Consolidated Statements of Cash Flows - USD ($) $ in Thousands	3 Months Ended				6 Months Ended		12 Months Ended
	Jun. 30, 2023	Mar. 31, 2023	Jun. 30, 2022	Mar. 31, 2022	Jun. 30, 2023	Jun. 30, 2022	Dec. 31, 2022
CASH FLOWS FROM OPERATING ACTIVITIES:
Net income	$ 14,830	$ 12,400	$ 10,562	$ 19,003	$ 27,230	$ 29,565
Adjustments to reconcile net income to net cash provided by operating activities:
Depreciation and amortization	31,615		32,259		62,657	64,287
Amortization of debt issuance costs and other non-cash interest					2,331	3,164
Expenses associated with debt repayments and refinancing transactions	226		6,805		226	6,805
Loss (gain) on sale of real estate assets, net	25		(1,060)		25	(3,321)
Deferred income taxes					(3,944)	3,671
Non-cash revenue and other income					(1,391)	(2,505)
Non-cash equity compensation					10,157	9,720
Other expenses and non-cash items					3,455	2,543
Changes in assets and liabilities, net:
Accounts receivable, prepaid expenses and other assets					48,942	(6,880)
Accounts payable, accrued expenses and other liabilities					(23,820)	(12,735)
Net cash provided by operating activities					125,868	94,314
CASH FLOWS FROM INVESTING ACTIVITIES:
Expenditures for facility development and expansions					(3,155)	(13,789)
Expenditures for other capital improvements					(23,251)	(20,075)
Net proceeds from sale of assets					5,918	10,957
Decrease (increase) in other assets					(1,137)	(161)
Net cash used in investing activities					(21,625)	(22,746)
CASH FLOWS FROM FINANCING ACTIVITIES:
Proceeds from borrowings from credit facility					100,000	100,000
Scheduled principal repayments					(5,518)	(10,278)
Principal repayments of credit facility					(100,000)	0
Other repayments of debt					(174,754)	(295,139)
Payment of debt defeasance, issuance and other refinancing and related costs					(83)	(8,046)
Payment of lease obligations for financing leases					(295)	(285)
Dividends paid on RSUs					(131)	(886)
Purchase and retirement of common stock					(30,531)	(40,236)
Net cash used in financing activities					(211,312)	(254,870)
NET DECREASE IN CASH, CASH EQUIVALENTS AND RESTRICTED CASH					(107,069)	(183,302)
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	$ 55,096		$ 127,405		55,096	127,405	$ 162,165
NON-CASH INVESTING AND FINANCING ACTIVITIES
Establishment of right of use assets and lease liabilities					224	1,590
Cash paid during the period for:
Interest (net of amounts capitalized of $0.2 million in 2022)					42,379	46,312
Income taxes paid					$ 13,225	$ 14,225