Loans - Loan Categories and Past Due Loans (Details) - USD ($) $ in Thousands	Sep. 30, 2020	Dec. 31, 2019	Sep. 30, 2019
Financing Receivable, Recorded Investment, Aging [Abstract]
Loans receivable held-for-sale, net, not part of disposal group	$ 10,580	$ 150	$ 1,905
Recorded investment, past due	12,808	13,606	11,399
Current Loans	2,579,647	2,372,514	2,324,192
Net Loans	2,592,455	2,386,120	2,335,591
Loans 90 or More Days Past Due and Still Accruing Interest	121	253	1,066
Nonaccrual Loans	6,004	4,005	3,465
Commercial Portfolio Segment
Financing Receivable, Recorded Investment, Aging [Abstract]
Recorded investment, past due	144	213	147
Current Loans	275,777	150,447	141,988
Net Loans	275,921	150,660	142,135
Loans 90 or More Days Past Due and Still Accruing Interest	0	0	0
Nonaccrual Loans	72	81	28
Commercial Real Estate
Financing Receivable, Recorded Investment, Aging [Abstract]
Recorded investment, past due	1,560	592	358
Current Loans	539,673	509,949	497,725
Net Loans	541,233	510,541	498,083
Loans 90 or More Days Past Due and Still Accruing Interest	0	0	0
Nonaccrual Loans	1,475	326	465
Consumer
Financing Receivable, Recorded Investment, Aging [Abstract]
Recorded investment, past due	8,394	8,815	7,255
Current Loans	841,132	802,383	798,542
Net Loans	849,526	811,198	805,797
Loans 90 or More Days Past Due and Still Accruing Interest	0	0	86
Nonaccrual Loans	1,559	663	564
Residential
Financing Receivable, Recorded Investment, Aging [Abstract]
Recorded investment, past due	2,710	3,986	3,639
Current Loans	923,065	909,735	885,937
Net Loans	925,775	913,721	889,576
Loans 90 or More Days Past Due and Still Accruing Interest	121	253	980
Nonaccrual Loans	2,898	2,935	2,408
Financing Receivables, 30 to 59 Days Past Due
Financing Receivable, Recorded Investment, Aging [Abstract]
Recorded investment, past due	4,709	5,972	5,556
Financing Receivables, 30 to 59 Days Past Due \| Commercial Portfolio Segment
Financing Receivable, Recorded Investment, Aging [Abstract]
Recorded investment, past due	43	150	99
Financing Receivables, 30 to 59 Days Past Due \| Commercial Real Estate
Financing Receivable, Recorded Investment, Aging [Abstract]
Recorded investment, past due	0	0	0
Financing Receivables, 30 to 59 Days Past Due \| Consumer
Financing Receivable, Recorded Investment, Aging [Abstract]
Recorded investment, past due	4,238	5,670	5,216
Financing Receivables, 30 to 59 Days Past Due \| Residential
Financing Receivable, Recorded Investment, Aging [Abstract]
Recorded investment, past due	428	152	241
Financing Receivables, 60 to 89 Days Past Due
Financing Receivable, Recorded Investment, Aging [Abstract]
Recorded investment, past due	3,782	5,035	2,713
Financing Receivables, 60 to 89 Days Past Due \| Commercial Portfolio Segment
Financing Receivable, Recorded Investment, Aging [Abstract]
Recorded investment, past due	79	42	48
Financing Receivables, 60 to 89 Days Past Due \| Commercial Real Estate
Financing Receivable, Recorded Investment, Aging [Abstract]
Recorded investment, past due	85	266	30
Financing Receivables, 60 to 89 Days Past Due \| Consumer
Financing Receivable, Recorded Investment, Aging [Abstract]
Recorded investment, past due	2,853	2,700	1,624
Financing Receivables, 60 to 89 Days Past Due \| Residential
Financing Receivable, Recorded Investment, Aging [Abstract]
Recorded investment, past due	765	2,027	1,011
Financing Receivables, Equal to Greater than 90 Days Past Due
Financing Receivable, Recorded Investment, Aging [Abstract]
Recorded investment, past due	4,317	2,599	3,130
Financing Receivables, Equal to Greater than 90 Days Past Due \| Commercial Portfolio Segment
Financing Receivable, Recorded Investment, Aging [Abstract]
Recorded investment, past due	22	21	0
Financing Receivables, Equal to Greater than 90 Days Past Due \| Commercial Real Estate
Financing Receivable, Recorded Investment, Aging [Abstract]
Recorded investment, past due	1,475	326	328
Financing Receivables, Equal to Greater than 90 Days Past Due \| Consumer
Financing Receivable, Recorded Investment, Aging [Abstract]
Recorded investment, past due	1,303	445	415
Financing Receivables, Equal to Greater than 90 Days Past Due \| Residential
Financing Receivable, Recorded Investment, Aging [Abstract]
Recorded investment, past due	$ 1,517	$ 1,807	$ 2,387

Amount of financing receivable 90 days or more past due and still accruing.

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