v3.22.2.2
CONDENSED CONSOLIDATED STATEMENTS OF OPERATIONS Percentage
 3 Months Ended 9 Months Ended
Sep. 30, 2022
Sep. 30, 2021
Sep. 30, 2022
Sep. 30, 2021
Revenues        
Revenues (as a percent) 100.00% 100.00% 100.00% 100.00%
Cost of revenues        
Labor and other operating expenses (as a percent) 57.50% 57.30% 60.70% 57.10%
Depreciation, depletion and amortization (as a percent) 8.50% 9.60% 9.20% 10.80%
Total cost of revenues (as a percent) 66.00% 66.90% 69.90% 67.90%
Gross profit (as a percent) 34.00% 33.10% 30.10% 32.10%
Selling, general and administrative expenses (as a percent) 5.30% 6.00% 6.20% 6.40%
Operating profit (as a percent) 28.70% 27.10% 23.90% 25.70%
Other expense (income)        
Interest expense (as a percent) 0.10% 0.10% 0.10% 0.10%
Interest and other income, net (as a percent) (0.90%) (0.30%) (0.50%) (0.20%)
Total other expense (income) (as a percent) (0.80%) (0.20%) (0.40%) (0.10%)
Income before income tax expense (as a percent) 29.50% 27.30% 24.30% 25.80%
Income tax expense (as a percent) 5.80% 5.70% 4.80% 5.20%
Net income (as a percent) 23.70% 21.60% 19.50% 20.60%