Loans (Past Due Loans) (Details) (USD $)	Jun. 30, 2012		Dec. 31, 2011
Financing Receivable, Recorded Investment, Past Due [Line Items]
Loans 30 to 59 Days Past Due	$ 8,889,000		$ 10,423,000
Loans 60 to 89 Days Past Due	2,944,000		3,065,000
Loans Over 90 Days Past Due	8,454,000		12,785,000
Total Loans Past Due	20,287,000		26,273,000
Current Loans	2,193,555,000		2,120,886,000
Total loans	2,213,842,000	[1]	2,147,159,000	[1]
Loans Past Due and Nonaccrual	12,700,000		17,600,000
Commercial Mortgages [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Loans 30 to 59 Days Past Due	411,000		1,621,000
Loans 60 to 89 Days Past Due	233,000		315,000
Loans Over 90 Days Past Due	2,339,000		4,995,000
Total Loans Past Due	2,983,000		6,931,000
Current Loans	661,427,000		617,882,000
Total loans	664,410,000		624,813,000
Commercial Construction and Development [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Loans 30 to 59 Days Past Due	0		0
Loans 60 to 89 Days Past Due	0		0
Loans Over 90 Days Past Due	0		0
Total Loans Past Due	0		0
Current Loans	17,365,000		10,955,000
Total loans	17,365,000		10,955,000
Commercial Other [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Loans 30 to 59 Days Past Due	849,000		3,760,000
Loans 60 to 89 Days Past Due	434,000		982,000
Loans Over 90 Days Past Due	1,714,000		633,000
Total Loans Past Due	2,997,000		5,375,000
Current Loans	507,223,000		483,485,000
Total loans	510,220,000		488,860,000
Residential Mortgage [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Loans 30 to 59 Days Past Due	4,969,000		3,969,000
Loans 60 to 89 Days Past Due	1,600,000		1,505,000
Loans Over 90 Days Past Due	4,039,000		6,283,000
Total Loans Past Due	10,608,000		11,757,000
Current Loans	670,164,000		666,825,000
Total loans	680,772,000		678,582,000
Homeowner Construction [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Loans 30 to 59 Days Past Due	0		0
Loans 60 to 89 Days Past Due	0		0
Loans Over 90 Days Past Due	0		0
Total Loans Past Due	0		0
Current Loans	21,247,000		21,832,000
Total loans	21,247,000		21,832,000
Home Equity Lines [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Loans 30 to 59 Days Past Due	1,996,000		645,000
Loans 60 to 89 Days Past Due	548,000		210,000
Loans Over 90 Days Past Due	139,000		525,000
Total Loans Past Due	2,683,000		1,380,000
Current Loans	221,867,000		222,050,000
Total loans	224,550,000		223,430,000
Home Equity Loans [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Loans 30 to 59 Days Past Due	482,000		362,000
Loans 60 to 89 Days Past Due	114,000		46,000
Loans Over 90 Days Past Due	223,000		202,000
Total Loans Past Due	819,000		610,000
Current Loans	39,871,000		42,511,000
Total loans	40,690,000		43,121,000
Other Consumer [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Loans 30 to 59 Days Past Due	182,000		66,000
Loans 60 to 89 Days Past Due	15,000		7,000
Loans Over 90 Days Past Due	0		147,000
Total Loans Past Due	197,000		220,000
Current Loans	54,391,000		55,346,000
Total loans	$ 54,588,000		$ 55,566,000

[1] Includes net unamortized loan origination costs of $6 thousand and $31 thousand, respectively, and net unamortized premiums on purchased loans of $58 thousand and $67 thousand, respectively, at June 30, 2012 and December 31, 2011.