Consolidated Statements of Operations - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2023	Jun. 30, 2022	Jun. 30, 2023	Jun. 30, 2022
Revenue	$ 137,469	$ 138,655	$ 303,829	$ 293,537
Costs and expenses
Cost of sales (exclusive of items shown separately below)	99,199	76,644	209,748	157,897
Asset retirement obligations accretion	349	755	700	990
Depreciation, depletion, and amortization	13,556	9,783	25,407	18,463
Selling, general and administrative	14,319	8,786	26,061	20,610
Total costs and expenses	127,423	95,968	261,916	197,960
Operating income	10,046	42,687	41,913	95,577
Other income, net	2,495	2,348	3,742	2,714
Interest expense, net	(2,518)	(1,937)	(4,826)	(3,068)
Income before tax	10,023	43,098	40,829	95,223
Income tax expense	2,467	9,818	8,016	20,472
Net income	$ 7,556	$ 33,280	$ 32,813	$ 74,751
Earnings per share
Basic (in dollars per share)	$ 0.17	$ 0.75	$ 0.74	$ 1.69
Diluted (in dollars per share)	$ 0.17	$ 0.74	$ 0.73	$ 1.66