Consolidated Statements of Changes in Shareholders' Equity (Unaudited) - USD ($) $ in Thousands		Capital Stock [Member]		Surplus [Member]		Undivided Profits [Member]	Accumulated Other Comprehensive Income [Member]	Treasury Stock [Member]	Total
Balance at Dec. 31, 2019	[1]	$ 20,041		$ 256,591		$ 288,067	$ 4,461	$ (30,903)	$ 538,257
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income		0	[1]	0	[1]	13,313	0	0	13,313
Other comprehensive income (loss), net of tax		0	[1]	0	[1]	0	6,931	0	6,931
Cash dividend declared	[2]	0	[1]	0	[1]	(6,827)	0	0	(6,827)
Purchase of treasury stock	[2]	0	[1]	0	[1]	0	0	(3,493)	(3,493)
Stock based compensation expense		0	[1]	4	[1]	0	0	0	4
Balance at Mar. 31, 2020	[1]	20,041		256,595		294,553	11,392	(34,396)	548,185
Balance at Dec. 31, 2019	[1]	20,041		256,591		288,067	4,461	(30,903)	538,257
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income									38,638
Other comprehensive income (loss), net of tax									7,076
Balance at Sep. 30, 2020	[1]	20,041		256,605		306,741	11,537	(34,396)	560,528
Balance at Mar. 31, 2020	[1]	20,041		256,595		294,553	11,392	(34,396)	548,185
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income		0	[1]	0	[1]	11,254	0	0	11,254
Other comprehensive income (loss), net of tax		0	[1]	0	[1]	0	544	0	544
Cash dividend declared	[2]	0	[1]	0	[1]	(6,568)	0	0	(6,568)
Stock based compensation expense		0	[1]	6	[1]	0	0	0	6
Balance at Jun. 30, 2020	[1]	20,041		256,601		299,239	11,936	(34,396)	553,421
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income		0	[1]	0	[1]	14,071	0	0	14,071
Other comprehensive income (loss), net of tax		0	[1]	0	[1]	0	(399)	0	(399)
Cash dividend declared	[2]	0	[1]	0	[1]	(6,569)	0	0	(6,569)
Stock based compensation expense		0	[1]	4	[1]	0	0	0	4
Balance at Sep. 30, 2020	[1]	20,041		256,605		306,741	11,537	(34,396)	560,528
Balance at Dec. 31, 2020	[1]	20,041		256,606		313,974	11,936	(34,396)	568,161
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income		0	[1]	0	[1]	14,083	0	0	14,083
Other comprehensive income (loss), net of tax		0	[1]	0	[1]	0	(4,668)	0	(4,668)
Stock options exercised	[1]	3		68		0	0	0	71
Cash dividend declared	[2]	0	[1]	0	[1]	(6,571)	0	0	(6,571)
Purchase of treasury stock	[2]	0	[1]	0	[1]	0	0	(45)	(45)
Balance at Mar. 31, 2021	[1]	20,044		256,674		321,486	7,268	(34,441)	571,031
Balance at Dec. 31, 2020	[1]	20,041		256,606		313,974	11,936	(34,396)	568,161
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income									45,278
Other comprehensive income (loss), net of tax									(4,632)
Balance at Sep. 30, 2021	[1]	20,042		256,565		339,554	7,304	(36,782)	586,683
Balance at Mar. 31, 2021	[1]	20,044		256,674		321,486	7,268	(34,441)	571,031
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income		0	[1]	0	[1]	14,433	0	0	14,433
Other comprehensive income (loss), net of tax		0	[1]	0	[1]	0	572	0	572
Cash used to settle fractional shares in the Reverse Stock Split	[1]	(5)		(195)		0	0	0	(200)
Stock options exercised	[1]	2		57		0	0	0	59
Cash dividend declared	[2]	0	[1]	0	[1]	(6,569)	0	0	(6,569)
Purchase of treasury stock	[2]	0	[1]	0	[1]	0	0	(733)	(733)
Balance at Jun. 30, 2021	[1]	20,041		256,536		329,350	7,840	(35,174)	578,593
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income		0	[1]	0	[1]	16,762	0	0	16,762
Other comprehensive income (loss), net of tax		0	[1]	0	[1]	0	(536)	0	(536)
Stock options exercised		1	[1]	29	[1]	0	0	0	30
Cash dividend declared		0	[1]	0	[1]	(6,558)	0	0	(6,558)
Purchase of treasury stock		0	[1]	0	[1]	0	0	(1,608)	(1,608)
Balance at Sep. 30, 2021	[1]	$ 20,042		$ 256,565		$ 339,554	$ 7,304	$ (36,782)	$ 586,683

[1] All periods presented have been adjusted for the 1 for 5 reverse stock split which occurred on May 28, 2021.

[2] Share amounts and per share amounts have been adjusted for all periods presented for the 1 for 5 reverse stock split which occurred on May 28, 2021.