CONDENSED CONSOLIDATED STATEMENTS OF OPERATIONS Percentage	3 Months Ended		6 Months Ended
	Jun. 30, 2024	Jun. 30, 2023	Jun. 30, 2024	Jun. 30, 2023
Revenues
Revenues (as a percent)	100.00%	100.00%	100.00%	100.00%
Cost of revenues
Labor and other operating expenses (as a percent)	46.80%	55.30%	47.90%	55.40%
Depreciation, depletion and amortization (as a percent)	7.70%	8.00%	8.00%	8.30%
Total cost of revenues (as a percent)	54.50%	63.30%	55.90%	63.70%
Gross profit (as a percent)	45.50%	36.70%	44.10%	36.30%
Selling, general and administrative expenses (as a percent)	6.40%	5.90%	6.50%	6.00%
Operating profit (as a percent)	39.10%	30.80%	37.60%	30.30%
Other (income) expense, net
Other (income) expense, net (as a percent)	(3.60%)	(2.50%)	(3.60%)	(2.40%)
Income before income tax expense (as a percent)	42.70%	33.30%	41.20%	32.70%
Income tax expense (as a percent)	8.70%	6.70%	8.50%	6.50%
Net income (as a percent)	34.00%	26.60%	32.70%	26.20%