Condensed Consolidated Statements of Shareholders' Equity - USD ($) $ in Thousands	Common stock	Paid-in Capital	Accumulated Other Comprehensive Earnings (Loss)	Retained Earnings Cumulative Effect, Period of Adoption, Adjustment	Retained Earnings	Deferred Compensation	Treasury Stock at Cost	Cumulative Effect, Period of Adoption, Adjustment	Total
Shareholders' Equity Attributable to Parent, Beginning Balance at Dec. 31, 2022	$ 684	$ 352,391	$ (229,076)	$ (951)	$ 1,446,341	$ 12,015	$ (405,014)	$ (951)	$ 1,177,341
Shares, Outstanding, Beginning Balance at Dec. 31, 2022	45,469,752
Increase Decrease In Shareholders Equity Roll Forward
Net Income (Loss)					98,811				98,811
Other comprehensive earnings (loss), net of tax			37,707						37,707
Deferred compensation						249	(249)
Share-based compensation	$ 1	2,863							2,864
Share-based compensation (in shares)	84,944
Dividends and dividend equivalents					(11,851)				(11,851)
Shareholders' Equity Attributable to Parent, Ending Balance at Mar. 31, 2023	$ 685	355,254	(191,369)		1,532,350	12,264	(405,263)		1,303,921
Shares, Outstanding, Ending Balance at Mar. 31, 2023	45,554,696
Shareholders' Equity Attributable to Parent, Beginning Balance at Dec. 31, 2022	$ 684	352,391	(229,076)	$ (951)	1,446,341	12,015	(405,014)	$ (951)	1,177,341
Shares, Outstanding, Beginning Balance at Dec. 31, 2022	45,469,752
Increase Decrease In Shareholders Equity Roll Forward
Net Income (Loss)									189,999
Other comprehensive earnings (loss), net of tax									(38,848)
Shareholders' Equity Attributable to Parent, Ending Balance at Sep. 30, 2023	$ 686	360,453	(267,924)		1,598,875	12,617	(405,616)		1,299,091
Shares, Outstanding, Ending Balance at Sep. 30, 2023	45,625,771
Shareholders' Equity Attributable to Parent, Beginning Balance at Mar. 31, 2023	$ 685	355,254	(191,369)		1,532,350	12,264	(405,263)		1,303,921
Shares, Outstanding, Beginning Balance at Mar. 31, 2023	45,554,696
Increase Decrease In Shareholders Equity Roll Forward
Net Income (Loss)					77,652				77,652
Other comprehensive earnings (loss), net of tax			(19,721)						(19,721)
Deferred compensation						243	(243)
Share-based compensation		2,402							2,402
Share-based compensation (in shares)	41,500
Dividends and dividend equivalents					(12,342)				(12,342)
Shareholders' Equity Attributable to Parent, Ending Balance at Jun. 30, 2023	$ 685	357,656	(211,090)		1,597,660	12,507	(405,506)		1,351,912
Shares, Outstanding, Ending Balance at Jun. 30, 2023	45,596,196
Increase Decrease In Shareholders Equity Roll Forward
Net Income (Loss)					13,536				13,536
Other comprehensive earnings (loss), net of tax			(56,834)						(56,834)
Deferred compensation						110	(110)
Share-based compensation	$ 1	2,797							2,798
Share-based compensation (in shares)	29,575
Dividends and dividend equivalents					(12,321)				(12,321)
Shareholders' Equity Attributable to Parent, Ending Balance at Sep. 30, 2023	$ 686	360,453	(267,924)		1,598,875	12,617	(405,616)		1,299,091
Shares, Outstanding, Ending Balance at Sep. 30, 2023	45,625,771
Shareholders' Equity Attributable to Parent, Beginning Balance at Dec. 31, 2023	$ 686	362,345	(166,303)		1,609,785	13,539	(406,538)		1,413,514
Shares, Outstanding, Beginning Balance at Dec. 31, 2023	45,640,047
Increase Decrease In Shareholders Equity Roll Forward
Net Income (Loss)					127,900				127,900
Other comprehensive earnings (loss), net of tax			(12,671)						(12,671)
Deferred compensation						(790)	790
Share-based compensation	$ 1	4,356							4,357
Share-based compensation (in shares)	69,834
Dividends and dividend equivalents					(12,348)				(12,348)
Shareholders' Equity Attributable to Parent, Ending Balance at Mar. 31, 2024	$ 687	366,701	(178,974)		1,725,337	12,749	(405,748)		1,520,752
Shares, Outstanding, Ending Balance at Mar. 31, 2024	45,709,881
Shareholders' Equity Attributable to Parent, Beginning Balance at Dec. 31, 2023	$ 686	362,345	(166,303)		1,609,785	13,539	(406,538)		1,413,514
Shares, Outstanding, Beginning Balance at Dec. 31, 2023	45,640,047
Increase Decrease In Shareholders Equity Roll Forward
Net Income (Loss)									304,919
Other comprehensive earnings (loss), net of tax									59,779
Shareholders' Equity Attributable to Parent, Ending Balance at Sep. 30, 2024	$ 687	371,398	(106,524)		1,875,788	11,917	(404,916)		1,748,350
Shares, Outstanding, Ending Balance at Sep. 30, 2024	45,809,920
Shareholders' Equity Attributable to Parent, Beginning Balance at Mar. 31, 2024	$ 687	366,701	(178,974)		1,725,337	12,749	(405,748)		1,520,752
Shares, Outstanding, Beginning Balance at Mar. 31, 2024	45,709,881
Increase Decrease In Shareholders Equity Roll Forward
Net Income (Loss)					81,992				81,992
Other comprehensive earnings (loss), net of tax			(7,843)						(7,843)
Deferred compensation						434	(434)
Share-based compensation		3,084							3,084
Share-based compensation (in shares)	36,173
Dividends and dividend equivalents					(13,278)				(13,278)
Shareholders' Equity Attributable to Parent, Ending Balance at Jun. 30, 2024	$ 687	369,785	(186,817)		1,794,051	13,183	(406,182)		1,584,707
Shares, Outstanding, Ending Balance at Jun. 30, 2024	45,746,054
Increase Decrease In Shareholders Equity Roll Forward
Net Income (Loss)					95,027				95,027
Other comprehensive earnings (loss), net of tax			80,293						80,293
Deferred compensation						(1,266)	1,266
Share-based compensation		1,613							1,613
Share-based compensation (in shares)	63,866
Dividends and dividend equivalents					(13,290)				(13,290)
Shareholders' Equity Attributable to Parent, Ending Balance at Sep. 30, 2024	$ 687	$ 371,398	$ (106,524)		$ 1,875,788	$ 11,917	$ (404,916)		$ 1,748,350
Shares, Outstanding, Ending Balance at Sep. 30, 2024	45,809,920