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, 2023	$ 1,343,442	$ 299	$ 547,861	$ 944,342	$ (149,060)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net (Loss) Income	101,891			101,891
Actuarially determined long-term liability adjustments	385				385
Investments in available-for-sale securities	(126)				(126)
Comprehensive (Loss) Income	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)
Beginning balance at Dec. 31, 2023	1,343,442	299	547,861	944,342	(149,060)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net (Loss) Income	159,952
Actuarially determined long-term liability adjustments	770
Investments in available-for-sale securities	(143)
Comprehensive (Loss) Income	160,579
Ending balance at Jun. 30, 2024	1,438,403	294	535,965	1,050,577	(148,433)
Beginning balance at Mar. 31, 2024	1,388,818	294	536,163	1,001,162	(148,801)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net (Loss) Income	58,061			58,061
Actuarially determined long-term liability adjustments	385				385
Investments in available-for-sale securities	(17)				(17)
Comprehensive (Loss) Income	58,429			58,061	368
Issuance of Common Stock	0	1	(1)
Repurchases of common stock	(10,997)	(1)	(2,407)	(8,589)
Excise Tax on Repurchases of Common Stock	(82)			(82)
Employee Stock-Based Compensation	2,262		2,237	25
Shares Withheld for Taxes	(27)		(27)
Ending balance at Jun. 30, 2024	1,438,403	294	535,965	1,050,577	(148,433)
Beginning balance at Dec. 31, 2024	1,568,247	294	540,412	1,162,114	(134,573)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net (Loss) Income	(69,277)			(69,277)
Actuarially determined long-term liability adjustments	378				378
Investments in available-for-sale securities	(301)				(301)
Comprehensive (Loss) Income	(69,200)			(69,277)	77
Issuance of Common Stock	0	3	(3)
Merger with Arch	2,481,368	243	2,481,125
Repurchases of common stock	(101,259)	(14)	(25,296)	(75,949)
Employee Stock-Based Compensation	36,094		36,094
Shares Withheld for Taxes	(14,068)		(14,068)
Dividends on common shares	(5,364)			(5,364)
Dividend Equivalents Earned on Stock-Based Compensation Awards	(44)			(44)
Ending balance at Mar. 31, 2025	3,895,774	526	3,018,264	1,011,480	(134,496)
Beginning balance at Dec. 31, 2024	1,568,247	294	540,412	1,162,114	(134,573)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net (Loss) Income	(105,833)
Actuarially determined long-term liability adjustments	756
Investments in available-for-sale securities	163
Comprehensive (Loss) Income	(104,914)
Ending balance at Jun. 30, 2025	3,767,586	515	2,992,600	908,125	(133,654)
Beginning balance at Mar. 31, 2025	3,895,774	526	3,018,264	1,011,480	(134,496)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net (Loss) Income	(36,556)			(36,556)
Actuarially determined long-term liability adjustments	378				378
Investments in available-for-sale securities	464				464
Comprehensive (Loss) Income	(35,714)			(36,556)	842
Repurchases of common stock	(81,893)	(11)	(21,597)	(60,285)
Excise Tax on Repurchases of Common Stock	(1,245)			(1,245)
Employee Stock-Based Compensation	(4,067)		(4,067)	0
Dividends on common shares	(5,223)			(5,223)
Dividend Equivalents Earned on Stock-Based Compensation Awards	(46)			(46)
Ending balance at Jun. 30, 2025	$ 3,767,586	$ 515	$ 2,992,600	$ 908,125	$ (133,654)