Condensed Consolidated Statements of Cash Flows - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2021	Mar. 31, 2020
Cash Flows from Operating Activities:
Net income	$ 209,070	$ 144,460
Adjustments to reconcile net income to net cash provided by operating activities:
Depreciation & amortization	131,403	124,394
Stock-based compensation expense	18,022	18,047
Changes in assets & liabilities, net of effects from acquisitions and dispositions:
Accounts receivable	56,851	69,763
Accrued interest	10,133	(4,412)
Accrued and deferred income taxes	53,769	45,200
Other working capital accounts	82,663	73,929
Medicare accelerated payments and deferred CARES Act and other grants	(509,448)
Other assets and deferred charges	(17)	11,084
Other	2,623	(3,038)
Accrued insurance expense, net of commercial premiums paid	35,467	49,559
Payments made in settlement of self-insurance claims	(18,741)	(26,924)
Net cash provided by operating activities	71,795	502,062
Cash Flows from Investing Activities:
Property and equipment additions, net of disposals	(247,459)	(184,102)
Inflows (outflows) from foreign exchange contracts that hedge our net U.K. investment	(14,264)	51,691
Decrease in capital reserves of commercial insurance subsidiary	100
Costs incurred for purchase and implementation of information technology applications	(575)	(1,857)
Investment in, and advances to, joint ventures and other	(129)	(751)
Net cash used in investing activities	(262,327)	(135,019)
Cash Flows from Financing Activities:
Reduction of long-term debt	(251,830)	(185,098)
Additional borrowings		5,453
Repurchase of common shares	(7,464)	(172,092)
Dividends paid	(17,018)	(17,344)
Issuance of common stock	3,357	3,002
Profit distributions to noncontrolling interests	(4,525)	(5,735)
Purchase of ownership interests by minority members	7,603
Net cash used in financing activities	(269,877)	(371,814)
Effect of exchange rate changes on cash, cash equivalents and restricted cash	423	(1,673)
Decrease in cash, cash equivalents and restricted cash	(459,986)	(6,444)
Cash, cash equivalents and restricted cash, beginning of period	1,279,154	105,667
Cash, cash equivalents and restricted cash, end of period	819,168	99,223
Supplemental Disclosures of Cash Flow Information:
Interest paid	11,421	39,483
Income taxes paid, net of refunds	8,654	6,783
Noncash purchases of property and equipment	$ 60,124	$ 58,935