Condensed Consolidated Statements of Cash Flows - USD ($) $ in Thousands	6 Months Ended
	Jun. 30, 2020	Jun. 30, 2019
Cash flows from operating activities
Net income	$ 4,614	$ 17,496
Adjustments to reconcile net income to net cash from operating activities:
Accretion of asset retirement obligations	300	256
Depreciation and amortization	10,343	8,938
Amortization of debt issuance costs	29	28
Stock-based compensation	2,029	1,954
Other income - PPP Loan	(7,305)
Deferred income taxes	1,370	3,429
Changes in operating assets and liabilities:
Accounts receivable	3,455	(15,370)
Prepaid expenses and other current assets	1,229	1,467
Inventories	(10,194)	(2,408)
Other assets and liabilities	(372)	67
Accounts payable	323	(4,121)
Accrued expenses	1,012	1,295
Net cash from operating activities	6,833	13,031
Cash flow from investing activities:
Purchases of property, plant and equipment	(18,019)	(19,737)
Cash flows from financing activities
Proceeds from PPP Loan	8,444
Proceeds from borrowings	29,443	44,300
Repayment of borrowings	(21,604)	(38,800)
Repayments of financed insurance payable	(562)	(287)
Restricted stock surrendered for withholding taxes payable	(193)
Net cash from financing activities	15,528	5,213
Net change in cash and cash equivalents and restricted cash	4,342	(1,493)
Cash and cash equivalents and restricted cash, beginning of period	6,865	7,380
Cash and cash equivalents and restricted cash, end of period	11,207	5,887
Supplemental cash flow information:
Cash paid for interest	532	568
Non-cash investing and financing activities:
Capital expenditures included in accounts payable and accrued expenses	152	5,373
Additional asset retirement obligations incurred	$ 17	$ 137