Condensed Consolidated Statements of Cash Flows - USD ($) $ in Thousands	6 Months Ended
	Jun. 30, 2019	Jun. 30, 2018
Cash flows from operating activities:
Net income	$ 261,599	$ 130,512
Adjustments to reconcile net income to net cash provided by operating activities:
Depreciation	533,650	513,248
Stock-based compensation	110,542	92,261
Amortization of intangible assets	98,752	101,651
Amortization of debt issuance costs and debt discounts and premiums	6,233	7,461
Provision for allowance for doubtful accounts	7,097	3,606
Impairment charges	14,834	0
Loss on debt extinguishment	382	40,706
Other items	8,725	7,998
Changes in operating assets and liabilities:
Accounts receivable	(126,720)	(38,441)
Income taxes, net	30,662	(22,866)
Other assets	(5,724)	3,536
Operating lease right-of-use assets	78,483
Operating lease liabilities	(73,805)
Accounts payable and accrued expenses	(3,987)	(24,325)
Other liabilities	23,341	24,288
Net cash provided by operating activities	964,064	839,635
Cash flows from investing activities:
Purchases of investments	(20,787)	(54,421)
Sales of investments	8,945	67,164
Business acquisitions, net of cash and restricted cash acquired	(34,143)	(830,993)
Purchases of real estate	(47,436)	(41,782)
Purchases of other property, plant and equipment	(808,138)	(869,968)
Net cash used in investing activities	(901,559)	(1,730,000)
Cash flows from financing activities:
Proceeds from employee equity awards	27,593	25,860
Payment of dividends and special distribution	(413,052)	(368,759)
Proceeds from public offering of common stock, net of issuance costs	1,561,555	7,622
Proceeds from senior notes	0	929,850
Repayments of finance lease liabilities	(43,112)
Repayments of finance lease liabilities		(69,856)
Repayments of mortgage and loans payable	(36,212)	(25,415)
Repayment of senior notes	(150,000)	0
Debt extinguishment costs	0	(20,556)
Debt issuance costs	0	(11,583)
Other financing activities	0	580
Net cash provided by financing activities	946,772	467,743
Effect of foreign currency exchange rates on cash, cash equivalents and restricted cash	411	(25,840)
Net increase (decrease) in cash, cash equivalents and restricted cash	1,009,688	(448,462)
Cash, cash equivalents and restricted cash at beginning of period	627,604	1,450,701
Cash, cash equivalents and restricted cash at end of period	1,637,292	1,002,239
Cash and cash equivalents	1,613,529	966,308
Current portion of restricted cash included in other current assets	13,673	25,277
Non-current portion of restricted cash included in other assets	$ 10,090	$ 10,654