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Income Taxes - Summary of Changes in Liability Related to Unrecognized Tax Benefits (Detail) - USD ($) $ in Thousands | 12 Months Ended
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Dec. 31, 2017 | Dec. 31, 2016 | Dec. 31, 2015
Income Tax Disclosure [Abstract] |  |  |
Unrecognized tax benefit liability, Beginning Balance | $ 4,357 | $ 4,755 | $ 5,740
New positions | 653 |  |
Prior period positions: |  |  |
Increases | 491 | 939 | 175
Decreases | (539) | (415) |
Increases from current period positions | 692 | 615 | 184
Lapse of statute of limitations | (781) | (1,290) | (1,114)
Other | (228) | (247) | (230)
Unrecognized tax benefit liability, Ending Balance | $ 4,645 | $ 4,357 | $ 4,755

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- Definition Unrecognized tax benefits increase decrease resulting from other adjustments. + References No definition available. + Details
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- Definition Unrecognized tax benefits increases resulting from new positions. + References No definition available. + Details
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- Definition Amount of unrecognized tax benefits pertaining to uncertain tax positions taken in prior year tax returns. + References No definition available. + Details
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- Definition Amount of unrecognized tax benefits. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 740 -SubTopic 10 -Section 50 -Paragraph 15A -Subparagraph (a) -URI http://asc.fasb.org/extlink&oid=84230637&loc=SL6600010-109319 + Details
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- Definition Amount of decrease in unrecognized tax benefits resulting from tax positions taken in prior period tax returns. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 740 -SubTopic 10 -Section 50 -Paragraph 15A -Subparagraph (a)(1) -URI http://asc.fasb.org/extlink&oid=84230637&loc=SL6600010-109319 + Details
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- Definition Amount of increase in unrecognized tax benefits resulting from tax positions that have been or will be taken in current period tax return. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 740 -SubTopic 10 -Section 50 -Paragraph 15A -Subparagraph (a)(2) -URI http://asc.fasb.org/extlink&oid=84230637&loc=SL6600010-109319 + Details
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- Definition Amount of decrease in unrecognized tax benefits resulting from lapses of applicable statutes of limitations. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 740 -SubTopic 10 -Section 50 -Paragraph 15A -Subparagraph (a)(4) -URI http://asc.fasb.org/extlink&oid=84230637&loc=SL6600010-109319 + Details
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