Fair Value Measurement and Fair Value of Financial Instruments- Carrying Values and Fair Values of Company's Financial Instruments (Detail) - USD ($) $ in Thousands	Jun. 30, 2022	Dec. 31, 2021
Financial Assets:
Carrying Value	$ 941,558	$ 824,956
Fair Value	808,663	815,211
Federal Home Loan Bank and other membership bank stocks, Carrying Value	25,647	9,049
Federal Home Loan Bank and other membership bank stocks, Fair Value	25,647	9,049
Loans	7,339,704	5,918,101
Fair Value	7,343,386	5,900,876
Financial Liabilities:
Certificates of deposit, Carrying Value	764,042	759,227
Certificates of deposit, Fair Value	739,857	753,483
Other borrowings, Carrying Value	25,000	25,000
Other borrowings, Fair Value	23,419	24,604
Subordinated debt, Carrying Value	194,027	179,043
Subordinated debentures, Fair Value	168,691	175,243
U.S. government agencies
Financial Assets:
Carrying Value	16,418	18,672
Fair Value	16,006	18,965
Mortgage-backed securities, residential
Financial Assets:
Carrying Value	363,071	370,247
Fair Value	319,938	364,976
Collateralized mortgage obligations, residential
Financial Assets:
Carrying Value	13,773	13,921
Fair Value	12,068	14,089
Mortgage-backed securities, multifamily
Financial Assets:
Carrying Value	5,139	2,710
Fair Value	4,662	2,734
Obligations of states and political subdivisions
Financial Assets:
Carrying Value	540,326	416,566
Fair Value	453,381	411,576
Corporate bonds
Financial Assets:
Carrying Value	2,831	2,840
Fair Value	2,608	2,871
Quoted Prices in Active Markets for Identical Assets (Level 1)
Financial Assets:
Fair Value	0	0
Federal Home Loan Bank and other membership bank stocks, Fair Value	0	0
Fair Value	0	0
Financial Liabilities:
Certificates of deposit, Fair Value	0	0
Other borrowings, Fair Value	0	0
Subordinated debentures, Fair Value	0	0
Quoted Prices in Active Markets for Identical Assets (Level 1) \| U.S. government agencies
Financial Assets:
Fair Value	0	0
Quoted Prices in Active Markets for Identical Assets (Level 1) \| Mortgage-backed securities, residential
Financial Assets:
Fair Value	0	0
Quoted Prices in Active Markets for Identical Assets (Level 1) \| Collateralized mortgage obligations, residential
Financial Assets:
Fair Value	0	0
Quoted Prices in Active Markets for Identical Assets (Level 1) \| Mortgage-backed securities, multifamily
Financial Assets:
Fair Value	0	0
Quoted Prices in Active Markets for Identical Assets (Level 1) \| Obligations of states and political subdivisions
Financial Assets:
Fair Value	0	0
Quoted Prices in Active Markets for Identical Assets (Level 1) \| Corporate bonds
Financial Assets:
Fair Value	0	0
Significant Other Observable Inputs (Level 2)
Financial Assets:
Fair Value	808,663	814,379
Federal Home Loan Bank and other membership bank stocks, Fair Value	25,647	9,049
Fair Value	0	0
Financial Liabilities:
Certificates of deposit, Fair Value	739,857	753,483
Other borrowings, Fair Value	23,419	24,604
Subordinated debentures, Fair Value	0	0
Significant Other Observable Inputs (Level 2) \| U.S. government agencies
Financial Assets:
Fair Value	16,006	18,965
Significant Other Observable Inputs (Level 2) \| Mortgage-backed securities, residential
Financial Assets:
Fair Value	319,938	364,976
Significant Other Observable Inputs (Level 2) \| Collateralized mortgage obligations, residential
Financial Assets:
Fair Value	12,068	14,089
Significant Other Observable Inputs (Level 2) \| Mortgage-backed securities, multifamily
Financial Assets:
Fair Value	4,662	2,734
Significant Other Observable Inputs (Level 2) \| Obligations of states and political subdivisions
Financial Assets:
Fair Value	453,381	410,744
Significant Other Observable Inputs (Level 2) \| Corporate bonds
Financial Assets:
Fair Value	2,608	2,871
Significant Unobservable Inputs (Level 3)
Financial Assets:
Fair Value	0	832
Federal Home Loan Bank and other membership bank stocks, Fair Value	0	0
Fair Value	7,343,386	5,900,876
Financial Liabilities:
Certificates of deposit, Fair Value	0	0
Other borrowings, Fair Value	0	0
Subordinated debentures, Fair Value	168,691	175,243
Significant Unobservable Inputs (Level 3) \| U.S. government agencies
Financial Assets:
Fair Value	0	0
Significant Unobservable Inputs (Level 3) \| Mortgage-backed securities, residential
Financial Assets:
Fair Value	0	0
Significant Unobservable Inputs (Level 3) \| Collateralized mortgage obligations, residential
Financial Assets:
Fair Value	0	0
Significant Unobservable Inputs (Level 3) \| Mortgage-backed securities, multifamily
Financial Assets:
Fair Value	0	0
Significant Unobservable Inputs (Level 3) \| Obligations of states and political subdivisions
Financial Assets:
Fair Value	0	832
Significant Unobservable Inputs (Level 3) \| Corporate bonds
Financial Assets:
Fair Value	$ 0	$ 0

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Other Borrowings Fair Value Disclosure

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Amount excluding accrued interest, after allowance for credit loss, of investment in debt security measured at amortized cost (held-to-maturity).

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Fair value of subordinated debt obligations including, but not limited to, subordinated loan, subordinated bond, subordinated debenture or junior debt.

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Federal Home Loan Bank (FHLB) stock represents an equity interest in a FHLB. It does not have a readily determinable fair value because its ownership is restricted and it lacks a market (liquidity).

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Amortized cost excluding accrued interest, after allowance for credit loss, of financing receivable. Excludes net investment in lease.

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Fair value of investment in debt security measured at amortized cost (held-to-maturity).

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