CONSOLIDATED STATEMENTS OF CHANGES IN SHAREHOLDERS' EQUITY (Unaudited) - USD ($) $ in Thousands	Total	Common Stock [Member]	Paid-in Capital [Member]	Retained Earnings [Member]	Accumulated Other Comprehensive Income (Loss) [Member]	Treasury Stock [Member]
Common stock, shares outstanding at Dec. 31, 2021		17,331,000
Shareholders' equity at Dec. 31, 2021	$ 564,808	$ 1,085	$ 126,511	$ 458,310	$ (19,981)	$ (1,117)
Net income	36,440			36,440
Total other comprehensive income (loss), net of tax	(98,060)				(98,060)
Cash dividends declared	(18,861)			(18,861)
Share-based compensation	1,613		1,613
Exercise of stock options and issuance of other compensation-related equity awards, net of awards surrendered, shares		34,000
Exercise of stock options and issuance of other compensation-related equity awards, net of awards surrendered, value	(723)	$ 0	(2,045)			1,322
Treasury stock repurchased		(175,000)
Treasury stock purchased under Stock Repurchase Program, amount acquired	(8,583)					(8,583)
Common stock, shares outstanding at Jun. 30, 2022		17,190,000
Shareholders' equity at Jun. 30, 2022	476,634	$ 1,085	126,079	475,889	(118,041)	(8,378)
Common stock, shares outstanding at Mar. 31, 2022		17,332,000
Shareholders' equity at Mar. 31, 2022	513,192	$ 1,085	127,355	465,295	(79,451)	(1,092)
Net income	19,957			19,957
Total other comprehensive income (loss), net of tax	(38,590)				(38,590)
Cash dividends declared	(9,363)			(9,363)
Share-based compensation	725		725
Exercise of stock options and issuance of other compensation-related equity awards, net of awards surrendered, shares		33,000
Exercise of stock options and issuance of other compensation-related equity awards, net of awards surrendered, value	(704)	$ 0	(2,001)			1,297
Treasury stock repurchased		(175,000)
Treasury stock purchased under Stock Repurchase Program, amount acquired	(8,583)					(8,583)
Common stock, shares outstanding at Jun. 30, 2022		17,190,000
Shareholders' equity at Jun. 30, 2022	$ 476,634	$ 1,085	126,079	475,889	(118,041)	(8,378)
Common stock, shares outstanding at Dec. 31, 2022	17,182,753	17,183,000
Shareholders' equity at Dec. 31, 2022	$ 453,669	$ 1,085	127,056	492,043	(157,800)	(8,715)
Net income	24,068			24,068
Total other comprehensive income (loss), net of tax	8,973				8,973
Cash dividends declared	(19,115)			(19,115)
Share-based compensation	945		945
Exercise of stock options and issuance of other compensation-related equity awards, net of awards surrendered, shares		36,000
Exercise of stock options and issuance of other compensation-related equity awards, net of awards surrendered, value	(638)	$ 0	(2,316)			1,678
Treasury stock repurchased		(200,000)
Treasury stock purchased under Stock Repurchase Program, amount acquired	$ (8,741)					(8,741)
Common stock, shares outstanding at Jun. 30, 2023	17,019,238	17,019,000
Shareholders' equity at Jun. 30, 2023	$ 459,161	$ 1,085	125,685	496,996	(148,827)	(15,778)
Common stock, shares outstanding at Mar. 31, 2023		16,986,000
Shareholders' equity at Mar. 31, 2023	464,983	$ 1,085	127,734	495,231	(141,760)	(17,307)
Net income	11,256			11,256
Total other comprehensive income (loss), net of tax	(7,067)				(7,067)
Cash dividends declared	(9,491)			(9,491)
Share-based compensation	87		87
Exercise of stock options and issuance of other compensation-related equity awards, net of awards surrendered, shares		33,000
Exercise of stock options and issuance of other compensation-related equity awards, net of awards surrendered, value	$ (607)	$ 0	(2,136)			1,529
Common stock, shares outstanding at Jun. 30, 2023	17,019,238	17,019,000
Shareholders' equity at Jun. 30, 2023	$ 459,161	$ 1,085	$ 125,685	$ 496,996	$ (148,827)	$ (15,778)