CONDENSED CONSOLIDATED STATEMENTS OF OPERATIONS - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2020	Sep. 30, 2019	Sep. 30, 2020	Sep. 30, 2019
Revenues
Revenues	$ 43,727	$ 43,559	$ 119,714	$ 120,312
Cost of revenues
Labor and other operating expenses	24,665	25,887	71,074	75,927
Depreciation, depletion and amortization	4,880	4,189	14,224	12,482
Total cost of revenues	29,545	30,076	85,298	88,409
Gross profit	14,182	13,483	34,416	31,903
Selling, general and administrative expenses	2,909	2,928	9,009	8,240
Operating profit	11,273	10,555	25,407	23,663
Other expense (income)
Interest expense	62	61	186	183
Interest and other income, net	(49)	(477)	(400)	(1,459)
Total other expense (income)	13	(416)	(214)	(1,276)
Income before income tax expense	11,260	10,971	25,621	24,939
Income tax expense	1,936	1,069	4,652	3,876
Net income	$ 9,324	$ 9,902	$ 20,969	$ 21,063
Net income per share of common stock
Basic (in dollars per share)	$ 1.66	$ 1.76	$ 3.73	$ 3.75
Diluted (in dollars per share)	$ 1.65	$ 1.76	$ 3.72	$ 3.75