UNAUDITED CONDENSED CONSOLIDATED STATEMENTS OF CASH FLOWS - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2018	Mar. 31, 2017
Operating activities:
Net (losses) earnings	$ 1,138	$ (860)
Adjustments to reconcile net (losses) earnings to net cash provided by operating activities:
Depreciation, depletion and amortization	2,412	3,969
Gains (losses) on sales of property	(26)	7
Impairment of oil and natural gas properties	0	3
Deferred income taxes	(709)	60
Net change in fair value contracts	(2)	(420)
Changes in assets and liabilities:
Accounts receivable	4,200	(1,968)
Inventories	(7,075)	(7,557)
Income tax receivable	880	(736)
Prepayments and other current assets	153	744
Accounts payable	1,377	17,746
Accrued liabilities	851	1,084
Other	86	78
Net cash provided by operating activities	3,285	12,150
Investing activities:
Property and equipment additions	(866)	(1,006)
Proceeds from property sales	132	39
Insurance and state collateral (deposits) refunds	603	476
Net cash used in investing activities	(131)	(491)
Financing activities:
Principal repayments of capital lease obligations	(83)	0
Dividends paid on common stock	(928)	(928)
Net cash used in financing activities	(1,011)	(928)
Increase in cash and cash equivalents	2,143	10,731
Cash and cash equivalents at beginning of period	109,393	87,342
Cash and cash equivalents at end of period	$ 111,536	$ 98,073