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	$ 719,307	$ 656,982	$ 987,632
Adjustments to reconcile net income to net cash provided by operating activities:
Depreciation & amortization	568,041	581,861	533,213
(Gain) loss on sales of assets and businesses	(6,250)	584	(5,170)
Stock-based compensation expense	87,720	85,378	73,686
Costs related to extinguishment of debt	0	0	16,831
Provision for asset impairment	0	57,550	14,391
Changes in assets & liabilities, net of effects from acquisitions and dispositions:
Accounts receivable	(182,444)	(258,338)	(8,873)
Accrued interest	1,193	1,835	4,950
Accrued and deferred income taxes	(43,450)	(29,510)	(54,030)
Other working capital accounts	(32,321)	(146,692)	46,526
Medicare accelerated payments and deferred CARES Act and other grants	2,978	2,391	(698,762)
Other assets and deferred charges	48,517	19,918	(39,337)
Other	39,133	(8,676)	(82,075)
Accrued insurance expense, net of commercial premiums paid	183,462	174,723	186,215
Payments made in settlement of self-insurance claims	(118,089)	(141,983)	(91,502)
Net cash provided by operating activities	1,267,797	996,023	883,695
Cash Flows from Investing Activities:
Property and equipment additions	(743,055)	(734,001)	(855,659)
Acquisition of businesses and property	(3,728)	(20,309)	(105,415)
(Outflows) inflows from foreign exchange contracts that hedge our net U.K. investment	(40,695)	94,913	1,357
Proceeds received from sales of assets and businesses	24,187	12,001	25,425
Costs incurred for purchase and implementation of information technology applications	0	0	19,726
Decrease (increase) in capital reserves of commercial insurance subsidiary	16	100	100
Net cash used in investing activities	(763,275)	(647,296)	(914,466)
Cash Flows from Financing Activities:
Repayments of long-term debt	(85,480)	(89,367)	(3,037,868)
Additional borrowings	185,100	705,321	3,254,974
Financing costs	(308)	(3,164)	(18,770)
Repurchase of common shares	(547,363)	(832,918)	(1,220,875)
Dividends paid	(55,480)	(58,449)	(65,896)
Issuance of common stock	13,654	14,068	13,372
Profit distributions to noncontrolling interests	(6,830)	(5,391)	(7,080)
Purchase (sale) of ownership interests by (from) minority member	2,762	(48,500)	13,193
Net cash used in financing activities	(493,945)	(318,400)	(1,068,950)
Effect of exchange rate changes on cash and cash equivalents	3,056	(8,424)	(499)
Increase decrease in cash, cash equivalents and restricted cash	13,633	21,903	(1,100,220)
Cash, cash equivalents and restricted cash, beginning of period	200,837	178,934	1,279,154
Cash, cash equivalents and restricted cash, end of period	214,470	200,837	178,934
Supplemental Disclosures of Cash Flow Information:
Interest paid	200,446	120,136	75,607
Income taxes paid, net of refunds	257,896	250,759	362,978
Noncash purchases of property and equipment	$ 66,899	$ 72,064	$ 167,234