Loans - Aging Analysis of Past Due and Nonaccrual Loans by Class (Details) - USD ($) $ in Thousands	Jun. 30, 2018	Dec. 31, 2017
Financing Receivable, Recorded Investment [Line Items]
Loans receivable, past due	$ 11,793	$ 8,308
Loans receivable, nonaccrual status	5,209	2,994
Loans receivable, current	1,219,829	1,139,556
Loan receivable, current	1,234,718	1,162,366
Total loans	1,231,622	1,147,864
SBA loans held for sale	14,889	22,810
Total loans	1,246,511	1,170,674
30-59 days past due
Financing Receivable, Recorded Investment [Line Items]
Loans receivable, past due	4,261	2,705
60-89 days past due
Financing Receivable, Recorded Investment [Line Items]
Loans receivable, past due	2,037	2,549
90 days and still accruing
Financing Receivable, Recorded Investment [Line Items]
Loans receivable, past due	286	60
SBA loans held for investment
Financing Receivable, Recorded Investment [Line Items]
Loans receivable, past due	1,480	1,185
Loans receivable, nonaccrual status	1,420	632
Loan receivable, current	39,871	42,814
Total loans	41,351	43,999
SBA loans held for investment \| 30-59 days past due
Financing Receivable, Recorded Investment [Line Items]
Loans receivable, past due	60	240
SBA loans held for investment \| 60-89 days past due
Financing Receivable, Recorded Investment [Line Items]
Loans receivable, past due	0	313
SBA loans held for investment \| 90 days and still accruing
Financing Receivable, Recorded Investment [Line Items]
Loans receivable, past due	0	0
SBA 504 loans
Financing Receivable, Recorded Investment [Line Items]
Loans receivable, past due	0	0
Loans receivable, nonaccrual status	0	0
Loan receivable, current	23,927	21,871
Total loans	23,927	21,871
SBA 504 loans \| 30-59 days past due
Financing Receivable, Recorded Investment [Line Items]
Loans receivable, past due	0	0
SBA 504 loans \| 60-89 days past due
Financing Receivable, Recorded Investment [Line Items]
Loans receivable, past due	0	0
SBA 504 loans \| 90 days and still accruing
Financing Receivable, Recorded Investment [Line Items]
Loans receivable, past due	0	0
Commercial loans
Financing Receivable, Recorded Investment [Line Items]
Loans receivable, nonaccrual status	2,000
Total loans	673,480	628,865
Commercial loans \| Other
Financing Receivable, Recorded Investment [Line Items]
Loans receivable, past due	58	108
Loans receivable, nonaccrual status	19	25
Loan receivable, current	96,701	82,717
Total loans	96,759	82,825
Commercial loans \| Commercial real estate
Financing Receivable, Recorded Investment [Line Items]
Loans receivable, past due	2,355	1,674
Loans receivable, nonaccrual status	2,043	43
Loan receivable, current	477,175	468,022
Total loans	479,530	469,696
Commercial loans \| Commercial real estate construction
Financing Receivable, Recorded Investment [Line Items]
Loans receivable, past due	0	0
Loans receivable, nonaccrual status	0	0
Loan receivable, current	73,264	54,473
Total loans	73,264	54,473
Commercial loans \| 30-59 days past due \| Other
Financing Receivable, Recorded Investment [Line Items]
Loans receivable, past due	39	23
Commercial loans \| 30-59 days past due \| Commercial real estate
Financing Receivable, Recorded Investment [Line Items]
Loans receivable, past due	312	558
Commercial loans \| 30-59 days past due \| Commercial real estate construction
Financing Receivable, Recorded Investment [Line Items]
Loans receivable, past due	0	0
Commercial loans \| 60-89 days past due \| Other
Financing Receivable, Recorded Investment [Line Items]
Loans receivable, past due	0	0
Commercial loans \| 60-89 days past due \| Commercial real estate
Financing Receivable, Recorded Investment [Line Items]
Loans receivable, past due	0	1,073
Commercial loans \| 60-89 days past due \| Commercial real estate construction
Financing Receivable, Recorded Investment [Line Items]
Loans receivable, past due	0	0
Commercial loans \| 90 days and still accruing \| Other
Financing Receivable, Recorded Investment [Line Items]
Loans receivable, past due	0	60
Commercial loans \| 90 days and still accruing \| Commercial real estate
Financing Receivable, Recorded Investment [Line Items]
Loans receivable, past due	0	0
Commercial loans \| 90 days and still accruing \| Commercial real estate construction
Financing Receivable, Recorded Investment [Line Items]
Loans receivable, past due	0	0
Residential mortgage loans
Financing Receivable, Recorded Investment [Line Items]
Loans receivable, past due	7,534	4,457
Loans receivable, nonaccrual status	1,660	1,669
Loan receivable, current	390,849	360,688
Total loans	398,383	365,145
Residential mortgage loans \| 30-59 days past due
Financing Receivable, Recorded Investment [Line Items]
Loans receivable, past due	3,749	1,830
Residential mortgage loans \| 60-89 days past due
Financing Receivable, Recorded Investment [Line Items]
Loans receivable, past due	1,839	958
Residential mortgage loans \| 90 days and still accruing
Financing Receivable, Recorded Investment [Line Items]
Loans receivable, past due	286	0
Consumer loans
Financing Receivable, Recorded Investment [Line Items]
Total loans	118,408	109,855
Consumer loans \| Other
Financing Receivable, Recorded Investment [Line Items]
Loans receivable, past due	0	3
Loans receivable, nonaccrual status	0	0
Loan receivable, current	57,434	54,035
Total loans	57,434	54,038
Consumer loans \| Home equity
Financing Receivable, Recorded Investment [Line Items]
Loans receivable, past due	366	881
Loans receivable, nonaccrual status	67	625
Loan receivable, current	60,608	54,936
Total loans	60,974	55,817
Consumer loans \| 30-59 days past due \| Other
Financing Receivable, Recorded Investment [Line Items]
Loans receivable, past due	0	3
Consumer loans \| 30-59 days past due \| Home equity
Financing Receivable, Recorded Investment [Line Items]
Loans receivable, past due	101	51
Consumer loans \| 60-89 days past due \| Other
Financing Receivable, Recorded Investment [Line Items]
Loans receivable, past due	0	0
Consumer loans \| 60-89 days past due \| Home equity
Financing Receivable, Recorded Investment [Line Items]
Loans receivable, past due	198	205
Consumer loans \| 90 days and still accruing \| Other
Financing Receivable, Recorded Investment [Line Items]
Loans receivable, past due	0	0
Consumer loans \| 90 days and still accruing \| Home equity
Financing Receivable, Recorded Investment [Line Items]
Loans receivable, past due	0	0
Small Business Administration
Financing Receivable, Recorded Investment [Line Items]
Loans receivable, nonaccrual status	579
Collateral Pledged \| Small Business Administration
Financing Receivable, Recorded Investment [Line Items]
Loans receivable, nonaccrual status	$ 129	$ 27

Financing receivables that are current.

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