CONDENSED CONSOLIDATED STATEMENTS OF OPERATIONS Percentage	3 Months Ended
	Mar. 31, 2024	Mar. 31, 2023
Revenues
Revenues (as a percent)	100.00%	100.00%
Cost of revenues
Labor and other operating expenses (as a percent)	49.00%	55.50%
Depreciation, depletion and amortization (as a percent)	8.30%	8.60%
Total cost of revenues (as a percent)	57.30%	64.10%
Gross profit (as a percent)	42.70%	35.90%
Selling, general and administrative expenses (as a percent)	6.80%	6.20%
Operating profit (as a percent)	35.90%	29.70%
Other (income) expense, net
Other (income) expense, net (as a percent)	(3.60%)	(2.30%)
Income before income tax expense (as a percent)	39.50%	32.00%
Income tax expense (as a percent)	8.20%	6.40%
Net income (as a percent)	31.30%	25.60%