Allowance For Loan Losses And Credit Quality Of Financing Receivables - Changes In The Allowance For Loan Losses (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2017	Mar. 31, 2016
Financing Receivable, Allowance for Credit Losses [Roll Forward]
Beginning balance	$ 6,696	$ 5,590
Charge-offs	(318)	(28)
Recoveries	12	39
Provision	407	211
Ending balance	6,797	5,812
Commercial And Industrial [Member]
Financing Receivable, Allowance for Credit Losses [Roll Forward]
Beginning balance	110	85
Charge-offs	(13)	0
Recoveries	0	7
Provision	(5)	6
Ending balance	92	98
Construction [Member]
Financing Receivable, Allowance for Credit Losses [Roll Forward]
Beginning balance	359	220
Provision	66	47
Ending balance	425	267
Commercial Real Estate [Member]
Financing Receivable, Allowance for Credit Losses [Roll Forward]
Beginning balance	3,932	3,646
Charge-offs	(266)	0
Recoveries	2	31
Provision	357	170
Ending balance	4,025	3,847
Residential Real Estate [Member]
Financing Receivable, Allowance for Credit Losses [Roll Forward]
Beginning balance	899	784
Charge-offs	(34)	(9)
Recoveries	8	0
Provision	52	133
Ending balance	925	908
Consumer And Other [Member]
Financing Receivable, Allowance for Credit Losses [Roll Forward]
Beginning balance	19	87
Charge-offs	(5)	(19)
Recoveries	2	1
Provision	1	52
Ending balance	17	121
Unallocated [Member]
Financing Receivable, Allowance for Credit Losses [Roll Forward]
Beginning balance	1,377	768
Provision	(64)	(197)
Ending balance	$ 1,313	$ 571