Loans and the Allowance for Loan Losses (Summary of Activity in Allowance for Loan Losses) (Details) (USD $) In Thousands, unless otherwise specified	3 Months Ended		9 Months Ended
	Sep. 30, 2012	Sep. 30, 2011	Sep. 30, 2012	Sep. 30, 2011
Financing Receivable, Impaired [Line Items]
Beginning Balance	$ 10,221	$ 9,836	$ 9,602	$ 8,867
Charge offs	(210)	(1,578)	(218)	(1,793)
Recoveries	4	258	631	314
Provision	225	1,020	225	2,148
Ending Balance	10,240	9,536	10,240	9,536
Commercial and industrial [Member]
Financing Receivable, Impaired [Line Items]
Beginning Balance	1,747	1,376	1,527	1,272
Charge offs				(185)
Recoveries		205		240
Provision	(55)	(205)	165	49
Ending Balance	1,692	1,376	1,692	1,376
Commercial real estate [Member]
Financing Receivable, Impaired [Line Items]
Beginning Balance	6,173	6,155	5,972	5,715
Charge offs		(940)		(940)
Recoveries				15
Provision	103	667	304	1,092
Ending Balance	6,276	5,882	6,276	5,882
Construction [Member]
Financing Receivable, Impaired [Line Items]
Beginning Balance	449	1,130	707	551
Charge offs		(631)		(631)
Recoveries			540
Provision	43	206	(755)	785
Ending Balance	492	705	492	705
Residential mortgage [Member]
Financing Receivable, Impaired [Line Items]
Beginning Balance	1,300	1,005	1,263	1,038
Charge offs	(207)		(207)	(23)
Recoveries		51	85	53
Provision	71	182	23	170
Ending Balance	1,164	1,238	1,164	1,238
Installment [Member]
Financing Receivable, Impaired [Line Items]
Beginning Balance	59	56	51	52
Charge offs	(3)	(7)	(11)	(14)
Recoveries	4	2	6	6
Provision	4	(3)	18	4
Ending Balance	64	48	64	48
Unallocated [Member]
Financing Receivable, Impaired [Line Items]
Beginning Balance	493	114	82	239
Provision	59	173	470	48
Ending Balance	$ 552	$ 287	$ 552	$ 287