CONDENSED 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
Revenues
Revenues	$ 73,983	$ 60,492	$ 140,760	$ 111,401
Cost of revenues
Labor and other operating expenses	40,940	38,538	77,969	69,797
Depreciation, depletion and amortization	5,912	5,473	11,668	10,656
Total cost of revenues	46,852	44,011	89,637	80,453
Gross profit	27,131	16,481	51,123	30,948
Selling, general and administrative expenses	4,319	3,848	8,471	7,483
Operating profit	22,812	12,633	42,652	23,465
Other expense (income)
Interest expense	64	63	128	126
Interest and other income, net	(1,889)	(177)	(3,460)	(237)
Total other expense (income)	(1,825)	(114)	(3,332)	(111)
Income before income tax expense	24,637	12,747	45,984	23,576
Income tax expense	4,925	2,509	9,168	4,670
Net income	$ 19,712	$ 10,238	$ 36,816	$ 18,906
Net income per share of common stock
Basic (in dollars per share)	$ 3.46	$ 1.80	$ 6.47	$ 3.33
Diluted (in dollars per share)	$ 3.45	$ 1.80	$ 6.46	$ 3.33