Fair Value Measurement and Fair Value of Financial Instruments - Fair Value of Financial Assets and Liabilities Measured on Recurring Basis (Detail) - USD ($) $ in Thousands	Jun. 30, 2021	Dec. 31, 2020
Assets:
Total securities	$ 988,673	$ 855,746
Equity securities, at fair value	15,440	14,694
U.S. Treasury and U.S. government agencies
Assets:
Total securities	106,444	65,002
Mortgage-backed securities, multifamily
Assets:
Total securities	1,900	1,944
Asset-backed securities
Assets:
Total securities	47,236	40,690
Obligations of states and political subdivisions
Assets:
Total securities	265,251	233,710
Fair Value, Measurements, Recurring
Assets:
Total securities	988,673	855,746
Equity securities, at fair value	15,440	14,694
Derivative assets	54,212	80,734
Total Assets	1,058,325	951,174
Liabilities:
Derivative liabilities	54,220	80,877
Total Liabilities	54,220	80,877
Fair Value, Measurements, Recurring \| U.S. Treasury and U.S. government agencies
Assets:
Total securities	106,444	65,002
Fair Value, Measurements, Recurring \| Mortgage-backed securities, residential
Assets:
Total securities	314,868	228,156
Fair Value, Measurements, Recurring \| Collateralized mortgage obligations, residential
Assets:
Total securities	187,926	209,038
Fair Value, Measurements, Recurring \| Mortgage-backed securities, multifamily
Assets:
Total securities	1,900	1,944
Fair Value, Measurements, Recurring \| Collateralized mortgage obligations, multifamily
Assets:
Total securities	29,879	41,535
Fair Value, Measurements, Recurring \| Asset-backed securities
Assets:
Total securities	47,236	40,690
Fair Value, Measurements, Recurring \| Obligations of states and political subdivisions
Assets:
Total securities	265,251	233,710
Fair Value, Measurements, Recurring \| Debt securities
Assets:
Total securities	35,169	35,671
Quoted Prices in Active Markets for Identical Assets (Level 1) \| Fair Value, Measurements, Recurring
Assets:
Total securities	22,794	9,392
Equity securities, at fair value	0	0
Derivative assets	0	0
Total Assets	22,794	9,392
Liabilities:
Derivative liabilities	0	0
Total Liabilities	0	0
Quoted Prices in Active Markets for Identical Assets (Level 1) \| Fair Value, Measurements, Recurring \| U.S. Treasury and U.S. government agencies
Assets:
Total securities	22,794	9,392
Quoted Prices in Active Markets for Identical Assets (Level 1) \| Fair Value, Measurements, Recurring \| Mortgage-backed securities, residential
Assets:
Total securities	0	0
Quoted Prices in Active Markets for Identical Assets (Level 1) \| Fair Value, Measurements, Recurring \| Collateralized mortgage obligations, residential
Assets:
Total securities	0	0
Quoted Prices in Active Markets for Identical Assets (Level 1) \| Fair Value, Measurements, Recurring \| Mortgage-backed securities, multifamily
Assets:
Total securities	0	0
Quoted Prices in Active Markets for Identical Assets (Level 1) \| Fair Value, Measurements, Recurring \| Collateralized mortgage obligations, multifamily
Assets:
Total securities	0	0
Quoted Prices in Active Markets for Identical Assets (Level 1) \| Fair Value, Measurements, Recurring \| Asset-backed securities
Assets:
Total securities	0	0
Quoted Prices in Active Markets for Identical Assets (Level 1) \| Fair Value, Measurements, Recurring \| Obligations of states and political subdivisions
Assets:
Total securities	0	0
Quoted Prices in Active Markets for Identical Assets (Level 1) \| Fair Value, Measurements, Recurring \| Debt securities
Assets:
Total securities	0	0
Significant Other Observable Inputs (Level 2) \| Fair Value, Measurements, Recurring
Assets:
Total securities	965,879	846,354
Equity securities, at fair value	15,440	14,694
Derivative assets	54,212	80,734
Total Assets	1,035,531	941,782
Liabilities:
Derivative liabilities	54,220	80,877
Total Liabilities	54,220	80,877
Significant Other Observable Inputs (Level 2) \| Fair Value, Measurements, Recurring \| U.S. Treasury and U.S. government agencies
Assets:
Total securities	83,650	55,610
Significant Other Observable Inputs (Level 2) \| Fair Value, Measurements, Recurring \| Mortgage-backed securities, residential
Assets:
Total securities	314,868	228,156
Significant Other Observable Inputs (Level 2) \| Fair Value, Measurements, Recurring \| Collateralized mortgage obligations, residential
Assets:
Total securities	187,926	209,038
Significant Other Observable Inputs (Level 2) \| Fair Value, Measurements, Recurring \| Mortgage-backed securities, multifamily
Assets:
Total securities	1,900	1,944
Significant Other Observable Inputs (Level 2) \| Fair Value, Measurements, Recurring \| Collateralized mortgage obligations, multifamily
Assets:
Total securities	29,879	41,535
Significant Other Observable Inputs (Level 2) \| Fair Value, Measurements, Recurring \| Asset-backed securities
Assets:
Total securities	47,236	40,690
Significant Other Observable Inputs (Level 2) \| Fair Value, Measurements, Recurring \| Obligations of states and political subdivisions
Assets:
Total securities	265,251	233,710
Significant Other Observable Inputs (Level 2) \| Fair Value, Measurements, Recurring \| Debt securities
Assets:
Total securities	35,169	35,671
Significant Unobservable Inputs (Level 3) \| Fair Value, Measurements, Recurring
Assets:
Total securities	0	0
Equity securities, at fair value	0	0
Derivative assets	0	0
Total Assets	0	0
Liabilities:
Derivative liabilities	0	0
Total Liabilities	0	0
Significant Unobservable Inputs (Level 3) \| Fair Value, Measurements, Recurring \| U.S. Treasury and U.S. government agencies
Assets:
Total securities	0	0
Significant Unobservable Inputs (Level 3) \| Fair Value, Measurements, Recurring \| Mortgage-backed securities, residential
Assets:
Total securities	0	0
Significant Unobservable Inputs (Level 3) \| Fair Value, Measurements, Recurring \| Collateralized mortgage obligations, residential
Assets:
Total securities	0	0
Significant Unobservable Inputs (Level 3) \| Fair Value, Measurements, Recurring \| Mortgage-backed securities, multifamily
Assets:
Total securities	0	0
Significant Unobservable Inputs (Level 3) \| Fair Value, Measurements, Recurring \| Collateralized mortgage obligations, multifamily
Assets:
Total securities	0	0
Significant Unobservable Inputs (Level 3) \| Fair Value, Measurements, Recurring \| Asset-backed securities
Assets:
Total securities	0	0
Significant Unobservable Inputs (Level 3) \| Fair Value, Measurements, Recurring \| Obligations of states and political subdivisions
Assets:
Total securities	0	0
Significant Unobservable Inputs (Level 3) \| Fair Value, Measurements, Recurring \| Debt securities
Assets:
Total securities	$ 0	$ 0

Fair value portion of probable future economic benefits obtained or controlled by an entity as a result of past transactions or events.

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