CONSOLIDATED STATEMENTS OF CASH FLOWS - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Operating activities:
Net (losses) earnings	$ 995	$ 8,207	$ 2,945
Adjustments to reconcile net earnings to net cash provided by (used in) operating activities:
Depreciation and amortization	18,573	16,641	10,654
Gains on sales of property	(1,859)	(1,400)	(1,240)
Provision for doubtful accounts	(27)	(12)	(150)
Stock-based compensation expense	643	478	255
Deferred income taxes	6,389	2,085	936
Net change in fair value contracts	(9)	23	(2)
Gain on dissolution of AREC	0	(573)	0
Changes in assets and liabilities:
Accounts receivable	(5,162)	(8,373)	36,350
Accounts receivable/payable, affiliates	(5)	(24)	24
Inventories	4,751	(3,628)	(10,587)
Income tax receivable	(10,719)	(165)	(1,087)
Prepayments and other current assets	(1,401)	(2)	(293)
Accounts payable	(61,116)	31,795	(10,252)
Accrued liabilities	5,052	1,154	1,744
Other	(104)	693	1,717
Net cash (used in) provided by operating activities	(43,999)	46,899	31,014
Investing activities:
Property and equipment additions	(5,008)	(35,743)	(11,731)
Acquisitions	(20,200)	(5,624)	(10,272)
Proceeds from property sales	4,515	3,680	2,038
Proceeds from dissolution of AREC	0	998	0
Insurance and state collateral (deposits) refunds	1,030	652	830
Net cash used in investing activities	(19,663)	(36,037)	(19,135)
Financing activities:
Principal repayments of finance lease obligations	(2,336)	(1,697)	(495)
Payment of contingent consideration liability	(111)	0	0
Dividends paid on common stock	(4,081)	(3,976)	(3,711)
Net cash used in financing activities	(6,528)	(5,673)	(4,206)
(Decrease) Increase in cash and cash equivalents, including restricted cash	(70,190)	5,189	7,673
Cash and cash equivalents, including restricted cash, at beginning of period	122,255	117,066	109,393
Cash and cash equivalents, including restricted cash, at end of period	$ 52,065	$ 122,255	$ 117,066