Condensed Consolidated Statements of Operations - USD ($) shares in Thousands, $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2024	Sep. 30, 2023	Sep. 30, 2024	Sep. 30, 2023
Condensed Consolidated Statements of Operations
Revenues	$ 617,899	$ 744,601	$ 1,906,840	$ 2,371,826
Costs, expenses and other operating
Cost of sales (exclusive of items shown separately below)	558,596	596,889	1,655,003	1,774,753
Depreciation, depletion and amortization	40,890	36,717	118,149	108,273
Accretion on asset retirement obligations	5,869	5,292	17,608	15,877
Selling, general and administrative expenses	20,603	24,279	68,708	73,092
Merger related costs	7,002		7,002
Severance costs related to voluntary separation plan	6,649		6,649
Other operating income, net	(5,461)	(2,858)	(23,854)	(10,037)
Costs, expenses and other operating	634,148	660,319	1,849,265	1,961,958
Income (loss) from operations	(16,249)	84,282	57,575	409,868
Interest expense, net
Interest expense	(3,912)	(3,120)	(12,161)	(10,783)
Interest and investment income	5,665	4,803	17,168	12,340
Interest expense, net	1,753	1,683	5,007	1,557
Income (loss) before nonoperating expenses	(14,496)	85,965	62,582	411,425
Nonoperating expense
Non-service related pension and postretirement benefit credits	1,667	4,507	1,096	5,692
Net loss resulting from early retirement of debt				(1,126)
Nonoperating expenses	1,667	4,507	1,096	4,566
Income (loss) before income taxes	(12,829)	90,472	63,678	415,991
(Benefit from) provision for income taxes	(6,608)	16,781	(887)	66,839
Net income (loss)	$ (6,221)	$ 73,691	$ 64,565	$ 349,152
Net income (loss) per common share
Basic earnings (loss) per share (in dollars per share)	$ (0.34)	$ 4.05	$ 3.55	$ 19.20
Diluted earnings (loss) per share (in dollars per share)	$ (0.34)	$ 3.91	$ 3.50	$ 18.12
Weighted average shares outstanding
Basic weighted average shares outstanding (in shares)	18,097	18,187	18,180	18,189
Diluted weighted average shares outstanding (in shares)	18,097	18,840	18,450	19,270
Dividends declared per common share (in dollars per share)	$ 0.25	$ 3.97	$ 3.01	$ 9.53