CONSOLIDATED STATEMENTS OF CHANGES IN SHAREHOLDERS' EQUITY - USD ($) $ in Thousands	Common stock amount	Additional paid-in capital	Retained earnings	Accumulated other comprehensive income (loss)	Treasury stock	Total
Balance at beginning of period (Accounting Standards Update 2016-13) at Dec. 31, 2020			$ (5,242)			$ (5,242)
Balance at beginning of period at Dec. 31, 2020	$ 32,857	$ 190,084	195,607	$ 6,740	$ (18,223)	407,065
Increase (Decrease) in Stockholders' Equity
Net income			9,480			9,480
Other comprehensive loss				(3,677)		(3,677)
Cash dividends declared			(3,284)			(3,284)
Net issuance to employee stock plans, including related tax effects		(186)			358	172
Recognition of stock based compensation		666				666
Balance at end of period at Mar. 31, 2021	32,857	190,564	196,561	3,063	(17,865)	405,180
Balance at beginning of period (Accounting Standards Update 2016-13) at Dec. 31, 2020			(5,242)			(5,242)
Balance at beginning of period at Dec. 31, 2020	32,857	190,084	195,607	6,740	(18,223)	407,065
Increase (Decrease) in Stockholders' Equity
Net income						18,505
Other comprehensive loss				(858)		(858)
Balance at end of period at Jun. 30, 2021	32,857	190,801	201,994	5,882	(17,774)	413,760
Balance at beginning of period at Mar. 31, 2021	32,857	190,564	196,561	3,063	(17,865)	405,180
Increase (Decrease) in Stockholders' Equity
Net income			9,025			9,025
Other comprehensive loss				2,819		2,819
Cash dividends declared			(3,592)			(3,592)
Net issuance to employee stock plans, including related tax effects		(94)			91	(3)
Recognition of stock based compensation		331				331
Balance at end of period at Jun. 30, 2021	32,857	190,801	201,994	5,882	(17,774)	413,760
Balance at beginning of period at Dec. 31, 2021	32,857	190,876	215,592	2,303	(17,481)	424,147
Increase (Decrease) in Stockholders' Equity
Net income			9,112			9,112
Other comprehensive loss				(23,658)		(23,658)
Cash dividends declared			(3,603)			(3,603)
Net issuance to employee stock plans, including related tax effects		436			111	547
Recognition of stock based compensation		454				454
Balance at end of period at Mar. 31, 2022	32,857	191,766	221,101	(21,355)	(17,370)	406,999
Balance at beginning of period at Dec. 31, 2021	32,857	190,876	215,592	2,303	(17,481)	424,147
Increase (Decrease) in Stockholders' Equity
Net income						19,615
Other comprehensive loss				(43,274)		(43,274)
Balance at end of period at Jun. 30, 2022	32,857	191,346	227,698	(40,971)	(17,333)	393,597
Balance at beginning of period at Mar. 31, 2022	32,857	191,766	221,101	(21,355)	(17,370)	406,999
Increase (Decrease) in Stockholders' Equity
Net income			10,503			10,503
Other comprehensive loss				(19,616)		(19,616)
Cash dividends declared			(3,906)			(3,906)
Net issuance to employee stock plans, including related tax effects		(60)			37	(23)
Recognition of stock based compensation		(360)				(360)
Balance at end of period at Jun. 30, 2022	$ 32,857	$ 191,346	$ 227,698	$ (40,971)	$ (17,333)	$ 393,597