CONDENSED CONSOLIDATED STATEMENTS OF OPERATIONS - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2019	Jun. 30, 2018	Jun. 30, 2019	Jun. 30, 2018
Revenues
Total revenues	$ 38,954	$ 39,242	$ 76,753	$ 74,529
Cost of revenues
Labor and other operating expenses	25,002	25,317	50,040	49,390
Depreciation, depletion and amortization	4,225	4,288	8,293	8,465
Total cost of revenues	29,227	29,605	58,333	57,855
Gross profit	9,727	9,637	18,420	16,674
Selling, general and administrative expenses	2,639	2,565	5,312	5,066
Operating profit	7,088	7,072	13,108	11,608
Other (income) expense
Interest expense	60	63	122	125
Interest and other income, net	(490)	(459)	(982)	(812)
Total other (income) expense	(430)	(396)	(860)	(687)
Income before income tax expense	7,518	7,468	13,968	12,295
Income tax expense	1,485	830	2,807	1,395
Net income	$ 6,033	$ 6,638	$ 11,161	$ 10,900
Net income per share of common stock
Basic (in dollars per share)	$ 1.07	$ 1.19	$ 1.99	$ 1.95
Diluted (in dollars per share)	$ 1.07	$ 1.18	$ 1.99	$ 1.95
Lime and limestone operations
Revenues
Total revenues	$ 38,581	$ 38,557	$ 76,046	$ 73,271
Natural gas interests
Revenues
Total revenues	$ 373	$ 685	$ 707	$ 1,258