Allowance For Loan Losses And Credit Quality Of Financing Receivables - Credit Risk Profile By Creditworthiness (Details) - USD ($) $ in Thousands	Mar. 31, 2017	Dec. 31, 2016
Financing Receivable, Recorded Investment [Line Items]
Total loans receivable	$ 719,690	$ 696,142
Commercial And Industrial [Member]
Financing Receivable, Recorded Investment [Line Items]
Total loans receivable	35,906	40,280
Construction [Member]
Financing Receivable, Recorded Investment [Line Items]
Total loans receivable	35,662	25,360
Commercial Real Estate [Member]
Financing Receivable, Recorded Investment [Line Items]
Total loans receivable	485,617	479,227
Residential Real Estate [Member]
Financing Receivable, Recorded Investment [Line Items]
Total loans receivable	161,543	150,237
Consumer And Other [Member]
Financing Receivable, Recorded Investment [Line Items]
Total loans receivable	962	1,038
Pass [Member]
Financing Receivable, Recorded Investment [Line Items]
Total loans receivable	701,795	678,060
Pass [Member] | Commercial And Industrial [Member]
Financing Receivable, Recorded Investment [Line Items]
Total loans receivable	35,783	40,247
Pass [Member] | Construction [Member]
Financing Receivable, Recorded Investment [Line Items]
Total loans receivable	35,662	25,360
Pass [Member] | Commercial Real Estate [Member]
Financing Receivable, Recorded Investment [Line Items]
Total loans receivable	470,313	463,889
Pass [Member] | Residential Real Estate [Member]
Financing Receivable, Recorded Investment [Line Items]
Total loans receivable	159,075	147,526
Pass [Member] | Consumer And Other [Member]
Financing Receivable, Recorded Investment [Line Items]
Total loans receivable	962	1,038
Special Mention [Member]
Financing Receivable, Recorded Investment [Line Items]
Total loans receivable	7,108	8,045
Special Mention [Member] | Commercial And Industrial [Member]
Financing Receivable, Recorded Investment [Line Items]
Total loans receivable	104	0
Special Mention [Member] | Construction [Member]
Financing Receivable, Recorded Investment [Line Items]
Total loans receivable	0	0
Special Mention [Member] | Commercial Real Estate [Member]
Financing Receivable, Recorded Investment [Line Items]
Total loans receivable	6,531	7,461
Special Mention [Member] | Residential Real Estate [Member]
Financing Receivable, Recorded Investment [Line Items]
Total loans receivable	473	584
Special Mention [Member] | Consumer And Other [Member]
Financing Receivable, Recorded Investment [Line Items]
Total loans receivable	0	0
Substandard [Member]
Financing Receivable, Recorded Investment [Line Items]
Total loans receivable	10,768	10,037
Substandard [Member] | Commercial And Industrial [Member]
Financing Receivable, Recorded Investment [Line Items]
Total loans receivable	0	33
Substandard [Member] | Construction [Member]
Financing Receivable, Recorded Investment [Line Items]
Total loans receivable	0	0
Substandard [Member] | Commercial Real Estate [Member]
Financing Receivable, Recorded Investment [Line Items]
Total loans receivable	8,773	7,877
Substandard [Member] | Residential Real Estate [Member]
Financing Receivable, Recorded Investment [Line Items]
Total loans receivable	1,995	2,127
Substandard [Member] | Consumer And Other [Member]
Financing Receivable, Recorded Investment [Line Items]
Total loans receivable	0	0
Doubtful [Member]
Financing Receivable, Recorded Investment [Line Items]
Total loans receivable	19	0
Doubtful [Member] | Commercial And Industrial [Member]
Financing Receivable, Recorded Investment [Line Items]
Total loans receivable	19	0
Doubtful [Member] | Construction [Member]
Financing Receivable, Recorded Investment [Line Items]
Total loans receivable	0	0
Doubtful [Member] | Commercial Real Estate [Member]
Financing Receivable, Recorded Investment [Line Items]
Total loans receivable	0	0
Doubtful [Member] | Residential Real Estate [Member]
Financing Receivable, Recorded Investment [Line Items]
Total loans receivable	0	0
Doubtful [Member] | Consumer And Other [Member]
Financing Receivable, Recorded Investment [Line Items]
Total loans receivable	$ 0	$ 0