CONSOLIDATED STATEMENTS OF CASH FLOWS - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2023	Dec. 31, 2022	Dec. 31, 2021
Cash flows from operating activities:
Net income	$ 82,448	$ 87,479	$ 68,488
Adjustments to reconcile net income to net cash provided by operating activities:
Depreciation and amortization	47,294	43,433	38,428
Amortization of deferred loan costs	307	1,541	990
Stock-based compensation - stock options	7,112	5,095	4,060
Stock-based compensation - restricted stock	364	80
Provision for bad debts	194	155	245
Loss (gain) on disposition of assets	159	(69)	136
Non-cash operating lease expense	39	9	(16)
Deferred income taxes	68	3,399	6,527
Changes in operating assets and liabilities:
Receivables	(2,618)	(840)	(5,390)
Income taxes receivable	23,983	1,957	(2,052)
Inventories	(56)	(399)	664
Prepaid expenses	(2,458)	(985)	841
Accounts payable	8,674	(4,157)	6,920
Accrued expenses	7,536	3,070	8,262
Net cash provided by operating activities	173,046	139,768	128,103
Cash flows from investing activities:
Proceeds from sale of assets	170	440	22
Change in construction accounts payable	(2,391)	(8,934)	9,120
Acquisition of property and equipment	(49,005)	(39,477)	(46,928)
Net cash used in investing activities	(51,226)	(47,971)	(37,786)
Cash flows from financing activities:
Payroll taxes from net exercise of stock options	(464)	(6,885)	(730)
Proceeds from exercise of stock options	2,573	9,841	8,129
Line-of-credit borrowings	71,500	3,000
Line-of-credit payments	(66,000)	(3,000)
Principal payments on long-term debt	(7,000)	(83,000)	(92,500)
Payment of dividends	(112,819)
Purchase of company common stock	(5,028)	(6,500)
Net cash used in financing activities	(117,238)	(86,544)	(85,101)
Change in cash and cash equivalents	4,582	5,253	5,216
Cash and cash equivalents at beginning of period	38,779	33,526	28,310
Cash and cash equivalents at end of period	43,361	38,779	33,526
Supplemental disclosure of cash flow information:
Cash paid for interest	1,968	1,450	3,069
Cash paid for income taxes	25,626	$ 15,620	$ 12,410
Cash received - income taxes refunds	$ 23,758