XML 31 R43.htm IDEA: XBRL DOCUMENT v2.4.1.9

Business Segments - Additional Information (Detail)	3 Months Ended
	Mar. 31, 2015 Segment Business
Segment Reporting Information [Line Items]
Number of reportable segments	4us-gaap_NumberOfReportableSegments
Number of business units	15nov_NumberOfBusinessUnits
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

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_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: