Unaudited Condensed Consolidated Statements of Operations - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2021	Mar. 31, 2020
Unaudited Condensed Consolidated Statements of Operations
Revenue	$ 43,455	$ 41,935
Cost and expenses
Cost of sales (exclusive of items shown separately below)	31,198	30,934
Asset retirement obligation accretion	151	141
Depreciation and amortization	6,155	5,002
Selling, general and administrative	4,707	4,717
Total costs and expenses	42,211	40,794
Operating income	1,244	1,141
Other income	2,935	1,210
Interest expense, net	(202)	(279)
Income before tax	3,977	2,072
Income tax (benefit) expense	(166)	110
Net income	$ 4,143	$ 1,962
Earnings (loss) per common share
Basic earnings (in dollars per share)	$ 0.10	$ 0.05
Diluted earnings (in dollars per share)	$ 0.10	$ 0.05
Weighted average common shares outstanding
Basic weighted average shares outstanding (in shares)	43,443	41,760
Diluted weighted average shares outstanding (in shares)	43,443	41,760