Condensed Consolidated Income Statements - USD ($) shares in Thousands, $ in Thousands	3 Months Ended
	Mar. 31, 2024	Mar. 31, 2023
Condensed Consolidated Income Statements
Revenues	$ 680,190	$ 869,931
Costs, expenses and other operating
Cost of sales (exclusive of items shown separately below)	567,723	571,737
Depreciation, depletion and amortization	38,820	35,479
Accretion on asset retirement obligations	5,869	5,292
Selling, general and administrative expenses	25,587	26,022
Other operating income, net	(15,983)	(5,169)
Costs, expenses and other operating	622,016	633,361
Income from operations	58,174	236,570
Interest expense, net
Interest expense	(4,316)	(4,126)
Interest and investment income	6,100	3,336
Interest expense, net	1,784	(790)
Income before nonoperating expenses	59,958	235,780
Nonoperating expense
Non-service related pension and postretirement benefit (costs) credits	(286)	592
Net loss resulting from early retirement of debt		(1,126)
Nonoperating expenses	(286)	(534)
Income before income taxes	59,672	235,246
Provision for income taxes	3,719	37,138
Net income	$ 55,953	$ 198,108
Net income per common share
Basic earnings per share (in dollars per share)	$ 3.05	$ 11.05
Diluted earnings per share (in dollars per share)	$ 2.98	$ 10.02
Weighted average shares outstanding
Basic weighted average shares outstanding (in shares)	18,347	17,924
Diluted weighted average shares outstanding (in shares)	18,775	19,784
Dividends declared per common share (in dollars per share)	$ 1.65	$ 3.11