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Business Combination & Asset Purchase - Summary of Carrying Amount of Loans (Parenthetical) (Detail) - USD ($) $ in Thousands | Dec. 31, 2020 | Jan. 01, 2020 | Dec. 31, 2019 | Jan. 01, 2019
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Business Combinations [Abstract] |  |  |  |
Fair value adjustment | $ 0 | $ 62 | $ 62 | $ 2,118

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- Definition Certain loans acquired in transfer accounted for as debt securities fair value adjustment. + References No definition available. + Details
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