XML 105 R42.htm IDEA: XBRL DOCUMENT v2.4.0.8

Business Segments - Additional Information (Detail)	3 Months Ended	6 Months Ended
	Jun. 30, 2013	Jun. 30, 2013
Segment Reporting [Abstract]
Revenue from shipyard customer	10.00%	10.00%

X

- Definition

Revenue from shipyard customer.

+ References

No definition available.

+ Details

Name:	nov_RevenueFromCustomer
Namespace Prefix:	nov_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	duration

X

- Details

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