CONSOLIDATED STATEMENTS OF STOCKHOLDERS' EQUITY (Unaudited) - USD ($) $ in Thousands	Total	Common Stock	Additional Paid-in Capital	Retained Earnings	Accumulated Other Comprehensive Income (Loss)	Treasury Stock
Beginning balance (in shares) at Dec. 31, 2020		54,404,379
Beginning balance at Dec. 31, 2020	$ 1,270,069	$ 56	$ 1,253,360	$ 20,830	$ 33,309	$ (37,486)
Increase (decrease) in shareholders' equity
Net income	93,523			93,523
OCI, net of tax	(34,675)				(34,675)
Stock issued in acquisition, net of stock issuance costs (in shares)		2,206,237
Stock issued in acquisition, net of stock issuance costs	58,955	$ 2	58,953
Repurchase of stock (in shares)		(905,000)
Repurchase of stock	(22,038)					(22,038)
Issuance of treasury stock for ESPP (in shares)		14,658
Issuance of treasury stock for ESPP	307		(70)			377
Net issuance of treasury stock for restricted/deferred stock unit vesting and related tax (in shares)		106,710
Net issuance of treasury stock for RSU/DSU vesting and related tax	(888)		(3,738)			2,850
Cash dividends on common stock	(37,953)			(37,953)
Stock dividend equivalents on RSUs	0		757	(757)
Stock-based compensation	5,776		5,776
Ending balance (in shares) at Sep. 30, 2021		55,826,984
Ending balance at Sep. 30, 2021	1,333,076	$ 58	1,315,038	75,643	(1,366)	(56,297)
Beginning balance (in shares) at Jun. 30, 2021		56,330,616
Beginning balance at Jun. 30, 2021	1,345,691	$ 58	1,316,716	62,926	10,725	(44,734)
Increase (decrease) in shareholders' equity
Net income	25,941			25,941
OCI, net of tax	(12,091)				(12,091)
Stock issued in acquisition, net of stock issuance costs	(29)		(29)
Repurchase of stock (in shares)		(625,000)
Repurchase of stock	(14,790)					(14,790)
Issuance of treasury stock for ESPP (in shares)		14,658
Issuance of treasury stock for ESPP	307		(70)			377
Net issuance of treasury stock for restricted/deferred stock unit vesting and related tax (in shares)		106,710
Net issuance of treasury stock for RSU/DSU vesting and related tax	(888)		(3,738)			2,850
Cash dividends on common stock	(12,956)			(12,956)
Stock dividend equivalents on RSUs	0		268	(268)
Stock-based compensation	1,891		1,891
Ending balance (in shares) at Sep. 30, 2021		55,826,984
Ending balance at Sep. 30, 2021	1,333,076	$ 58	1,315,038	75,643	(1,366)	(56,297)
Beginning balance (in shares) at Dec. 31, 2021		55,434,910
Beginning balance at Dec. 31, 2021	1,319,112	$ 58	1,316,984	92,463	(23,758)	(66,635)
Increase (decrease) in shareholders' equity
Net income	93,924			93,924
OCI, net of tax	(265,237)				(265,237)
Repurchase of stock (in shares)		(388,614)
Repurchase of stock	(9,912)					(9,912)
Issuance of treasury stock for ESPP (in shares)		50,033
Issuance of treasury stock for ESPP	1,017		(271)			1,288
Net issuance of treasury stock for restricted/deferred stock unit vesting and related tax (in shares)		136,105
Net issuance of treasury stock for RSU/DSU vesting and related tax	(878)		(4,383)			3,505
Cash dividends on common stock	(38,159)			(38,159)
Stock dividend equivalents on RSUs	0		870	(870)
Stock-based compensation	6,721		6,721
Ending balance (in shares) at Sep. 30, 2022		55,232,434
Ending balance at Sep. 30, 2022	1,106,588	$ 58	1,319,921	147,358	(288,995)	(71,754)
Beginning balance (in shares) at Jun. 30, 2022		55,335,703
Beginning balance at Jun. 30, 2022	1,161,957	$ 58	1,317,675	124,685	(211,107)	(69,354)
Increase (decrease) in shareholders' equity
Net income	35,661			35,661
OCI, net of tax	(77,888)				(77,888)
Repurchase of stock (in shares)		(130,000)
Repurchase of stock	(3,088)					(3,088)
Issuance of treasury stock for ESPP (in shares)		10,993
Issuance of treasury stock for ESPP	206		(77)			283
Net issuance of treasury stock for restricted/deferred stock unit vesting and related tax (in shares)		15,738
Net issuance of treasury stock for RSU/DSU vesting and related tax	(29)		(434)			405
Cash dividends on common stock	(12,707)			(12,707)
Stock dividend equivalents on RSUs	0		281	(281)
Stock-based compensation	2,476		2,476
Ending balance (in shares) at Sep. 30, 2022		55,232,434
Ending balance at Sep. 30, 2022	$ 1,106,588	$ 58	$ 1,319,921	$ 147,358	$ (288,995)	$ (71,754)