Fair Value Measurement and Fair Value of Financial Instruments - Fair Value of Financial Assets and Liabilities Measured on Recurring Basis (Detail) - USD ($) $ in Thousands	Mar. 31, 2024	Dec. 31, 2023
Assets:
Total	$ 914,029	$ 946,282
Equity securities, at fair value	17,646	17,697
U.S. government agencies
Assets:
Total	304,889	319,769
Mortgage-backed securities, multifamily
Assets:
Total	667	676
Asset-backed securities
Assets:
Total	40,909	43,693
Obligations of states and political subdivisions
Assets:
Total	18,408	19,128
Corporate bonds
Assets:
Total	97,098	97,033
Fair Value, Measurements, Recurring
Assets:
Total	914,029	946,282
Equity securities, at fair value	17,646	17,697
Derivative assets	97,737	87,566
Total Assets	1,029,412	1,051,545
Liabilities:
Derivative liabilities	97,741	87,570
Total Liabilities	97,741	87,570
Fair Value, Measurements, Recurring | U.S. government agencies
Assets:
Total	304,889	319,769
Fair Value, Measurements, Recurring | Mortgage-backed securities, residential
Assets:
Total	278,079	286,417
Fair Value, Measurements, Recurring | Collateralized mortgage obligations, residential
Assets:
Total	132,206	137,070
Fair Value, Measurements, Recurring | Mortgage-backed securities, multifamily
Assets:
Total	667	676
Fair Value, Measurements, Recurring | Collateralized mortgage obligations, multifamily
Assets:
Total	41,773	42,496
Fair Value, Measurements, Recurring | Asset-backed securities
Assets:
Total	40,909	43,693
Fair Value, Measurements, Recurring | Obligations of states and political subdivisions
Assets:
Total	18,408	19,128
Fair Value, Measurements, Recurring | Corporate bonds
Assets:
Total	97,098	97,033
Quoted Prices in Active Markets for Identical Assets (Level 1) | Fair Value, Measurements, Recurring
Assets:
Total	135,076	147,484
Equity securities, at fair value	0	0
Derivative assets	0	0
Total Assets	135,076	147,484
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. government agencies
Assets:
Total	135,076	147,484
Quoted Prices in Active Markets for Identical Assets (Level 1) | Fair Value, Measurements, Recurring | Mortgage-backed securities, residential
Assets:
Total	0	0
Quoted Prices in Active Markets for Identical Assets (Level 1) | Fair Value, Measurements, Recurring | Collateralized mortgage obligations, residential
Assets:
Total	0	0
Quoted Prices in Active Markets for Identical Assets (Level 1) | Fair Value, Measurements, Recurring | Mortgage-backed securities, multifamily
Assets:
Total	0	0
Quoted Prices in Active Markets for Identical Assets (Level 1) | Fair Value, Measurements, Recurring | Collateralized mortgage obligations, multifamily
Assets:
Total	0	0
Quoted Prices in Active Markets for Identical Assets (Level 1) | Fair Value, Measurements, Recurring | Asset-backed securities
Assets:
Total	0	0
Quoted Prices in Active Markets for Identical Assets (Level 1) | Fair Value, Measurements, Recurring | Obligations of states and political subdivisions
Assets:
Total	0	0
Quoted Prices in Active Markets for Identical Assets (Level 1) | Fair Value, Measurements, Recurring | Corporate bonds
Assets:
Total	0	0
Significant Other Observable Inputs (Level 2) | Fair Value, Measurements, Recurring
Assets:
Total	778,953	798,798
Equity securities, at fair value	17,646	17,697
Derivative assets	97,737	87,566
Total Assets	894,336	904,061
Liabilities:
Derivative liabilities	97,741	87,570
Total Liabilities	97,741	87,570
Significant Other Observable Inputs (Level 2) | Fair Value, Measurements, Recurring | U.S. government agencies
Assets:
Total	169,813	172,285
Significant Other Observable Inputs (Level 2) | Fair Value, Measurements, Recurring | Mortgage-backed securities, residential
Assets:
Total	278,079	286,417
Significant Other Observable Inputs (Level 2) | Fair Value, Measurements, Recurring | Collateralized mortgage obligations, residential
Assets:
Total	132,206	137,070
Significant Other Observable Inputs (Level 2) | Fair Value, Measurements, Recurring | Mortgage-backed securities, multifamily
Assets:
Total	667	676
Significant Other Observable Inputs (Level 2) | Fair Value, Measurements, Recurring | Collateralized mortgage obligations, multifamily
Assets:
Total	41,773	42,496
Significant Other Observable Inputs (Level 2) | Fair Value, Measurements, Recurring | Asset-backed securities
Assets:
Total	40,909	43,693
Significant Other Observable Inputs (Level 2) | Fair Value, Measurements, Recurring | Obligations of states and political subdivisions
Assets:
Total	18,408	19,128
Significant Other Observable Inputs (Level 2) | Fair Value, Measurements, Recurring | Corporate bonds
Assets:
Total	97,098	97,033
Significant Unobservable Inputs (Level 3) | Fair Value, Measurements, Recurring
Assets:
Total	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. government agencies
Assets:
Total	0	0
Significant Unobservable Inputs (Level 3) | Fair Value, Measurements, Recurring | Mortgage-backed securities, residential
Assets:
Total	0	0
Significant Unobservable Inputs (Level 3) | Fair Value, Measurements, Recurring | Collateralized mortgage obligations, residential
Assets:
Total	0	0
Significant Unobservable Inputs (Level 3) | Fair Value, Measurements, Recurring | Mortgage-backed securities, multifamily
Assets:
Total	0	0
Significant Unobservable Inputs (Level 3) | Fair Value, Measurements, Recurring | Collateralized mortgage obligations, multifamily
Assets:
Total	0	0
Significant Unobservable Inputs (Level 3) | Fair Value, Measurements, Recurring | Asset-backed securities
Assets:
Total	0	0
Significant Unobservable Inputs (Level 3) | Fair Value, Measurements, Recurring | Obligations of states and political subdivisions
Assets:
Total	0	0
Significant Unobservable Inputs (Level 3) | Fair Value, Measurements, Recurring | Corporate bonds
Assets:
Total	$ 0	$ 0