CONSOLIDATED STATEMENTS OF CASH FLOWS - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Cash flows from operating activities:
Net income	$ 333,040	$ 830,555	$ 1,033,082
Adjustments to reconcile net income to net cash provided by operating activities:
Depreciation and amortization	591,035	777,485	720,252
Impairment charges	61,981	981,589	296,408
Valuation adjustment on disposal group	316,840	0	0
Stock-based compensation expense	73,061	35,092	38,338
Deferred income taxes	273,660	(395,217)	52,010
Equity investment income, net	26,449	28,925	17,766
Gain on sales of business interests, net	(85,699)	(23,402)	(404,165)
Other non-cash charges, net	82,374	66,920	(7,343)
Changes in operating assets and liabilities, net of effect of acquisitions and divestitures:
Accounts receivable	(81,176)	(156,305)	(152,240)
Inventories	73,505	(18,625)	22,920
Other receivables and other current assets	236,995	(111,432)	(45,351)
Other long-term assets	3,497	(11,945)	35,893
Accounts payable	(35,959)	26,876	11,897
Accrued compensation and benefits	84,165	(78,239)	68,272
Other current liabilities	(157,462)	1,908	176,494
Income taxes	(23,635)	(52,176)	77,376
Other long-term liabilities	(1,031)	11,157	30,517
Net cash provided by operating activities	1,771,640	1,913,166	1,972,126
Cash flows from investing activities:
Additions of property and equipment	(987,138)	(905,250)	(829,095)
Acquisitions	(183,156)	(803,879)	(563,856)
Proceeds from asset and business sales	150,205	92,336	64,725
Purchase of investments available for sale	(8,448)	(13,117)	(13,539)
Purchase of investments held-to-maturity	(5,963)	(228,990)	(1,133,192)
Proceeds from sale of investments available for sale	9,526	6,408	18,963
Proceeds from investments held-to-maturity	34,862	492,470	1,240,502
Purchase of equity investments	(19,177)	(4,816)	(27,096)
Proceeds from sale of equity investments	0	0	40,920
Distributions received on equity investments	3,646	106	0
Net cash used in investing activities	(1,005,643)	(1,364,732)	(1,201,668)
Cash flows from financing activities:
Borrowings	59,934,750	50,991,960	51,991,490
Payments on long-term debt and other financing costs	(59,239,973)	(50,837,112)	(52,116,120)
Purchase of treasury stock	(1,161,511)	(802,949)	(1,097,822)
Distributions to noncontrolling interests	(196,441)	(211,467)	(192,401)
Stock award exercises and other share issuances, net	13,577	21,252	23,543
Excess tax benefits from stock award exercises	0	0	13,251
Contributions from noncontrolling interests	52,311	74,552	47,590
Proceeds from sales of additional noncontrolling interests	15	2,864	0
Purchases of noncontrolling interests	(28,082)	(5,357)	(21,512)
Net cash used in financing activities	(625,354)	(766,257)	(1,351,981)
Effect of exchange rate changes on cash, cash equivalents and restricted cash	(3,350)	254	4,276
Less: Net increase (decrease) in cash, cash equivalents and restricted cash from discontinued operations	137,293	(217,569)	(577,247)
Cash, cash equivalents and restricted cash of continuing operations at beginning of the year	518,920	683,463	1,244,917
Cash, cash equivalents and restricted cash of continuing operations at end of the year	415,420	518,920	683,463
Discontinued Operations
Cash flows from financing activities:
Less: Net increase (decrease) in cash, cash equivalents and restricted cash from discontinued operations	240,793	(53,026)	(15,793)
Continuing Operations
Cash flows from financing activities:
Less: Net increase (decrease) in cash, cash equivalents and restricted cash from discontinued operations	$ (103,500)	$ (164,543)	$ (561,454)