Condensed Consolidated Statements of Cash Flows - USD ($) $ in Thousands	6 Months Ended
	Jun. 30, 2021	Jun. 30, 2020
Cash Flows from Operating Activities:
Net income	$ 534,346	$ 400,964
Adjustments to reconcile net income to net cash provided by operating activities:
Depreciation & amortization	265,388	250,602
(Gain) loss on sale of assets and businesses	(4,803)	2,161
Stock-based compensation expense	37,031	33,954
Provision for asset impairment	7,195
Changes in assets & liabilities, net of effects from acquisitions and dispositions:
Accounts receivable	(35,903)	131,294
Accrued interest	(1,459)	(2,191)
Accrued and deferred income taxes	(26,769)	116,707
Other working capital accounts	3,560	26,361
Medicare accelerated payments and deferred CARES Act and other grants	(697,011)	477,099
Other assets and deferred charges	(28,763)	5,095
Other	5,052	(7,659)
Accrued insurance expense, net of commercial premiums paid	104,079	81,016
Payments made in settlement of self-insurance claims	(42,495)	(64,034)
Net cash provided by operating activities	119,448	1,451,369
Cash Flows from Investing Activities:
Property and equipment additions	(482,211)	(354,610)
Proceeds received from sales of assets and businesses	21,143	6,440
Acquisition of businesses and property		(968)
Inflows (outflows) from foreign exchange contracts that hedge our net U.K. investment	(21,487)	57,029
Decrease in capital reserves of commercial insurance subsidiary	100
Costs incurred for purchase and implementation of information technology applications	(1,246)	(4,421)
Investment in, and advances to, joint ventures and other		(285)
Net cash used in investing activities	(483,701)	(296,815)
Cash Flows from Financing Activities:
Reduction of long-term debt	(278,785)	(459,332)
Additional borrowings	6,578	5,453
Repurchase of common shares	(368,080)	(200,054)
Dividends paid	(33,844)	(17,344)
Issuance of common stock	6,442	5,852
Profit distributions to noncontrolling interests	(5,617)	(8,885)
Purchase of ownership interests by minority members	11,433
Net cash used in financing activities	(661,873)	(674,310)
Effect of exchange rate changes on cash, cash equivalents and restricted cash	660	(1,639)
(Decrease) increase in cash, cash equivalents and restricted cash	(1,025,466)	478,605
Cash, cash equivalents and restricted cash, beginning of period	1,279,154	105,667
Cash, cash equivalents and restricted cash, end of period	253,688	584,272
Supplemental Disclosures of Cash Flow Information:
Interest paid	43,641	61,802
Income taxes paid, net of refunds	189,979	14,394
Noncash purchases of property and equipment	$ 95,979	$ 80,031