Consolidated Statements Of Changes In Shareholders' Equity - USD ($)	Common Stock [Member]	Additional Paid-in Capital [Member]	Retained Earnings [Member]	Accumulated Other Comprehensive Income (Loss) [Member]	Treasury Stock [Member]	Total
Balance at Dec. 31, 2019	$ 4,710,000	$ 42,268,000	$ 94,946,000	$ (5,986,000)	$ (8,410,000)	$ 127,528,000
Balance, shares at Dec. 31, 2019	4,352,753
Net income			8,248,000			8,248,000
Other comprehensive income				7,353,000		7,353,000
Cash dividends declared			(3,914,000)			(3,914,000)
Acquisition of treasury stock					$ (1,172,000)	(1,172,000)
Acquisition of treasury stock, shares					(36,401)
Treasury shares issued under dividend reinvestment plan		78,000			$ 1,284,000	1,362,000
Treasury shares issued under dividend reinvestment plan, shares	52,928
Stock Compensation Plans:
Treasury shares issued		1,000			9,000	10,000
Treasury shares issued, shares	364
Common shares issued	$ 1,000	17,000				18,000
Common shares issued, shares	1,023
Compensation expense		141,000				141,000
Balance at Sep. 30, 2020	$ 4,711,000	42,505,000	99,280,000	1,367,000	(8,289,000)	139,574,000
Balance, shares at Sep. 30, 2020	4,370,667
Balance at Jun. 30, 2020	$ 4,711,000	42,461,000	97,124,000	(725,000)	(8,731,000)	134,840,000
Balance, shares at Jun. 30, 2020	4,352,484
Net income			3,462,000			3,462,000
Other comprehensive income				2,092,000		2,092,000
Cash dividends declared			(1,306,000)			(1,306,000)
Treasury shares issued under dividend reinvestment plan		(13,000)			435,000	422,000
Treasury shares issued under dividend reinvestment plan, shares	17,840
Stock Compensation Plans:
Treasury shares issued					7,000	7,000
Treasury shares issued, shares	293
Common shares issued		1,000				1,000
Common shares issued, shares	50
Compensation expense		56,000				56,000
Balance at Sep. 30, 2020	$ 4,711,000	42,505,000	99,280,000	1,367,000	(8,289,000)	139,574,000
Balance, shares at Sep. 30, 2020	4,370,667
Balance at Dec. 31, 2020	$ 4,711,000	42,589,000	102,520,000	3,190,000	(7,834,000)	$ 145,176,000
Balance, shares at Dec. 31, 2020	4,389,355					4,389,355
Net income			15,963,000			$ 15,963,000
Other comprehensive income				(5,363,000)		(5,363,000)
Cash dividends declared			(4,105,000)			(4,105,000)
Acquisition of treasury stock					$ (1,105,000)	(1,105,000)
Acquisition of treasury stock, shares					(35,718)
Treasury shares issued under dividend reinvestment plan		381,000			$ 1,630,000	2,011,000
Treasury shares issued under dividend reinvestment plan, shares	66,235
Stock Compensation Plans:
Treasury shares issued		(182,000)			282,000	100,000
Treasury shares issued, shares	11,575
Compensation expense		161,000				161,000
Balance at Sep. 30, 2021	$ 4,711,000	42,949,000	114,378,000	(2,173,000)	(7,027,000)	$ 152,838,000
Balance, shares at Sep. 30, 2021	4,431,447					4,431,447
Balance at Jun. 30, 2021	$ 4,711,000	42,774,000	109,930,000	844,000	(7,103,000)	$ 151,156,000
Balance, shares at Jun. 30, 2021	4,425,092
Net income			5,862,000			5,862,000
Other comprehensive income				(3,017,000)		(3,017,000)
Cash dividends declared			(1,414,000)			(1,414,000)
Acquisition of treasury stock					$ (387,000)	(387,000)
Acquisition of treasury stock, shares					(12,089)
Treasury shares issued under dividend reinvestment plan		129,000			$ 458,000	587,000
Treasury shares issued under dividend reinvestment plan, shares	18,226
Stock Compensation Plans:
Treasury shares issued					5,000	5,000
Treasury shares issued, shares	218
Compensation expense		46,000				46,000
Balance at Sep. 30, 2021	$ 4,711,000	$ 42,949,000	$ 114,378,000	$ (2,173,000)	$ (7,027,000)	$ 152,838,000
Balance, shares at Sep. 30, 2021	4,431,447					4,431,447