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Financial Instruments - Additional Information (Detail) - USD ($) | Dec. 31, 2017 | Dec. 31, 2016
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Financial Instrument [Line Items] |  |
Estimated fair value of contingent liability | $ 0 |
Standby Letters of Credit |  |
Financial Instrument [Line Items] |  |
Fair value of contingent liability | 2,430,000 | $ 2,430,000
Performance Bonds |  |
Financial Instrument [Line Items] |  |
Fair value of contingent liability | $ 4,000,000 | $ 8,000,000

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- Definition The fair value of financial liabilities, which are not recognized in the financial statements (off-balance sheet) because they fail to meet some other criterion for recognition. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 825 -SubTopic 10 -Section 50 -Paragraph 10 -Subparagraph (a) -URI http://asc.fasb.org/extlink&oid=77997519&loc=d3e13433-108611 + Details
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- Definition The face amount of financial liabilities, which are not recognized in the financial statements (off-balance sheet) because they fail to meet some other criterion for recognition. + References No definition available. + Details
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- Definition Financial Instrument [Line Items] + References No definition available. + Details
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- Details
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- Details
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