Loans and Allowance for Loan Losses - Aging (Details) - USD ($) $ in Thousands	Sep. 30, 2019	Dec. 31, 2018	Sep. 30, 2018
Aging categories of performing loans and nonaccrual loans
Current	$ 1,376,600	$ 1,288,346
Total Past Due	5,690	16,236
Total Loans	1,382,290	1,304,582	$ 1,296,125
Non-Accrual	5,627	7,103
90 Plus Days Still Accruing	0	0
Commercial and Non-Residential Real Estate
Aging categories of performing loans and nonaccrual loans
Current	1,020,121	928,621
Total Past Due	3,745	12,412
Total Loans	1,023,866	941,033	929,284
Non-Accrual	3,761	4,495
90 Plus Days Still Accruing	0	0
Commercial and Non-Residential Real Estate | Commercial Business
Aging categories of performing loans and nonaccrual loans
Current	501,063	432,097
Total Past Due	3,303	11,434
Total Loans	504,366	443,531
Non-Accrual	3,059	3,684
90 Plus Days Still Accruing	0	0
Commercial and Non-Residential Real Estate | Commercial Real Estate
Aging categories of performing loans and nonaccrual loans
Current	434,309	374,880
Total Past Due	159	681
Total Loans	434,468	375,561
Non-Accrual	303	385
90 Plus Days Still Accruing	0	0
Commercial and Non-Residential Real Estate | Acquisition & Development
Aging categories of performing loans and nonaccrual loans
Current	84,749	121,644
Total Past Due	283	297
Total Loans	85,032	121,941
Non-Accrual	399	426
90 Plus Days Still Accruing	0	0
Residential Real Estate
Aging categories of performing loans and nonaccrual loans
Current	289,432	291,665
Total Past Due	1,546	3,264
Total Loans	290,978	294,929	298,749
Non-Accrual	1,724	2,442
90 Plus Days Still Accruing	0	0
Home Equity
Aging categories of performing loans and nonaccrual loans
Current	59,196	58,575
Total Past Due	278	440
Total Loans	59,474	59,015	57,629
Non-Accrual	112	84
90 Plus Days Still Accruing	0	0
Consumer
Aging categories of performing loans and nonaccrual loans
Current	7,851	9,485
Total Past Due	121	120
Total Loans	7,972	9,605	$ 10,463
Non-Accrual	30	82
90 Plus Days Still Accruing	0	0
Financing Receivables, 30 to 59 Days Past Due
Aging categories of performing loans and nonaccrual loans
Total Past Due	645	8,489
Financing Receivables, 30 to 59 Days Past Due | Commercial and Non-Residential Real Estate
Aging categories of performing loans and nonaccrual loans
Total Past Due	414	7,061
Financing Receivables, 30 to 59 Days Past Due | Commercial and Non-Residential Real Estate | Commercial Business
Aging categories of performing loans and nonaccrual loans
Total Past Due	255	6,380
Financing Receivables, 30 to 59 Days Past Due | Commercial and Non-Residential Real Estate | Commercial Real Estate
Aging categories of performing loans and nonaccrual loans
Total Past Due	159	681
Financing Receivables, 30 to 59 Days Past Due | Commercial and Non-Residential Real Estate | Acquisition & Development
Aging categories of performing loans and nonaccrual loans
Total Past Due	0	0
Financing Receivables, 30 to 59 Days Past Due | Residential Real Estate
Aging categories of performing loans and nonaccrual loans
Total Past Due	0	1,000
Financing Receivables, 30 to 59 Days Past Due | Home Equity
Aging categories of performing loans and nonaccrual loans
Total Past Due	153	400
Financing Receivables, 30 to 59 Days Past Due | Consumer
Aging categories of performing loans and nonaccrual loans
Total Past Due	78	28
Financing Receivables, 60 to 89 Days Past Due
Aging categories of performing loans and nonaccrual loans
Total Past Due	956	2,556
Financing Receivables, 60 to 89 Days Past Due | Commercial and Non-Residential Real Estate
Aging categories of performing loans and nonaccrual loans
Total Past Due	308	1,746
Financing Receivables, 60 to 89 Days Past Due | Commercial and Non-Residential Real Estate | Commercial Business
Aging categories of performing loans and nonaccrual loans
Total Past Due	308	1,746
Financing Receivables, 60 to 89 Days Past Due | Commercial and Non-Residential Real Estate | Commercial Real Estate
Aging categories of performing loans and nonaccrual loans
Total Past Due	0	0
Financing Receivables, 60 to 89 Days Past Due | Commercial and Non-Residential Real Estate | Acquisition & Development
Aging categories of performing loans and nonaccrual loans
Total Past Due	0	0
Financing Receivables, 60 to 89 Days Past Due | Residential Real Estate
Aging categories of performing loans and nonaccrual loans
Total Past Due	615	760
Financing Receivables, 60 to 89 Days Past Due | Home Equity
Aging categories of performing loans and nonaccrual loans
Total Past Due	13	40
Financing Receivables, 60 to 89 Days Past Due | Consumer
Aging categories of performing loans and nonaccrual loans
Total Past Due	20	10
Financing Receivables, Equal to Greater than 90 Days Past Due
Aging categories of performing loans and nonaccrual loans
Total Past Due	4,089	5,191
Financing Receivables, Equal to Greater than 90 Days Past Due | Commercial and Non-Residential Real Estate
Aging categories of performing loans and nonaccrual loans
Total Past Due	3,023	3,605
Financing Receivables, Equal to Greater than 90 Days Past Due | Commercial and Non-Residential Real Estate | Commercial Business
Aging categories of performing loans and nonaccrual loans
Total Past Due	2,740	3,308
Financing Receivables, Equal to Greater than 90 Days Past Due | Commercial and Non-Residential Real Estate | Commercial Real Estate
Aging categories of performing loans and nonaccrual loans
Total Past Due	0	0
Financing Receivables, Equal to Greater than 90 Days Past Due | Commercial and Non-Residential Real Estate | Acquisition & Development
Aging categories of performing loans and nonaccrual loans
Total Past Due	283	297
Financing Receivables, Equal to Greater than 90 Days Past Due | Residential Real Estate
Aging categories of performing loans and nonaccrual loans
Total Past Due	931	1,504
Financing Receivables, Equal to Greater than 90 Days Past Due | Home Equity
Aging categories of performing loans and nonaccrual loans
Total Past Due	112	0
Financing Receivables, Equal to Greater than 90 Days Past Due | Consumer
Aging categories of performing loans and nonaccrual loans
Total Past Due	$ 23	$ 82