Unaudited Condensed Consolidated Statements of Cash Flows - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2021	Mar. 31, 2020
Cash flows from operating activities
Net income	$ 4,143	$ 1,962
Adjustments to reconcile net income (loss) to net cash from operating activities:
Accretion of asset retirement obligations	151	141
Depreciation and amortization	6,155	5,002
Amortization of debt issuance costs	14	14
Stock-based compensation	1,055	923
Other income - employee retention tax credit	(2,462)
Deferred income taxes	(166)	110
Changes in operating assets and liabilities:
Accounts receivable	(1,444)	4,836
Prepaid expenses and other current assets	1,127	(554)
Inventories	(12,243)	(8,197)
Other assets and liabilities	(220)	(214)
Accounts payable	5,324	2,649
Accrued expenses	(935)	(256)
Net cash from operating activities	499	6,416
Cash flow from investing activities:
Purchases of property, plant and equipment	(3,725)	(8,900)
Net cash from investing activities	(3,725)	(8,900)
Cash flows from financing activities
Proceeds from borrowings	11,600	22,200
Repayment of borrowings	(8,208)	(9,533)
Repayments of financed insurance payable	(377)	(281)
Net cash from financing activities	3,015	12,386
Net change in cash and cash equivalents and restricted cash	(211)	9,902
Cash and cash equivalents and restricted cash, beginning of period	6,710	6,865
Cash and cash equivalents and restricted cash, end of period	6,499	16,767
Supplemental cash flow information:
Cash paid for interest	186	242
Non-cash investing and financing activities:
Capital expenditures included in accounts payable and accrued expenses	913	2,689
Additional asset retirement obligations incurred	$ 26	$ 9