Loans and the Allowance for Loan Losses (Allowance for Loan and Lease Losses) (Details) (USD $) In Thousands, unless otherwise specified	Sep. 30, 2013	Jun. 30, 2013	Dec. 31, 2012	Sep. 30, 2012	Jun. 30, 2012	Dec. 31, 2011
Financing Receivable, Impaired [Line Items]
Allowance for loan and lease losses: Individually evaluated for impairment	$ 219		$ 645
Allowance for loan and lease losses: Collectively evaluated for impairment	9,975		9,592
Allowance for loan and lease losses: Total	10,194	10,202	10,237	10,240	10,221	9,602
Loans Receivable: Individually evaluated for impairment	2,563		6,935
Loans Receivable: Collectively evaluated for impairment	919,649		834,516
Loans receivable: Loans acquired with discounts related to credit quality	35,124		48,098
Total Loans Receivable	957,336		889,549
Commercial and industrial [Member]
Financing Receivable, Impaired [Line Items]
Allowance for loan and lease losses: Individually evaluated for impairment	0		0
Allowance for loan and lease losses: Collectively evaluated for impairment	1,714		2,424
Allowance for loan and lease losses: Total	1,714	2,422	2,424	1,692	1,747	1,527
Loans Receivable: Individually evaluated for impairment	0		0
Loans Receivable: Collectively evaluated for impairment	226,664		177,644
Loans receivable: Loans acquired with discounts related to credit quality	2,548		4,038
Total Loans Receivable	229,212		181,682
Commercial real estate [Member]
Financing Receivable, Impaired [Line Items]
Allowance for loan and lease losses: Individually evaluated for impairment	76		493
Allowance for loan and lease losses: Collectively evaluated for impairment	5,712		4,830
Allowance for loan and lease losses: Total	5,788	5,333	5,323	6,276	6,173	5,972
Loans Receivable: Individually evaluated for impairment	1,450		5,680
Loans Receivable: Collectively evaluated for impairment	512,949		470,797
Loans receivable: Loans acquired with discounts related to credit quality	17,275		20,915
Total Loans Receivable	531,674		497,392
Construction [Member]
Financing Receivable, Impaired [Line Items]
Allowance for loan and lease losses: Individually evaluated for impairment	0		0
Allowance for loan and lease losses: Collectively evaluated for impairment	369		313
Allowance for loan and lease losses: Total	369	318	313	492	449	707
Loans Receivable: Individually evaluated for impairment	0		0
Loans Receivable: Collectively evaluated for impairment	41,640		38,172
Loans receivable: Loans acquired with discounts related to credit quality	1,087		2,105
Total Loans Receivable	42,727		40,277
Residential mortgage [Member]
Financing Receivable, Impaired [Line Items]
Allowance for loan and lease losses: Individually evaluated for impairment	143		152
Allowance for loan and lease losses: Collectively evaluated for impairment	1,161		1,380
Allowance for loan and lease losses: Total	1,304	1,341	1,532	1,164	1,300	1,263
Loans Receivable: Individually evaluated for impairment	1,113		1,255
Loans Receivable: Collectively evaluated for impairment	137,733		146,930
Loans receivable: Loans acquired with discounts related to credit quality	14,088		20,909
Total Loans Receivable	152,934		169,094
Installment [Member]
Financing Receivable, Impaired [Line Items]
Allowance for loan and lease losses: Individually evaluated for impairment	0		0
Allowance for loan and lease losses: Collectively evaluated for impairment	94		113
Allowance for loan and lease losses: Total	94	29	113	64	59	51
Loans Receivable: Individually evaluated for impairment	0		0
Loans Receivable: Collectively evaluated for impairment	663		973
Loans receivable: Loans acquired with discounts related to credit quality	126		131
Total Loans Receivable	789		1,104
Unallocated [Member]
Financing Receivable, Impaired [Line Items]
Allowance for loan and lease losses: Individually evaluated for impairment	0		0
Allowance for loan and lease losses: Collectively evaluated for impairment	925		532
Allowance for loan and lease losses: Total	925	759	532	552	493	82
Loans Receivable: Individually evaluated for impairment	0		0
Loans Receivable: Collectively evaluated for impairment	0		0
Loans receivable: Loans acquired with discounts related to credit quality	0		0
Total Loans Receivable	$ 0		$ 0