Condensed Consolidated Statements of Cash Flows $ in Thousands	3 Months Ended
	Mar. 31, 2018 USD ($)	Mar. 31, 2017 USD ($)
Cash flows from operating activities:
Net income	$ 62,894	$ 42,062
Adjustments to reconcile net income to net cash provided by operating activities:
Depreciation	256,952	187,989
Stock-based compensation	42,536	38,323
Amortization of intangible assets	50,616	29,017
Amortization of debt issuance costs and debt discounts	4,099	11,580
Provision for allowance for doubtful accounts	3,281	6,710
Loss on debt extinguishment	21,491	3,503
Other items	4,504	3,677
Changes in operating assets and liabilities:
Accounts receivable	(71,275)	(39,664)
Income taxes, net	(15,381)	(20,637)
Other assets	(6,694)	47,132
Accounts payable and accrued expenses	(35,143)	(65,414)
Other liabilities	(16,973)	3,093
Net cash provided by operating activities	300,907	247,371
Cash flows from investing activities:
Purchases of investments	(29,265)	(26,256)
Sales and maturities of investments	28,768	19,152
Business acquisitions, net of cash and restricted cash acquired	0	(36,041)
Purchases of real estate	(14,700)	(41,739)
Purchases of other property, plant and equipment	(349,729)	(277,242)
Proceeds from sale of assets, net of cash transferred	0	47,767
Net cash used in investing activities	(364,926)	(314,359)
Cash flows from financing activities:
Proceeds from employee equity awards	25,847	20,074
Payment of dividends and special distribution	(186,999)	(148,083)
Proceeds from public offering of common stock, net of issuance costs	0	2,126,258
Proceeds from senior notes	929,850	1,250,000
Proceeds from loans payable	0	1,059,800
Repayments of capital lease and other financing obligations	(55,787)	(16,596)
Repayments of mortgage and loans payable	(6,599)	(21,510)
Debt extinguishment costs	(20,704)	(3,132)
Debt issuance costs	(11,583)	(40,665)
Other financing activities	0	(900)
Net cash provided by financing activities	674,025	4,225,246
Effect of foreign currency exchange rates on cash, cash equivalents and restricted cash	7,903	11,541
Net increase in cash, cash equivalents and restricted cash	617,909	4,169,799
Cash, cash equivalents and restricted cash at beginning of period	1,450,701	773,247
Cash, cash equivalents and restricted cash at end of period	2,068,610	4,943,046
Cash and cash equivalents	2,023,808	4,923,259
Current portion of restricted cash included in other current assets	33,460	9,927
Non-current portion of restricted cash included in other assets	$ 11,342	$ 9,860