Consolidated Statements of Cash Flows - USD ($) shares in Thousands, $ in Thousands	9 Months Ended
	Sep. 30, 2020	Sep. 30, 2019
CASH FLOWS FROM OPERATING ACTIVITIES:
Net (loss) income	$ (82,139)	$ 79,727
Adjustments to reconcile net (loss) income to net cash provided by operating activities:
Depreciation, accretion, and amortization	541,587	517,590
Loss on remeasurement of U.S. dollar denominated intercompany loans	299,913	25,880
Non-cash compensation expense	51,915	60,633
Non-cash asset impairment and decommission costs	28,675	22,816
Loss from extinguishment of debt	19,463	235
Deferred income tax (benefit) expense	(93,104)	5,988
Other non-cash items reflected in the Statements of Operations	28,700	14,604
Changes in operating assets and liabilities, net of acquisitions:
Accounts receivable and costs and estimated earnings in excess of billings on uncompleted contracts, net	48,272	(13,909)
Prepaid expenses and other assets	(2,571)	669
Operating lease right-of-use assets, net	88,470	68,518
Accounts payable and accrued expenses	5,672	(2,521)
Accrued interest	(17,010)	(14,228)
Long-term lease liabilities	(75,199)	(64,057)
Other liabilities	40,264	3,039
Net cash provided by operating activities	882,908	704,984
CASH FLOWS FROM INVESTING ACTIVITIES:
Acquisitions	(199,899)	(283,701)
Capital expenditures	(95,371)	(111,381)
Purchase of investments	(1,288,267)	(528,915)
Proceeds from sale of investments	1,235,000	515,557
Other investing activities	(4,841)	(6,626)
Net cash used in investing activities	(353,378)	(415,066)
CASH FLOWS FROM FINANCING ACTIVITIES:
Borrowings under Revolving Credit Facility	515,000	265,000
Repayments under Revolving Credit Facility	(1,005,000)	(590,000)
Proceeds from issuance of Senior Notes, net of fees	1,479,522
Repayment of Senior Notes	(759,143)
Proceeds from issuance of Tower Securities, net of fees	1,336,003	1,153,036
Repayment of Tower Securities	(1,200,000)	(920,000)
Termination of interest rate swap	(176,200)
Proceeds from employee stock purchase/stock option plans, net of taxes	50,283	112,909
Repurchase and retirement of common stock	(378,988)	(267,534)
Payment of dividends on common stock	(156,199)	(41,873)
Other financing activities	(19,528)	(19,119)
Net cash used in financing activities	(314,250)	(307,581)
Effect of exchange rate changes on cash, cash equivalents, and restricted cash	(20,427)	(1,957)
NET CHANGE IN CASH, CASH EQUIVALENTS, AND RESTRICTED CASH	194,853	(19,620)
CASH, CASH EQUIVALENTS, AND RESTRICTED CASH:
Beginning of period	141,120	178,300
End of period	335,973	158,680
Cash paid during the period for:
Interest	298,140	306,810
Income taxes	14,061	14,860
SUPPLEMENTAL CASH FLOW INFORMATION OF NON-CASH ACTIVITIES:
Right-of-use assets obtained in exchange for new operating lease liabilities	21,785	37,913
Operating lease modifications and reassessments	23,811	(67,794)
Right-of-use assets obtained in exchange for new finance lease liabilities	$ 893	$ 1,706
Common stock issued in connection with acquisitions		1,680
Consolidation of an equity method investment		$ 71,990