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		6 Months Ended
	Jun. 30, 2012	Jun. 30, 2011	Jun. 30, 2012	Jun. 30, 2011
Financing Receivable, Impaired [Line Items]
Beginning Balance	$ 9,754	$ 9,591	$ 9,602	$ 8,867
Charge offs	(5)	(24)	(8)	(215)
Recoveries	579	19	627	56
Provision	(107)	250	0	1,128
Ending Balance	10,221	9,836	10,221	9,836
Commercial and industrial [Member]
Financing Receivable, Impaired [Line Items]
Beginning Balance	1,784	1,378	1,527	1,272
Charge offs		(20)		(185)
Recoveries				35
Provision	(37)	18	220	254
Ending Balance	1,747	1,376	1,747	1,376
Commercial real estate [Member]
Financing Receivable, Impaired [Line Items]
Beginning Balance	5,876	6,183	5,972	5,715
Recoveries		15		15
Provision	297	(43)	201	425
Ending Balance	6,173	6,155	6,173	6,155
Construction [Member]
Financing Receivable, Impaired [Line Items]
Beginning Balance	637	900	707	551
Recoveries	540		540
Provision	(728)	230	(798)	579
Ending Balance	449	1,130	449	1,130
Residential mortgage [Member]
Financing Receivable, Impaired [Line Items]
Beginning Balance	1,234	952	1,263	1,038
Charge offs				(23)
Recoveries	38	2	85	2
Provision	28	51	(48)	(12)
Ending Balance	1,300	1,005	1,300	1,005
Installment [Member]
Financing Receivable, Impaired [Line Items]
Beginning Balance	54	51	51	52
Charge offs	(5)	(4)	(8)	(7)
Recoveries	1	2	2	4
Provision	9	7	14	7
Ending Balance	59	56	59	56
Unallocated [Member]
Financing Receivable, Impaired [Line Items]
Beginning Balance	169	127	82	239
Provision	324	(13)	411	(125)
Ending Balance	$ 493	$ 114	$ 493	$ 114