Consolidated Statement of Income - USD ($)	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
INTEREST AND DIVIDEND INCOME:
Interest and fees on loans	$ 63,538,000	$ 54,911,000	$ 50,458,000
Interest-bearing deposits with banks	401,000	407,000	319,000
Investment securities:
Taxable	4,090,000	4,673,000	3,790,000
Nontaxable	1,869,000	1,492,000	1,744,000
Dividends	398,000	497,000	447,000
TOTAL INTEREST AND DIVIDEND INCOME	70,296,000	61,980,000	56,758,000
INTEREST EXPENSE:
Deposits	6,851,000	9,219,000	6,910,000
Borrowed funds	1,254,000	2,821,000	2,664,000
TOTAL INTEREST EXPENSE	8,105,000	12,040,000	9,574,000
NET INTEREST INCOME	62,191,000	49,940,000	47,184,000
Provision for loan losses	2,400,000	1,675,000	1,925,000
NET INTEREST INCOME AFTER PROVISION FOR LOAN LOSSES	59,791,000	48,265,000	45,259,000
NON-INTEREST INCOME:
Revenue from customers	6,660,000	6,926,000	6,512,000
Equity security (losses) gains, net	(41,000)	120,000	0
Available for sale security gains (losses), net	305,000	24,000	(19,000)
Gains on loans sold	2,168,000	473,000	382,000
Earnings on bank owned life insurance	695,000	623,000	622,000
Other	1,974,000	568,000	588,000
TOTAL NON-INTEREST INCOME	11,422,000	8,386,000	7,735,000
NON-INTEREST EXPENSES:
Salaries and employee benefits	24,190,000	20,456,000	19,094,000
Occupancy	2,557,000	2,174,000	2,126,000
Furniture and equipment	757,000	674,000	536,000
Professional fees	1,517,000	1,423,000	1,925,000
Federal depository insurance	476,000	75,000	417,000
Pennsylvania shares tax	868,000	808,000	835,000
Amortization of intangibles	216,000	259,000	296,000
Merger and acquisition	2,179,000	466,000	0
ORE expenses	451,000	376,000	158,000
Software expenses	1,155,000	948,000	876,000
Other	6,481,000	5,682,000	5,294,000
TOTAL NON-INTEREST EXPENSES	40,847,000	33,341,000	31,557,000
Income before provision for income taxes	30,366,000	23,310,000	21,437,000
Provision for income taxes	5,263,000	3,820,000	3,403,000
NET INCOME	$ 25,103,000	$ 19,490,000	$ 18,034,000
PER COMMON SHARE DATA:
EARNINGS PER SHARE - BASIC (in dollars per share)	$ 6.60	$ 5.48	$ 5.04
EARNINGS PER SHARE - DILUTED (in dollars per share)	6.59	5.47	5.04
Cash Dividends Paid (in dollars per share)	$ 1.92	$ 1.76	$ 1.71
Number of shares used in computation - basic (in shares)	3,805,682	3,559,150	3,577,992
Number of shares used in computation - diluted (in shares)	3,807,523	3,561,246	3,579,980
Service Charges [Member]
NON-INTEREST INCOME:
Revenue from customers	$ 4,221,000	$ 4,687,000	$ 4,667,000
Trust [Member]
NON-INTEREST INCOME:
Revenue from customers	803,000	750,000	705,000
Brokerage and Insurance [Member]
NON-INTEREST INCOME:
Revenue from customers	$ 1,297,000	$ 1,141,000	$ 790,000