Consolidated Statements Of Cash Flows - USD ($) shares in Thousands, $ in Thousands	6 Months Ended
	Jun. 30, 2018	Jun. 30, 2017
CASH FLOWS FROM OPERATING ACTIVITIES:
Net (loss) income	$ (25,846)	$ 46,832
Adjustments to reconcile net (loss) income to net cash provided by operating activities:
Depreciation, accretion, and amortization	334,956	318,551
Non-cash asset impairment and decommission costs	15,678	13,719
Non-cash compensation expense	21,707	19,471
Amortization of deferred financing fees	10,285	11,647
Loss on remeasurement of U.S. dollar denominated intercompany loans	87,275	6,758
Loss from extinguishment of debt, net	14,087	1,961
Deferred income tax benefit	(21,411)	(601)
Other non-cash items reflected in the Statements of Operations	580	149
Changes in operating assets and liabilities, net of acquisitions:
Accounts receivable and costs and estimated earnings in excess of billings on uncompleted contracts, net	2,828	(1,079)
Prepaid expenses and other assets	(15,602)	(11,075)
Accounts payable and accrued expenses	(7,894)	581
Accrued interest	765	(2,461)
Other liabilities	7,648	(254)
Net cash provided by operating activities	425,056	404,199
CASH FLOWS FROM INVESTING ACTIVITIES:
Acquisitions	(285,363)	(82,181)
Capital expenditures	(68,614)	(69,435)
Other investing activities	(16,178)	(17,025)
Net cash used in investing activities	(370,155)	(168,641)
CASH FLOWS FROM FINANCING ACTIVITIES:
Borrowings under Revolving Credit Facility	545,000	100,000
Repayments under Revolving Credit Facility	(500,000)	(340,000)
Repayment of Tower Securities	(755,000)	(610,000)
Proceeds from issuance of Tower Securities, net of fees	631,490	750,153
Proceeds from Term Loans, net of fees	2,377,264
Repayment of Term Loans	(1,935,000)	(10,000)
Repurchase and retirement of common stock	(345,524)	(144,438)
Other financing activities	8,487	30,175
Net cash provided by (used in) financing activities	26,717	(224,110)
Effect of exchange rate changes on cash, cash equivalents, and restricted cash	(9,550)	(225)
NET CHANGE IN CASH, CASH EQUIVALENTS, AND RESTRICTED CASH	72,068	11,223
CASH, CASH EQUIVALENTS, AND RESTRICTED CASH:
Beginning of period	104,295	185,970
End of period	176,363	197,193
Cash paid during the period for:
Interest	182,009	158,569
Income taxes	11,294	$ 8,561
SUPPLEMENTAL DISCLOSURE OF NON-CASH ACTIVITIES:
Assets acquired through capital leases	$ 905
Common stock issued in connection with acquisitions		63,313