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Reconciliation of Unrecognized Tax Benefits (Detail) - USD ($) $ in Thousands | 12 Months Ended
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Dec. 31, 2019 | Dec. 31, 2018
Income Tax Disclosure [Abstract] |  |
Unrecognized tax benefits at beginning of period | $ 11,063 | $ 11,062
Decreases related to expired carryforwards | (729) | (401)
Increases related to current year tax positions | 508 | 402
Unrecognized tax benefits at end of period | $ 10,842 | $ 11,063

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