Consolidated Statement of Income (USD $)	12 Months Ended
	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
INTEREST AND DIVIDEND INCOME:
Interest and fees on loans	$ 28,982,000	$ 29,770,000	$ 29,916,000
Interest-bearing deposits with banks	40,000	21,000	81,000
Investment securities:
Taxable	3,721,000	4,521,000	4,575,000
Nontaxable	3,405,000	3,702,000	3,666,000
Dividends	86,000	71,000	55,000
TOTAL INTEREST AND DIVIDEND INCOME	36,234,000	38,085,000	38,293,000
INTEREST EXPENSE:
Deposits	5,107,000	6,113,000	7,944,000
Borrowed funds	1,208,000	1,546,000	1,739,000
TOTAL INTEREST EXPENSE	6,315,000	7,659,000	9,683,000
NET INTEREST INCOME	29,919,000	30,426,000	28,610,000
Provision for loan losses	405,000	420,000	675,000
NET INTEREST INCOME AFTER PROVISION FOR LOAN LOSSES	29,514,000	30,006,000	27,935,000
NON-INTEREST INCOME:
Service charges	4,299,000	4,475,000	4,380,000
Trust	694,000	644,000	665,000
Brokerage and insurance	444,000	392,000	352,000
Investment securities gains, net	441,000	604,000	334,000
Gains on loans sold	443,000	759,000	208,000
Earnings on bank owned life insurance	502,000	507,000	498,000
Other	446,000	456,000	479,000
TOTAL NON-INTEREST INCOME	7,269,000	7,837,000	6,916,000
NON-INTEREST EXPENSES:
Salaries and employee benefits	11,392,000	11,018,000	9,996,000
Occupancy	1,271,000	1,265,000	1,331,000
Furniture and equipment	492,000	411,000	449,000
Professional fees	781,000	891,000	744,000
Federal depository insurance	450,000	468,000	592,000
Pennsylvania shares tax	640,000	602,000	541,000
Other	4,630,000	4,642,000	4,756,000
TOTAL NON-INTEREST EXPENSES	19,656,000	19,297,000	18,409,000
Income before provision for income taxes	17,127,000	18,546,000	16,442,000
Provision for income taxes	3,752,000	4,331,000	3,610,000
NET INCOME	$ 13,375,000	$ 14,215,000	$ 12,832,000
PER COMMON SHARE DATA:
NET INCOME - BASIC (in dollars per share)	$ 4.42	$ 4.65	$ 4.16
NET INCOME - DILUTED (in dollars per share)	$ 4.42	$ 4.65	$ 4.16
CASH DIVIDENDS PER SHARE (in dollars per share)	$ 1.22	$ 1.51	$ 1.09
Number of shares used in computation - basic (in shares)	3,025,315	3,056,078	3,087,221
Number of shares used in computation - diluted (in shares)	3,026,485	3,057,720	3,087,221