Allowance for Loan Losses and Reserve for Unfunded Loan Commitments - Activity in the Allowance for Loan Losses by Portfolio Segment (Details) - USD ($) $ in Thousands	3 Months Ended
Mar. 31, 2022	Mar. 31, 2021
Allowance for Loan and Lease Losses [Roll Forward]
Balance, beginning of period	$ 22,302	$ 23,105
Charge-offs	(6)	(656)
Recoveries	50	16
Net recoveries (charge-offs)	44	(640)
Provision for (credit to) loan losses charged to expense	(178)	500
Balance, end of period	22,168	22,965
SBA loans held for investment
Allowance for Loan and Lease Losses [Roll Forward]
Balance, beginning of period	1,074	1,301
Charge-offs		(282)
Recoveries	22	15
Net recoveries (charge-offs)	22	(267)
Provision for (credit to) loan losses charged to expense	(155)	620
Balance, end of period	941	1,654
Commercial loans
Allowance for Loan and Lease Losses [Roll Forward]
Balance, beginning of period	15,053	14,992
Charge-offs		(373)
Recoveries	28	1
Net recoveries (charge-offs)	28	(372)
Provision for (credit to) loan losses charged to expense	(376)	107
Balance, end of period	14,705	14,727
Residential mortgage loans
Allowance for Loan and Lease Losses [Roll Forward]
Balance, beginning of period	4,114	5,318
Provision for (credit to) loan losses charged to expense	170	(309)
Balance, end of period	4,284	5,009
Consumer loans
Allowance for Loan and Lease Losses [Roll Forward]
Balance, beginning of period	671	681
Charge-offs	(6)	(1)
Net recoveries (charge-offs)	(6)	(1)
Provision for (credit to) loan losses charged to expense	(23)	(131)
Balance, end of period	642	549
Residential construction loans
Allowance for Loan and Lease Losses [Roll Forward]
Balance, beginning of period	1,390	813
Provision for (credit to) loan losses charged to expense	206	213
Balance, end of period	$ 1,596	$ 1,026

Amount of recovery of loans and lease receivables which had previously been fully or partially written-off as bad debts.

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 310
-SubTopic 10
-Section 50
-Paragraph 11B
-Subparagraph (c)(4)
-URI http://asc.fasb.org/extlink&oid=123577603&loc=SL6953423-111524

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Amount of loans and leases that have been written off from both loan receivables and allowance reserve for credit loss.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 310
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Amount, after recoveries, of loans and leases that have been written-off.

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Amount of allowance to cover probable credit losses on loans and leases. Includes carryover of or adjustments to the allowance for loan losses in connection with business combinations. Excludes allowance for loans and leases covered under loss sharing agreements.

+ References

Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef
-Publisher FASB
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-Topic 310
-SubTopic 10
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Amount of expense related to estimated loss from loan and lease transactions.

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