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Business Segments and Geographic Areas - Additional Information (Detail) | 12 Months Ended
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Dec. 31, 2013 | Dec. 31, 2012 | Dec. 31, 2011
Segment Reporting [Abstract] |  |  |
Revenue from shipyard customer | 9.00% | 10.00% | 12.00%

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- 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

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