Allowance for Loan Losses and Reserve for Unfunded Loan Commitments - Allowance for Credit Losses on Basis of Impairment Method (Details) - USD ($) $ in Thousands	Mar. 31, 2021	Dec. 31, 2020	Mar. 31, 2020	Dec. 31, 2019
Financing Receivable, Allowance for Credit Losses [Line Items]
Total	$ 22,965	$ 23,105	$ 17,376	$ 16,395
Total	1,659,639	1,618,482
SBA loans held for investment
Financing Receivable, Allowance for Credit Losses [Line Items]
Total	1,654	1,301	1,005	1,079
Total	38,296	39,587
SBA including PPP loans held for investment
Financing Receivable, Allowance for Credit Losses [Line Items]
Individually evaluated for impairment	319	324
Collectively evaluated for impairment	1,335	977
Total	1,654	1,301
Individually evaluated for impairment	1,421	2,102
Collectively evaluated for impairment	205,992	155,742
Total	207,413	157,844
Commercial loans
Financing Receivable, Allowance for Credit Losses [Line Items]
Individually evaluated for impairment	2,999	3,682
Collectively evaluated for impairment	11,728	11,310
Total	14,727	14,992	10,129	9,722
Individually evaluated for impairment	5,018	5,702
Collectively evaluated for impairment	848,060	834,086
Total	853,078	839,788
Residential mortgage loans
Financing Receivable, Allowance for Credit Losses [Line Items]
Individually evaluated for impairment	44	101
Collectively evaluated for impairment	4,965	5,217
Total	5,009	5,318	4,763	4,254
Individually evaluated for impairment	6,711	5,217
Collectively evaluated for impairment	441,438	462,369
Total	448,149	467,586
Consumer loans
Financing Receivable, Allowance for Credit Losses [Line Items]
Collectively evaluated for impairment	549	681
Total	549	681	671	625
Individually evaluated for impairment	427	1,295
Collectively evaluated for impairment	60,075	64,805
Total	60,502	66,100
Consumer construction loans
Financing Receivable, Allowance for Credit Losses [Line Items]
Individually evaluated for impairment	189
Collectively evaluated for impairment	837	813
Total	1,026	813	$ 808	$ 715
Individually evaluated for impairment	2,565	1,750
Collectively evaluated for impairment	87,932	85,414
Total	90,497	87,164
Total
Financing Receivable, Allowance for Credit Losses [Line Items]
Individually evaluated for impairment	3,551	4,107
Collectively evaluated for impairment	19,414	18,998
Total	22,965	23,105
Individually evaluated for impairment	16,142	16,066
Collectively evaluated for impairment	1,643,497	1,602,416
Total	$ 1,659,639	$ 1,618,482

The valuation allowance for financing receivables that are expected to be uncollectible that were collectively evaluated for impairment.

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-Publisher FASB
-Name Accounting Standards Codification
-Topic 310
-SubTopic 10
-Section 50
-Paragraph 11B
-Subparagraph (g)
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Amount of valuation allowance for financing receivables that are expected to be uncollectible that were individually evaluated for impairment.

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The balance of financing receivables that were collectively evaluated for impairment.

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The balance of financing receivables that were individually evaluated for impairment.

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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.

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Amount before allowance of loans and leases held in portfolio, including but not limited to, commercial and consumer loans. Includes deferred interest and fees, undisbursed portion of loan balance, unamortized costs and premiums and discounts from face amounts. Excludes loans and leases covered under loss sharing agreements.

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