CONSOLIDATED STATEMENTS OF CHANGES IN SHAREHOLDERS' EQUITY - USD ($) $ in Thousands	Total	Cumulative Effect, Period of Adoption, Adjustment	Common Stock [Member]	Additional Paid-in Capital [Member]	Retained Earnings [Member]	Retained Earnings [Member] Cumulative Effect, Period of Adoption, Adjustment	Accumulated Other Comprehensive Income (Loss) [Member]	Treasury Stock [Member]
Common stock, shares outstanding, beginning balance at Dec. 31, 2018			17,302,000
Stockholders' equity, beginning balance at Dec. 31, 2018	$ 448,184		$ 1,081	$ 119,888	$ 355,524		$ (28,309)	$ 0
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income	69,118				69,118
Total other comprehensive income (loss), net of tax	17,072						17,072
Cash dividends declared	(35,001)				(35,001)
Share-based compensation	3,124			3,124
Exercise of stock options, issuance of other compensation-related equity awards, net of awards surrendered, shares			61,000
Exercise of stock options, issuance of other compensation-related equity awards, net of awards surrendered	273		$ 4	269
Common stock, shares outstanding, ending balance at Dec. 31, 2019			17,363,000
Stockholders' equity, ending balance at Dec. 31, 2019	503,492		$ 1,085	123,281	390,363		(11,237)	0
Stockholders' equity, ending balance (Accounting Standards Update 2016-02 [Member]) at Dec. 31, 2019		$ 722				$ 722
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income	69,829				69,829
Total other comprehensive income (loss), net of tax	3,846						3,846
Cash dividends declared	(35,838)				(35,838)
Share-based compensation	3,766			3,766
Exercise of stock options, issuance of other compensation-related equity awards, net of awards surrendered, shares			27,000
Exercise of stock options, issuance of other compensation-related equity awards, net of awards surrendered	$ (470)		$ 0	(1,437)				967
Treasury shares purchased, shares	(125,000)
Treasury stock purchased	$ (4,322)							(4,322)
Common stock, shares outstanding, ending balance at Dec. 31, 2020	17,265,337		17,265,000
Stockholders' equity, ending balance at Dec. 31, 2020	$ 534,195		$ 1,085	125,610	418,246		(7,391)	(3,355)
Stockholders' equity, ending balance (Accounting Standards Update 2016-13 [Member]) at Dec. 31, 2020		$ (6,108)				$ (6,108)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income	76,870				76,870
Total other comprehensive income (loss), net of tax	(12,590)						(12,590)
Cash dividends declared	(36,806)				(36,806)
Share-based compensation	3,316			3,316
Exercise of stock options, issuance of other compensation-related equity awards, net of awards surrendered, shares			66,000
Exercise of stock options, issuance of other compensation-related equity awards, net of awards surrendered	$ (177)			(2,415)				2,238
Common stock, shares outstanding, ending balance at Dec. 31, 2021	17,330,818		17,331,000
Stockholders' equity, ending balance at Dec. 31, 2021	$ 564,808		$ 1,085	$ 126,511	$ 458,310		$ (19,981)	$ (1,117)