Allowance for Loan Losses and Reserve for Unfunded Loan Commitments - Loans and their Related Allowance for Loan Losses, by Portfolio Segment) (Details) - USD ($) $ in Thousands	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Financing Receivable, Allowance for Credit Losses [Line Items]
Individually evaluated for impairment	$ 414	$ 667
Collectively evaluated for impairment	15,981	14,821
Total	16,395	15,488	$ 13,556	$ 12,579
Individually evaluated for impairment	2,339	3,292
Collectively evaluated for impairment	1,409,690	1,290,103
Total	1,412,029	1,293,395
SBA loans held for investment
Financing Receivable, Allowance for Credit Losses [Line Items]
Individually evaluated for impairment	41	540
Collectively evaluated for impairment	1,038	1,115
Total	1,079	1,655	1,471	1,576
Individually evaluated for impairment	1,105	1,471
Collectively evaluated for impairment	34,662	37,862
Total	35,767	39,333
Commercial loans
Financing Receivable, Allowance for Credit Losses [Line Items]
Individually evaluated for impairment	373	127
Collectively evaluated for impairment	9,349	8,578
Total	9,722	8,705	7,825	7,302
Individually evaluated for impairment	1,234	1,821
Collectively evaluated for impairment	763,798	692,281
Total	765,032	694,102
Residential mortgage loans
Financing Receivable, Allowance for Credit Losses [Line Items]
Individually evaluated for impairment	0	0
Collectively evaluated for impairment	4,254	3,900
Total	4,254	3,900	3,130	2,593
Individually evaluated for impairment	0	0
Collectively evaluated for impairment	467,706	436,056
Total	467,706	436,056
Consumer loans
Financing Receivable, Allowance for Credit Losses [Line Items]
Individually evaluated for impairment	0	0
Collectively evaluated for impairment	1,340	1,228
Total	1,340	1,228	$ 1,130	$ 925
Individually evaluated for impairment	0	0
Collectively evaluated for impairment	143,524	123,904
Total	$ 143,524	$ 123,904

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
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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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