Loans and Allowance for Loan Losses (Loan Aging Analysis by Portfolio Segment (Including Loans Past Due Over Ninety Days and Non Accrual Loans) and Summary of Non Accrual Loans) (Details) (USD $) In Thousands, unless otherwise specified	Dec. 31, 2012	Dec. 31, 2011
Financing Receivable, Recorded Investment, Past Due [Line Items]
30-59 days Past Due	$ 6,006	$ 6,613
60-89 days Past Due	3,699	2,470
Greater Than 90 Days	18,123	16,770
Total Past Due	27,828	25,853
Current	1,536,038	1,488,175
Loans ending balance	1,563,866	1,514,028
Loans > 90 Days Past Due and Accruing	611	236
Non-Accrual Loans	22,483	24,110
Residential real estate loans
Financing Receivable, Recorded Investment, Past Due [Line Items]
30-59 days Past Due	1,459	2,207
60-89 days Past Due	850	575
Greater Than 90 Days	8,410	7,373
Total Past Due	10,719	10,155
Current	561,454	568,107
Loans ending balance	572,173	578,262
Loans > 90 Days Past Due and Accruing	193	99
Non-Accrual Loans	10,584	9,503
Commercial real estate loans
Financing Receivable, Recorded Investment, Past Due [Line Items]
30-59 days Past Due	896	2,105
60-89 days Past Due	2,227	739
Greater Than 90 Days	5,380	5,009
Total Past Due	8,503	7,853
Current	497,728	462,208
Loans ending balance	506,231	470,061
Loans > 90 Days Past Due and Accruing	138
Non-Accrual Loans	6,719	7,830
Commercial loans
Financing Receivable, Recorded Investment, Past Due [Line Items]
30-59 days Past Due	1,079	1,020
60-89 days Past Due	68	184
Greater Than 90 Days	2,969	2,309
Total Past Due	4,116	3,513
Current	186,338	181,532
Loans ending balance	190,454	185,045
Loans > 90 Days Past Due and Accruing	160	135
Non-Accrual Loans	3,409	3,955
Home equity loans
Financing Receivable, Recorded Investment, Past Due [Line Items]
30-59 days Past Due	2,230	1,208
60-89 days Past Due	355	962
Greater Than 90 Days	1,105	1,927
Total Past Due	3,690	4,097
Current	274,685	264,685
Loans ending balance	278,375	268,782
Loans > 90 Days Past Due and Accruing	118	2
Non-Accrual Loans	1,514	2,670
Consumer loans
Financing Receivable, Recorded Investment, Past Due [Line Items]
30-59 days Past Due	342	73
60-89 days Past Due	199	10
Greater Than 90 Days	259	152
Total Past Due	800	235
Current	15,833	11,643
Loans ending balance	16,633	11,878
Loans > 90 Days Past Due and Accruing	2
Non-Accrual Loans	$ 257	$ 152