Loans (Past Due Loans) (Details) (USD $)	Sep. 30, 2013		Dec. 31, 2012
Financing Receivable, Recorded Investment, Past Due [Line Items]
Loans Receivable, Past Due, Nonaccrual	$ 17,300,000		$ 21,000,000
Loans 30 to 59 Days Past Due	6,285,000		6,607,000
Loans 60 to 89 Days Past Due	3,026,000		3,040,000
Loans Over 90 Days Past Due	14,691,000		18,449,000
Total Loans Past Due	24,002,000		28,096,000
Current Loans	2,329,764,000		2,265,907,000
Total loans	2,353,766,000	[1]	2,294,003,000	[1]
Commercial Mortgages [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Loans 30 to 59 Days Past Due	0		373,000
Loans 60 to 89 Days Past Due	730,000		408,000
Loans Over 90 Days Past Due	8,226,000		10,300,000
Total Loans Past Due	8,956,000		11,081,000
Current Loans	718,419,000		699,732,000
Total loans	727,375,000		710,813,000
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	51,951,000		27,842,000
Total loans	51,951,000		27,842,000
Commercial Other [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Loans 30 to 59 Days Past Due	2,648,000		260,000
Loans 60 to 89 Days Past Due	8,000		296,000
Loans Over 90 Days Past Due	929,000		3,647,000
Total Loans Past Due	3,585,000		4,203,000
Current Loans	514,981,000		509,561,000
Total loans	518,566,000		513,764,000
Residential Mortgage [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Loans 30 to 59 Days Past Due	2,624,000		4,840,000
Loans 60 to 89 Days Past Due	1,960,000		1,951,000
Loans Over 90 Days Past Due	4,843,000		3,658,000
Total Loans Past Due	9,427,000		10,449,000
Current Loans	702,000,000		682,349,000
Total loans	711,427,000		692,798,000
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	20,265,000		24,883,000
Total loans	20,265,000		24,883,000
Home Equity Lines [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Loans 30 to 59 Days Past Due	636,000		753,000
Loans 60 to 89 Days Past Due	220,000		207,000
Loans Over 90 Days Past Due	262,000		528,000
Total Loans Past Due	1,118,000		1,488,000
Current Loans	225,945,000		225,373,000
Total loans	227,063,000		226,861,000
Home Equity Loans [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Loans 30 to 59 Days Past Due	339,000		252,000
Loans 60 to 89 Days Past Due	104,000		114,000
Loans Over 90 Days Past Due	416,000		250,000
Total Loans Past Due	859,000		616,000
Current Loans	40,299,000		38,713,000
Total loans	41,158,000		39,329,000
Other Consumer [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Loans 30 to 59 Days Past Due	38,000		129,000
Loans 60 to 89 Days Past Due	4,000		64,000
Loans Over 90 Days Past Due	15,000		66,000
Total Loans Past Due	57,000		259,000
Current Loans	55,904,000		57,454,000
Total loans	$ 55,961,000		$ 57,713,000

[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.