CONSOLIDATED STATEMENTS OF INCOME AND COMPREHENSIVE INCOME - USD ($) shares in Thousands, $ in Thousands	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
INTEREST AND DIVIDEND INCOME:
Loans, including related fees	$ 100,541	$ 91,100	$ 86,128
Securities:
Taxable	16,942	14,325	14,506
Tax-exempt	7,455	7,391	7,269
Other	1,286	1,379	1,477
TOTAL INTEREST AND DIVIDEND INCOME	126,224	114,195	109,380
INTEREST EXPENSE:
Deposits	9,032	6,011	4,159
Short-term borrowings	501	245	134
Other borrowings	112	82	114
TOTAL INTEREST EXPENSE	9,645	6,338	4,407
NET INTEREST INCOME	116,579	107,857	104,973
Provision for loan losses	5,768	5,295	3,300
NET INTEREST INCOME AFTER PROVISION FOR LOAN LOSSES	110,811	102,562	101,673
Trust And Financial Services Revenue	5,286	5,001	5,208
Service Charges And Fees On Deposit Accounts	11,733	11,895	10,530
Service Charges And Fees, Other	13,012	12,499	12,307
NON-INTEREST INCOME:
Securities gain (loss), net	2	59	34
Insurance commissions	144	74	2,346
Gain on Sale of certain assets and liabilities of Insurance Brokerage Operation	0	0	12,822
Gain on sale of mortgage loans	1,829	1,688	1,842
Other	6,200	4,722	1,842
TOTAL NON-INTEREST INCOME	38,206	35,938	46,931
Labor and Related Expense	50,658	50,116	50,091
NON-INTEREST EXPENSES:
Occupancy expense	7,030	6,897	6,865
Equipment expense	6,827	7,186	7,300
Federal Deposit Insurance	929	915	1,300
Other	25,845	23,633	24,752
TOTAL NON-INTEREST EXPENSE	91,289	88,747	90,308
INCOME BEFORE INCOME TAXES	57,728	49,753	58,296
Provision for income taxes	11,145	20,622	19,883
NET INCOME	46,583	29,131	38,413
OTHER COMPREHENSIVE INCOME
Change in unrealized gains/losses on securities, net of reclassifications and taxes	(8,861)	3,335	(10,130)
Change in funded status of post-retirement benefits, net of taxes	2,477	(3,875)	5,367
COMPREHENSIVE INCOME	$ 40,199	$ 28,591	$ 33,650
EARNINGS PER SHARE:
BASIC AND DILUTED (in dollars per share)	$ 3.80	$ 2.38	$ 3.12
Weighted average number of shares outstanding (in shares)	12,256	12,225	12,317