CONSOLIDATED STATEMENTS OF CASH FLOWS (Unaudited) - USD ($) $ in Thousands	6 Months Ended
	Jun. 30, 2021	Jun. 30, 2020
Cash flows from operating activities:
Net income (loss)	$ 26,303	$ (2,327)
Adjustments to reconcile net income to net cash provided by operating activities:
Depreciation and amortization	18,874	7,653
Amortization of deferred loan costs	238	269
Stock-based compensation	2,527	2,182
Provision for bad debts	24	46
Non cash operating lease expense	(9)
Deferred income taxes	1
(Gain) loss on disposition of assets	(14)	5
Changes in operating assets and liabilities:
Receivables	(4,960)	(339)
Income taxes	(169)	(1,043)
Inventories	1,746	(259)
Prepaid expenses	1,310	2,823
Accounts payable	2,135	(10,446)
Accrued expenses	7,197	(8,581)
Net cash provided by (used in) operating activities	55,203	(10,017)
Cash flows from investing activities:
Proceeds from sale of assets	13	24
Change in construction payable	285	(4,428)
Acquisition of property and equipment	(12,205)	(18,164)
Net cash used in investing activities	(11,907)	(22,568)
Cash flows from financing activities:
Payroll taxes from net exercise of stock options	(403)	(634)
Proceeds from exercise of stock options	4,593
Long-term debt borrowings		16,000
Principal payments on long-term debt	(47,500)	(5,000)
Net cash (used in) provided by financing activities	(43,310)	10,366
Change in cash and cash equivalents	(14)	(22,219)
Cash and cash equivalents at beginning of period	28,310	60,539
Cash and cash equivalents at end of period	28,296	$ 38,320
Supplemental disclosure of cash flow information:
Cash paid for interest, net of amounts capitalized	2,207
Cash paid for income taxes	$ 6,005