Allowance for Loan Losses (Allowance for Loan Losses Rollforward Analysis) (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, Allowance for Credit Losses [Line Items]
Allowance, Beginning Balance	$ 30,045	$ 29,109	$ 29,802	$ 28,583
Charge-offs	(696)	(1,044)	(1,377)	(2,096)
Recoveries	499	88	523	166
Provision	600	1,200	1,500	2,700
Allowance, Ending Balance	30,448	29,353	30,448	29,353
Commercial Mortgages [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Allowance, Beginning Balance	9,352	7,600	8,195	7,330
Charge-offs	0	(124)	(9)	(459)
Recoveries	388	2	390	4
Provision	(795)	(104)	369	499
Allowance, Ending Balance	8,945	7,374	8,945	7,374
Commercial Construction and Development [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Allowance, Beginning Balance	110	532	95	723
Charge-offs	0	0	0	0
Recoveries	0	0	0	0
Provision	54	(315)	69	(506)
Allowance, Ending Balance	164	217	164	217
Commercial Other [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Allowance, Beginning Balance	5,906	6,256	6,200	6,495
Charge-offs	(580)	(617)	(910)	(1,195)
Recoveries	31	76	37	146
Provision	882	1,278	912	1,547
Allowance, Ending Balance	6,239	6,993	6,239	6,993
Commercial Segment [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Allowance, Beginning Balance	15,368	14,388	14,490	14,548
Charge-offs	(580)	(741)	(919)	(1,654)
Recoveries	419	78	427	150
Provision	141	859	1,350	1,540
Allowance, Ending Balance	15,348	14,584	15,348	14,584
Residential Segment [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Allowance, Beginning Balance	4,325	4,805	4,694	4,129
Charge-offs	(16)	(146)	(250)	(265)
Recoveries	63	0	73	1
Provision	341	(188)	196	606
Allowance, Ending Balance	4,713	4,471	4,713	4,471
Consumer Segment [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Allowance, Beginning Balance	2,133	2,046	2,452	1,903
Charge-offs	(100)	(157)	(208)	(177)
Recoveries	17	10	23	15
Provision	331	253	114	411
Allowance, Ending Balance	2,381	2,152	2,381	2,152
Unallocated [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Allowance, Beginning Balance	8,219	7,870	8,166	8,003
Charge-offs	0	0	0	0
Recoveries	0	0	0	0
Provision	(213)	276	(160)	143
Allowance, Ending Balance	$ 8,006	$ 8,146	$ 8,006	$ 8,146