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Loans and Allowance for Loan Losses - Allowance for Loan Losses Activity by Portfolio Segment (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2022	Mar. 31, 2021
Allowances for Loan Losses [Roll Forward]
Balance at beginning of period	$ 35,273	$ 49,006
Loans charged-off	(555)	(795)
Recoveries of loans charged-off	540	622
Net loans (charged-off) recovered	(15)	(173)
Provision for (reversal of) loan losses(1)	266	(7,379)
Balance at end of period	35,524	41,454
Construction Real Estate Loans
Allowances for Loan Losses [Roll Forward]
Balance at beginning of period	3,787	6,490
Loans charged-off	0	0
Recoveries of loans charged-off	0	1
Net loans (charged-off) recovered	0	1
Provision for (reversal of) loan losses(1)	(183)	1,710
Balance at end of period	3,604	8,201
1-4 Family Residential Real Estate Loans
Allowances for Loan Losses [Roll Forward]
Balance at beginning of period	1,866	2,270
Loans charged-off	0	(73)
Recoveries of loans charged-off	39	55
Net loans (charged-off) recovered	39	(18)
Provision for (reversal of) loan losses(1)	77	256
Balance at end of period	1,982	2,508
Commercial Real Estate Loans
Allowances for Loan Losses [Roll Forward]
Balance at beginning of period	26,980	35,709
Loans charged-off	0	0
Recoveries of loans charged-off	47	0
Net loans (charged-off) recovered	47	0
Provision for (reversal of) loan losses(1)	198	(8,473)
Balance at end of period	27,225	27,236
Commercial loans
Allowances for Loan Losses [Roll Forward]
Balance at beginning of period	2,397	4,107
Loans charged-off	(131)	(319)
Recoveries of loans charged-off	216	282
Net loans (charged-off) recovered	85	(37)
Provision for (reversal of) loan losses(1)	(28)	(962)
Balance at end of period	2,454	3,108
Municipal loans
Allowances for Loan Losses [Roll Forward]
Balance at beginning of period	47	46
Loans charged-off	0	0
Recoveries of loans charged-off	0	0
Net loans (charged-off) recovered	0	0
Provision for (reversal of) loan losses(1)	1	0
Balance at end of period	48	46
Loans to individuals
Allowances for Loan Losses [Roll Forward]
Balance at beginning of period	196	384
Loans charged-off	(424)	(403)
Recoveries of loans charged-off	238	284
Net loans (charged-off) recovered	(186)	(119)
Provision for (reversal of) loan losses(1)	201	90
Balance at end of period	$ 211	$ 355

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Amount, after recovery, of writeoff of financing receivable, charged against allowance for credit loss.

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Amount of allowance for credit loss on financing receivable. Excludes allowance for financing receivable covered under loss sharing agreement.

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