Consolidated Balance Sheets (unaudited) (USD $) In Thousands, unless otherwise specified	Mar. 31, 2013	Dec. 31, 2012
Assets
Cash and due from banks	$ 47,504	$ 53,646
Federal funds sold and interest-bearing deposits in other banks	197,281	98,637
Total cash and cash equivalents	244,785	152,283
Short-term investments	12,111	17,367
Securities available-for-sale, amortized cost $1,392,193 and $1,414,595, respectively	1,407,260	1,434,801
Securities held-to-maturity, fair value $266,047 and $281,924, respectively	260,545	275,507
Federal Home Loan Bank of Boston stock, at cost	14,862	15,146
Loans, net:
Commercial and industrial	110,537	88,475
Construction and land development	34,021	38,618
Commercial real estate	570,441	576,465
Residential real estate	292,871	281,857
Home equity	121,989	118,923
Consumer and other	7,910	7,450
Total loans, net	1,137,769	1,111,788
Less: allowance for loan losses	19,759	19,197
Net loans	1,118,010	1,092,591
Bank premises and equipment	23,669	23,899
Accrued interest receivable	6,011	5,811
Goodwill	2,714	2,714
Other assets	72,168	66,090
Total assets	3,162,135	3,086,209
Deposits:
Demand deposits	416,109	438,429
Savings and NOW deposits	935,995	933,316
Money Market Accounts	730,791	653,345
Time deposits	442,980	419,983
Total deposits	2,525,875	2,445,073
Securities sold under agreements to repurchase	187,080	191,390
Other borrowed funds	182,144	195,144
Subordinated debentures	36,083	36,083
Due to broker	10,019
Other liabilities	39,916	38,529
Total liabilities	2,981,117	2,906,219
Stockholders' Equity
Preferred stock - $1.00 par value; 100,000 shares authorized; no shares issued and outstanding
Additional paid-in capital	11,931	11,891
Retained earnings	166,821	162,892
Total stockholder's equity	184,308	180,337
Unrealized gains on securities available-for-sale, net of taxes	9,214	12,330
Pension liability, net of taxes	(12,504)	(12,677)
Total accumulated other comprehensive loss, net of taxes	(3,290)	(347)
Total stockholders' equity	181,018	179,990
Total liabilities and stockholders' equity	3,162,135	3,086,209
Class A Common Stock
Stockholders' Equity
Common stock value	3,570	3,568
Total stockholders' equity	3,570	3,568
Class B Common Stock
Stockholders' Equity
Common stock value	1,986	1,986
Total stockholders' equity	$ 1,986	$ 1,986