Income Taxes - Reconciliation of Total Amounts of Unrecognized Tax Benefits Excluding Interest and Penalties (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 | |||
| Balance at Beginning of the Year | $ 0 | $ 0 | $ 181 |
| Decreases as a Result of Tax Positions Taken in Prior Years | 0 | 0 | (181) |
| Increases as a Result of Tax Positions Taken in the Current Year | 0 | 0 | 0 |
| Balance at End of the Year | $ 0 | $ 0 | $ 0 |
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- Definition Unrecognized Tax Benefits, Increase (Decrease) Resulting From Prior Period Tax Positions No definition available.
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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 that have been or will be taken in current period tax return. Reference 1: http://www.xbrl.org/2003/role/presentationRef
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