Allowance for Loan Losses (Allowance for Loan Losses by Segment & Impairment Methodology) (Details) (USD $) In Thousands, unless otherwise specified	Sep. 30, 2013		Dec. 31, 2012
Financing Receivable, Allowance for Credit Losses [Line Items]
Financing Receivable, Individually Evaluated for Impairment	$ 39,704		$ 35,547
Financing Receivable, Allowance for Credit Losses, Individually Evaluated for Impairment	2,013		2,880
Financing Receivable, Collectively Evaluated for Impairment	2,314,062		2,258,456
Financing Receivable, Allowance for Credit Losses, Collectively Evaluated for Impairment	17,812		19,700
Total loans	2,353,766	[1]	2,294,003	[1]
Financing Receivable, Allowance for Credit Losses	28,008		30,873
Commercial Mortgages [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Financing Receivable, Individually Evaluated for Impairment	32,849		20,250
Financing Receivable, Allowance for Credit Losses, Individually Evaluated for Impairment	1,110		1,720
Financing Receivable, Collectively Evaluated for Impairment	694,526		690,563
Financing Receivable, Allowance for Credit Losses, Collectively Evaluated for Impairment	5,529		7,687
Total loans	727,375		710,813
Commercial Construction and Development [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Financing Receivable, Individually Evaluated for Impairment	0		0
Financing Receivable, Allowance for Credit Losses, Individually Evaluated for Impairment	0		0
Financing Receivable, Collectively Evaluated for Impairment	51,951		27,842
Financing Receivable, Allowance for Credit Losses, Collectively Evaluated for Impairment	441		224
Total loans	51,951		27,842
Commercial Other [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Financing Receivable, Individually Evaluated for Impairment	2,822		10,989
Financing Receivable, Allowance for Credit Losses, Individually Evaluated for Impairment	331		694
Financing Receivable, Collectively Evaluated for Impairment	515,744		502,775
Financing Receivable, Allowance for Credit Losses, Collectively Evaluated for Impairment	5,239		5,302
Total loans	518,566		513,764
Residential Segment [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Financing Receivable, Individually Evaluated for Impairment	3,674		3,868
Financing Receivable, Allowance for Credit Losses, Individually Evaluated for Impairment	569		463
Financing Receivable, Collectively Evaluated for Impairment	728,018		713,813
Financing Receivable, Allowance for Credit Losses, Collectively Evaluated for Impairment	4,111		3,806
Consumer Segment [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Financing Receivable, Individually Evaluated for Impairment	359		440
Financing Receivable, Allowance for Credit Losses, Individually Evaluated for Impairment	3		3
Financing Receivable, Collectively Evaluated for Impairment	323,823		323,463
Financing Receivable, Allowance for Credit Losses, Collectively Evaluated for Impairment	2,492		2,681
Unallocated [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Total loans	0		0
Financing Receivable, Allowance for Credit Losses	$ 8,183		$ 8,293

[1] Includes net unamortized loan origination costs of $531 thousand and $39 thousand, respectively, and net unamortized premiums on purchased loans of $100 thousand and $83 thousand, respectively, at September 30, 2013 and December 31, 2012.