Allowance For Loan Losses And Credit Quality Of Financing Receivables - Age Analysis Of Loans Receivable (Details) - USD ($) $ in Thousands	Jun. 30, 2017	Dec. 31, 2016
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Past Due	$ 8,373	$ 8,141
Current	764,844	688,001
Total Financing Receivables	773,217	696,142
Recorded Investment 90 Days and Accruing	2,229	468
Financing Receivables, 30 to 59 Days Past Due [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Past Due	521	874
Financing Receivables, 60 to 89 Days Past Due [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Past Due	0	966
Financing Receivables, Greater than 90 Days [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Past Due	7,852	6,301
Commercial And Industrial [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Past Due	1,020	137
Current	39,782	40,143
Total Financing Receivables	40,802	40,280
Recorded Investment 90 Days and Accruing	1,000	104
Commercial And Industrial [Member] | Financing Receivables, 30 to 59 Days Past Due [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Past Due	0	0
Commercial And Industrial [Member] | Financing Receivables, 60 to 89 Days Past Due [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Past Due	0	0
Commercial And Industrial [Member] | Financing Receivables, Greater than 90 Days [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Past Due	1,020	137
Construction [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Past Due	0	309
Current	41,213	25,051
Total Financing Receivables	41,213	25,360
Recorded Investment 90 Days and Accruing	0	309
Construction [Member] | Financing Receivables, 30 to 59 Days Past Due [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Past Due	0	0
Construction [Member] | Financing Receivables, 60 to 89 Days Past Due [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Past Due	0	0
Construction [Member] | Financing Receivables, Greater than 90 Days [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Past Due	0	309
Commercial Real Estate [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Past Due	5,637	4,906
Current	520,417	474,321
Total Financing Receivables	526,054	479,227
Recorded Investment 90 Days and Accruing	1,229	55
Commercial Real Estate [Member] | Financing Receivables, 30 to 59 Days Past Due [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Past Due	355	84
Commercial Real Estate [Member] | Financing Receivables, 60 to 89 Days Past Due [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Past Due	0	719
Commercial Real Estate [Member] | Financing Receivables, Greater than 90 Days [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Past Due	5,282	4,103
Residential Real Estate [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Past Due	1,711	2,785
Current	162,470	147,452
Total Financing Receivables	164,181	150,237
Recorded Investment 90 Days and Accruing	0	0
Residential Real Estate [Member] | Financing Receivables, 30 to 59 Days Past Due [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Past Due	161	786
Residential Real Estate [Member] | Financing Receivables, 60 to 89 Days Past Due [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Past Due	0	247
Residential Real Estate [Member] | Financing Receivables, Greater than 90 Days [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Past Due	1,550	1,752
Consumer And Other [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Past Due	5	4
Current	962	1,034
Total Financing Receivables	967	1,038
Recorded Investment 90 Days and Accruing	0	0
Consumer And Other [Member] | Financing Receivables, 30 to 59 Days Past Due [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Past Due	5	4
Consumer And Other [Member] | Financing Receivables, 60 to 89 Days Past Due [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Past Due	0	0
Consumer And Other [Member] | Financing Receivables, Greater than 90 Days [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Past Due	$ 0	$ 0