Allowance For Loan Losses And Credit Quality Of Financing Receivables - Age Analysis Of Loans Receivable (Details) - USD ($) $ in Thousands	Mar. 31, 2017	Dec. 31, 2016
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Past Due	$ 7,718	$ 8,141
Current	711,972	688,001
Total Financing Receivables	719,690	696,142
Recorded Investment 90 Days and Accruing	104	468
Financing Receivables, 30 to 59 Days Past Due [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Past Due	2,061	874
Financing Receivables, 60 to 89 Days Past Due [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Past Due	105	966
Financing Receivables, Greater than 90 Days [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Past Due	5,552	6,301
Commercial And Industrial [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Past Due	123	137
Current	35,783	40,143
Total Financing Receivables	35,906	40,280
Recorded Investment 90 Days and Accruing	104	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	123	137
Construction [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Past Due	0	309
Current	35,662	25,051
Total Financing Receivables	35,662	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	5,181	4,906
Current	480,436	474,321
Total Financing Receivables	485,617	479,227
Recorded Investment 90 Days and Accruing	0	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	1,233	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	105	719
Commercial Real Estate [Member] | Financing Receivables, Greater than 90 Days [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Past Due	3,843	4,103
Residential Real Estate [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Past Due	2,409	2,785
Current	159,134	147,452
Total Financing Receivables	161,543	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	823	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	1,586	1,752
Consumer And Other [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Past Due	5	4
Current	957	1,034
Total Financing Receivables	962	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