Consolidated Statements of Stockholders' Equity - USD ($) $ in Thousands	Total	Common Stock	Capital in Excess of Par Value	Retained Earnings	Accumulated Other Comprehensive (Loss) Income
Beginning balance at Dec. 31, 2022	$ 1,165,826	$ 347	$ 646,237	$ 668,882	$ (149,640)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income (loss)	230,377			230,377
Actuarially determined long-term liability adjustments	(901)				(901)
Interest Rate Hedge, net	212				212
Investments in available-for-sale securities	212
Comprehensive Income (Loss)	229,688			230,377	(689)
Issuance of Common Stock	0	3	(3)
Repurchases of common stock	(67,133)	(11)	(22,446)	(44,676)
Excise Tax on Repurchases of Common Stock	(478)			(478)
Employee Stock-Based Compensation	4,792		4,792
Shares Withheld for Taxes	(12,708)		(12,708)
Dividends on common shares	(38,287)			(38,287)
Dividend Equivalents Earned on Stock-Based Compensation Awards	(803)			(803)
Ending balance at Mar. 31, 2023	1,280,897	339	615,872	815,015	(150,329)
Beginning balance at Dec. 31, 2023	1,343,442	299	547,861	944,342	(149,060)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income (loss)	101,891			101,891
Actuarially determined long-term liability adjustments	385				385
Investments in available-for-sale securities	(126)				(126)
Comprehensive Income (Loss)	102,150			101,891	259
Issuance of Common Stock	0	1	(1)
Repurchases of common stock	(55,881)	(6)	(11,264)	(44,611)
Excise Tax on Repurchases of Common Stock	(471)			(471)
Employee Stock-Based Compensation	5,129		5,118	11
Shares Withheld for Taxes	(5,551)		(5,551)
Ending balance at Mar. 31, 2024	$ 1,388,818	$ 294	$ 536,163	$ 1,001,162	$ (148,801)