Consolidated Statements of Cash Flows - USD ($) shares in Thousands, $ in Thousands	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
CASH FLOWS FROM OPERATING ACTIVITIES:
Net income	$ 237,624	$ 24,047	$ 147,284
Adjustments to reconcile net income to net cash provided by operating activities:
Depreciation, accretion, and amortization	700,161	721,970	697,078
Non-cash asset impairment and decommission costs	31,790	39,501	32,241
Non-cash compensation expense	84,402	68,890	73,214
Loss (gain) on remeasurement of U.S. denominated intercompany loans	66,285	220,354	(13,134)
Loss from extinguishment of debt, net	36,718	17,838	235
Deferred income tax (benefit) expense	(8,510)	(63,187)	15,935
Non-cash interest expense	47,085	24,870	3,193
Amortization of deferred financing fees	19,589	20,058	20,358
Other non-cash items reflected in the Statements of Operations	9,881	2,979	(1,888)
Changes in operating assets and liabilities, net of acquisitions:
Accounts receivable and costs and estimated earnings in excess of billings on uncompleted contracts, net	(38,237)	38,195	(12,146)
Prepaid expenses and other assets	(28,243)	2,614	878
Operating lease right-of-use assets, net	114,321	109,935	93,665
Accounts payable and accrued expenses	(473)	13,173	(5,951)
Long-term lease liabilities	(113,292)	(100,847)	(87,544)
Other liabilities	30,795	(14,357)	6,627
Net cash provided by operating activities	1,189,896	1,126,033	970,045
CASH FLOWS FROM INVESTING ACTIVITIES:
Acquisitions	(1,257,704)	(271,418)	(773,957)
Capital expenditures	(133,694)	(128,566)	(154,236)
Purchase of investments	(1,731,111)	(1,288,705)	(638,963)
Proceeds from sale of investments	1,730,477	1,239,206	625,807
Other investing activities	(31,228)	3,117	(5,809)
Net cash used in investing activities	(1,423,260)	(446,366)	(947,158)
CASH FLOWS FROM FINANCING ACTIVITIES:
Borrowings under Revolving Credit Facility	1,935,000	895,000	755,000
Repayments under Revolving Credit Facility	(1,965,000)	(1,005,000)	(590,000)
Proceeds from issuance of Senior Notes, net of fees	1,485,373	1,479,484
Repayment of Senior Notes	(1,870,909)	(759,143)
Proceeds from issuance of Tower Securities, net of fees	2,924,005	1,335,895	1,152,458
Repayment of Tower Securities	(1,335,000)	(1,200,000)	(920,000)
Termination of interest rate swap		(176,200)
Repurchase and retirement of common stock	(582,578)	(859,335)	(466,982)
Payment of dividends on common stock	(253,580)	(207,689)	(83,387)
Proceeds from employee stock purchase/stock option plans	86,688	99,129	130,290
Payments related to taxes on net settlement of stock options and restricted stock units	(71,904)	(45,080)	(14,088)
Other financing activities	(12,831)	(26,078)	(25,605)
Net cash provided by (used in) financing activities	339,264	(469,017)	(62,314)
Effect of exchange rate changes on cash, cash equivalents, and restricted cash	(13,082)	(8,962)	2,247
NET CHANGE IN CASH, CASH EQUIVALENTS, AND RESTRICTED CASH	92,818	201,688	(37,180)
CASH, CASH EQUIVALENTS, AND RESTRICTED CASH:
Beginning of year	342,808	141,120	178,300
End of year	435,626	342,808	141,120
Cash paid during the period for:
Interest	360,098	351,886	386,615
Income taxes	25,568	20,275	21,598
SUPPLEMENTAL CASH FLOW INFORMATION OF NON-CASH ACTIVITIES:
Right-of-use assets obtained in exchange for new operating lease liabilities	33,315	78,674	175,517
Operating lease modifications and reassessments	36,817	(10,550)	(52,383)
Right-of-use assets obtained in exchange for new finance lease liabilities	$ 2,100	1,087	$ 3,499
Common stock issued in connection with acquisitions			1,680
Consolidation of an equity method investment			$ 71,990
Deferred payment on acquired assets		$ 77,124