Fair Value Measurement - Estimated Fair Values of Financial Instruments that are Reported at Amortized Cost in Consolidated Balance Sheets (Detail) - USD ($)	Mar. 31, 2023	Dec. 31, 2022
Financial assets:
Cash and due from banks	$ 77,933,000	$ 96,323,000
Cash at Federal Reserve and other banks	32,402,000	10,907,000
Securities held to maturity	152,067,000	160,983,000
Restricted equity securities	0	0
Financial liabilities:
Other borrowings	434,140,000	264,605,000
Junior subordinated debt	101,051,000	101,040,000
Level 3 | Overdraft Privilege Commitments
Off-balance sheet:
Contract Amount	129,147,000	126,634,000
Level 3 | Standby letters of credit
Off-balance sheet:
Contract Amount	24,070,000	26,599,000
Level 3 | Commitments
Off-balance sheet:
Contract Amount	2,258,744,000	2,188,560,000
Carrying Amount | Level 1
Financial assets:
Cash and due from banks	77,933,000	96,323,000
Cash at Federal Reserve and other banks	32,402,000	10,907,000
Carrying Amount | Level 2
Financial assets:
Securities held to maturity	152,067,000	160,983,000
Restricted equity securities	17,250,000	17,250,000
Financial liabilities:
Deposits	8,025,865,000	8,329,013,000
Other borrowings	434,140,000	264,605,000
Carrying Amount | Level 3
Financial assets:
Loans, net	6,314,014,000	6,344,767,000
Financial liabilities:
Junior subordinated debt	101,051,000	101,040,000
Fair Value | Level 1
Financial assets:
Cash and due from banks	77,933,000	96,323,000
Cash at Federal Reserve and other banks	32,402,000	10,907,000
Fair Value | Level 2
Financial assets:
Securities held to maturity	142,135,000	149,938,000
Financial liabilities:
Deposits	8,018,642,000	8,321,517,000
Other borrowings	434,140,000	264,605,000
Fair Value | Level 3
Financial assets:
Loans, net	6,073,450,000	6,153,155,000
Financial liabilities:
Junior subordinated debt	94,442,000	92,613,000
Fair Value | Level 3 | Overdraft Privilege Commitments
Off-balance sheet:
Fair Value	1,291,000	1,266,000
Fair Value | Level 3 | Standby letters of credit
Off-balance sheet:
Fair Value	241,000	266,000
Fair Value | Level 3 | Commitments
Off-balance sheet:
Fair Value	$ 22,587,000	$ 21,886,000