Consolidated Statements of Cash Flows - USD ($) $ in Thousands	3 Months Ended				9 Months Ended		12 Months Ended
	Sep. 30, 2023	Mar. 31, 2023	Sep. 30, 2022	Mar. 31, 2022	Sep. 30, 2023	Sep. 30, 2022	Dec. 31, 2022
CASH FLOWS FROM OPERATING ACTIVITIES:
Net income	$ 13,892	$ 12,400	$ 68,318	$ 19,003	$ 41,122	$ 97,883
Adjustments to reconcile net income to net cash provided by operating activities:
Depreciation and amortization	32,526		31,931		95,183	96,218
Asset impairments	2,710		3,513		2,710	3,513
Amortization of debt issuance costs and other non-cash interest					3,438	4,421
Expenses associated with debt repayments and refinancing transactions	100		783		326	7,588
Gain on sale of real estate assets, net	(368)		(83,828)		(343)	(87,149)
Deferred income taxes					(1,494)	9,532
Non-cash revenue and other income					(2,087)	(3,155)
Non-cash equity compensation					15,442	11,707
Other expenses and non-cash items					4,839	4,565
Changes in assets and liabilities, net:
Accounts receivable, prepaid expenses and other assets					44,750	(14,963)
Accounts payable, accrued expenses and other liabilities					5,691	(11,971)
Net cash provided by operating activities					209,577	118,189
CASH FLOWS FROM INVESTING ACTIVITIES:
Expenditures for facility development and expansions					(5,001)	(17,249)
Expenditures for other capital improvements					(39,347)	(33,669)
Net proceeds from sale of assets					6,431	156,169
Increase in other assets					(1,297)	(3,363)
Net cash used in investing activities					(39,214)	101,888
CASH FLOWS FROM FINANCING ACTIVITIES:
Proceeds from borrowings from credit facility					125,000	100,000
Scheduled principal repayments					(8,637)	(12,664)
Principal repayments of credit facility					(125,000)	0
Other repayments of debt					(174,754)	(332,159)
Payment of debt defeasance, issuance and other refinancing and related costs					(119)	(6,402)
Payment of lease obligations for financing leases					(445)	(432)
Dividends paid on RSUs					(131)	(886)
Purchase and retirement of common stock					(30,531)	(79,080)
Net cash used in financing activities					(214,617)	(331,623)
NET DECREASE IN CASH, CASH EQUIVALENTS AND RESTRICTED CASH					(44,254)	(111,546)
CASH, CASH EQUIVALENTS AND RESTRICTED CASH, beginning of period		$ 162,165		$ 310,707	162,165	310,707	$ 310,707
CASH, CASH EQUIVALENTS AND RESTRICTED CASH, end of period	$ 117,911		$ 199,161		117,911	199,161	$ 162,165
NON-CASH INVESTING AND FINANCING ACTIVITIES
Establishment of right of use assets and lease liabilities					566	1,610
Cash paid during the period for:
Interest (net of amounts capitalized of $0.8 million in 2022)					46,809	50,840
Income taxes paid					$ 18,475	$ 25,191