Income Taxes - Reconciliation of Unrecognized Tax Benefits (Detail) - USD ($) $ in Thousands |
12 Months Ended | ||
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Dec. 31, 2017 |
Dec. 31, 2016 |
Dec. 31, 2015 |
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| Reconciliation of Unrecognized Tax Benefits, Excluding Amounts Pertaining to Examined Tax Returns [Roll Forward] | |||
| Unrecognized tax benefits at beginning of year | $ 1,039 | $ 934 | $ 1,765 |
| Gross increases for tax positions of prior years | 0 | 105 | 0 |
| Lapse of statute of limitations | 0 | 0 | (831) |
| Unrecognized tax benefits at end of year | $ 1,039 | $ 1,039 | $ 934 |
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- Definition A roll forward is a reconciliation of a concept from the beginning of a period to the end of a period. No definition available.
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- Definition Amount of unrecognized tax benefits. Reference 1: http://www.xbrl.org/2003/role/presentationRef
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- Definition Amount of increase in unrecognized tax benefits resulting from tax positions taken in prior period tax returns. Reference 1: http://www.xbrl.org/2003/role/presentationRef
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- Definition Amount of decrease in unrecognized tax benefits resulting from lapses of applicable statutes of limitations. Reference 1: http://www.xbrl.org/2003/role/presentationRef
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