CONSOLIDATED STATEMENTS OF CASH FLOWS - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
Cash flows from operating activities:
Net income	$ 68,488	$ 23,678	$ 31,816
Adjustments to reconcile net income to net cash provided by operating activities:
Depreciation and amortization	38,428	17,324	14,875
Amortization of deferred loan costs	990	764	538
Stock-based compensation	4,060	3,855	8,203
Provision for bad debts	245	159	189
Loss on disposition of assets	136	63
Write off of unamortized debt issuance costs		95
Non-cash operating lease expense	(16)	(1)	14
Deferred income taxes	6,527	15,774	1,344
Changes in operating assets and liabilities:
Receivables	(5,390)	1,563	1,093
Income taxes receivable	(2,052)	(24,709)	94
Inventories	664	(1,088)	(3,043)
Prepaid expenses	841	(1,247)	(730)
Accounts payable	6,920	(5,382)	5,855
Accrued expenses	8,262	596	2,998
Net cash provided by operating activities	128,103	31,444	63,246
Cash flows from investing activities:
Proceeds from sale of assets	22	31	72
Change in construction accounts payable	9,120	42,243	(9,624)
Acquisition of property and equipment	(46,928)	(88,667)	(125,367)
Net cash used in investing activities	(37,786)	(46,393)	(134,919)
Cash flows from financing activities:
Payroll taxes from net exercise of stock options	(730)	(4,428)
Proceeds from exercise of stock options	8,129	3,760
Long-term debt borrowings		10,813	105,500
Principal payments on long-term debt	(92,500)	(24,563)	(3,750)
Loan issuance cost		(2,862)
Net cash (used in) provided by financing activities	(85,101)	(17,280)	101,750
Change in cash and cash equivalents	5,216	(32,229)	30,077
Cash and cash equivalents at beginning of period	28,310	60,539	30,462
Cash and cash equivalents at end of period	33,526	28,310	60,539
Supplemental disclosure of cash flow information:
Cash paid for interest, net of amounts capitalized	3,069	380
Cash paid for income taxes	$ 12,410		$ 6,322
Conversion of long-term deposit to short term deposit		$ 908