CONSOLIDATED STATEMENTS OF CASH FLOWS (unaudited) - USD ($) $ in Thousands	6 Months Ended
	Jun. 30, 2021	Jun. 30, 2020
Cash flows from operating activities:
Net income	$ 642,576	$ 542,767
Adjustments to reconcile net income to net cash provided by operating activities:
Depreciation and amortization	335,390	312,055
Debt refinancing charges	0	884
Stock-based compensation expense	51,717	42,125
Deferred income taxes	40,685	132,101
Equity investment income, net	(2,764)	(6,494)
Loss on sales of business interests, net	0	16,252
Other non-cash charges, net	1,274	(5,885)
Changes in operating assets and liabilities, net of effect of acquisitions and divestitures:
Accounts receivable	(117,171)	15,194
Inventories	(3,270)	(696)
Other receivables and prepaid and other current assets	14,465	(131,988)
Other long-term assets	(13,706)	1,950
Accounts payable	(47,390)	(15,858)
Accrued compensation and benefits	(90,381)	(19,325)
Other current liabilities	25,090	146,490
Income taxes	10,753	(4,800)
Other long-term liabilities	(13,232)	(13,269)
Net cash provided by operating activities	834,036	1,011,503
Cash flows from investing activities:
Additions of property and equipment	(294,438)	(291,667)
Acquisitions	(23,890)	(44,267)
Proceeds from asset and business sales	29,774	70,615
Purchase of debt investments held-to-maturity	(7,923)	(142,483)
Purchase of other debt and equity investments	(2,164)	(3,034)
Proceeds from debt investments held-to-maturity	7,923	7,621
Proceeds from sale of other debt and equity investments	11,908	3,438
Purchase of equity method investments	(6,029)	(8,101)
Distributions from equity method investments	1,140	739
Net cash used in investing activities	(283,699)	(407,139)
Cash flows from financing activities:
Borrowings	1,611,086	2,324,300
Payments on long-term debt	(754,407)	(635,695)
Deferred financing costs	(9,089)	(20,375)
Purchase of treasury stock	(560,507)	(321,798)
Distributions to noncontrolling interests	(99,362)	(118,553)
Net payments related to stock purchases and awards	(43,605)	(2,106)
Contributions from noncontrolling interests	15,925	20,582
Purchases of noncontrolling interests	(4,493)	(6,782)
Net cash provided by financing activities	155,548	1,239,573
Effect of exchange rate changes on cash, cash equivalents and restricted cash	(1,197)	(16,936)
Net increase in cash, cash equivalents and restricted cash	704,688	1,827,001
Cash, cash equivalents and restricted cash of continuing operations at beginning of the year	501,790	1,208,718
Cash, cash equivalents and restricted cash of continuing operations at end of the year	1,206,478	3,035,719
Discontinued Operations
Cash flows from financing activities:
Net increase in cash, cash equivalents and restricted cash	0	0
Continuing Operations
Cash flows from financing activities:
Net increase in cash, cash equivalents and restricted cash	$ 704,688	$ 1,827,001