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Other Operating Income (Expense) - Additional Information (Detail) - USD ($) $ in Thousands | 3 Months Ended | 12 Months Ended
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Dec. 31, 2015 | Sep. 30, 2015 | Jun. 30, 2015 | Mar. 31, 2015 | Dec. 31, 2016 | Dec. 31, 2015 | Dec. 31, 2014
Component Of Other Income And Expense [Abstract] |  |  |  |  |  |  |
Insurance recoveries | $ 200 | $ 100 | $ 300 | $ 3,100 | $ 443 | $ 3,657 | $ 10,368

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- Definition Component of other income and expense. + References No definition available. + Details
Name: | nl_ComponentOfOtherIncomeAndExpenseAbstract
Namespace Prefix: | nl_
Data Type: | xbrli:stringItemType
Balance Type: | na
Period Type: | duration

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- Definition The amount recovered from insurance. These recoveries reduce costs and losses that are reported as a separate line item under operating expenses. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 225 -SubTopic 10 -Section S99 -Paragraph 2 -Subparagraph (SX 210.5-03.3) -URI http://asc.fasb.org/extlink&oid=63488584&loc=d3e20235-122688 + Details
Name: | us-gaap_InsuranceRecoveries
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