Consolidated Statements of Cash Flows - USD ($) shares in Thousands, $ in Thousands	6 Months Ended
	Jun. 30, 2020	Jun. 30, 2019
CASH FLOWS FROM OPERATING ACTIVITIES:
Net (loss) income	$ (104,816)	$ 57,962
Adjustments to reconcile net (loss) income to net cash provided by operating activities:
Depreciation, accretion, and amortization	361,285	342,602
Non-cash asset impairment and decommission costs	20,160	14,737
Non-cash compensation expense	34,857	47,901
Amortization of deferred financing fees	10,328	10,176
Loss (gain) on remeasurement of U.S. dollar denominated intercompany loans	261,308	(7,007)
Deferred income tax (benefit) expense	(77,707)	14,822
Other non-cash items reflected in the Statements of Operations	16,875	(3,577)
Changes in operating assets and liabilities, net of acquisitions:
Accounts receivable and costs and estimated earnings in excess of billings on uncompleted contracts, net	34,127	(4,546)
Prepaid expenses and other assets	1,979	3,915
Operating lease right-of-use assets, net	59,559	47,237
Accounts payable and accrued expenses	4,093	1,853
Accrued interest	(474)	513
Long-term lease liabilities	(49,828)	(41,732)
Other liabilities	20,672	(18,750)
Net cash provided by operating activities	592,418	466,106
CASH FLOWS FROM INVESTING ACTIVITIES:
Acquisitions	(119,035)	(151,182)
Capital expenditures	(66,979)	(72,785)
Purchase of investments	(1,135,026)	(285,599)
Proceeds from sale of investments	910,000	255,557
Other investing activities	(2,930)	(1,466)
Net cash used in investing activities	(413,970)	(255,475)
CASH FLOWS FROM FINANCING ACTIVITIES:
Borrowings under Revolving Credit Facility	515,000	90,000
Repayments under Revolving Credit Facility	(1,005,000)	(335,000)
Proceeds from issuance of Senior Notes, net of fees	1,480,206
Repayment of Senior Notes	(759,143)
Proceeds from employee stock purchase/stock option plans, net of taxes	37,316	87,921
Repurchase and retirement of common stock	(203,330)	(94,572)
Payment of dividends on common stock	(104,171)
Other financing activities	(12,999)	(12,812)
Net cash used in financing activities	(52,121)	(264,463)
Effect of exchange rate changes on cash, cash equivalents, and restricted cash	(15,809)	2,344
NET CHANGE IN CASH, CASH EQUIVALENTS, AND RESTRICTED CASH	110,518	(51,488)
CASH, CASH EQUIVALENTS, AND RESTRICTED CASH:
Beginning of period	141,120	178,300
End of period	251,638	126,812
Cash paid during the period for:
Interest	191,929	195,671
Income taxes	8,940	11,777
SUPPLEMENTAL CASH FLOW INFORMATION OF NON-CASH ACTIVITIES:
Right-of-use assets obtained in exchange for new operating lease liabilities	12,269	27,225
Operating lease modifications and reassessments	20,501	(52,644)
Right-of-use assets obtained in exchange for new finance lease liabilities	$ 893	$ 1,678
Common stock issued in connection with acquisitions		1,680