Fair Value - Carrying Amounts and Estimated Fair Values of Financial Instruments (Details) - USD ($)	Dec. 31, 2023	Dec. 31, 2022	Dec. 31, 2021	Dec. 31, 2020
Assets
Securities available-for-sale	$ 442,636,000	$ 489,596,000
Securities held-to-maturity, fair value	564,127,000	614,452,000
FHLB stock, FRB stock, and other investments	32,540,000	32,522,000
Liabilities
Subordinated debt	39,502,000	39,350,000
Allowance for credit losses on loans	47,958,000	47,512,000	$ 43,290,000	$ 44,400,000
Carrying Amounts
Assets
Cash and cash equivalents	408,129,000	306,603,000
Securities available-for-sale	442,636,000	489,596,000
Securities held-to-maturity, fair value	650,565,000	714,990,000
Loans (including loans held-for-sale)	3,352,583,000	3,301,006,000
FHLB stock, FRB stock, and other investments	32,540,000	32,522,000
Accrued interest receivable	14,959,000	15,047,000
I/O strips receivables	117,000	152,000
Liabilities
Time deposits	469,472,000	143,958,000
Other deposits	3,908,986,000	4,245,646,000
Subordinated debt	39,502,000	39,350,000
Accrued interest payable	4,688,000	600,000
Balance
Assets
Cash and cash equivalents	408,129,000	306,603,000
Securities available-for-sale	442,636,000	489,596,000
Securities held-to-maturity, fair value	564,127,000	614,452,000
Loans (including loans held-for-sale)	3,174,717,000	3,082,941,000
Accrued interest receivable	14,959,000	15,047,000
I/O strips receivables	117,000	152,000
Liabilities
Time deposits	471,693,000	144,702,000
Other deposits	3,908,986,000	4,245,646,000
Subordinated debt	31,902,000	36,025,000
Accrued interest payable	4,688,000	600,000
Balance | Quoted Prices in Active Markets for Identical Assets (Level 1)
Assets
Cash and cash equivalents	408,129,000	306,603,000
Securities available-for-sale	382,369,000	418,474,000
Accrued interest receivable	1,255,000	1,328,000
Balance | Significant Other Observable Inputs (Level 2)
Assets
Securities available-for-sale	60,267,000	71,122,000
Securities held-to-maturity, fair value	564,127,000	614,452,000
Loans (including loans held-for-sale)	2,205,000	2,456,000
Accrued interest receivable	1,764,000	1,836,000
I/O strips receivables	117,000	152,000
Liabilities
Time deposits	471,693,000	144,702,000
Other deposits	3,908,986,000	4,245,646,000
Subordinated debt	31,902,000	36,025,000
Accrued interest payable	4,688,000	600,000
Balance | Significant Unobservable Inputs (Level 3)
Assets
Loans (including loans held-for-sale)	3,172,512,000	3,080,485,000
Accrued interest receivable	$ 11,940,000	$ 11,883,000