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, 2023	Dec. 31, 2022
Assets:
Total	$ 1,029,127	$ 1,054,312
Equity securities, at fair value	17,496	17,283
U.S. government agencies
Assets:
Total	348,419	355,639
Mortgage-backed securities, multifamily
Assets:
Total	788	785
Asset-backed securities
Assets:
Total	49,249	52,395
Obligations of states and political subdivisions
Assets:
Total	21,290	21,122
Corporate bonds
Assets:
Total	103,058	113,367
Fair Value, Measurements, Recurring
Assets:
Total	1,029,127	1,054,312
Equity securities, at fair value	17,496	17,283
Derivative assets	80,725	97,848
Total Assets	1,127,348	1,169,443
Liabilities:
Derivative liabilities	80,725	97,848
Total Liabilities	80,725	97,848
Fair Value, Measurements, Recurring | U.S. government agencies
Assets:
Total	348,419	355,639
Fair Value, Measurements, Recurring | Mortgage-backed securities, residential
Assets:
Total	308,183	310,613
Fair Value, Measurements, Recurring | Collateralized mortgage obligations, residential
Assets:
Total	151,718	154,058
Fair Value, Measurements, Recurring | Mortgage-backed securities, multifamily
Assets:
Total	788	785
Fair Value, Measurements, Recurring | Collateralized mortgage obligations, multifamily
Assets:
Total	46,422	46,333
Fair Value, Measurements, Recurring | Asset-backed securities
Assets:
Total	49,249	52,395
Fair Value, Measurements, Recurring | Obligations of states and political subdivisions
Assets:
Total	21,290	21,122
Fair Value, Measurements, Recurring | Corporate bonds
Assets:
Total	103,058	113,367
Quoted Prices in Active Markets for Identical Assets (Level 1) | Fair Value, Measurements, Recurring
Assets:
Total	155,661	162,438
Equity securities, at fair value	0	0
Derivative assets	0	0
Total Assets	155,661	162,438
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	155,661	162,438
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	873,466	891,874
Equity securities, at fair value	17,496	17,283
Derivative assets	80,725	97,848
Total Assets	971,687	1,007,005
Liabilities:
Derivative liabilities	80,725	97,848
Total Liabilities	80,725	97,848
Significant Other Observable Inputs (Level 2) | Fair Value, Measurements, Recurring | U.S. government agencies
Assets:
Total	192,758	193,201
Significant Other Observable Inputs (Level 2) | Fair Value, Measurements, Recurring | Mortgage-backed securities, residential
Assets:
Total	308,183	310,613
Significant Other Observable Inputs (Level 2) | Fair Value, Measurements, Recurring | Collateralized mortgage obligations, residential
Assets:
Total	151,718	154,058
Significant Other Observable Inputs (Level 2) | Fair Value, Measurements, Recurring | Mortgage-backed securities, multifamily
Assets:
Total	788	785
Significant Other Observable Inputs (Level 2) | Fair Value, Measurements, Recurring | Collateralized mortgage obligations, multifamily
Assets:
Total	46,422	46,333
Significant Other Observable Inputs (Level 2) | Fair Value, Measurements, Recurring | Asset-backed securities
Assets:
Total	49,249	52,395
Significant Other Observable Inputs (Level 2) | Fair Value, Measurements, Recurring | Obligations of states and political subdivisions
Assets:
Total	21,290	21,122
Significant Other Observable Inputs (Level 2) | Fair Value, Measurements, Recurring | Corporate bonds
Assets:
Total	103,058	113,367
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