities
Foreign dividends, net of foreign tax credits	7us-gaap_IncomeTaxReconciliationDeductionsDividends	9us-gaap_IncomeTaxReconciliationDeductionsDividends
Tax impact of foreign exchange	1nov_TaxImpactOfForeignExchange	(8)nov_TaxImpactOfForeignExchange
Tax rate change on temporary differences	(4)us-gaap_IncomeTaxReconciliationChangeInEnactedTaxRate
Change in tax reserves	69us-gaap_IncomeTaxReconciliationTaxSettlements
Other	(13)us-gaap_OtherTaxExpenseBenefit	(1)us-gaap_OtherTaxExpenseBenefit
Provision for income taxes	$ 189us-gaap_IncomeTaxExpenseBenefit	$ 239us-gaap_IncomeTaxExpenseBenefit

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