XML 71 R58.htm IDEA: XBRL DOCUMENT
v2.4.0.8

Spin-off of distribution business - Additional Information (Detail) (Now Inc [Member], USD $) In Millions, unless otherwise specified | 3 Months Ended | 0 Months Ended
--- | --- | ---
Mar. 31, 2014 | Mar. 31, 2013 | May 22, 2014 Subsequent Event [Member]
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items] |  |  |
Ratio of common stock sharing |  |  | 4
Sales prior to the spin-off | $ 140 | $ 109 |
Purchases prior to the spin-off | $ 50 | $ 31 |

X
- Definition Share Exchange Ratio In Spin Off + References No definition available. + Details
Name: | nov_ShareExchangeRatioInSpinOff
Namespace Prefix: | nov_
Data Type: | xbrli:pureItemType
Balance Type: | na
Period Type: | duration

X
- Definition For a disposal group that is a component of the entity (discontinued operation), in the period in which the operations are initially classified as discontinued, the amounts of intercompany costs that were previously eliminated in consolidation for periods before the disposal transaction (in situations where revenue and cost producing activities with the disposed component will continue after disposal). + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 205 -SubTopic 20 -Section 50 -Paragraph 6 -URI http://asc.fasb.org/extlink&oid=6360339&loc=d3e1518-107760 + Details
Name: | us-gaap_DiscontinuedOperationIntercompanyAmountsWithDiscontinuedOperationBeforeDisposalTransactionCosts
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | duration

X
- Definition For a disposal group that is a component of the entity (discontinued operation), in the period in which the operations are initially classified as discontinued, the amounts of intercompany revenue that were previously eliminated in consolidation for periods before the disposal transaction (in situations where revenue and cost producing activities with the disposed component will continue after disposal). + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 205 -SubTopic 20 -Section 50 -Paragraph 6 -URI http://asc.fasb.org/extlink&oid=6360339&loc=d3e1518-107760 + Details
Name: | us-gaap_DiscontinuedOperationIntercompanyAmountsWithDiscontinuedOperationBeforeDisposalTransactionRevenue
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | duration

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