XML 86 R90.htm IDEA: XBRL DOCUMENT v2.4.1.9

Business Segments and Geographic Areas - Additional Information (Detail)	0 Months Ended	12 Months Ended
	Apr. 01, 2014 Segment Business	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Segment Reporting Information [Line Items]
Number of reportable segments	4us-gaap_NumberOfReportableSegments
Number of business units	15nov_NumberOfBusinessUnits
Revenue [Member] | Customer Concentration Risk [Member]
Segment Reporting Information [Line Items]
Revenue from shipyard customer		7.00%us-gaap_ConcentrationRiskPercentage1 / us-gaap_ConcentrationRiskByTypeAxis = us-gaap_CustomerConcentrationRiskMember / us-gaap_IncomeStatementLocationAxis = us-gaap_SalesMember	11.00%us-gaap_ConcentrationRiskPercentage1 / us-gaap_ConcentrationRiskByTypeAxis = us-gaap_CustomerConcentrationRiskMember / us-gaap_IncomeStatementLocationAxis = us-gaap_SalesMember	11.00%us-gaap_ConcentrationRiskPercentage1 / us-gaap_ConcentrationRiskByTypeAxis = us-gaap_CustomerConcentrationRiskMember / us-gaap_IncomeStatementLocationAxis = us-gaap_SalesMember
Rig Systems [Member]
Segment Reporting Information [Line Items]
Number of business units	2nov_NumberOfBusinessUnits / us-gaap_StatementBusinessSegmentsAxis = nov_RigSystemsMember
Rig Aftermarket [Member]
Segment Reporting Information [Line Items]
Number of business units	1nov_NumberOfBusinessUnits / us-gaap_StatementBusinessSegmentsAxis = nov_RigAfterMarketMember
Wellbore Technologies [Member]
Segment Reporting Information [Line Items]
Number of business units	6nov_NumberOfBusinessUnits / us-gaap_StatementBusinessSegmentsAxis = nov_WellboreTechnologiesMember
Completion & Production Solutions [Member]
Segment Reporting Information [Line Items]
Number of business units	6nov_NumberOfBusinessUnits / us-gaap_StatementBusinessSegmentsAxis = nov_CompletionAndProductionSolutionsMember

X

- Definition

Number Of Business Units

+ References

No definition available.

+ Details

Name:	nov_NumberOfBusinessUnits
Namespace Prefix:	nov_
Data Type:	xbrli:integerItemType
Balance Type:	na
Period Type:	instant

X

- Definition

For an entity that discloses a concentration risk in relation to quantitative amount, which serves as the "benchmark" (or denominator) in the equation, this concept represents the concentration percentage derived from the division.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 825

-SubTopic 10

-Section 50

-Paragraph 21

-Subparagraph (a)

-URI http://asc.fasb.org/extlink&oid=35750535&loc=d3e13537-108611



Reference 2: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 275

-SubTopic 10

-Section 50

-Paragraph 20

-URI http://asc.fasb.org/extlink&oid=6927468&loc=d3e6404-108592



Reference 3: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 825

-SubTopic 10

-Section 50

-Paragraph 20

-URI http://asc.fasb.org/extlink&oid=35750535&loc=d3e13531-108611



Reference 4: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 275

-SubTopic 10

-Section 50

-Paragraph 18

-URI http://asc.fasb.org/extlink&oid=6927468&loc=d3e6351-108592

+ Details

Name:	us-gaap_ConcentrationRiskPercentage1
Namespace Prefix:	us-gaap_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	duration

X

- Definition

Number of segments reported by the entity. A reportable segment is a component of an entity for which there is an accounting requirement to report separate financial information on that component in the entity's financial statements.

+ References

No definition available.

+ Details

Name:	us-gaap_NumberOfReportableSegments
Namespace Prefix:	us-gaap_
Data Type:	xbrli:integerItemType
Balance Type:	na
Period Type:	duration

X

- Details

Name:	us-gaap_SegmentReportingInformationLineItems
Namespace Prefix:	us-gaap_
Data Type:	xbrli:stringItemType
Balance Type:	na
Period Type:	duration

X

- Details

Name:	us-gaap_IncomeStatementLocationAxis=us-gaap_SalesMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

X

- Details

Name:	us-gaap_StatementBusinessSegmentsAxis=nov_CompletionAndProductionSolutionsMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

X

- Details

Name:	us-gaap_StatementBusinessSegmentsAxis=nov_RigAfterMarketMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

X

- Details

Name:	us-gaap_StatementBusinessSegmentsAxis=nov_RigSystemsMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

X

- Details

Name:	us-gaap_StatementBusinessSegmentsAxis=nov_WellboreTechnologiesMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type: