American Tower (AMT) 10-K 26 Feb 16 2015 FY Annual report Financial data

Document and Entity Information

Document and Entity Information - USD ($) $ in Billions	12 Months Ended
	Dec. 31, 2015	Feb. 19, 2016	Jun. 30, 2015
Document And Entity Information [Abstract]
Entity Registrant Name	AMERICAN TOWER CORP /MA/
Entity Central Index Key	1,053,507
Current Fiscal Year End Date	--12-31
Entity Filer Category	Large Accelerated Filer
Document Type	10-K
Document Period End Date	Dec. 31, 2015
Document Fiscal Year Focus	2,015
Document Fiscal Period Focus	FY
Amendment Flag	false
Entity Common Stock, Shares Outstanding		423,897,556
Entity Well-known Seasoned Issuer	Yes
Entity Voluntary Filers	No
Entity Current Reporting Status	Yes
Entity Public Float			$ 39.2

CONSOLIDATED BALANCE SHEETS

CONSOLIDATED BALANCE SHEETS - USD ($) $ in Thousands	Dec. 31, 2015	Dec. 31, 2014
CURRENT ASSETS:
Cash and cash equivalents	$ 320,686	$ 313,492
Restricted cash	142,193	160,206
Short-term investments	0	6,302	[1]
Accounts receivable, net	227,354	199,074
Prepaid and other current assets	306,235	264,793	[2]
Deferred income taxes	0	14,000
Total current assets	996,468	957,867
PROPERTY AND EQUIPMENT, net	9,866,424	7,590,112	[3]
GOODWILL	4,091,805	4,032,174	[4]
OTHER INTANGIBLE ASSETS, net	9,837,876	6,824,273
DEFERRED INCOME TAXES	212,041	253,186
DEFERRED RENT ASSET	1,166,755	1,030,707
NOTES RECEIVABLE AND OTHER NON-CURRENT ASSETS	732,903	575,246	[5]
TOTAL	26,904,272	21,263,565	[6],[7]
CURRENT LIABILITIES:
Accounts payable	96,714	90,366
Accrued expenses	516,413	417,836	[8]
Distributions payable	210,027	159,864
Accrued interest	115,672	130,265
Current portion of long-term obligations	50,202	897,386	[9]
Unearned revenue	211,001	233,819
Total current liabilities	1,200,029	1,929,536
LONG-TERM OBLIGATIONS	17,068,807	13,642,955
ASSET RETIREMENT OBLIGATIONS	856,936	609,035
OTHER NON-CURRENT LIABILITIES	1,065,682	1,028,687	[10]
Total liabilities	$ 20,191,454	$ 17,210,213
COMMITMENTS AND CONTINGENCIES
EQUITY:
Common stock: $.01 par value; 1,000,000,000 shares authorized; 426,695,279 and 399,508,751 shares issued; and 423,885,253 and 396,698,725 shares outstanding, respectively	$ 4,267	$ 3,995
Additional paid-in capital	9,690,609	5,788,786
Distributions in excess of earnings	(998,535)	(837,320)
Accumulated other comprehensive loss	(1,836,996)	(794,221)
Treasury stock (2,810,026 shares at cost)	(207,740)	(207,740)
Total American Tower Corporation equity	6,651,679	3,953,560
Noncontrolling interest	61,139	99,792
Total equity	6,712,818	4,053,352
TOTAL	26,904,272	21,263,565
Preferred Stock | Convertible Preferred Stock Subject to Mandatory Redemption | Series A Preferred Stock
EQUITY:
Preferred stock: $.01 par value: 20,000,000 authorized: 5.25%, Series A, 6,000,000 shares issued and outstanding; aggregate liquidation value of $600,000 - 5.50% Series B, 1,375,000 and no shares issued and outstanding, respectively; aggregate liquidation value of $1,375,000	60	60
Total equity	60	60
Preferred Stock | Convertible Preferred Stock Subject to Mandatory Redemption | Series B Preferred Stock
EQUITY:
Preferred stock: $.01 par value: 20,000,000 authorized: 5.25%, Series A, 6,000,000 shares issued and outstanding; aggregate liquidation value of $600,000 - 5.50% Series B, 1,375,000 and no shares issued and outstanding, respectively; aggregate liquidation value of $1,375,000	14	0
Total equity	$ 14	$ 0
[1]	Consists of highly liquid investments with original maturities in excess of three months.
[2]	December 31, 2014 balances have been revised to reflect purchase accounting measurement period adjustments.
[3]	December 31, 2014 balances have been revised to reflect purchase accounting measurement period adjustments.
[4]	Balances have been revised to reflect purchase accounting measurement period adjustments.
[5]	December 31, 2014 balances have been revised to reflect purchase accounting measurement period adjustments and debt issuance costs.
[6]	Balances have been revised to reflect debt issuance cost adjustments.
[7]	Balances have been revised to reflect purchase accounting measurement period adjustments.
[8]	December 31, 2014 balances have been revised to reflect purchase accounting measurement period adjustments.
[9]	December 31, 2014 balances have been revised to reflect debt issuance costs as a direct deduction from the carrying amounts, with the exception of debt issuance costs associated with the 2013 Credit Facility and the 2014 Credit Facility (as defined below) which are reflected in Notes receivable and other non-current assets on the consolidated balance sheets. Amortization of deferred financing costs is included in interest expense on the consolidated statements of operations.
[10]	December 31, 2014 balances have been revised to reflect purchase accounting measurement period adjustments.

CONSOLIDATED BALANCE SHEETS (Pa

CONSOLIDATED BALANCE SHEETS (Parenthetical) - USD ($)	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014
Class of Stock [Line Items]
Common stock, par value (in dollars per share)	$ 0.01	$ 0.01
Common stock, shares authorized	1,000,000,000	1,000,000,000
Common stock, shares issued	426,695,279	399,508,751
Common stock, shares outstanding	423,885,253	396,698,725
Treasury stock, shares	2,810,026	2,810,026
Series A Preferred Stock | Convertible Preferred Stock Subject to Mandatory Redemption
Class of Stock [Line Items]
Preferred stock, par value (in dollars per share)	$ 0.01
Preferred stock, shares issued	6,000,000
Preferred stock, aggregate liquidation value	5.25%
Series B Preferred Stock
Class of Stock [Line Items]
Preferred stock, par value (in dollars per share)	$ 0.01
Preferred stock, aggregate liquidation value	5.50%
Series B Preferred Stock | Convertible Preferred Stock Subject to Mandatory Redemption
Class of Stock [Line Items]
Preferred stock, aggregate liquidation value	5.50%
Preferred Stock | Convertible Preferred Stock Subject to Mandatory Redemption
Class of Stock [Line Items]
Preferred stock, par value (in dollars per share)	$ 0.01	$ 0.01
Preferred stock, shares authorized	20,000,000	20,000,000
Preferred Stock | Series A Preferred Stock | Convertible Preferred Stock Subject to Mandatory Redemption
Class of Stock [Line Items]
Preferred stock, par value (in dollars per share)	$ 0.01	$ 0.01
Preferred stock, shares issued	6,000,000	6,000,000
Preferred stock, shares outstanding	6,000,000	6,000,000
Preferred stock, aggregate liquidation value	$ 600,000	$ 600,000
Preferred stock, aggregate liquidation value	5.25%	5.25%
Preferred Stock | Series B Preferred Stock | Convertible Preferred Stock Subject to Mandatory Redemption
Class of Stock [Line Items]
Preferred stock, par value (in dollars per share)	$ 0.01
Preferred stock, shares issued	1,375,000
Preferred stock, shares outstanding	1,375,000
Preferred stock, aggregate liquidation value	$ 1,375,000
Preferred stock, aggregate liquidation value	5.50%

CONSOLIDATED STATEMENTS OF OPER

CONSOLIDATED STATEMENTS OF OPERATIONS - USD ($) shares in Thousands, $ in Thousands	12 Months Ended
	Dec. 31, 2015		Dec. 31, 2014	Dec. 31, 2013
REVENUES:
Property	$ 4,680,388		$ 4,006,854	$ 3,287,090
Services	91,128		93,194	74,317
Total operating revenues	4,771,516		4,100,048	3,361,407
OPERATING EXPENSES:
Property (including stock-based compensation expense of $1,614, $1,397 and $977, respectively)	1,275,436		1,056,177	828,742
Services (including stock-based compensation expense of $439, $440 and $567, respectively)	33,432		38,088	31,131
Depreciation, amortization and accretion	1,285,328		1,003,802	800,145
Selling, general, administrative and development expense (including stock-based compensation expense of $88,484, $78,316 and $66,594, respectively)	497,835		446,542	415,545
Other operating expenses	66,696		68,517	71,539
Total operating expenses	3,158,727	[1]	2,613,126	2,147,102
OPERATING INCOME	1,612,789		1,486,922	1,214,305
OTHER INCOME (EXPENSE):
Loss on retirement of long-term obligations	(79,606)		(3,473)	(38,701)
Other expense (including unrealized foreign currency losses of $71,473, $49,319 and $211,722, respectively)	(134,960)		(62,060)	(207,500)
Total other expense	(782,827)		(621,218)	(672,556)
INCOME FROM CONTINUING OPERATIONS BEFORE INCOME TAXES	829,962		865,704	541,749
Income tax provision	(157,955)		(62,505)	(59,541)
NET INCOME	672,007		803,199	482,208
Net loss attributable to noncontrolling interest	13,067		21,711	69,125
NET INCOME ATTRIBUTABLE TO AMERICAN TOWER CORPORATION STOCKHOLDERS	685,074		824,910	551,333
Dividends on preferred stock	(90,163)		(23,888)	0
NET INCOME ATTRIBUTABLE TO AMERICAN TOWER CORPORATION COMMON STOCKHOLDERS	$ 594,911		$ 801,022	$ 551,333
NET INCOME PER COMMON SHARE AMOUNTS:
Basic net income attributable to American Tower Corporation common stockholders (in dollars per share)	$ 1.42		$ 2.02	$ 1.40
Diluted net income attributable to American Tower Corporation common stockholders (in dollars per share)	$ 1.41		$ 2	$ 1.38
WEIGHTED AVERAGE COMMON SHARES OUTSTANDING:
BASIC (in shares)	418,907		395,958	395,040
DILUTED (in shares)	423,015		400,086	399,146
TV Azteca
OTHER INCOME (EXPENSE):
Interest income, TV Azteca, net of interest expense of $820, $1,482 and $1,483, respectively	$ 11,209		$ 10,547	$ 22,235
Interest expense	(820)		(1,482)	(1,483)
Excluding TV Azteca
OTHER INCOME (EXPENSE):
Interest income	16,479		14,002	9,706
Interest expense	$ (595,949)		$ (580,234)	$ (458,296)
[1]	Represents Operating expenses, exclusive of Depreciation, amortization and accretion, Selling, general, administrative and development expense, and Other operating expenses.

CONSOLIDATED STATEMENTS OF OPE5

CONSOLIDATED STATEMENTS OF OPERATIONS (Parenthetical) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Stock-based compensation expense	$ 90,537	$ 80,153	$ 68,138
TV Azteca
Interest expense	820	1,482	1,483
Rental And Management
Stock-based compensation expense	1,614	1,397	977
Network Development Services
Stock-based compensation expense	439	440	567
Selling General Administrative And Development Expense
Stock-based compensation expense	88,484	78,316	66,594
Other Expense
Unrealized foreign currency (losses) gains	$ 71,473	$ 49,319	$ 211,722

CONSOLIDATED STATEMENTS OF COMP

CONSOLIDATED STATEMENTS OF COMPREHENSIVE (LOSS) INCOME - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Statement of Comprehensive Income [Abstract]
Net income	$ 672,007	$ 803,199	$ 482,208
Other comprehensive (loss) income:
Changes in fair value of cash flow hedges, net of tax expense (benefit) of $73, $(151) and $374, respectively	948	(1,931)	1,107
Reclassification of unrealized losses on cash flow hedges to net income, net of tax expense (benefit) of $84, $(158) and $(237), respectively	2,440	3,448	2,572
Foreign currency translation adjustments, net of tax benefit of $24,857, $14,247 and $9,207, respectively	(1,078,950)	(526,890)	(135,079)
Other comprehensive loss	(1,075,562)	(525,373)	(131,400)
Comprehensive (loss) income	(403,555)	277,826	350,808
Comprehensive loss attributable to noncontrolling interest	45,854	64,083	72,652
Comprehensive (loss) income attributable to American Tower Corporation stockholders	$ (357,701)	$ 341,909	$ 423,460

CONSOLIDATED STATEMENTS OF COM7

CONSOLIDATED STATEMENTS OF COMPREHENSIVE (LOSS) INCOME (Parenthetical) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Statement of Comprehensive Income [Abstract]
Reclassification of unrealized losses on cash flow hedges to net income, tax	$ 84	$ (158)	$ (237)
Foreign currency translation adjustments, tax	(24,857)	(14,247)	(9,207)
Net change in fair value of cash flow hedges, tax	$ 73	$ (151)	$ 374

CONSOLIDATED STATEMENTS OF EQUI

CONSOLIDATED STATEMENTS OF EQUITY - USD ($) $ in Thousands	Total	Common Stock	Treasury Stock	Additional Paid-in Capital	Accumulated Other Comprehensive (Loss) Income	Earnings (Distributions) in Excess of Distributions (Earnings)	Noncontrolling Interest	Series A Preferred StockConvertible Preferred Stock Subject to Mandatory RedemptionPreferred Stock	Series B Preferred StockConvertible Preferred Stock Subject to Mandatory RedemptionPreferred Stock
BALANCE at Dec. 31, 2012	$ 3,684,181	$ 3,959	$ (62,728)	$ 5,012,124	$ (183,347)	$ (1,196,907)	$ 111,080
BALANCE (shares) at Dec. 31, 2012		395,963,218	(872,005)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Stock-based compensation related activity	113,582	$ 16		113,566
Stock based compensation related activity (shares)		1,633,380
Issuance of common stock—stock purchase plan	4,927	$ 1		4,926
Issuance of common stock - stock purchase plan (shares)		77,752
Treasury stock activity	(145,012)		$ (145,012)
Treasury stock activity (shares)			(1,938,021)
Net change in fair value of cash flow hedges, net of tax	1,107				867		240
Reclassification of unrealized losses on cash flow hedges to net income	2,572				2,420		152
Foreign currency translation adjustment, net of tax	(135,079)				(131,160)		(3,919)
Contributions from noncontrolling interest	18,020						18,020
Distributions to noncontrolling interest	(573)						(573)
Common stock distributions declared	(435,893)					(435,893)
Net income	482,208					551,333	(69,125)
BALANCE at Dec. 31, 2013	3,590,040	$ 3,976	$ (207,740)	5,130,616	(311,220)	(1,081,467)	55,875
BALANCE (shares) at Dec. 31, 2013		397,674,350	(2,810,026)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Stock-based compensation related activity	119,734	$ 18		119,716
Stock based compensation related activity (shares)		1,753,286
Issuance of common stock—stock purchase plan	5,718	$ 1		5,717
Issuance of common stock - stock purchase plan (shares)		81,115
Issuance of preferred stock	582,659			582,599				$ 60
Issuance of preferred stock (shares)								6,000,000
Net change in fair value of cash flow hedges, net of tax	(1,931)				(1,966)		35
Reclassification of unrealized losses on cash flow hedges to net income	3,448				3,288		160
Foreign currency translation adjustment, net of tax	(526,890)				(484,323)		(42,567)
Contributions from noncontrolling interest	123,526						123,526
Distributions to noncontrolling interest	(566)						(566)
Purchase of noncontrolling interest	(64,822)			(49,862)			(14,960)
Common stock distributions declared	(556,875)					(556,875)
Preferred stock dividends declared	(23,888)					(23,888)
Net income	803,199					824,910	(21,711)
BALANCE at Dec. 31, 2014	4,053,352	$ 3,995	$ (207,740)	5,788,786	(794,221)	(837,320)	99,792	$ 60	$ 0
BALANCE (shares) at Dec. 31, 2014		399,508,751	(2,810,026)					6,000,000	0
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Stock-based compensation related activity	117,218	$ 12		117,206
Stock based compensation related activity (shares)		1,253,236
Issuance of common stock—stock purchase plan	6,618	$ 1		6,617
Issuance of common stock - stock purchase plan (shares)		83,292
Issuance of common stock	2,440,327	$ 259		2,440,068
Issuance of common stock (shares)		25,850,000
Issuance of preferred stock	1,337,946			1,337,932				$ 0	$ 14
Issuance of preferred stock (shares)								0	1,375,000
Net change in fair value of cash flow hedges, net of tax	948				901		47
Reclassification of unrealized losses on cash flow hedges to net income	2,440				2,494		(54)
Foreign currency translation adjustment, net of tax	(1,078,950)				(1,046,170)		(32,780)
Contributions from noncontrolling interest	8,073						8,073
Distributions to noncontrolling interest	(872)						(872)
Common stock distributions declared	(769,517)					(769,517)
Preferred stock dividends declared	(76,772)					(76,772)
Net income	672,007					685,074	(13,067)
BALANCE at Dec. 31, 2015	$ 6,712,818	$ 4,267	$ (207,740)	$ 9,690,609	$ (1,836,996)	$ (998,535)	$ 61,139	$ 60	$ 14
BALANCE (shares) at Dec. 31, 2015		426,695,279	(2,810,026)					6,000,000	1,375,000

CONSOLIDATED STATEMENTS OF CASH

CONSOLIDATED STATEMENTS OF CASH FLOWS - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
CASH FLOWS FROM OPERATING ACTIVITIES:
Net income	$ 672,007	$ 803,199	$ 482,208
Adjustments to reconcile net income to cash provided by operating activities:
Depreciation, amortization and accretion	1,285,328	1,003,802	800,145
Stock-based compensation expense	90,537	80,153	68,138
Decrease (increase) in restricted cash	16,112	7,522	(52,717)
Loss on investments, unrealized foreign currency loss and other non-cash expense	142,697	65,881	222,390
Impairments, net loss on sale of long-lived assets, non-cash restructuring and merger related expenses	29,852	26,143	32,672
Loss on early retirement of long-term obligations	79,750	3,379	35,288
Amortization of deferred financing costs, debt discounts and premiums and other non-cash interest	6,932	(4,870)	7,596
Provision for losses on (recovery of) accounts receivable	3,473	(1,748)	(1,410)
Deferred income taxes	7,764	1,384	(29,485)
Changes in assets and liabilities, net of acquisitions:
Accounts receivable	(56,312)	(84,529)	(19,080)
Prepaid and other assets	(91,113)	(1,437)	(96,038)
Deferred rent asset	(154,959)	(122,230)	(145,689)
Accounts payable and accrued expenses	95,858	34,711	83,746
Accrued interest	(15,641)	45,514	51,076
Unearned revenue	12,945	218,393	108,487
Deferred rent liability	56,076	38,378	30,246
Other non-current liabilities	1,746	20,944	21,474
Cash provided by operating activities	2,183,052	2,134,589	1,599,047
CASH FLOWS FROM INVESTING ACTIVITIES
Payments for purchase of property and equipment and construction activities	(728,753)	(974,404)	(724,532)
Payments for acquisitions, net of cash acquired	(1,961,056)	(1,010,637)	(4,461,764)
Payment for Verizon transaction	(5,059,462)	0	0
Proceeds from sale of assets, net of cash	0	15,464	0
Proceeds from sales of short-term investments and other non-current assets	1,032,320	1,434,831	421,714
Payments for short-term investments	(1,022,816)	(1,395,316)	(427,267)
Deposits, restricted cash and other	(1,968)	(19,486)	18,512
Cash used for investing activities	(7,741,735)	(1,949,548)	(5,173,337)
CASH FLOWS FROM FINANCING ACTIVITIES
Proceeds from short-term borrowings, net	9,043	0	8,191
Borrowings under credit facilities	6,126,618	2,187,000	3,507,000
Proceeds from issuance of senior notes, net	1,492,298	1,415,844	2,221,792
Proceeds from term loan	500,000	0	1,500,000
Proceeds from other long-term borrowings	54,549	102,070	402,688
Proceeds from issuance of securities in securitization transaction	875,000	0	1,778,496
Repayments of notes payable, credit facilities, term loan, senior notes and capital leases	(6,393,405)	(3,903,144)	(5,337,339)
Contributions from noncontrolling interest holders, net	7,201	9,098	17,447
Purchases of common stock	0	0	(145,012)
Proceeds from stock options and stock purchase plan	50,716	62,276	45,496
Distributions paid on common stock	(710,852)	(404,631)	(434,687)
Distributions paid on preferred stock	(84,647)	(16,013)	0
Proceeds from the issuance of common stock, net	2,440,327	0	0
Proceeds from the issuance of preferred stock, net	1,337,946	583,105	0
Purchase of preferred stock assumed in acquisition	0	(59,111)	0
Payment for early retirement of long-term obligations	(85,672)	(11,593)	(29,234)
Deferred financing costs and other financing activities	(30,021)	(34,670)	(9,273)
Purchase of noncontrolling interest	0	(64,822)	0
Cash provided by (used for) financing activities	5,589,101	(134,591)	3,525,565
Net effect of changes in foreign currency exchange rates on cash and cash equivalents	(23,224)	(30,534)	(26,317)
NET INCREASE (DECREASE) IN CASH AND CASH EQUIVALENTS	7,194	19,916	(75,042)
CASH AND CASH EQUIVALENTS, BEGINNING OF YEAR	313,492	293,576	368,618
CASH AND CASH EQUIVALENTS, END OF YEAR	$ 320,686	$ 313,492	$ 293,576

Business and Summary of Signifi

Business and Summary of Significant Accounting Policies	12 Months Ended
	Dec. 31, 2015
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Business and Summary of Significant Accounting Policies	BUSINESS AND SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES Business —American Tower Corporation (together with its subsidiaries, “ATC” or the “Company”) is one of the largest global real estate investment trusts and a leading independent owner, operator and developer of multitenant communications real estate. The Company’s primary business is the leasing of space on communications sites to wireless service providers, radio and television broadcast companies, wireless data providers, government agencies and municipalities and tenants in a number of other industries, which the Company refers to as its property operations. Additionally, the Company offers tower-related services in the United States, including site acquisition, zoning and permitting and structural analysis, which primarily support its site leasing business, including the addition of new tenants and equipment on its sites, which the Company refers to as its services operations. The Company’s portfolio primarily consists of towers it owns and towers it operates pursuant to long-term lease arrangements, as well as distributed antenna system (“DAS”) networks, which provide seamless coverage solutions in certain in-building and outdoor wireless environments. In addition to the communications sites in its portfolio, the Company manages rooftop and tower sites for property owners under various contractual arrangements. The Company also holds property interests that it leases to communications service providers and third-party tower operators. ATC is a holding company that conducts its operations through its directly and indirectly owned subsidiaries and its joint ventures. ATC’s principal domestic operating subsidiaries are American Towers LLC and SpectraSite Communications, LLC. ATC conducts its international operations primarily through its subsidiary, American Tower International, Inc., which in turn conducts operations through its various international holding and operating subsidiaries and joint ventures. The Company operates as a real estate investment trust for U.S. federal income tax purposes (“REIT”). Accordingly, the Company generally is not subject to U.S. federal income taxes on income generated by its U.S. REIT operations, including the income derived from leasing space on its towers, as the Company receives a dividends paid deduction for distributions to stockholders that generally offsets its income and gains. However, the Company remains obligated to pay U.S. federal income taxes on earnings from its domestic taxable REIT subsidiaries (“TRSs”). In addition, the Company’s international assets and operations, regardless of their designation for U.S. tax purposes, continue to be subject to taxation in the foreign jurisdictions where those assets are held or those operations are conducted. The use of TRSs enables the Company to continue to engage in certain businesses while complying with REIT qualification requirements. The Company may, from time to time, change the election of previously designated TRSs to be included as part of the REIT. As of December 31, 2015 , the Company’s U.S. REIT qualified business included its U.S. tower leasing business, most of its operations in Costa Rica, Germany and Mexico and a majority of its services segment and indoor DAS networks business. Principles of Consolidation and Basis of Presentation —The accompanying consolidated financial statements include the accounts of the Company and those entities in which it has a controlling interest. Investments in entities that the Company does not control are accounted for using the equity or cost method, depending upon the Company’s ability to exercise significant influence over operating and financial policies. All intercompany accounts and transactions have been eliminated. As of December 31, 2015, the Company has a controlling interest in two joint ventures. The Company established joint ventures in Ghana and Uganda with MTN Group Limited (“MTN Group”). The joint ventures are controlled by a holding company of which a wholly owned subsidiary of the Company holds a 51% interest and a wholly owned subsidiary of MTN Group holds a 49% interest. In addition, the Company holds an approximate 75% controlling interest in a subsidiary of the Company in South Africa and the South African investors hold an approximate 25% noncontrolling interest. Significant Accounting Policies and Use of Estimates —The preparation of financial statements in conformity with accounting principles generally accepted in the United States (“GAAP”) requires management to make estimates and assumptions that affect the amounts reported in the consolidated financial statements and accompanying notes. Actual results may differ from those estimates, and such differences could be material to the accompanying consolidated financial statements. The significant estimates in the accompanying consolidated financial statements include impairment of long-lived assets (including goodwill), asset retirement obligations, revenue recognition, rent expense, stock-based compensation, income taxes and accounting for business combinations and acquisitions of assets. The Company considers events or transactions that occur after the balance sheet date but before the financial statements are issued as additional evidence for certain estimates or to identify matters that require additional disclosure. Accounts Receivable and Deferred Rent Asset —The Company derives the largest portion of its revenues, corresponding accounts receivable and the related deferred rent asset from a relatively small number of tenants in the telecommunications industry, and 63% of its current year revenues are derived from four tenants. The Company’s deferred rent asset is associated with non-cancellable tenant leases that contain fixed escalation clauses over the terms of the applicable lease in which revenue is recognized on a straight-line basis over the lease term. The Company mitigates its concentrations of credit risk with respect to notes and trade receivables and the related deferred rent assets by actively monitoring the creditworthiness of its borrowers and tenants. In recognizing customer revenue, the Company assesses the collectibility of both the amounts billed and the portion recognized in advance of billing on a straight-line basis. This assessment takes tenant credit risk and business and industry conditions into consideration to ultimately determine the collectibility of the amounts billed. To the extent the amounts, based on management’s estimates, may not be collectible, recognition is deferred until such point as collectibility is determined to be reasonably assured. Any amounts that were previously recognized as revenue and subsequently determined to be uncollectible are charged to bad debt expense included in Selling, general, administrative and development expense in the accompanying consolidated statements of operations. Accounts receivable is reported net of allowances for doubtful accounts related to estimated losses resulting from a tenant’s inability to make required payments and allowances for amounts invoiced whose collectibility is not reasonably assured. These allowances are generally estimated based on payment patterns, days past due and collection history, and incorporate changes in economic conditions that may not be reflected in historical trends, such as tenants in bankruptcy, liquidation or reorganization. Receivables are written-off against the allowances when they are determined to be uncollectible. Such determination includes analysis and consideration of the particular conditions of the account. Changes in the allowances were as follows for the years ended December 31, (in thousands): 2015 2014 2013 Balance as of January 1 $ 17,306 $ 19,895 $ 20,406 Current year increases 19,878 8,243 7,025 Write-offs, net of recoveries and other (14,088 ) (10,832 ) (7,536 ) Balance as of December 31 $ 23,096 $ 17,306 $ 19,895 Functional Currency —The functional currency of each of the Company’s foreign operating subsidiaries is the respective local currency, except for Costa Rica, where the functional currency is the U.S. Dollar. All foreign currency assets and liabilities held by the subsidiaries are translated into U.S. Dollars at the exchange rate in effect at the end of the applicable fiscal reporting period and all foreign currency revenues and expenses are translated at the average monthly exchange rates. Translation adjustments are reflected in equity as a component of Accumulated other comprehensive (loss) income (“AOCI”) in the consolidated balance sheets and included as a component of comprehensive loss (income) in the consolidated statements of comprehensive (loss) income. Transactional gains and losses on foreign currency transactions are reflected in Other expense in the consolidated statements of operations. However, the effect from fluctuations in foreign currency exchange rates on intercompany debt that is considered to be permanently reinvested is reflected in AOCI in the consolidated balance sheets and included as a component of comprehensive income. During the year ended December 31, 2015, the Company recorded net foreign currency losses of $867.6 million , of which $732.9 million was recorded in AOCI and $134.7 million was recorded in Other expense. Cash and Cash Equivalents —Cash and cash equivalents include cash on hand, demand deposits and short-term investments with original maturities of three months or less. The Company maintains its deposits at high quality financial institutions and monitors the credit ratings of those institutions. Restricted Cash— Restricted cash includes cash pledged as collateral to secure obligations and all cash whose use is otherwise limited by contractual provisions. Property and Equipment —Property and equipment is recorded at cost or, in the case of acquired properties at estimated fair value on the date acquired. Cost for self-constructed towers includes direct materials and labor, capitalized interest and certain indirect costs associated with construction of the tower, such as transportation costs, employee benefits and payroll taxes. The Company begins the capitalization of costs during the pre-construction period, which is the period during which costs are incurred to evaluate the site, and continues to capitalize costs until the tower is substantially completed and ready for occupancy by a tenant. Labor costs capitalized for the years ended December 31, 2015 , 2014 and 2013 were $44.7 million , $48.5 million and $44.1 million , respectively. Interest costs capitalized for the years ended December 31, 2015 , 2014 and 2013 were $1.8 million , $2.8 million and $1.8 million , respectively. Expenditures for repairs and maintenance are expensed as incurred. Augmentation and improvements that extend an asset’s useful life or enhance capacity are capitalized. Depreciation expense is recorded using the straight-line method over the assets’ estimated useful lives. Towers and related assets on leased land are depreciated over the shorter of the estimated useful life of the asset or the term of the corresponding ground lease, taking into consideration lease renewal options and residual value. Towers or assets acquired through capital leases are recorded net at the present value of future minimum lease payments or the fair value of the leased asset at the inception of the lease. Property and equipment and assets held under capital leases are amortized over the shorter of the applicable lease term or the estimated useful life of the respective assets for periods generally not exceeding twenty years. The Company reviews its tower portfolio for indicators of impairment on an individual tower basis. Impairments primarily result from a tower not having current tenant leases or from having expenses in excess of revenues. The Company reviews other long-lived assets for impairment whenever events, changes in circumstances or other evidence indicate that the carrying amount of the Company’s assets may not be recoverable. The Company records impairment charges in Other operating expenses in the consolidated statement of operations in the period in which the Company identifies such impairment. Goodwill and Other Intangible Assets —The Company reviews goodwill for impairment at least annually (as of December 31) or whenever events or circumstances indicate the carrying value of an asset may not be recoverable. Goodwill is recorded in the applicable segment and assessed for impairment at the reporting unit level. The Company utilizes the two-step impairment test when testing goodwill for impairment and employs a discounted cash flow analysis. The key assumptions utilized in the discounted cash flow analysis include current operating performance, terminal sales growth rate, management’s expectations of future operating results and cash requirements, the current weighted average cost of capital and an expected tax rate. Under the first step of this test, the Company compares the fair value of the reporting unit, as calculated under an income approach using future discounted cash flows, to the carrying amount of the applicable reporting unit. If the carrying amount exceeds the fair value, the Company conducts the second step of this test, in which the implied fair value of the applicable reporting unit’s goodwill is compared to the carrying amount of that goodwill. If the carrying amount of goodwill exceeds its implied fair value, an impairment loss would be recognized for the amount of the excess. During the years ended December 31, 2015 , 2014 and 2013 , no potential impairment was identified under the first step of the test, as the fair value of each of the reporting units was in excess of its carrying amount. Intangible assets that are separable from goodwill and are deemed to have a definite life are amortized over their useful lives, generally ranging from three to twenty years and are evaluated separately for impairment at least annually or whenever events or circumstances indicate that the carrying amount of an asset may not be recoverable. The Company reviews its network location intangible assets for indicators of impairment on an individual tower basis. Impairments primarily result from a tower not having current tenant leases or from having expenses in excess of revenues. The Company monitors its customer-related intangible assets on a customer by customer basis for indicators of impairment, such as high levels of turnover or attrition, non-renewal of a significant number of contracts, or the cancellation or termination of a relationship. The Company assesses recoverability by determining whether the carrying amount of the related assets will be recovered, either through projected undiscounted future cash flows or anticipated proceeds from sales of the assets. If the Company determines that the carrying amount of an asset may not be recoverable, the Company measures any impairment loss based on the projected future discounted cash flows to be provided from the asset or available market information relative to the asset’s fair value, as compared to the asset’s carrying amount. The Company records impairment charges in Other operating expenses in the consolidated statement of operations in the period in which the Company identifies such impairment. Derivative Financial Instruments —Derivatives are recorded on the consolidated balance sheet at fair value. If a derivative is designated as a cash flow hedge, the effective portions of changes in the fair value of the derivative are recorded in AOCI, as well as a component of comprehensive income, and are recognized in the results of operations when the hedged item affects earnings. Changes in fair value of the ineffective portions of cash flow hedges are recognized in the results of operations. For derivative instruments not designated as hedging instruments, changes in fair value are recognized in the results of operations in the period that the change occurs. The primary risk managed through the use of derivative instruments is interest rate risk. From time to time, the Company enters into interest rate protection agreements to manage exposure to variability in cash flows relating to forecasted interest payments. Under these agreements, the Company is exposed to credit risk to the extent that a counterparty fails to meet the terms of a contract. The Company’s credit risk exposure is limited to the current value of the contract at the time the counterparty fails to perform. The Company assesses, both at the inception of the hedge and on an ongoing basis, whether the derivatives that are used in hedging transactions are highly effective in offsetting changes in cash flows of hedged items. The Company does not hold derivatives for trading purposes. Fair Value Measurements —The Company determines the fair value of its financial instruments based on the fair value hierarchy, which requires an entity to maximize the use of observable inputs and minimize the use of unobservable inputs when measuring fair value. Asset Retirement Obligations —When required, the Company recognizes the fair value of obligations to remove its tower assets and remediate the leased land upon which certain of its tower assets are located. Generally, the associated retirement costs are capitalized as part of the carrying amount of the related tower assets and depreciated over their estimated useful lives and the liability is accreted through the obligation’s estimated settlement date. Fair value estimates of asset retirement obligations generally involve discounting of estimated future cash flows. Periodic accretion of such liabilities due to the passage of time is included in Depreciation, amortization and accretion expense in the consolidated statements of operations. Adjustments are also made to the asset retirement obligation liability to reflect changes in the estimates of timing and amount of expected cash flows, with an offsetting adjustment made to the related tangible long-lived asset. The significant assumptions used in estimating the Company’s aggregate asset retirement obligation are: timing of tower removals; cost of tower removals; timing and number of land lease renewals; expected inflation rates; and credit-adjusted, risk-free interest rates that approximate the Company’s incremental borrowing rate. Income Taxes —As a REIT, the Company generally is not subject to U.S. federal income taxes on income generated by its U.S. REIT operations. However, the Company remains obligated to pay U.S. federal income taxes on certain earnings and continues to be subject to taxation in its foreign jurisdictions. Accordingly, the consolidated financial statements reflect provisions for federal, state, local and foreign income taxes. The Company recognizes deferred tax assets and liabilities for the future tax consequences attributable to differences between the financial statement carrying amounts of existing assets and liabilities and their respective tax basis, as well as operating loss and tax credit carryforwards. The Company measures deferred tax assets and liabilities using enacted tax rates expected to apply to taxable income in the years in which those temporary differences and carryforwards are expected to be recovered or settled. The effect on deferred tax assets and liabilities as a result of a change in tax rates is recognized in income in the period that includes the enactment date. The Company periodically reviews its deferred tax assets, and provides valuation allowances if, based on the available evidence, it is more likely than not that some or all of the deferred tax assets will not be realized. Management assesses the available positive and negative evidence to estimate if sufficient future taxable income will be generated to use the existing deferred tax assets. Valuation allowances would be reversed as a reduction to the provision for income taxes if related deferred tax assets are deemed realizable based on changes in facts and circumstances relevant to the assets’ recoverability. The Company classifies uncertain tax positions as non-current income tax liabilities unless expected to be paid within one year. The Company reports penalties and tax-related interest expense as a component of the income tax provision and interest income from tax refunds as a component of Other income (expense) in the consolidated statements of operations. Other Comprehensive Income (Loss) —Other comprehensive income (loss) refers to items excluded from net income that are recorded as an adjustment to equity, net of tax. The Company’s other comprehensive income (loss) is primarily comprised of changes in fair value of effective derivative cash flow hedges, foreign currency translation adjustments and reclassification of unrealized losses on effective derivative cash flow hedges. The balance in AOCI related to foreign currency translation adjustments was losses of $1,837.3 million , $790.6 million and $306.3 million for the years ended December 31, 2015, 2014 and 2013, respectively. Distributions —As a REIT, the Company must annually distribute to its stockholders an amount equal to at least 90% of its REIT taxable income (determined before the deduction for distributed earnings and excluding any net capital gain). Generally, the Company has distributed, and expects to continue to distribute all or substantially all of its REIT taxable income after taking into consideration its utilization of net operating losses (“NOLs”). The amount, timing and frequency of future distributions will be at the sole discretion of the Board of Directors and will be dependent upon various factors, a number of which may be beyond the Company’s control, including the Company’s financial condition and operating cash flows, the amount required to maintain its qualification for taxation as a REIT and reduce any income and excise taxes that the Company otherwise would be required to pay, limitations on distributions in the Company’s existing and future debt and preferred equity instruments, the Company’s ability to utilize NOLs to offset the Company’s distribution requirements, limitations on its ability to fund distributions using cash generated through its TRSs and other factors that the Board of Directors may deem relevant. Acquisitions —For acquisitions that meet the definition of a business combination, the Company applies the acquisition method of accounting where assets acquired and liabilities assumed are recorded at fair value at the date of each acquisition, and the results of operations are included with those of the Company from the dates of the respective acquisitions. Any excess of the purchase price paid by the Company over the amounts recognized for assets acquired and liabilities assumed is recorded as goodwill. The Company continues to evaluate acquisitions for a period not to exceed one year after the applicable acquisition date of each transaction to determine whether any additional adjustments are needed to the allocation of the purchase price paid for the assets acquired and liabilities assumed. The fair value of the assets acquired and liabilities assumed is typically determined by using either estimates of replacement costs or discounted cash flow valuation methods. When determining the fair value of tangible assets acquired, the Company must estimate the cost to replace the asset with a new asset taking into consideration such factors as age, condition and the economic useful life of the asset. When determining the fair value of intangible assets acquired, the Company must estimate the applicable discount rate and the timing and amount of future customer cash flows, including rate and terms of renewal and attrition. Revenue Recognition —The Company’s revenue from leasing arrangements, including fixed escalation clauses present in non-cancellable lease agreements, is reported on a straight-line basis over the term of the respective leases when collectibility is reasonably assured. Escalation clauses tied to the Consumer Price Index (“CPI”) or other inflation-based indices, and other incentives present in lease agreements with the Company’s tenants are excluded from the straight-line calculation. Total property straight-line revenues for the years ended December 31, 2015 , 2014 and 2013 was $155.0 million , $123.7 million and $147.7 million , respectively. Amounts billed upfront in connection with the execution of lease agreements are initially deferred and reflected in Unearned revenue in the accompanying consolidated balance sheets and recognized as revenue over the terms of the applicable leases. Amounts billed or received for services prior to being earned are deferred and reflected in Unearned revenue in the accompanying consolidated balance sheets until the criteria for recognition have been met. Services revenues are derived under contracts or arrangements with customers that provide for billings either on a fixed price basis or a variable price basis, which includes factors such as time and expenses. Revenues are recognized as services are performed, and include estimates for percentage completed. Amounts billed or received for services prior to being earned are deferred and reflected in Unearned revenue in the accompanying consolidated balance sheets until the criteria for recognition have been met. Rent Expense —Many of the leases underlying the Company’s tower sites have fixed rent escalations, which provide for periodic increases in the amount of ground rent payable by the Company over time. In addition, certain of the Company’s tenant leases require the Company to exercise available renewal options pursuant to the underlying ground lease if the tenant exercises its renewal option. The Company calculates straight-line ground rent expense for these leases based on the fixed non-cancellable term of the underlying ground lease plus all periods, if any, for which failure to renew the lease imposes an economic penalty to the Company such that renewal appears to be reasonably assured. Total property straight-line ground rent expense for the years ended December 31, 2015 , 2014 and 2013 was $56.1 million , $38.4 million and $29.7 million , respectively. The Company records a liability for straight-line ground rent expense in Other non-current liabilities. The Company records prepaid ground rent in Prepaid and other current assets and Notes receivable and other non-current assets in the accompanying consolidated balance sheets according to the anticipated period of benefit. Selling, General, Administrative and Development Expense —Selling, general and administrative expense consists of overhead expenses related to the Company’s property and services operations and corporate overhead costs not specifically allocable to any of the Company’s individual business operations. Development expense consists of costs related to the Company’s acquisition efforts, costs associated with new business initiatives and project cancellation costs. Stock-Based Compensation —Stock-based compensation expense is measured at the accounting measurement date based on the fair value of the award and is generally recognized as an expense over the service period, which generally represents the vesting period. The Company’s Compensation Committee adopted a death, disability and retirement benefits program in connection with equity awards granted on or after January 1, 2013, which provides for accelerated vesting and extended exercise periods of stock options and restricted stock units upon an employee’s death or permanent disability, or upon an employee’s qualified retirement, provided certain eligibility criteria are met. Accordingly, for grants made on or after January 1, 2013, the Company recognizes compensation expense for stock options and time-based restricted stock units (“RSUs”) over the shorter of (i) the four -year vesting period or (ii) the period from the date of grant to the date the employee becomes eligible for such retirement benefits, which may occur upon grant. The expense recognized includes an estimate of awards that will not fully vest and be forfeited. In March 2015, the Company granted performance-based restricted stock units (“PSUs”) to its executive officers. Threshold, target and maximum parameters were established for the metric for each year in the three -year performance period, and will be used to calculate the number of shares that will be issuable when the award vests, which may range from zero to 200% of the target amount. The Company recognizes compensation expense for PSUs over the three -year vesting period, subject to adjustment based on the date the employee becomes eligible for such retirement benefits. The fair value of stock options is determined using the Black-Scholes option-pricing model and the fair value of restricted stock units is based on the fair value of the Company’s common stock on the date of grant. The Company recognizes all stock-based compensation expense in either Selling, general, administrative and development expense, costs of operations or as part of the costs associated with the construction of the tower assets. Compensation expense for PSUs may be adjusted based on the Compensation Committee’s assessment of performance relative to grant parameters. Litigation Costs —The Company periodically becomes involved in various claims and lawsuits that are incidental to its business. The Company regularly monitors the status of pending legal actions to evaluate both the magnitude and likelihood of any potential loss. The Company accrues for these potential losses when it is probable that a liability has been incurred and the amount of loss, or possible range of loss, can be reasonably estimated. Should the ultimate losses on contingencies or litigation vary from estimates, adjustments to those liabilities may be required. The Company also incurs legal costs in connection with these matters and records estimates of these expenses, which are reflected in Selling, general, administrative and development expense in the accompanying consolidated statements of operations. Earnings Per Common Share — Basic and Diluted —Basic net income per common share represents net income attributable to American Tower Corporation common stockholders divided by the weighted average number of common shares outstanding during the period. Diluted net income per common share represents net income attributable to American Tower Corporation common stockholders divided by the weighted average number of common shares outstanding during the period and any dilutive common share equivalents, including (A) shares issuable upon (i) the vesting of RSUs, (ii) exercise of stock options, and (iii) conversion of the Company’s mandatory convertible preferred stock and (B) shares earned upon the achievement of the parameters established for the PSUs, each to the extent not anti-dilutive. Dilutive common share equivalents also include the dilutive impact of the shares issuable in the ALLTEL transaction, which is described in note 17. The Company uses the treasury stock method to calculate the effect of its outstanding RSUs, PSUs and stock options and uses the if-converted method to calculate the effect of its outstanding mandatory convertible preferred stock. Retirement Plan —The Company has a 401(k) plan covering substantially all employees who meet certain age and employment requirements. For the years ended December 31, 2015, 2014 and 2013, the Company matched 75% of the first 6% of a participant’s contributions. For the years ended December 31, 2015 , 2014 and 2013 , the Company contributed $7.4 million , $6.5 million and $6.0 million to the plan, respectively. Accounting Standards Updates —In May 2014, the Financial Accounting Standards Board (the “FASB”) issued new revenue recognition guidance, which requires an entity to recognize revenue in an amount that reflects the consideration to which the entity expects to be entitled in exchange for the transfer of promised goods or services to customers. The standard will replace most existing revenue recognition guidance in GAAP and will become effective for the Company on January 1, 2018. Early adoption is permitted for fiscal years, and interim periods within those years, beginning after December 15, 2016. The standard permits the use of either the retrospective or cumulative effect transition method and leases are not included in the scope of this standard. The Company is evaluating the impact this standard will have on its financial statements. In June 2014, the FASB issued stock-based compensation guidance, which requires a performance target that co

Prepaid and Other Current Asset

Prepaid and Other Current Assets	12 Months Ended
	Dec. 31, 2015
Prepaid Expense and Other Assets, Current [Abstract]
Prepaid and Other Current Assets	PREPAID AND OTHER CURRENT ASSETS Prepaid and other current assets consisted of the following as of December 31, (in thousands): 2015 2014 (1) Prepaid operating ground leases $ 128,542 $ 88,053 Prepaid income tax 45,056 34,512 Unbilled receivables 34,173 25,352 Prepaid assets 32,892 23,848 Value added tax and other consumption tax receivables 30,239 23,228 Other miscellaneous current assets 35,333 69,800 Balance $ 306,235 $ 264,793 _______________ (1) December 31, 2014 balances have been revised to reflect purchase accounting measurement period adjustments.

Property and Equipment

Property and Equipment	12 Months Ended
	Dec. 31, 2015
Property, Plant and Equipment [Abstract]
Property and Equipment	PROPERTY AND EQUIPMENT Property and equipment (including assets held under capital leases) consisted of the following as of December 31, (in thousands): Estimated Useful Lives (years) (1) 2015 2014 (2) Towers Up to 20 $ 10,726,656 $ 8,265,732 Equipment 2 - 15 1,095,906 995,667 Buildings and improvements 3 - 32 607,661 617,064 Land and improvements (3) Up to 20 1,728,115 1,565,871 Construction-in-progress 238,960 214,760 Total 14,397,298 11,659,094 Less accumulated depreciation (4,530,874 ) (4,068,982 ) Property and equipment, net $ 9,866,424 $ 7,590,112 _______________ (1) Assets on leased land are depreciated over the shorter of the estimated useful life of the asset or the term of the corresponding ground lease taking into consideration lease renewal options and residual value. (2) December 31, 2014 balances have been revised to reflect purchase accounting measurement period adjustments. (3) Estimated useful lives apply to land improvements only. Depreciation expense for the years ended December 31, 2015 , 2014 and 2013 was $661.4 million , $551.8 million and $483.6 million , respectively. As of December 31, 2015 , property and equipment included $5,112.4 million and $1,414.6 million of capital lease assets and accumulated depreciation, respectively, which included the consideration transferred for the exclusive right to lease 11,286 communications sites from Verizon Communications Inc. (“Verizon”). As of December 31, 2014 , property and equipment included $2,921.4 million and $1,256.3 million of capital lease assets and accumulated depreciation, respectively. As of December 31, 2015 and 2014, capital lease assets were primarily classified as towers and land and improvements.

Goodwill and Other Intangible A

Goodwill and Other Intangible Assets	12 Months Ended
	Dec. 31, 2015
Goodwill and Intangible Assets Disclosure [Abstract]
Goodwill and Other Intangible Assets	GOODWILL AND OTHER INTANGIBLE ASSETS The changes in the carrying value of goodwill for the Company’s business segments were as follows (in thousands): Property Services Total U.S. Asia EMEA Latin America Balance as of January 1, 2014 $ 3,293,899 $ 182,114 $ 90,035 $ 286,754 $ 2,000 $ 3,854,802 Additions (1) 62,197 — 40 170,068 — 232,305 Effect of foreign currency translation — (3,593 ) (11,428 ) (36,259 ) — (51,280 ) Other (2) — — — (3,641 ) (12 ) (3,653 ) Balance as of December 31, 2014 (1) $ 3,356,096 $ 178,521 $ 78,647 $ 416,922 $ 1,988 $ 4,032,174 Additions 23,067 610 68,663 122,345 — 214,685 Effect of foreign currency translation — (8,412 ) (14,740 ) (131,902 ) — (155,054 ) Balance as of December 31, 2015 $ 3,379,163 $ 170,719 $ 132,570 $ 407,365 $ 1,988 $ 4,091,805 _______________ (1) Balances have been revised to reflect purchase accounting measurement period adjustments. (2) Other represents the goodwill associated with the Company’s operations in Panama and the Company’s third-party structural analysis business. Both businesses were sold during the year ended December 31, 2014 (see note 11). The Company’s other intangible assets subject to amortization consisted of the following (in thousands): As of December 31, 2015 As of December 31, 2014 (1) Estimated Useful Lives Gross Carrying Value Accumulated Amortization Net Book Value Gross Carrying Value Accumulated Amortization Net Book Value (years) (in thousands) Acquired network location intangibles (2) Up to 20 $ 3,980,281 $ (1,052,393 ) $ 2,927,888 $ 2,513,788 $ (901,903 ) $ 1,611,885 Acquired customer-related intangibles 15-20 8,640,554 (1,763,853 ) 6,876,701 6,594,469 (1,429,572 ) 5,164,897 Acquired licenses and other intangibles 3-20 28,293 (5,486 ) 22,807 38,443 (3,514 ) 34,929 Economic Rights, TV Azteca 70 21,688 (11,208 ) 10,480 25,522 (12,960 ) 12,562 Total other intangible assets $ 12,670,816 $ (2,832,940 ) $ 9,837,876 $ 9,172,222 $ (2,347,949 ) $ 6,824,273 _______________ (1) December 31, 2014 balances have been revised to reflect purchase accounting measurement period adjustments. (2) Acquired network location intangibles are amortized over the shorter of the term of the corresponding ground lease taking into consideration lease renewal options and residual value or up to 20 years, as the Company considers these intangibles to be directly related to the tower assets. The acquired network location intangibles represent the value to the Company of the incremental revenue growth that could potentially be obtained from leasing the excess capacity on acquired communications sites, as well as those in the Verizon Transaction. The acquired customer-related intangibles typically represent the value to the Company of customer contracts and relationships in place at the time of an acquisition or similar transaction, including assumptions regarding estimated renewals. The Company amortizes its acquired network location intangibles and customer-related intangibles on a straight-line basis over the estimated useful lives. As of December 31, 2015 , the remaining weighted average amortization period of the Company’s intangible assets, excluding the TV Azteca Economic Rights detailed in note 5, was 16 years. Amortization of intangible assets for the years ended December 31, 2015 , 2014 and 2013 was $568.3 million , $411.7 million and $282.5 million , respectively. Based on current exchange rates, the Company expects to record amortization expense as follows over the next five subsequent years (in millions): Year Ending December 31, 2016 $ 598.8 2017 597.1 2018 596.0 2019 593.7 2020 576.0

Notes Receivable and Other Non-

Notes Receivable and Other Non-current Assets	12 Months Ended
	Dec. 31, 2015
Notes Receivable And Other Long Term Assets [Abstract]
Notes Receivable and Other Non-Current Assets	NOTES RECEIVABLE AND OTHER NON-CURRENT ASSETS Notes receivable and other non-current assets consisted of the following as of December 31, (in thousands): 2015 2014 (1) Long-term prepaid ground rent $ 388,790 $ 311,502 Notes receivable 83,658 87,515 Other miscellaneous assets 260,455 176,229 Balance $ 732,903 $ 575,246 _______________ (1) December 31, 2014 balances have been revised to reflect purchase accounting measurement period adjustments and debt issuance costs. TV Azteca Note Receivable —In 2000, the Company loaned TV Azteca, S.A. de C.V. (“TV Azteca”), the owner of a major national television network in Mexico, $119.8 million . The loan has an interest rate of 13.11% , payable quarterly, which at the time of issuance was determined to be below market and therefore a corresponding discount was recorded. The term of the loan is 70 years ; however, the loan may be prepaid by TV Azteca without penalty during the last 50 years of the agreement. The discount on the loan is being amortized to Interest income, TV Azteca, net of interest expense on the Company’s consolidated statements of operations, using the effective interest method over the 70 -year term of the loan. Since inception, TV Azteca has repaid $28.0 million of principal on the loan. As of December 31, 2015 and 2014 , the outstanding balance on the loan was $91.8 million , or $82.9 million , net of discount. TV Azteca Economic Rights —Simultaneous with the signing of the loan agreement, the Company also entered into a 70 -year Economic Rights Agreement with TV Azteca regarding space not used by TV Azteca on approximately 190 of its broadcast towers. In exchange for the issuance of the below market interest rate loan and the annual payment of $1.5 million to TV Azteca (under the Economic Rights Agreement), the Company has the right to market and lease the unused tower space on the broadcast towers (the “Economic Rights”). TV Azteca retains title to these towers and is responsible for their operation and maintenance. The Company is entitled to 100% of the revenues generated from leases with tenants on the unused space and is responsible for any incremental operating expenses associated with those tenants. The term of the Economic Rights Agreement is 70 years ; however, TV Azteca has the right to purchase, at fair market value, the Economic Rights from the Company at any time during the last 50 years of the agreement. Should TV Azteca elect to purchase the Economic Rights, in whole or in part, it would also be obligated to repay a proportional amount of the loan discussed above at the time of such election. The Company’s obligation to pay TV Azteca $1.5 million annually would also be reduced proportionally. The Company accounted for the annual payment of $1.5 million as a capital lease by initially recording an asset and a corresponding liability of $18.6 million . The capital lease asset also included the original discount on the note. The capital lease asset and original discount on the note aggregated $30.2 million at the time of the transaction and represents the cost to acquire the Economic Rights. The Economic Rights asset was recorded as an intangible asset and is being amortized over the 70 -year life of the Economic Rights Agreement.

Acquisitions

Acquisitions	12 Months Ended
	Dec. 31, 2015
Business Combination, Description [Abstract]
Acquisitions	ACQUISITIONS The estimates of the fair value of the assets or rights acquired and liabilities assumed at the date of the applicable acquisition are subject to adjustment during the measurement period (up to one year from the particular acquisition date). The primary areas of the accounting for the acquisitions that are not yet finalized relate to the fair value of certain tangible and intangible assets acquired and liabilities assumed, which may include contingent consideration, residual goodwill and any related tax impact. The fair value of these net assets acquired are based on management’s estimates and assumptions, as well as other information compiled by management, including valuations that utilize customary valuation procedures and techniques. While the Company believes that such preliminary estimates provide a reasonable basis for estimating the fair value of assets acquired and liabilities assumed, it evaluates any necessary information prior to finalization of the fair value. During the measurement period, the Company will adjust assets or liabilities if new information is obtained about facts and circumstances that existed as of the acquisition date that, if known, would have resulted in the revised estimated values of those assets or liabilities as of that date. The effect of measurement period adjustments to the estimated fair value is reflected as if the adjustments had been completed on the acquisition date. The impact of all changes that do not qualify as measurement period adjustments are included in current period earnings. If the actual results differ from the estimates and judgments used in these fair values, the amounts recorded in the consolidated financial statements could be subject to a possible impairment of the intangible assets or goodwill, or require acceleration of the amortization expense of intangible assets in subsequent periods. During the year ended December 31, 2015 , the Company made certain measurement period adjustments related to several acquisitions consummated in 2014 and therefore, retrospectively adjusted the fair value of the assets acquired and liabilities assumed in the consolidated balance sheet as of December 31, 2014 . Impact of current year acquisitions —The Company typically acquires communications sites from wireless carriers or other tower operators and subsequently integrates those sites into its existing portfolio of communications sites. The financial results of the Company’s acquisitions have been included in the Company’s consolidated statements of operations for the year ended December 31, 2015 from the date of the respective acquisition. The date of acquisition, and by extension the point at which the Company begins to recognize the results of an acquisition, may be dependent upon, among other things, the receipt of contractual consents, the commencement and extent of leasing arrangements and the timing of the transfer of title or rights to the assets, which may be accomplished in phases. Sites acquired from communications service providers may never have been operated as a business and may have been utilized solely by the seller as a component of its network infrastructure. An acquisition may or may not involve the transfer of business operations or employees. The estimated aggregate impact of the 2015 acquisitions and the Verizon Transaction (described below) on the Company’s revenues and gross margin for the year ended December 31, 2015 was approximately $455.8 million and $218.9 million , respectively. The revenues and gross margin amounts also reflect incremental revenues from the addition of new tenants to such sites subsequent to the transaction date. Incremental amounts of segment selling, general, administrative and development expense have not been reflected as the amounts attributable to transactions are not comparable. For those acquisitions accounted for as business combinations, the Company recognizes acquisition and merger related expenses in the period in which they are incurred and services are received. Acquisition and merger related expenses may include finder’s fees, advisory, legal, accounting, valuation and other professional or consulting fees, fair value adjustments to contingent consideration and general administrative costs directly related to the transaction. Integration costs include incremental and non-recurring costs necessary to convert data, retain employees and otherwise enable the Company to operate new businesses efficiently. The Company records acquisition and merger related expenses, as well as integration costs in Other operating expenses in the consolidated statements of operations. During the years ended December 31, 2015 , 2014 and 2013 the Company recorded the following acquisition and merger related expenses and integration costs (in thousands): Year Ended December 31, 2015 2014 2013 Acquisition and merger related expenses (1) $ 18,799 $ 26,969 $ 36,172 Integration costs $ 18,097 $ 13,057 $ 1,424 _______________ (1) Acquisition and merger related expenses for the year ended December 31, 2015 does not reflect transaction costs related to the Verizon Transaction, as these costs have been capitalized as part of the assets’ fair value. Verizon Transaction On March 27, 2015, the Company completed its acquisition of the exclusive right to lease, acquire or otherwise operate and manage 11,449 wireless communications sites from Verizon in the United States (the “Verizon Transaction”) pursuant to the Master Agreement entered into on February 5, 2015 and the related Master Prepaid Lease, Management Agreement, Sale Site Master Lease Agreement and MPL Site Master Lease Agreement, subject to certain post-closing adjustments. The Company, through its wholly-owned subsidiary, leased or subleased from certain Verizon subsidiaries 11,286 communications sites, including the interest in the land, the tower and certain related improvements and tower related assets pursuant to the Master Prepaid Lease. Under the Master Prepaid Lease, the Company has the exclusive right to lease and operate the Verizon communications sites for a weighted average term of approximately 28 years and the Company will have the option to purchase the communications sites in various tranches at the end of the respective lease or sublease terms at a fixed amount stated in the sublease for such tranche plus the fair market value of certain alterations made to the related towers. The Company accounted for the payment with respect to the leased sites as a capital lease and the respective lease and non-lease elements related to tower assets and intangible assets, as described below. In addition, the Company, through its wholly-owned subsidiary, acquired 163 communications sites. The Company accounted for these sites as a business combination and the purchase price is reflected below in “2015 Acquisitions.” Upon closing, the Company agreed to lease, sublease or otherwise make available collocation space at each of the communications sites to Verizon for an initial non-cancellable term of ten years , subject to automatic extension for eight additional five -year renewal terms. The initial collocation rent is $1,900 per month for each communications site, with annual rent increases of 2% . The Company funded the Verizon Transaction with (i) proceeds from its concurrent registered public offerings of its common stock and 5.50% Mandatory Convertible Preferred Stock, Series B, par value $0.01 per share (the “Series B Preferred Stock”), (ii) borrowings under the Company’s revolving credit facilities and (iii) cash on hand. The Company included the Verizon Transaction in the unaudited pro forma financial results included herein as if the capital lease began on January 1, 2014. Management relied on various estimates and assumptions due to the fact that Verizon did not operate the sites as a business and the sites were utilized primarily by Verizon as a component of its network infrastructure. The consideration for the Verizon Transaction consisted of the following (in thousands): Cash consideration for sites under the Master Prepaid Lease $ 4,959,006 Capitalized transaction costs 8,037 Total consideration for sites under the Master Prepaid Lease 4,967,043 Cash consideration for acquired sites 99,000 Total consideration for the Verizon Transaction (1) $ 5,066,043 _______________ (1) Includes $6.6 million of accrued costs that have not been paid as of December 31, 2015. The following table summarizes the final allocation of consideration transferred for the 11,286 communications sites under the Master Prepaid Lease (in thousands). Balances are reflected in the accompanying consolidated balance sheets as of December 31, 2015 and represent the asset balances of the capital lease. Current assets $ 14,132 Non-current assets 53,339 Property and equipment 2,094,678 Intangible assets (1): Customer-related intangible assets 1,886,443 Network location intangible assets 1,186,428 Current liabilities (31,012 ) Other non-current liabilities (2) (236,965 ) Fair value of consideration transferred $ 4,967,043 _______________ (1) Customer-related intangible assets and network location intangible assets are amortized on a straight-line basis over periods of up to 20 years . (2) Primarily represents liabilities recorded for asset retirement obligations. The acquisitions described below under “2015 Acquisitions” and “2014 Acquisitions” are accounted for as business combinations and are consistent with the Company’s strategy to expand in selected geographic areas. 2015 Acquisitions Airtel Acquisition —On July 1, 2015, the Company acquired 4,699 communications sites in Nigeria from certain subsidiaries of Bharti Airtel Limited (“Airtel”), and subsequently acquired 17 additional sites, pursuant to its previously announced agreement for a total purchase price of $1.112 billion , including value added tax. The purchase price is subject to post-closing adjustments. TIM Acquisition —On April 29, 2015, the Company acquired 4,176 communications sites from TIM Celular S.A. (“TIM”) pursuant to its previously announced agreement for a purchase price of 1.9 billion Brazilian Reais (“BRL”) ( $644.3 million at the date of acquisition). On September 30, 2015, the Company acquired an additional 1,125 communications sites from TIM for an initial aggregate purchase price of 516.9 million BRL ( $130.9 million at the date of acquisition). On December 16, 2015, the Company acquired an additional 182 communications sites from TIM for an initial aggregate purchase price of 84.1 million BRL ( $21.7 million at the date of acquisition). The purchase price for each TIM acquisition is subject to post-closing adjustments. Pursuant to the terms of the agreement, the Company has the ability to purchase the remaining sites as they become available through October 2016. Following these closings, the amount of the letters of credit with Banco Santander was reduced to 40.6 million BRL ( $10.4 million ), corresponding to certain obligations under the terms of the agreement. Other Acquisitions —During the year ended December 31, 2015 , the Company acquired a total of 439 communications sites and related assets in Brazil, India, Mexico and Uganda for an aggregate purchase price of $22.5 million (including $0.3 million for the estimated fair value of contingent consideration), which was satisfied with cash consideration and by the issuance of credits to be applied against trade accounts receivable. The Company also acquired a total of 210 communications sites and equipment, as well as four property interests, in the United States for an aggregate purchase price of $142.4 million (including $1.3 million for the estimated fair value of contingent consideration), which included the 163 communications sites acquired as part of the Verizon Transaction, described above. The purchase prices are subject to post-closing adjustments. The following table summarizes the preliminary allocation of the purchase price for the fiscal year 2015 acquisitions based upon their estimated fair value at the date of acquisition (in thousands). Balances are reflected in the accompanying consolidated balance sheet as of December 31, 2015 . EMEA Latin America Other Airtel TIM Current assets $ 15,828 $ — $ 1,113 Non-current assets 69,277 — 995 Property and equipment 415,246 275,630 42,716 Intangible assets (1): Customer-related intangible assets 231,788 361,822 63,001 Network location intangible assets 328,334 115,562 37,691 Current liabilities (4,246 ) (3,192 ) (624 ) Other non-current liabilities (12,534 ) (74,966 ) (4,028 ) Net assets acquired 1,043,693 674,856 140,864 Goodwill (2) 68,663 122,011 24,011 Fair value of net assets acquired 1,112,356 796,867 164,875 Debt assumed — — — Purchase Price $ 1,112,356 $ 796,867 $ 164,875 _______________ (1) Customer-related intangible assets and network location intangible assets are amortized on a straight-line basis over periods of up to 20 years . (2) Goodwill was allocated to the Company’s property segments. The Company expects goodwill recorded in its U.S. and Asia property segments will be deductible for local tax purposes. The Company expects goodwill recorded in its Europe, Middle East and Africa (“EMEA”) property segment will not be deductible for local tax purposes and goodwill recorded in its Latin America property segment will be deductible in certain jurisdictions for local tax purposes. 2014 Acquisitions BR Towers Acquisition —On November 19, 2014, the Company completed the acquisition of 100% of the equity interests of BR Towers S.A. (“BR Towers”). At closing, BR Towers owned 2,504 towers and four property interests, as well as the exclusive use rights for 2,113 additional towers and 43 property interests in Brazil. The Company completed the acquisition for an estimated preliminary purchase price of $568.9 million , which was subsequently reduced to $558.7 million during the year ended December 31, 2015 . In addition, the Company paid $61.1 million to acquire all outstanding preferred equity and assumed $261.1 million of BR Towers’ existing indebtedness. As of December 31, 2015 , the remaining balance of the debt assumed was $85.2 million . Richland Acquisition —On April 3, 2014, the Company, through one of its wholly-owned subsidiaries, acquired entities holding a portfolio of 59 communications sites, which at the time of acquisition were leased primarily to radio and television broadcast tenants, and four property interests in the United States from Richland Properties LLC and other related entities (“Richland”) for an aggregate purchase price of $189.4 million , which was subsequently reduced to $188.9 million during the year ended December 31, 2015 . In addition, the Company assumed $196.5 million of Richland’s existing indebtedness, which it repaid in June 2014. Other Acquisitions —During the year ended December 31, 2014, the Company acquired 159 additional communications sites and related assets in Brazil, Ghana, Mexico and Uganda, for an aggregate purchase price of $28.3 million (including value added tax of $1.2 million ). The Company also acquired 299 communications sites in Mexico for a purchase price of $40.3 million (including value added tax of $5.6 million ), which reflected $3.4 million of net liabilities assumed. Total purchase price was satisfied by the issuance of $36.3 million of credits to be applied against trade accounts receivable and cash consideration of $4.0 million . Additionally, during the year ended December 31, 2014, the Company acquired 184 additional communications sites and equipment, as well as six property interests, in the United States for an aggregate purchase price of $180.8 million (including $6.3 million for the estimated fair value of contingent consideration). The following table summarizes the preliminary and final allocations of the purchase prices paid and the amounts of assets acquired and liabilities assumed for the fiscal year 2014 acquisitions based upon their estimated fair value at the date of acquisition (in thousands). Preliminary balances are reflected in the consolidated balance sheets in the Company’s Annual Report on Form 10-K for the year ended December 31, 2014 . Final balances are reflected in the accompanying consolidated balance sheets herein. Preliminary Allocation Final Allocation (1) U.S. Latin America Other U.S. Latin America Other Richland BR Towers Richland BR Towers Current assets $ 8,583 $ 31,832 $ 7,869 $ 8,583 $ 31,568 $ 7,404 Non-current assets — 9,135 1,521 — 9,365 2,562 Property and equipment 185,777 141,422 70,638 154,899 135,916 70,317 Intangible assets (2): Customer-related intangible assets 169,452 495,279 110,207 186,455 495,151 108,707 Network location intangible assets 1,700 136,233 50,199 3,409 135,549 49,199 Other intangible assets — 37,664 — — 33,095 — Current liabilities (3,635 ) (23,930 ) (2,860 ) (3,635 ) (24,012 ) (2,860 ) Other non-current liabilities (2,922 ) (101,508 ) (7,938 ) (2,922 ) (101,814 ) (7,938 ) Net assets acquired 358,955 726,127 229,636 346,789 714,818 227,391 Goodwill (3) 32,423 164,955 19,835 44,128 166,097 22,080 Fair value of net assets acquired 391,378 891,082 249,471 390,917 880,915 249,471 Debt assumed (4) (201,999 ) (261,136 ) — (201,999 ) (261,136 ) — Preferred stock outstanding — (61,056 ) — — (61,056 ) — Purchase Price $ 189,379 $ 568,890 $ 249,471 $ 188,918 $ 558,723 $ 249,471 _______________ (1) The allocation of the purchase price was finalized during the year ended December 31, 2015 . (2) Customer-related intangible assets and network location intangible assets are amortized on a straight-line basis over periods of up to 20 years . Other intangible assets are amortized on a straight-line basis over the life of the lease, which is a period of 11 years . (3) Goodwill was allocated to the Company’s property operating segments, as applicable, and the Company expects goodwill recorded will be deductible for local tax purposes except for goodwill associated with BR Towers, where goodwill is expected to be partially deductible. (4) Assumed BR Towers debt approximated fair value at the date of acquisition and included $11.5 million of current indebtedness. Assumed Richland debt included $196.5 million of Richland’s indebtedness and a fair value adjustment of $5.5 million . The fair value adjustments were based primarily on reported market values using Level 2 inputs. Pro Forma Consolidated Results (Unaudited) The following table presents the unaudited pro forma financial results as if the 2015 acquisitions, as well as the Verizon Transaction described above, had occurred on January 1, 2014 and the 2014 acquisitions had occurred on January 1, 2013 (in thousands, except per share data). Management relied on various estimates and assumptions due to the fact that some of the transactions never operated as a business and were utilized solely by the seller as a component of their network infrastructure. As a result, historical operating results may not be available. The pro forma results do not include any anticipated cost synergies, costs or other integration impacts. Accordingly, such pro forma amounts are not necessarily indicative of the results that actually would have occurred had the transactions been completed on the dates indicated, nor are they indicative of the future operating results of the Company. Year Ended December 31, 2015 2014 Pro forma revenues $ 5,034,746 $ 5,000,208 Pro forma net income attributable to American Tower Corporation common stockholders $ 564,579 $ 587,999 Pro forma net income per common share amounts: Basic net income attributable to American Tower Corporation common stockholders $ 1.33 $ 1.39 Diluted net income attributable to American Tower Corporation common stockholders $ 1.32 $ 1.38 Other Signed Acquisitions Viom— On October 21, 2015, the Company, through its wholly owned subsidiary, ATC Asia Pacific Pte. Ltd. (“ATC Asia”), entered into a definitive agreement (the “Share Purchase Agreement”) with Viom Networks Limited (“Viom”), a telecommunications infrastructure company that owns and operates over 42,000 wireless communications towers and 200 indoor DAS networks in India, and certain existing Viom shareholders, including the current managing shareholder, SREI Infrastructure Finance Limited, several other minority shareholders and Tata Teleservices Limited (collectively, the “Selling Shareholders”), to acquire a 51% controlling ownership interest in Viom from the Selling Shareholders for cash consideration of approximately 76 billion Indian Rupee (“INR”) (approximately $1.2 billion at December 31, 2015), subject to certain adjustments (the “Viom Transaction”). The Viom Transaction is expected to close in the first half of 2016, subject to certain conditions, and the Company anticipates that it will consolidate the full financial results for Viom. On October 21, 2015, ATC Asia also entered into a shareholders agreement (the “Shareholders Agreement”) with Viom and certain remaining Viom shareholders, including Tata Sons Limited, Tata Teleservices Limited, IDFC Private Equity Fund III, Macquarie SBI Investments Pte Limited and SBI Macquarie Infrastructure Trust (collectively, the “Remaining Shareholders”). The Shareholders Agreement will become effective on the closing date of the Viom Transaction. The Shareholders Agreement provides that, among other things, the Remaining Shareholders will have certain governance, anti-dilution and contractual rights. The Remaining Shareholders will have put options and ATC Asia will have a call option pursuant to the time periods and conditions outlined in the Shareholders Agreement. Acquisition-Related Contingent Consideration The Company may be required to pay additional consideration under certain agreements for the acquisition of communications sites if specific conditions are met or events occur. In Colombia and Ghana, the Company may be required to pay additional consideration upon the conversion of certain barter agreements with other wireless carriers to cash-paying lease agreements. In the United States and India, the Company may be required to pay additional consideration if certain pre-designated tenant leases commence during a specified period of time. A summary of the value of the Company’s contingent consideration is as follows (in thousands): Year Ended December 31, 2015 Maximum potential value (1) Estimated value at December 31, 2015 (2) Additions (3) Settlements Change in Fair Value Colombia $ 22,444 $ 9,829 $ — $ — $ (5,011 ) Costa Rica — — — (1,898 ) — Ghana 569 569 — — 99 India 1,164 163 315 (139 ) — United States 1,875 1,875 1,311 (5,906 ) 131 Total $ 26,052 $ 12,436 $ 1,626 $ (7,943 ) $ (4,781 ) _______________ (1) The maximum potential value is based on exchange rates at December 31, 2015 . The minimum value could be zero. (2) Estimate is determined using a probability weighted average of expected outcomes as of December 31, 2015 . (3) Based on preliminary acquisition accounting upon closing of certain acquisitions during the year ended December 31, 2015 . For more information regarding contingent consideration, see note 11.

Accrued Expenses

Accrued Expenses	12 Months Ended
	Dec. 31, 2015
Accrued Liabilities, Current [Abstract]
Accrued Expenses	ACCRUED EXPENSES Accrued expenses consisted of the following as of December 31, (in thousands): 2015 2014 (1) Accrued property and real estate taxes $ 75,827 $ 61,206 Payroll and related withholdings 62,334 57,110 Accrued rent 54,732 34,074 Accrued construction costs 19,857 46,024 Other accrued expenses 303,663 219,422 Balance $ 516,413 $ 417,836 _______________ (1) December 31, 2014 balances have been revised to reflect purchase accounting measurement period adjustments.

Long-Term Obligations

Long-Term Obligations	12 Months Ended
	Dec. 31, 2015
Long-term Debt, Excluding Current Maturities [Abstract]
Long-Term Obligations	LONG-TERM OBLIGATIONS Outstanding amounts under the Company’s long-term obligations, reflecting discounts, premiums and debt issuance costs, consisted of the following as of December 31, (in thousands): 2015 2014 (1) Contractual Interest Rate (2) Maturity Date (2) Series 2013-1A Securities (3) $ 497,478 $ 496,314 1.551 % March 15, 2018 Series 2013-2A Securities (4) 1,288,689 1,287,110 3.070 % March 15, 2023 Series 2015-1 Notes (5) 346,262 — 2.350 % June 15, 2020 Series 2015-2 Notes (6) 518,776 — 3.482 % June 16, 2025 GTP AP Notes (7) — 973,397 N/A N/A 2012 GTP Notes (7)(8) 281,902 290,586 3.721% - 7.358% Various Unison Notes (9) 201,930 203,683 5.349% - 9.522% Various BR Towers Debentures (10) 85,219 118,688 7.400 % October 15, 2023 Shareholder loans (11) 145,540 137,655 Various Various South African Facility (12) 53,175 73,156 8.575 % December 17, 2020 Colombian Credit Facility (13) 59,640 82,501 9.853 % April 24, 2021 Brazil Credit Facility (14) 21,868 — Various January 15, 2022 Indian Working Capital Facility (15) 8,752 — 9.700 % January 31, 2016 Mexican Loan — 263,426 N/A N/A BR Towers Credit Facility — 16,389 N/A N/A Total American Tower subsidiary debt 3,509,231 3,942,905 2013 Credit Facility (16) 1,225,000 — 1.652 % June 28, 2019 Term Loan (16) 1,993,601 1,495,284 1.680 % January 29, 2021 2014 Credit Facility (16) 1,980,000 1,100,000 1.680 % January 29, 2021 4.625% Notes — 599,720 N/A N/A 7.000% Notes — 497,750 N/A N/A 4.500% Notes 997,693 996,571 4.500 % January 15, 2018 3.40% Notes 999,769 999,607 3.400 % February 15, 2019 7.25% Notes 296,242 295,229 7.250 % May 15, 2019 2.800% Notes 743,557 — 2.800 % June 1, 2020 5.050% Notes 697,216 696,560 5.050 % September 1, 2020 3.450% Notes 642,786 641,579 3.450 % September 15, 2021 5.900% Notes 497,188 496,715 5.900 % November 1, 2021 4.70% Notes 695,374 694,694 4.700 % March 15, 2022 3.50% Notes 987,966 986,389 3.500 % January 31, 2023 5.00% Notes 1,003,453 1,003,628 5.000 % February 15, 2024 4.000% Notes 739,057 — 4.000 % June 1, 2025 Total American Tower Corporation debt 13,498,902 10,503,726 Other debt, including capital lease obligations 110,876 93,710 Total 17,119,009 14,540,341 Less current portion long-term obligations (50,202 ) (897,386 ) Long-term obligations $ 17,068,807 $ 13,642,955 _______________ (1) December 31, 2014 balances have been revised to reflect debt issuance costs as a direct deduction from the carrying amounts, with the exception of debt issuance costs associated with the 2013 Credit Facility and the 2014 Credit Facility (as defined below) which are reflected in Notes receivable and other non-current assets on the consolidated balance sheets. Amortization of deferred financing costs is included in interest expense on the consolidated statements of operations. (2) Represents the interest rate or maturity date as of December 31, 2015 and does not reflect the impact of interest rate swap agreements. (3) Maturity date reflects the anticipated repayment date; final legal maturity is March 15, 2043. (4) Maturity date reflects the anticipated repayment date; final legal maturity is March 15, 2048. (5) Maturity date reflects the anticipated repayment date; final legal maturity is June 15, 2045. (6) Maturity date reflects the anticipated repayment date; final legal maturity is June 15, 2050. (7) Secured debt assumed in connection with the acquisition of MIP Tower Holdings LLC (“MIPT”). (8) Anticipated repayment dates begin March 15, 2017. (9) Secured debt assumed in connection with the acquisition of certain legal entities holding a portfolio of property interests from Unison Holdings, LLC and Unison Site Management II, L.L.C. (together, “Unison”). Anticipated repayment dates begin April 15, 2017; final legal maturity date is April 15, 2040. (10) Publicly issued debentures assumed in connection with the acquisition of BR Towers and denominated in BRL. Debt accrues interest at a variable rate. (11) Reflects balances owed to the Company’s joint venture partners in Ghana and Uganda. The Ghana loan is denominated in Ghanaian Cedi (“GHS”) and the Uganda loan is denominated in U.S. Dollars (“USD”). The Uganda loan accrues interest at a variable rate. (12) Denominated in South African Rand (“ZAR”). Debt accrues interest at a variable rate. (13) Denominated in Colombian Pesos (“COP”). Debt accrues interest at a variable rate. (14) Denominated in BRL. Debt accrues interest at variable rate. (15) Denominated in INR. This agreement provides that the maturity date may be extended for additional 30-day periods. (16) Debt accrues interest at a variable rate. American Tower Subsidiary Debt Securitized Debt The Company has several securitizations in place. Cash flows generated by the sites that secure the securitized debt are only available for payment of such debt and are not available to pay the Company’s other obligations or the claims of its creditors. However, subject to certain restrictions, the Company holds the right to the excess cash flows not needed to pay the securitized debt and other obligations arising out of the securitizations. The securitized debt is the obligation of the issuers thereof or borrowers thereunder, as applicable, and their subsidiaries, and not of the Company or its other subsidiaries. Secured Tower Revenue Securities, Series 2013-1A and Series 2013-2A —In March 2013, the Company completed a private issuance (the “2013 Securitization”) of $1.8 billion of Secured Tower Revenue Securities, Series 2013-1A and Series 2013-2A (the “2013 Securities”) issued by American Tower Trust I (the “Trust”), a trust established by American Tower Depositor Sub, LLC, an indirect wholly owned special purpose subsidiary of the Company. The net proceeds of the transaction were $1.78 billion . The assets of the Trust consist of a nonrecourse loan (the “Loan”) to American Tower Asset Sub, LLC and American Tower Asset Sub II, LLC (the “AMT Asset Subs”), pursuant to a First Amended and Restated Loan and Security Agreement dated as of March 15, 2013 (the “Loan Agreement”). The Loan is secured by (i) mortgages, deeds of trust and deeds to secure debt on substantially all of the 5,186 wireless and broadcast communications towers owned by the AMT Asset Subs (the “2013 Secured Towers”), (ii) a pledge of the AMT Asset Subs’ operating cash flows from the Secured Towers, (iii) a security interest in substantially all of the AMT Asset Subs’ personal property and fixtures and (iv) the AMT Asset Subs’ rights under the tenant leases and the management agreement entered into in connection with the 2013 Securitization. American Tower Holding Sub, LLC, whose only material assets are its equity interests in each of the AMT Asset Subs, and American Tower Guarantor Sub, LLC, whose only material asset are its equity interests in American Tower Holding Sub, LLC, each have guaranteed repayment of the Loan and pledged their equity interests in their respective subsidiary or subsidiaries as security for such payment obligations. The 2013 Securities were issued in two separate series of the same class pursuant to a First Amended and Restated Trust and Servicing Agreement (the “Trust Agreement”), with terms identical to the Loan. The effective weighted average life and interest rate of the 2013 Securities was 8.6 years and 2.648% , respectively, as of the date of issuance. Refinancing of GTP Acquisition Partners Securitization —On May 29, 2015, GTP Acquisition Partners I, LLC (“GTP Acquisition Partners”), one of the Company’s wholly owned subsidiaries, repaid all amounts outstanding under the Secured Tower Revenue Notes, Global Tower Series 2011-1, Class C, Secured Tower Revenue Notes, Global Tower Series 2011-2, Class C and Class F and Secured Tower Revenue Notes, Global Tower Series 2013-1, Class C and Class F, (collectively, the “GTP AP Notes”) plus prepayment consideration and other costs and expenses related thereto, with cash on hand and proceeds from a private issuance (the “2015 Securitization”) of $350.0 million of American Tower Secured Revenue Notes, Series 2015-1, Class A (the “Series 2015-1 Notes”) and $525.0 million of American Tower Secured Revenue Notes, Series 2015-2, Class A (the “Series 2015-2 Notes,” and together with the Series 2015-1 Notes, the “2015 Notes”). The 2015 Notes are secured by (i) mortgages, deeds of trust and deeds to secure debt on substantially all of the 3,609 communications sites (the “2015 Secured Sites”) owned by GTP Acquisition Partners and its subsidiaries (the “GTP Entities”) and their operating cash flows, (ii) a security interest in substantially all of the personal property and fixtures of the GTP Entities, including GTP Acquisition Partners’ equity interests in its subsidiaries and (iii) the rights of the GTP Entities under a management agreement. American Tower Holding Sub II, LLC, whose only material assets are its equity interests in GTP Acquisition Partners, has guaranteed repayment of the 2015 Notes and pledged its equity interests in GTP Acquisition Partners as security for such payment obligations. The 2015 Notes were issued by GTP Acquisition Partners pursuant to a Third Amended and Restated Indenture and related series supplements, each dated as of May 29, 2015 (collectively, the “2015 Indenture”), between the GTP Entities and The Bank of New York Mellon, as trustee. The effective weighted average life and interest rate of the 2015 Notes was 8.1 years and 3.029% , respectively, as of the date of issuance. Under the terms of the Loan Agreement and 2015 Indenture, amounts due will be paid from the cash flows generated by the 2013 Secured Towers or the 2015 Secured Sites, as applicable, which must be deposited into certain reserve accounts, and thereafter distributed solely pursuant to the terms of the Loan Agreement or 2015 Indenture, as applicable. On a monthly basis, after payment of all required amounts under the Loan Agreement or 2015 Indenture, as applicable, including interest payments, subject to the conditions described below, the excess cash flows generated from the operation of such assets are released to the AMT Asset Subs or GTP Acquisition Partners, as applicable, which can then be distributed to, and used by, the Company. In order to distribute any excess cash flow to the Company, the AMT Asset Subs and GTP Acquisition Partners must each maintain a specified debt service coverage ratio (the “DSCR”), generally defined as the net cash flow divided by the amount of interest, servicing fees and trustee fees required to be paid over the succeeding 12 months on the principal amount of the Loan or the 2015 Notes, as applicable, that will be outstanding on the payment date following such date of determination. If the DSCR were equal to or below 1.30 x (the “Cash Trap DSCR”) for such quarter, and the DSCR continues to be equal to or below the Cash Trap DSCR for two consecutive calendar quarters, then all cash flow in excess of amounts required to make debt service payments, to fund required reserves, to pay management fees and budgeted operating expenses and to make other payments required under the applicable transaction documents, referred to as excess cash flow, will be deposited into a reserve account instead of being released to the AMT Asset Subs or GTP Acquisition Partners, as applicable. The funds in the reserve account will not be released to the AMT Asset Subs or GTP Acquisition Partners unless the DSCR, as applicable, exceeds the Cash Trap DSCR for two consecutive calendar quarters. Additionally, an “amortization period” commences if, as of the end of any calendar quarter, the DSCR falls below 1.15 x (the “Minimum DSCR”) and will continue to exist until the DSCR exceeds the Minimum DSCR for two consecutive calendar quarters. With respect to the 2013 Securities, an “amortization period” also commences if, on the anticipated repayment date the component of the Loan corresponding to the applicable subclass of the 2013 Securities has not been repaid in full, provided that such amortization period shall apply with respect to such component that has not been repaid in full. If either series of the 2015 Notes have not been repaid in full on the applicable anticipated repayment date, additional interest will accrue on the unpaid principal balance of the applicable series of the 2015 Notes, and such series will begin to amortize on a monthly basis from excess cash flow. During an amortization period, all excess cash flow and any amounts then in the applicable reserve account because the Cash Trap DSCR was not met would be applied to payment of the principal on the Loan or the 2015 Notes, as applicable. The Loan and the 2015 Notes may be prepaid in whole or in part at any time, provided such payment is accompanied by the applicable prepayment consideration. If the prepayment occurs within 12 months of the anticipated repayment date with respect to the Series 2013-1A Securities or the Series 2015-1 Notes, or 18 months of the anticipated repayment date with respect to the Series 2013-2A Securities or the Series 2015-2 Notes, no prepayment consideration is due. The Loan may be defeased in whole at any time prior to the anticipated repayment date for any component of the Loan then outstanding. The Loan Agreement and the 2015 Indenture include operating covenants and other restrictions customary for transactions subject to rated securitizations. Among other things, the AMT Asset Subs and the GTP Entities, as applicable, are prohibited from incurring other indebtedness for borrowed money or further encumbering their assets subject to customary carve-outs for ordinary course trade payables and permitted encumbrances (as defined in the Loan Agreement or the 2015 Indenture, as applicable). The organizational documents of the AMT Asset Subs and the GTP Entities contain provisions consistent with rating agency securitization criteria for special purpose entities, including the requirement that they maintain independent directors. The Loan Agreement and the 2015 Indenture also contain certain covenants that require the AMT Asset Subs or GTP Acquisition Partners, as applicable, to provide the respective trustee with regular financial reports and operating budgets, promptly notify such trustee of events of default and material breaches under the Loan Agreement and other agreements related to the 2013 Secured Towers or the 2015 Indenture and other agreements related to the 2015 Secured Sites, as applicable, and allow the applicable trustee reasonable access to the sites, including the right to conduct site investigations. A failure to comply with the covenants in the Loan Agreement or the 2015 Indenture could prevent the AMT Asset Subs or GTP Acquisition Partners from distributing excess cash flow to the Company. Furthermore, if the AMT Asset Subs or GTP Acquisition Partners were to default on the Loan or a series of the 2015 Notes, the applicable trustee may seek to foreclose upon or otherwise convert the ownership of all or any portion of the 2013 Secured Towers or the 2015 Secured Sites, respectively, in which case the Company could lose the revenue associated with those assets. With respect to the 2015 Notes, upon occurrence and during an event of default, the trustee may, in its discretion or at direction of holders of more than 50% of the aggregate outstanding principal of any series of the 2015 Notes, declare such series of 2015 Notes immediately due and payable, in which case any excess cash flow would need to be used to pay holders of such notes. Further, under the Loan Agreement and the 2015 Indenture, the AMT Asset Subs or GTP Acquisition Partners, as applicable, are required to maintain reserve accounts, including for amounts received or due from tenants related to future periods, property taxes, insurance, ground rents, certain expenses and debt service. Based on the terms of the Loan Agreement and the 2015 Indenture, all rental cash receipts received for each month are reserved for the succeeding month and held in an account controlled by the applicable trustee and then released. The $95.0 million held in the reserve accounts with respect to the 2013 Securitization and the $16.3 million held in the reserve accounts with respect to the 2015 Securitization as of December 31, 2015 are classified as Restricted cash on the Company’s accompanying consolidated balance sheets. Assumed Securitized Debt 2012 GTP Notes —In connection with the acquisition of MIPT, the Company assumed existing indebtedness issued by certain subsidiaries of Global Tower Partners (“GTP”) in several securitization transactions, including the Secured Tower Revenue Notes, Series 2012-1 Class A, Series 2012-2 Class A, Series 2012-2 Class B, and Series 2012-2 Class C (collectively, the “2012 GTP Notes”) issued by GTP Cellular Sites, LLC (“GTP Cellular Sites”). The four classes of 2012 GTP Notes bear interest at rates of 3.721% , 4.336% , 6.413% and 7.358% , respectively, with anticipated repayment dates of March 15, 2017 for the Series 2012-1 Class A Notes and March 15, 2019 for each class of Series 2012-2 Notes and a final maturity date of March 15, 2042. As of December 31, 2015, the aggregate amount outstanding was $272.1 million plus $9.8 million of unamortized premium. Unison Notes —In connection with the acquisition of Unison, the Company assumed $196.0 million of existing indebtedness under the Secured Cellular Site Revenue Notes, Series 2010-1 Class C, Series 2010-2 Class C and Series 2010-2 Class F (collectively, the “Unison Notes”) issued by Unison Ground Lease Funding, LLC (the “Unison Issuer”) in a securitization transaction (the “Unison Securitization”). The three classes of Unison Notes bear interest at rates of 5.349% , 6.392% and 9.522% , respectively, with anticipated repayment dates of April 15, 2017, April 15, 2020 and April 15, 2020, respectively, and a final maturity date of April 15, 2040. As of December 31, 2015, the aggregate amount outstanding was $196.0 million plus $5.9 million of unamortized premium. The 2012 GTP Notes and the Unison Notes may be prepaid in whole or in part at any time, provided such payment is accompanied by applicable prepayment consideration. No prepayment consideration is due if, with respect to the 2012 GTP Notes, the prepayment occurs within one year of the anticipated repayment date, or, with respect to the Unison Notes, the prepayment occurs within six months of the anticipated repayment date. As of December 31, 2015, the 2012 GTP Notes are secured by, among other things, an aggregate of 105 sites and 1,064 property interests owned by certain subsidiaries of GTP and other related assets (the “GTP Secured Sites”) and the Unison Notes are secured by, among other things, liens on 1,516 real property interests owned by two special purpose subsidiaries of the Unison Issuer (together with the Unison Issuer, the “Unison Obligors”) and other related assets (the “Unison Secured Sites”). The indenture and each series supplement governing the 2012 GTP Notes (collectively, the “GTP Indenture”) and the indenture governing the Unison Notes (the “Unison Indenture”) each include certain financial ratios and operating covenants and other restrictions customary for notes subject to rated securitizations. Among other things, GTP Cellular Sites and the Unison Obligors are restricted from incurring other indebtedness or further encumbering their applicable assets. Under the terms of the applicable indentures, amounts due will be paid from the cash flows generated by the GTP Secured Sites or the Unison Secured Sites (as applicable), which must be deposited into certain reserve accounts, and thereafter distributed, solely pursuant to the terms of the applicable agreement. The Unison Indenture requires the Unison Issuer to make monthly payments of interest to holders of the Unison Notes. The GTP Indenture requires GTP Cellular Sites to make monthly payments of principal and interest to holders of the 2012 GTP Notes from available funds. On a monthly basis, cash flows in excess of amounts needed to make debt service payments and other payments required under the GTP Indenture of the Unison Indenture, as applicable, are to be distributed to GTP Cellular Sites or the Unison Issuer, which may then be distributed to, and used by, the Company. Additionally, under the GTP Indenture or the Unison Indenture, GTP Cellular Sites and the Unison Obligors, respectively, are required to maintain reserve accounts, including for amounts received or due from tenants related to future periods, property taxes, insurance, ground rents, certain expenses and debt service. The $5.3 million held in the reserve accounts with respect to the 2012 GTP Notes and the $4.9 million held in the reserve accounts with respect to the Unison Securitization, as of December 31, 2015 are classified as Restricted cash on the accompanying consolidated balance sheets. A failure to comply with the covenants in the GTP Indenture or the Unison Indenture could prevent GTP Cellular Sites or the Unison Obligors, as applicable, from taking certain actions with respect to each of their sites and from distributing excess cash flow to the Company. In addition, with respect to the 2012 GTP Notes, upon occurrence and during an event of default, the trustee may, in its discretion or at direction of holders of more than 50% of the aggregate outstanding principal of any series of the 2012 GTP Notes, declare such series of the 2012 GTP Notes immediately due and payable, in which case any excess cash flow would need to be used to pay holders of such series of the 2012 GTP Notes. Furthermore, if GTP Cellular Sites or the Unison Issuer were to default on their respective notes, the applicable trustee could seek to foreclose upon the GTP Secured Sites or the Unison Secured Sites, as applicable, in which case the Company could lose ownership of such property interests and the revenue associated with them. Other Subsidiary Debt BR Towers Debt —In connection with the acquisition of BR Towers in November 2014, the Company assumed 313.1 million BRL ( $80.2 million at December 31, 2015) of publicly issued simple debentures (“BR Towers Debentures”) (with an original principal amount of 300.0 million BRL) issued by a subsidiary of BR Towers (the “BRT Issuer”), and a BRL denominated credit facility with Banco Nacional de Desenvolvimento Econômico e Social (“BNDES”), which allowed a subsidiary of BR Towers to borrow up to 48.1 million BRL through an intermediary bank (the “BR Towers Credit Facility”). On March 30, 2015, the Company repaid all amounts outstanding and terminated the BR Towers Credit Facility. The aggregate principal amount of the BR Towers Debentures may be adjusted periodically relative to changes in the National Extended Consumer Price Index. Any such increase in the principal amount will be capitalized in a manner consistent with the agreement governing the BR Towers Debentures (the “Debenture Agreement”). Payments of principal and interest are made quarterly, beginning on January 15, 2014, in accordance with the amortization schedule set forth in the Debenture Agreement. The Company may redeem the BR Towers Debentures beginning on October 15, 2018 at the then outstanding principal amount plus a surcharge, calculated in accordance with the Debenture Agreement, and all accrued and unpaid interest thereon. As of December 31, 2015, 332.8 million BRL ( $85.2 million ) aggregate principal amount is outstanding under the BR Towers Debentures. The BR Towers Debentures are secured by (i) 100% of the shares of the BRT Issuer and (ii) all proceeds and rights from the issuance of the BR Towers Debentures, including amounts in a Resource Account, as defined in the applicable agreement. The Debenture Agreement includes contractual covenants and other restrictions customary for public debentures. Shareholder Loans —In connection with the establishment of certain of the Company’s joint ventures and related acquisitions of communications sites in Ghana and Uganda, the Company’s majority owned subsidiaries entered into shareholder loan agreements, as the borrower, with wholly owned subsidiaries of the Company and of the Company’s joint venture partners, as lenders. The portions of the loans made by the Company’s wholly owned subsidiaries are eliminated in consolidation and the portions of the loans made by each of the Company’s joint venture partner’s wholly owned subsidiaries are reported as outstanding debt of the Company. Outstanding amounts under each of the Company’s shareholder loans consisted of the following as of December 31, (in thousands): 2015 2014 Contractual Interest Rate Maturity Date Ghana loan (1) $ 70,314 $ 68,651 21.87 % December 31, 2019 Uganda loan (2)(3) 75,226 69,004 6.066 % June 29, 2019 _______________ (1) Denominated in GHS. As of December 31, 2015, the aggregate principal amount outstanding under the Ghana loan was 267.5 million GHS, which included 46.7 million GHS ( $12.3 million ) of interest which was capitalized during the year ended December 31, 2015. (2) Interest rate as of December 31, 2015. Interest accrues at a variable rate. (3) Includes $6.3 million of interest which was capitalized during the year ended December 31, 2015. South African Facility —On December 19, 2015, one of the Company’s South African subsidiaries (the “SA Borrower”) entered into a loan agreement for a new 830.0 million ZAR denominated credit facility (the “South African Facility”). On December 23, 2015, the SA Borrower borrowed 830.0 million ZAR ( $54.5 million at the date of borrowing), which it used primarily to repay its previously existing ZAR-denominated credit facility. The South African Facility provides that the SA Borrower may request increases up to an aggregate of an additional 830.0 million ZAR. Principal and interest are payable quarterly in arrears with principal due in accordance with the repayment schedule included in the loan agreement. Outstanding principal and accrued but unpaid interest will be due and payable in full at maturity. The South African Facility may be prepaid in whole or in part without prepayment consideration. The South African Facility is secured by, among other things, liens on towers owned by the SA Borrower. The loan agreement contains certain reporting, information, financial ratios and operating covenants. Failure to comply with certain of the financial and operating covenants would constitute a default, which could result in, among other things, the amounts outstanding, including all accrued interest and unpaid fees, becoming immediately due and payable. Under the terms of the South African Facility, interest is payable quarterly at a rate per annum equal to 1.95% , plus the three month Johannesburg Interbank Agreed Rate (JIBAR). As of December 31, 2015, 830.0 million ZAR ( $53.7 million ) was outstanding under the South African Facility. Colombian Credit Facility —In October 2014, one of the Company’s Colombian subsidiaries (“ATC Sitios”) entered into a loan agreement for a 200.0 billion COP ( $63.5 million at December 31, 2015) long-term credit facility (the “Colombian Credit Facility”). Any outstanding principal and accrued but unpaid interest will be due and payable in full at maturity. The Colombian Credit Facility may be prepaid in whole or in part at any time, subject to certain limitations and prepayment consideration. Principal and interest are payable quarterly in arrears with principal due in accordance with the repayment schedule included in the loan agreement. Interest accrues at a per annum rate equal to 4.00% above the three-month Inter-bank Rate (“IBR”) in effect at the beginning of each Interest Period, as defined in the loan agreement. The loan agreement also requires that ATC Sitios manage exposure to variability in interest rates on certain of the amounts outstanding under the Colombian Credit Facility. As of December 31, 2015 , the interest rate, after giving effect to the interest rate swap agreements, was 9.80% . The Colombian Credit Facility is secured by, among other things, liens on towers owned by ATC Sitios. The loan agreement contains certain reporting, information, financial ratios and operating covenants. Failure to comply with certain of the financial and operating covenants would constitute a default, which could result in, among other things, the amounts outstanding, including all accrued interest and unpaid fees, becoming immediately due and payable. As of December 31, 2015, 190.0 billion COP ( $60.3 million ) was outstanding under the Colombian Credit Facility. Brazil Credit Facility— In December 2014, one of the Company’s Brazilian subsidiaries (“ATC Brazil”) entered into a 271.0 million BRL ( $69.4 million at December 31, 2015) credit facility with BNDES, (the “Brazil Credit Facility”). ATC Brazil maintains the ability to draw on the Brazil Credit Facility until December 30, 2016. The Brazil Credit Facility bears interest at a margin over the long-term interest rate, as defined by BNDES (“TJLP”), and the Special Clearance and Escrow System (“SELIC”). Outstanding amounts and key terms under the Brazil Credit Facility consisted of the following as of December 31, 2015 (in millions): Amounts Outstanding (BRL) Amounts Outstanding (USD at December 31, 2015) Maximum Borrowing Amount (BRL) Maximum Borrowing Amount (USD at December 31, 2015) Contractual Interest Rate Tranche A 23.4 $ 6.0 34.8 $ 8.9 TJLP + 4.25% Tranche B 24.5 $ 6.3 34.8 $ 8.9 SELIC + 4.25% Tranche C 37.5 $ 9.6 200.0 $ 51.2 6.00 % Tranche D — $ — 1.4 $ 0.4 TJLP Indian Working Capital Facility —In April 2013, one of the Company’s Indian subsidiaries (“ATC India”) entered into a working capital facility agreement (the “Indian Working Capital Facility”), which allows ATC India to borrow an amount not to exceed the INR equivalent of $10.0 million through two separate facilities. Advances under one facility (“Facility A”) are payable on the earlier of demand or six months following the borrowing date and advances under the other facility (“Facility B”) are payable on the earlier of demand or thirty days following the borrowing date, with the option to extend for additional 30-day periods. The interest rate is determined at the time of advance by the bank. As of December 31, 2015, the Company had no amounts outstanding under Facility A and 579.0 million INR ( $8.8 million ) outstanding under Facility B. ATC India maintains the ability to draw down and repay amounts under the Indian Working Capital Facility in the ordinary course. Mexican Loan —In May 2015, upon maturity of its 5.2 billion Mexican Peso (“MXN”) denominated unsecured bridge loan, the Company repaid the remaining outstanding principal balance of 3.9 billion MXN ( $251.2 million on the date of repayment) with cash on hand and borrowings under its multicurrency senior unsecured revolving credit facility entered into in June 2013, as amended (the “2013 Credit Facility”). American Tower Corporation Debt Bank Facilities —In February 2015, the Company entered into amendment agreements with respect to (i) its unsecured term loan entered into in October 2013 (the “Term Loan”), (ii) the 2013 Credit Facility and (iii) its senior unsecured revolving credit facility entered into in January 2012, as amended and restated in September 2014 (the “2014 Credit Facility”). After giving effect to these amendments, the permitted ratio of Total Debt to Adjusted EBITDA (as defined in the loan agreements for each of the facilities) is (i) 7.00 to 1.00 for the quarter ended December 31, 2015 and (ii) 6.00 to 1.00 thereafter. In addition, the maximum Incremental Term Loan Commitments (as defined in the agreement governing the Term Loan) was increased to $1.0 billion and the maximum Revolving Loan Commitments, after giving effect to any Incremental Commitments (each as defined in the loan agreements for each of the revolving credit facilities) was increased to $3.5 billion and $2.5 billion under the 2013 Credit Facility and the 2014 Credit Facility, respectively. Effective October 28, 2015, the Company entered into additional amendment agreements to the Term Loan, the 2013 Credit Facility and the 2014 Credit Facility, which, among other things, (i) extended the maturity dates to January 29, 2021, June 28, 2019 and January 29, 2021, respectively, and (ii) increased the threshold for certain defaults with respect to judgments, attachments or acceleration of indebtedness from $250.0 million to $300.0 million . All of the other material terms of the Term Loan, the 2013 Credit Facility and the 2014 Credit Facility remain in full force and effect. Term Loan —Effective February 20, 2015, the Company borrowed an additional $500.0 million under the Term L

Other Non-Current Liabilities

Other Non-Current Liabilities	12 Months Ended
	Dec. 31, 2015
Other Liabilities, Noncurrent [Abstract]
Other Non-Current Liabilities	OTHER NON-CURRENT LIABILITIES Other non-current liabilities consisted of the following as of December 31, (in thousands): 2015 2014 (1) Unearned revenue $ 451,844 $ 415,809 Deferred rent liability 348,532 303,442 Other miscellaneous liabilities 265,306 309,436 Balance $ 1,065,682 $ 1,028,687 _______________ (1) December 31, 2014 balances have been revised to reflect purchase accounting measurement period adjustments.

Asset Retirement Obligations

Asset Retirement Obligations	12 Months Ended
	Dec. 31, 2015
Asset Retirement Obligation [Abstract]
Asset Retirement Obligations	ASSET RETIREMENT OBLIGATIONS The changes in the carrying amount of the Company’s asset retirement obligations were as follows (in thousands): 2015 2014 Beginning balance as of January 1, $ 609,035 $ 549,548 Additions 277,982 52,623 Accretion expense 55,592 40,325 Revisions in estimates (1) (83,636 ) (32,311 ) Settlements (2,037 ) (1,150 ) Balance as of December 31, $ 856,936 $ 609,035 _______________ (1) Revisions in estimates include the negative impact of $81.7 million and $38.5 million of foreign currency translation for the years ended December 31, 2015 and 2014, respectively. As of December 31, 2015 , the estimated undiscounted future cash outlay for asset retirement obligations was $2.6 billion .

Fair Value Measurements

Fair Value Measurements	12 Months Ended
	Dec. 31, 2015
Fair Value Disclosures [Abstract]
Fair Value Measurements	FAIR VALUE MEASUREMENTS The Company determines the fair value of its financial instruments based on the fair value hierarchy, which requires an entity to maximize the use of observable inputs and minimize the use of unobservable inputs when measuring fair value. Below are the three levels of inputs that may be used to measure fair value: Level 1 Quoted prices in active markets for identical assets or liabilities that the Company has the ability to access at the measurement date. Level 2 Observable inputs other than Level 1 prices, such as quoted prices for similar assets or liabilities; quoted prices in markets that are not active; or other inputs that are observable or can be corroborated by observable market data for substantially the full term of the assets or liabilities. Level 3 Unobservable inputs that are supported by little or no market activity and that are significant to the fair value of the assets or liabilities. Items Measured at Fair Value on a Recurring Basis —The fair value of the Company’s financial assets and liabilities that are required to be measured on a recurring basis at fair value was as follows (in thousands): December 31, 2015 December 31, 2014 Fair Value Measurements Using Assets/Liabilities at Fair Value Fair Value Measurements Using Assets/Liabilities Level 1 Level 2 Level 3 Level 1 Level 2 Level 3 Assets: Short-term investments (1) — — — — — $ 6,302 — $ 6,302 Interest rate swap agreements — $ 692 — $ 692 — $ 88 — $ 88 Embedded derivative in lease agreement — — $ 14,176 $ 14,176 — — — — Liabilities: Acquisition-related contingent consideration — — $ 12,436 $ 12,436 — — $ 28,524 $ 28,524 Interest rate swap agreements — — — — — $ 647 — $ 647 _______________ (1) Consists of highly liquid investments with original maturities in excess of three months. Interest Rate Swap Agreements Certain of the Company’s foreign subsidiaries have entered into interest rate swap agreements, which have been designated as cash flow hedges, to manage exposure to variability in interest rates on debt. The fair value of the Company’s interest rate swap agreements is determined using pricing models with inputs that are observable in the market or can be derived principally from, or corroborated by, observable market data. The Company records the change in fair value for the effective portion of the cash flow hedges in Other comprehensive income (“OCI”) in the consolidated balance sheets and reclassifies a portion of the value from OCI into Interest expense on a quarterly basis as the cash flows from the hedged item affects earnings. The Company records the settlement of interest rate swap agreements in Loss on retirement of long-term obligations in the consolidated statement of operations in the period in which the settlement occurs. One of the Company’s Colombian subsidiaries entered into an interest rate swap agreement with an aggregate notional value of 100.0 billion COP ( $31.8 million ) with certain of the lenders under the Colombian Credit Facility. The interest rate swap agreement requires the payment of a fixed interest rate of 5.74% and pays variable interest at the three-month IBR through the earlier of termination of the underlying debt or April 24, 2021. The notional value is reduced in accordance with the repayment schedule under the Colombian Credit Facility. In December 2015, one of the Company’s South African subsidiaries settled the interest rate swap agreements related to its previously existing ZAR-denominated South African credit facility. The notional amount and fair value of the interest rate swap agreements were as follows as of December 31, (in thousands): 2015 (1) 2014 (2) Local USD Local USD South Africa (ZAR) Notional — — 440,614 38,080 Fair Value — — 1,016 88 Colombia (COP) Notional 95,000,000 30,164 100,000,000 41,798 Fair Value 2,179,374 692 (1,548,688 ) (647 ) _______________ (1) As of December 31, 2015, the interest rate swap agreement in Colombia was included in Notes receivable and other non-current assets on the consolidated balance sheet. (2) As of December 31, 2014, the interest rate swap agreement in Colombia was included in Other non-current liabilities on the consolidated balance sheet and the interest rate swap agreements in South Africa were included in Notes receivable and other non-current assets on the consolidated balance sheet. Embedded Derivative in Lease Agreement In connection with the acquisition of communications sites in Nigeria, the Company entered into a site lease agreement where a portion of the monthly rent to be received is escalated based on an index outside the lessor’s economic environment. The fair value of the portion of the lease tied to the U.S. CPI was $14.6 million at the date of acquisition and was recorded in Notes receivable and other non-current assets on the consolidated balance sheet. The fair value of the Company’s embedded derivative is determined using a discounted cash flow approach, which takes into consideration Level 3 unobservable inputs, including expected future cash flows over the period in which the associated payment is expected to be received and applies a discount factor that captures uncertainties in the future periods associated with the expected payment. During the year ended December 31, 2015, the Company recorded $0.4 million of a fair value adjustment which was recorded in Other expense in the consolidated statements of operations. Acquisition-Related Contingent Consideration Acquisition-related contingent consideration is initially measured and recorded at fair value as an element of consideration paid in connection with an acquisition with subsequent adjustments recognized in Other operating expenses in the consolidated statements of operations. The fair value of acquisition-related contingent consideration, and any subsequent changes in fair value, is determined by using a discounted probability-weighted approach, which takes into consideration Level 3 unobservable inputs including assessments of expected future cash flows over the period in which the obligation is expected to be settled and applies a discount factor that captures the uncertainties associated with the obligation. Changes in the unobservable inputs of Level 3 assets or liabilities could significantly impact the fair value of these assets or liabilities recorded in the accompanying consolidated balance sheets, with the adjustments being recorded in the consolidated statements of operations. As of December 31, 2015 , the Company estimates that the value of all potential acquisition-related contingent consideration required payments to be between zero and $26.1 million . The changes in fair value of the contingent consideration were as follows during the years ended December 31, (in thousands): 2015 2014 Balance as of January 1 $ 28,524 $ 31,890 Additions 1,626 6,412 Settlements (7,943 ) (3,889 ) Change in fair value (4,781 ) (225 ) Foreign currency translation adjustment (4,990 ) (4,934 ) Other (1) — (730 ) Balance as of December 31 $ 12,436 $ 28,524 _______________ (1) In connection with the sale of operations in Panama in September 2014, the buyer assumed the Company’s potential obligations related to additional purchase price consideration. Items Measured at Fair Value on a Nonrecurring Basis Assets Held and Used —The Company’s long-lived assets are recorded at amortized cost and, if impaired, are adjusted to fair value using Level 3 inputs. During the year ended December 31, 2015 , certain long-lived assets held and used with a carrying value of $12.6 billion were written down to their net realizable value as a result of an asset impairment charge of $15.1 million . During the year ended December 31, 2014 , certain long-lived assets held and used with a carrying value of $8.9 billion were written down to their net realizable value as a result of an asset impairment charge of $11.2 million . The asset impairment charges are recorded in Other operating expenses in the accompanying consolidated statements of operations. These adjustments were determined by comparing the estimated fair value utilizing projected future discounted cash flows to be provided from the long-lived assets to the asset’s carrying value. Sale of Assets —During the year ended December 31, 2014, the Company completed the sale of its operations in Panama and its third-party structural analysis business for an aggregate sale price of $17.9 million , plus a working capital adjustment. At the time of sale, the carrying amount of these assets primarily included $8.1 million of property and equipment, $7.8 million of intangible assets and $3.6 million of goodwill. The Company recorded a net charge of $2.2 million in Other operating expenses in the accompanying consolidated statements of operations. There were no other items measured at fair value on a nonrecurring basis during the year ended December 31, 2015. Fair Value of Financial Instruments —The Company’s financial instruments for which the carrying value reasonably approximates fair value at December 31, 2015 and 2014 include cash and cash equivalents, restricted cash, accounts receivable and accounts payable. The Company’s estimates of fair value of its long-term obligations, including the current portion, are based primarily upon reported market values. For long-term debt not actively traded, fair value is estimated using either indicative price quotes or a discounted cash flow analysis using rates for debt with similar terms and maturities. As of December 31, 2015 , the carrying value and fair value of long-term obligations, including the current portion, were $17.1 billion and $17.4 billion , respectively, of which $8.7 billion was measured using Level 1 inputs and $8.7 billion was measured using Level 2 inputs. As of December 31, 2014 , the carrying value and fair value of long-term obligations, including the current portion, were $14.5 billion and $15.0 billion , respectively, of which $9.7 billion was measured using Level 1 inputs and $5.3 billion was measured using Level 2 inputs.

Income Taxes

Income Taxes	12 Months Ended
	Dec. 31, 2015
Income Tax Expense (Benefit), Continuing Operations [Abstract]
Income Taxes	INCOME TAXES The Company has filed, for prior taxable years through its taxable year ended December 31, 2011, consolidated U.S. federal tax returns, which included all of its then wholly owned domestic subsidiaries. For its taxable year commencing January 1, 2012, the Company filed, and intends to continue to file, as a REIT, and its domestic TRSs filed, and intend to continue to file, as C corporations. The Company also files tax returns in various states and countries. The Company’s state tax returns reflect different combinations of the Company’s subsidiaries and are dependent on the connection each subsidiary has with a particular state. The following information pertains to the Company’s income taxes on a consolidated basis. The income tax provision from continuing operations consisted of the following for the years ended December 31, (in thousands): 2015 2014 2013 Current: Federal $ (73,930 ) $ (2,390 ) $ (30,322 ) State (21,216 ) (797 ) (13,731 ) Foreign (55,045 ) (57,934 ) (44,973 ) Deferred: Federal 9,131 (4,180 ) (16,318 ) State 8 (973 ) (5,139 ) Foreign (16,903 ) 3,769 50,942 Income tax provision $ (157,955 ) $ (62,505 ) $ (59,541 ) The effective tax rate on income from continuing operations for the years ended December 31, 2015, 2014 and 2013 differs from the federal statutory rate primarily due to our qualification for taxation as a REIT, as well as adjustments for foreign items. As a REIT, the Company may deduct earnings distributed to stockholders against the income generated by its REIT operations. In addition, the Company is able to offset certain income by utilizing its NOLs, subject to specified limitations. Effective July 25, 2015, the Company filed a tax election, pursuant to which MIPT no longer operates as a separate REIT for federal and state income tax purposes. In connection with this and related elections, the Company incurred a one-time cash tax charge of $93.0 million and a one-time deferred income tax benefit of $5.8 million in the year ended December 31, 2015. The increase in the income tax provision during the year ended December 31, 2015 was primarily attributable to the MIPT tax election and charge of $13.1 million resulting from a change in income tax law in Ghana. During the years ended December 31, 2014 and 2013, the income tax provision included an expense of $2.6 million and $21.5 million , respectively, resulting from the restructuring of certain of the Company’s domestic TRSs. Reconciliation between the U.S. statutory rate and the effective rate from continuing operations is as follows for the years ended December 31: 2015 2014 2013 Statutory tax rate 35 % 35 % 35 % Tax adjustment related to REIT (1) (35 ) (35 ) (35 ) State taxes, net of federal benefit — 1 3 Foreign taxes 3 2 (5 ) Foreign withholding taxes 3 3 6 Domestic TRS restructuring — — 4 Change in tax law 2 — — MIPT tax election (2) 11 — — Other — 1 3 Effective tax rate 19 % 7 % 11 % _______________ (1) Includes 36% , 24% and 28% from dividend paid deductions in 2015, 2014 and 2013, respectively. (2) Includes federal and state taxes, net of federal benefit. The domestic and foreign components of income from continuing operations before income taxes are as follows for the years ended December 31, (in thousands): 2015 2014 2013 United States $ 785,201 $ 857,457 $ 766,772 Foreign 44,761 8,247 (225,023 ) Total $ 829,962 $ 865,704 $ 541,749 The components of the net deferred tax asset and related valuation allowance were as follows as of December 31, (in thousands): 2015 (1) 2014 (2) Current assets: Allowances, accruals and other items not currently deductible $ — $ 19,893 Current deferred liabilities — (2,799 ) Subtotal — 17,094 Valuation allowance — (3,094 ) Net current deferred tax assets $ — $ 14,000 Non-current items: Assets: Net operating loss carryforwards 277,977 242,788 Accrued asset retirement obligations 92,295 103,975 Stock-based compensation 3,889 693 Unearned revenue 25,654 18,947 Unrealized loss on foreign currency 37,440 15,952 Items not currently deductible and other 31,432 22,142 Liabilities: Depreciation and amortization (194,230 ) (131,678 ) Deferred rent (20,720 ) (18,355 ) Other (11,077 ) (1,791 ) Subtotal 242,660 252,673 Valuation allowance (136,952 ) (138,147 ) Net non-current deferred tax assets $ 105,708 $ 114,526 _______________ (1) Change in accounting pronouncement, as described below. (2) December 31, 2014 balances have been revised to reflect purchase accounting measurement period adjustments. In November 2015, the FASB issued new guidance on the balance sheet classification of all deferred income taxes. The guidance requires that deferred tax assets and liabilities, along with the related valuation allowance, be classified as noncurrent in a classified balance sheet. The Company has early adopted this guidance for the year ended December 31, 2015, and it did not have a material effect on the Company’s financial statements. Prior periods were not retrospectively adjusted. At December 31, 2015 and 2014, the Company has provided a valuation allowance of $137.0 million and $141.2 million , respectively, which primarily relates to foreign items. During 2015 , the Company increased the amounts recorded as valuation allowances due to the uncertainty as to the timing of, and the Company’s ability to recover, net deferred tax assets in certain foreign operations in the foreseeable future. The increase in the valuation allowance for the year ending December 31, 2015, was offset by fluctuations in foreign currency exchange rates and a reversal of previously reserved deferred tax assets resulting from a change in income tax law in Ghana. The amount of deferred tax assets considered realizable, however, could be adjusted if objective evidence in the form of cumulative losses is no longer present and additional weight may be given to subjective evidence such as the Company’s projections for growth. A summary of the activity in the valuation allowance is as follows (in thousands): 2015 2014 2013 Balance as of January 1, $ 141,241 $ 136,006 $ 95,558 Additions (1) 19,512 40,124 48,411 Reversals — (10,769 ) — Foreign currency translation (23,801 ) (24,120 ) (7,963 ) Balance as of December 31, $ 136,952 $ 141,241 $ 136,006 _______________ (1) Includes net charges to expense and allowances established through goodwill at acquisition. The recoverability of the Company’s net deferred tax asset has been assessed utilizing projections based on its current operations. Accordingly, the recoverability of the net deferred tax asset is not dependent on material asset sales or other non-routine transactions. Based on its current outlook of future taxable income during the carryforward period, the Company believes that the net deferred tax asset will be realized. The Company considers the earnings of certain non-U.S. subsidiaries to be indefinitely invested outside the United States on the basis of estimates that future domestic cash generation will be sufficient to meet future domestic cash needs. The Company has not recorded a deferred tax liability related to the U.S. federal and state income taxes and foreign withholding taxes on $490.6 million of undistributed earnings of foreign subsidiaries indefinitely invested outside of the United States. Should the Company decide to repatriate the foreign earnings, it may have to adjust the income tax provision in the period it determined that the earnings will no longer be indefinitely invested outside of the United States. At December 31, 2015 , the Company had net federal, state and foreign operating loss carryforwards available to reduce future taxable income, which includes losses of $51.6 million related to employee stock options. If not utilized, the Company’s net operating loss carryforwards expire as follows (in thousands): Years ended December 31, Federal State Foreign 2016 to 2020 $ — $ 79,928 $ 14,727 2021 to 2025 — 281,061 195,694 2026 to 2030 51,596 188,030 — 2031 to 2035 23,670 10,853 — Indefinite carryforward — — 695,052 Total $ 75,266 $ 559,872 $ 905,473 In addition, the Company has Mexican tax credits of $1.8 million , which if not utilized will expire in 2017. As of December 31, 2015 and 2014 , the total amount of unrecognized tax benefits that would impact the effective tax rate, if recognized, is $28.1 million and $31.9 million , respectively. The Company expects the unrecognized tax benefits to change over the next 12 months if certain tax matters ultimately settle with the applicable taxing jurisdiction during this timeframe, or if the applicable statute of limitations lapses. The impact of the amount of such changes to previously recorded uncertain tax positions could range from zero to $14.3 million . A reconciliation of the beginning and ending amount of unrecognized tax benefits are as follows for the years ended December 31, (in thousands): 2015 2014 2013 Balance at January 1 $ 31,947 $ 32,545 $ 34,337 Additions based on tax positions related to the current year 5,042 4,187 1,427 Additions for tax positions of prior years — 3,780 — Reductions for tax positions of prior years — — (320 ) Foreign currency (5,371 ) (3,216 ) (1,681 ) Reduction as a result of the lapse of statute of limitations and effective settlements (3,504 ) (5,349 ) (1,218 ) Balance at December 31 $ 28,114 $ 31,947 $ 32,545 During the years ended December 31, 2015 , 2014 and 2013 , the statute of limitations on certain unrecognized tax benefits lapsed and certain positions were effectively settled, which resulted in a decrease of $3.5 million , $5.3 million and $1.2 million , respectively, in the liability for uncertain tax benefits, all of which reduced the income tax provision. The Company recorded penalties and tax-related interest expense (benefit) to the tax provision of $0.1 million , ( $3.4 million ) and $3.4 million for the years ended December 31, 2015 , 2014 and 2013 , respectively. As of December 31, 2015 and 2014 , the total amount of accrued income tax-related interest and penalties included the consolidated balance sheets were $20.2 million and $24.9 million , respectively. The Company has filed for prior taxable years, and for its taxable year ended December 31, 2015 will file, numerous consolidated and separate income tax returns, including U.S. federal and state tax returns and foreign tax returns. The Company is subject to examination in the U.S. and various state and foreign jurisdictions for certain tax years. As a result of the Company’s ability to carryforward federal, state and foreign NOLs, the applicable tax years generally remain open to examination several years after the applicable loss carryforwards have been used or expired. The Company regularly assesses the likelihood of additional assessments in each of the tax jurisdictions resulting from these examinations. The Company believes that adequate provisions have been made for income taxes for all periods through December 31, 2015 .

Stock-Based Compensation

Stock-Based Compensation	12 Months Ended
	Dec. 31, 2015
Share-based Compensation, Allocation and Classification in Financial Statements [Abstract]
Stock-Based Compensation	STOCK-BASED COMPENSATION Summary of Stock-Based Compensation Plans —The Company maintains equity incentive plans that provide for the grant of stock-based awards to its directors, officers and employees. The 2007 Equity Incentive Plan (the “2007 Plan”) provides for the grant of non-qualified and incentive stock options, as well as restricted stock units, restricted stock and other stock-based awards. Exercise prices in the case of non-qualified and incentive stock options are not less than the fair value of the underlying common stock on the date of grant. Equity awards typically vest ratably, generally over four years for RSUs and stock options and three years for PSUs. Stock options generally expire ten years from the date of grant. As of December 31, 2015 , the Company had the ability to grant stock-based awards with respect to an aggregate of 11.6 million shares of common stock under the 2007 Plan. In addition, the Company maintains an employee stock purchase plan (“ESPP”) pursuant to which eligible employees may purchase shares of the Company’s common stock on the last day of each bi-annual offering period at a 15% discount of the lower of the closing market value on the first or last day of such offering period. The offering periods run from June 1 through November 30 and from December 1 through May 31 of each year. The Company recognized stock-based compensation expense of $90.5 million , $80.2 million and $68.1 million for the years ended December 31, 2015 , 2014 and 2013 , respectively. The Company capitalized stock-based compensation expense of $2.1 million and $1.6 million during the years ended December 31, 2015 and 2014 , respectively, as property and equipment. Stock Options —The fair value of each option granted during the period was estimated on the date of grant using the Black-Scholes option pricing model based on the assumptions noted in the table below. The expected life of stock options (estimated period of time outstanding) was estimated using the vesting term and historical exercise behavior of the Company’s employees. The risk-free interest rate was based on the U.S. Treasury yield which term approximated the estimated life in effect at the accounting measurement date. The expected volatility of the underlying stock price was based on historical volatility for a period equal to the expected life of the stock options. The expected annual dividend yield was the Company’s best estimate of expected future dividend yield. Key assumptions used to apply this pricing model were as follows: 2015 2014 2013 Range of risk-free interest rate 1.32% - 1.62% 1.46% - 1.74% 0.75% - 1.42% Weighted average risk-free interest rate 1.61% 1.64% 0.91% Expected life of stock options 4.5 years 4.5 years 4.4 years Range of expected volatility of the underlying stock price 21.09% - 21.24% 21.94% - 23.35% 24.43% - 36.09% Weighted average expected volatility of underlying stock price 21.09% 23.08% 33.37% Range of expected annual dividend yield 1.50% - 1.85% 1.50% 1.50% The weighted average grant date fair value per share during the years ended December 31, 2015 , 2014 and 2013 was $15.06 , $14.86 and $19.05 , respectively. The intrinsic value of stock options exercised during the years ended December 31, 2015 , 2014 and 2013 was $32.1 million , $58.0 million and $42.1 million , respectively. As of December 31, 2015 , total unrecognized compensation expense related to unvested stock options was $29.2 million and is expected to be recognized over a weighted average period of approximately two years . The amount of cash received from the exercise of stock options was $44.1 million during the year ended December 31, 2015 . The Company’s option activity for the year ended December 31, 2015 was as follows: Options Weighted Average Exercise Price Weighted Average Remaining Life (Years) Aggregate Intrinsic Value (in millions) Outstanding as of January 1, 2015 6,508,435 $62.14 Granted 2,059,600 94.43 Exercised (779,615 ) 56.56 Forfeited (105,226 ) 82.47 Expired (2,375 ) 23.74 Outstanding as of December 31, 2015 7,680,819 $71.10 6.72 $198.6 Exercisable as of December 31, 2015 3,549,709 $54.13 4.76 $152.0 Vested or expected to vest as of December 31, 2015 7,674,324 $71.08 6.72 $198.6 The following table sets forth information regarding options outstanding at December 31, 2015 : Options Outstanding Options Exercisable Outstanding Number of Options Range of Exercise Price Per Share Weighted Average Exercise Price Per Share Weighted Average Remaining Life (Years) Options Exercisable Weighted Average Exercise Price Per Share 2,064,426 $25.43 - $50.78 $40.73 3.21 2,064,426 $40.73 852,265 51.03 - 74.06 61.88 6.16 578,340 61.43 1,091,181 76.90 - 79.45 76.94 7.17 467,735 76.92 1,707,519 81.18 - 94.23 81.63 8.21 376,025 81.35 1,965,428 94.57 - 99.67 94.60 9.12 63,183 94.57 7,680,819 $25.43 - $99.67 $71.10 6.72 3,549,709 $54.13 Restricted Stock Units and Performance-Based Restricted Stock Units —The Company’s RSU and PSU activity for the year ended December 31, 2015 was as follows: RSUs Weighted Average Grant Date Fair Value PSUs (1) Weighted Average Grant Date Fair Value Outstanding as of January 1, 2015 1,758,817 $73.80 — $— Granted 715,379 94.55 33,377 94.57 Vested (703,955 ) 69.24 — — Forfeited (113,248 ) 82.20 — — Outstanding as of December 31, 2015 1,656,993 $84.12 33,377 $94.57 Expected to vest, net of estimated forfeitures, as of December 31, 2015 1,578,040 $83.87 33,377 $94.57 _______________ (1) Represents the target number of shares issuable at the end of the three-year performance cycle attributable to the first year’s performance period and incremental shares issuable based on exceeding the performance metric for the first year’s performance period. Restricted Stock Units— The total fair value of RSUs that vested during the year ended December 31, 2015 was $67.0 million . As of December 31, 2015 , total unrecognized compensation expense related to unvested RSUs granted under the 2007 Plan was $77.0 million and is expected to be recognized over a weighted average period of approximately two years . Performance-Based Restricted Stock Units— During the year ended December 31, 2015 , the Compensation Committee granted an aggregate of 70,135 PSUs to its executive officers and established the performance metric for this award. Threshold, target and maximum parameters were established for the metric for each year in the three -year performance period, and will be used to calculate the number of shares that will be issuable when the award vests, which may range from zero to 200% of the target amount. At the end of the three -year performance period, the number of shares that are earned and vest will depend on the degree of achievement against the pre-established performance goal. PSUs that have been earned over the performance period will be paid out in common stock at the end of the performance period, subject generally to the executive’s continued employment and will accrue dividend equivalents prior to vesting, which will be paid out only in respect of shares actually earned and vested. As the performance metric is tied to year-over-year growth and actual results for the metric will not be determined until the end of each respective fiscal year, as of December 31, 2015, the Company was unable to determine the annual target for the second and third years of the performance period for this award. Accordingly, an aggregate of 46,756 PSUs granted on March 10, 2015 were not included in the table above. During the year ended December 31, 2015 , the Company recorded $2.5 million in stock-based compensation expense for equity awards in which the performance goals have been established and were probable of being achieved. The remaining unrecognized compensation expense related to these awards at December 31, 2015 was $0.7 million based on the Company’s current assessment of the probability of achieving the performance goals. The weighted-average period over which the cost will be recognized is approximately one year .

Equity

Equity	12 Months Ended
	Dec. 31, 2015
Stockholders' Equity Attributable to Parent [Abstract]
Equity	EQUITY Common Stock Offering —On March 3, 2015, the Company completed a registered public offering of 23,500,000 shares of its common stock, par value $0.01 per share, at $97.00 per share. On March 5, 2015, the Company issued an additional 2,350,000 shares of its common stock in connection with the underwriters’ exercise in full of their over-allotment option. Aggregate net proceeds were approximately $2.44 billion after deducting commissions and estimated expenses. The Company used the net proceeds from this offering to fund a portion of the Verizon Transaction. Series B Preferred Stock Offering —On March 3, 2015, the Company completed a registered public offering of 12,500,000 depositary shares, each representing a 1/10th interest in a share of its Series B Preferred Stock, at $100.00 per depositary share. On March 5, 2015, the Company issued an additional 1,250,000 depositary shares in connection with the underwriters’ exercise in full of their over-allotment option. Aggregate net proceeds were approximately $1.34 billion after deducting commissions and estimated expenses. The Company used the net proceeds from this offering to fund a portion of the Verizon Transaction. On March 3, 2015, upon receipt of the proceeds of this offering and the common stock offering described above, the Company terminated the commitment letter dated February 5, 2015 with Goldman Sachs Bank USA and Goldman Sachs Lending Partners LLC entered into in connection with the Verizon Transaction. Unless converted or redeemed earlier, each share of the Series B Preferred Stock will convert automatically on February 15, 2018, into between 8.5911 and 10.3093 shares of common stock, depending on the applicable market value of the Company’s common stock and subject to anti-dilution adjustments. Subject to certain restrictions, at any time prior to February 15, 2018, holders of the Series B Preferred Stock may elect to convert all or a portion of their shares into common stock at the minimum conversion rate then in effect. Dividends on shares of the Series B Preferred Stock are payable on a cumulative basis when, as and if declared by the Company’s Board of Directors at an annual rate of 5.50% on the liquidation preference of $1,000.00 per share (and, correspondingly, $100.00 per share with respect to the depositary shares) on February 15, May 15, August 15 and November 15 of each year, commencing on May 15, 2015 to, and including, February 15, 2018. Series A Preferred Stock —The Company has 6,000,000 shares outstanding of its 5.25% Mandatory Convertible Preferred Stock, Series A, par value $0.01 per share (the “Series A Preferred Stock” and, together with the Series B Preferred Stock, the “Mandatory Convertible Preferred Stock”), which was originally issued on May 12, 2014. Unless converted earlier, each share of the Series A Preferred Stock will automatically convert on May 15, 2017, into between 0.9174 and 1.1468 shares of the Company’s common stock, depending on the applicable market value of the Company’s common stock and subject to anti-dilution adjustments. Subject to certain restrictions, at any time prior to May 15, 2017, holders of the Series A Preferred Stock may elect to convert all or a portion of their shares into common stock at the minimum conversion rate then in effect. Dividends on shares of the Series A Preferred Stock are payable on a cumulative basis when, as and if declared by the Company’s Board of Directors at an annual rate of 5.25% on the liquidation preference of $100.00 per share, on February 15, May 15, August 15 and November 15 of each year, commencing on August 15, 2014 to, and including, May 15, 2017. The Company may pay dividends in cash or, subject to certain limitations, in shares of common stock or any combination of cash and shares of common stock. The terms of the Mandatory Convertible Preferred Stock provide that, unless full cumulative dividends have been paid or set aside for payment on all outstanding Mandatory Convertible Preferred Stock for all prior dividend periods, no dividends may be declared or paid on common stock. Stock Repurchase Program —In March 2011, the Board of Directors approved a $1.5 billion stock repurchase program, pursuant to which the Company is authorized to purchase up to an additional $1.1 billion of the Company’s common stock. Since September 2013, the Company has temporarily suspended repurchases under the program. Sales of Equity Securities —The Company receives proceeds from sales of its equity securities pursuant to the ESPP and upon exercise of stock options granted under its equity incentive plans. Distributions —During the years ended December 31, 2015 , 2014 and 2013, the Company declared regular cash distributions to its common stockholders of an aggregate of $766.4 million , or $1.81 per share, $554.6 million , or $ 1.40 per share, and $434.5 million , or $1.10 per share, respectively. During the years ended December 31, 2015 and 2014, the Company declared an aggregate of $23.7 million , or $3.94 per share, and $23.9 million , or $3.98 per share, respectively, in cash distributions to holders of the Series A Preferred Stock. During the year ended December 31, 2015, the Company declared an aggregate of $53.1 million , or $38.65 per share, in cash distributions to holders of the Series B Preferred Stock. The following table characterizes the tax treatment of distributions declared per share of common stock and Mandatory Convertible Preferred Stock. For the year ended December 31, 2015 2014 (1) 2013 (1) Per Share % Per Share % Per Share % Common Stock Ordinary dividend $ 1.2694 70.13 % $ 1.4000 100.00 % $ 1.1000 100.00 % Capital gains distribution 0.5406 29.87 — — — — Total $ 1.8100 100.00 % $ 1.4000 100.00 % $ 1.1000 100.00 % Series A Preferred Stock Ordinary dividend $ 3.6818 (2) 70.13 % $ 2.6688 100.00 % $ — — % Capital gains distribution 1.5682 29.87 — — — — Total $ 5.2500 100.00 % $ 2.6688 100.00 % $ — — % Series B Preferred Stock (3) Ordinary dividend $ 2.7107 70.13 % $ — — % $ — — % Capital gains distribution 1.1546 29.87 — — — — Total $ 3.8653 100.00 % $ — — % $ — — % _______________ (1) The Company had no Series A Preferred Stock outstanding during the year ended December 31, 2013 and no Series B Preferred Stock outstanding during the years ended December 31, 2014 and 2013. (2) Includes dividend declared on December 2, 2014 of $1.3125 per share, payable on February 16, 2015 to preferred stockholders of record at the close of business on February 1, 2015. (3) Represents the tax treatment on dividends per depositary share, each of which represents a 1/10th interest in a share of Series B Preferred Stock. The Company accrues distributions on unvested restricted stock units, which are payable upon vesting. As of December 31, 2015 , the amount accrued for distributions payable related to unvested restricted stock units was $5.1 million . During the year ended December 31, 2015 , the Company paid $1.3 million of distributions payable upon the vesting of restricted stock units. To maintain its qualification for taxation as a REIT, the Company expects to continue paying distributions, the amount, timing and frequency of which will be determined and subject to adjustment by the Company’s Board of Directors.

Impairments, Net Loss on Sale o

Impairments, Net Loss on Sale of Long-Lived Assets	12 Months Ended
	Dec. 31, 2015
Property, Plant and Equipment Impairment or Disposal [Abstract]
Impairments, Net Loss on Sale of Long-lived Assets	IMPAIRMENTS, NET LOSS ON SALES OF LONG-LIVED ASSETS During the years ended December 31, 2015 , 2014 and 2013 , the Company recorded impairment charges and net losses on sales or disposals of long-lived assets of $29.8 million , $28.5 million and $32.5 million , respectively. These charges were primarily related to assets included in the Company’s U.S. property segment and are included in Other operating expenses in the consolidated statements of operations. Included in these amounts were impairment charges of $15.1 million , $15.3 million and $15.9 million for the years ended December 31, 2015 , 2014 and 2013 , respectively, to write down certain assets to net realizable value after an indicator of impairment was identified. These assets consisted primarily of towers, which are assessed on an individual basis, and network location intangibles, which relate directly to towers. Also included in these amounts were net losses associated with the sale or disposal of certain non-core towers, other assets and other miscellaneous items of $14.7 million , $13.2 million and $16.6 million for the years ended December 31, 2015 , 2014 and 2013 , respectively.

Earnings Per Common Share

Earnings Per Common Share	12 Months Ended
	Dec. 31, 2015
Earnings Per Share [Abstract]
Earnings Per Common Share	EARNINGS PER COMMON SHARE The following table sets forth basic and diluted net income per common share computational data for the years ended December 31, (in thousands, except per share data): 2015 2014 2013 Net income attributable to American Tower Corporation stockholders $ 685,074 $ 824,910 $ 551,333 Dividends on preferred stock (90,163 ) (23,888 ) — Net income attributable to American Tower Corporation common stockholders 594,911 801,022 551,333 Basic weighted average common shares outstanding 418,907 395,958 395,040 Dilutive securities 4,108 4,128 4,106 Diluted weighted average common shares outstanding 423,015 400,086 399,146 Basic net income attributable to American Tower Corporation common stockholders per common share $ 1.42 $ 2.02 $ 1.40 Diluted net income attributable to American Tower Corporation common stockholders per common share $ 1.41 $ 2.00 $ 1.38 Shares Excluded From Dilutive Effect The following shares were not included in the computation of diluted earnings per share because the effect would be anti-dilutive for the years ended December 31, (in thousands, on a weighted average basis): 2015 2014 2013 Restricted stock awards — 5 — Stock options 1,606 1,290 1,161 Preferred stock 15,408 4,303 —

Commitments and Contingencies

Commitments and Contingencies	12 Months Ended
	Dec. 31, 2015
Commitments and Contingencies Disclosure [Abstract]
Commitments and Contingencies	COMMITMENTS AND CONTINGENCIES Litigation —The Company periodically becomes involved in various claims, lawsuits and proceedings that are incidental to its business. In the opinion of Company management, after consultation with counsel, there are no matters currently pending that would, in the event of an adverse outcome, materially impact the Company’s consolidated financial position, results of operations or liquidity. Lease Obligations —The Company leases certain land, office and tower space under operating leases that expire over various terms. Many of the leases contain renewal options with specified increases in lease payments upon exercise of the renewal option. Escalation clauses present in operating leases, excluding those tied to CPI or other inflation-based indices, are recognized on a straight-line basis over the non-cancellable term of the leases. Future minimum rental payments under non-cancellable operating leases include payments for certain renewal periods at the Company’s option because failure to renew could result in a loss of the applicable communications sites and related revenues from tenant leases, thereby making it reasonably assured that the Company will renew the leases. Such payments at December 31, 2015 are as follows (in millions): Year Ending December 31, 2016 $ 722 2017 709 2018 690 2019 670 2020 643 Thereafter 6,416 Total $ 9,850 Aggregate rent expense (including the effect of straight-line rent expense) under operating leases for the years ended December 31, 2015 , 2014 and 2013 approximated $804.8 million , $655.0 million and $495.2 million , respectively. Future minimum payments under capital leases in effect at December 31, 2015 were as follows (in millions): Year Ending December 31, 2016 $ 21 2017 18 2018 17 2019 15 2020 12 Thereafter 173 Total minimum lease payments 256 Less amounts representing interest (143 ) Present value of capital lease obligations $ 113 Tenant Leases —The Company’s lease agreements with its tenants vary depending upon the region and the industry of the tenant, and typically have initial terms of ten years with multiple renewal terms at the option of the tenant. Future minimum rental receipts expected from tenants under non-cancellable operating lease agreements in effect at December 31, 2015 were as follows (in millions): Year Ending December 31, 2016 $ 4,082 2017 4,004 2018 3,874 2019 3,654 2020 3,369 Thereafter 11,294 Total $ 30,277 Verizon Transaction —On March 27, 2015, the Company entered into an agreement with various operating entities of Verizon that provides for the lease, sublease or management of 11,286 wireless communications sites from Verizon commencing March 27, 2015. The average term of the lease or sublease for all sites at the inception of the agreement was approximately 28 years , assuming renewals or extensions of the underlying ground leases for the sites. The Company has the option to purchase the leased sites in tranches, subject to the applicable lease, sublease or management right upon its scheduled expiration. Each tower is assigned to an annual tranche, ranging from 2034 to 2047, which represents the outside expiration date for the sublease rights to the towers in each tranche. The purchase price for each tranche is a fixed amount stated in the lease for such tranche plus the fair market value of certain alterations made to the related towers. The aggregate purchase option price for the towers leased and subleased is approximately $5.0 billion . Verizon will occupy the sites as a tenant for an initial term of ten years with eight optional successive five -year terms; each such term shall be governed by standard master lease agreement terms established as a part of the transaction. AT&T Transaction —The Company has an agreement with SBC Communications Inc., a predecessor entity to AT&T Inc. (“AT&T”), that currently provides for the lease or sublease of approximately 2,370 towers from AT&T with the lease commencing between December 2000 and August 2004. Substantially all of the towers are part of the 2013 Securitization. The average term of the lease or sublease for all sites at the inception of the agreement was approximately 27 years , assuming renewals or extensions of the underlying ground leases for the sites. The Company has the option to purchase the sites subject to the applicable lease or sublease upon its expiration. Each tower is assigned to an annual tranche, ranging from 2013 to 2032, which represents the outside expiration date for the sublease rights to that tower. The purchase price for each site is a fixed amount stated in the lease for that site plus the fair market value of certain alterations made to the related tower by AT&T. As of December 31, 2015 , the Company has purchased an aggregate of 60 of the subleased towers upon expiration of the applicable agreement. The aggregate purchase option price for the remaining towers leased and subleased is $697.2 million and will accrete at a rate of 10% per annum through the applicable expiration of the lease or sublease of a site. For all such sites purchased by the Company prior to June 30, 2020, AT&T will continue to lease the reserved space at the then-current monthly fee which shall escalate in accordance with the standard master lease agreement for the remainder of AT&T’s tenancy. Thereafter, AT&T shall have the right to renew such lease for up to four successive five -year terms. For all such sites purchased by the Company subsequent to June 30, 2020, AT&T has the right to continue to lease the reserved space for successive one -year terms at a rent equal to the lesser of the agreed upon market rate and the then-current monthly fee, which is subject to an annual increase based on changes in the U.S. Consumer Price Index. ALLTEL Transaction —In December 2000, the Company entered into an agreement with ALLTEL, a predecessor entity to Verizon Wireless, to acquire towers through a 15 -year sublease agreement. Pursuant to the agreement, as amended, with Verizon Wireless, the Company acquired rights to approximately 1,800 towers in tranches between April 2001 and March 2002. The Company has the option to purchase each tower at the expiration of the applicable sublease, which will occur in tranches between April 2016 and March 2017 based on the original closing date for such tranche of towers. The purchase price per tower as of the original closing date was $27,500 and will accrete at a rate of 3% per annum through the expiration of the applicable sublease. The aggregate purchase option price for the subleased towers is $75.3 million as of December 31, 2015 . At the expiration of the sublease, the purchase price would be payable in cash or, at Verizon Wireless’s or its assignee’s option, as applicable, with 769 shares of the Company’s common stock per tower. Guaranties and Indemnifications —The Company enters into agreements from time to time in the ordinary course of business pursuant to which it agrees to guarantee or indemnify third parties for certain claims. The Company has also entered into purchase and sale agreements relating to the sale or acquisition of assets containing customary indemnification provisions. The Company’s indemnification obligations under these agreements generally are limited solely to damages resulting from breaches of representations and warranties or covenants under the applicable agreements, but do not guaranty future performance. In addition, payments under such indemnification clauses are generally conditioned on the other party making a claim that is subject to whatever defenses the Company may have and are governed by dispute resolution procedures specified in the particular agreement. Further, the Company’s obligations under these agreements may be limited in duration and/or amount, and in some instances, the Company may have recourse against third parties for payments made by the Company. The Company has not historically made any material payments under these agreements and, as of December 31, 2015 , is not aware of any agreements that could result in a material payment. Other Contingencies —The Company is subject to income tax and other taxes in the geographic areas where it operates, and periodically receives notifications of audits, assessments or other actions by taxing authorities. The Company evaluates the circumstances of each notification based on the information available and records a liability for any potential outcome that is probable or more likely than not unfavorable if the liability is also reasonably estimable.

Supplemental Cash Flow Informat

Supplemental Cash Flow Information	12 Months Ended
	Dec. 31, 2015
Supplemental Cash Flow Information [Abstract]
Supplemental Cash Flow Information	SUPPLEMENTAL CASH FLOW INFORMATION Supplemental cash flow information and non-cash investing and financing activities are as follows for the years ended December 31, (in thousands): 2015 2014 2013 Supplemental cash flow information: Cash paid for interest $ 577,952 $ 548,089 $ 397,366 Cash paid for income taxes (net of refunds of $7,053, $8,476 and $19,701, respectively) 157,058 69,212 51,676 Non-cash investing and financing activities: Increase in accounts payable and accrued expenses for purchases of property and equipment and construction activities 2,780 1,121 9,147 Purchases of property and equipment under capital leases 36,851 36,486 27,416 Fair value of debt assumed through acquisitions — 463,135 1,576,186 Settlement of accounts receivable related to acquisitions 899 31,849 — Conversion of third-party debt to equity — 111,181 —

Business Segments

Business Segments	12 Months Ended
	Dec. 31, 2015
Segment Reporting, Measurement Disclosures [Abstract]
Business Segments	BUSINESS SEGMENTS During the fourth quarter of 2015, as a result of recent investment activity, including signed acquisitions, the Company reviewed and changed its reportable segments to divide its international segment into three regional segments: Asia property, EMEA property and Latin America property. Prior to this revision, the Company operated in three business segments: (i) domestic rental and management, (ii) international rental and management and (iii) network development services. In addition, the Company changed the title of its domestic segment from domestic rental and management to U.S. property and changed the title of its network development services segment to services. There were no other changes to the U.S. property or the services segments. The change is consistent with how the chief operating decision maker reviews financial performance and operating and business management strategies for each of the five segments. The change in reportable segments had no impact on the Company’s consolidated financial statements for any periods. However, certain expenses previously reflected in segment selling, general, administrative and development expense have been reclassified and are now reflected as Other selling, general, administrative and development expense. Historical financial information included in this Annual Report on Form 10-K has been adjusted to reflect the change in reportable segments. The Company’s primary business is leasing space on multitenant communications sites to wireless service providers, radio and television broadcast companies, wireless data providers, government agencies and municipalities and tenants in a number of other industries. This business is referred to as the Company’s property operations, which as of December 31, 2015 , consisted of the following: • U.S.: property operations in the United States; • Asia: property operations in India; • EMEA: property operations in Germany, Ghana, Nigeria, South Africa and Uganda; and • Latin America: property operations in Brazil, Chile, Colombia, Costa Rica, Mexico and Peru. The Company has applied the aggregation criteria to operations within the EMEA and Latin America property operating segments on a basis consistent with management’s review of information and performance evaluations of these regions. The Company’s services segment offers tower-related services in the United States, including site acquisition, zoning and permitting services and structural analysis services, which primarily support its site leasing business and the addition of new tenants and equipment on its sites. The services segment is a strategic business unit that offers different services from the property operating segments and requires different resources, skill sets and marketing strategies. The accounting policies applied in compiling segment information below are similar to those described in note 1. Among other factors, in evaluating financial performance in each business segment, management uses segment gross margin and segment operating profit. The Company defines segment gross margin as segment revenue less segment operating expenses excluding stock-based compensation expense recorded in costs of operations; Depreciation, amortization and accretion; Selling, general, administrative and development expense; and Other operating expenses. The Company defines segment operating profit as segment gross margin less Selling, general, administrative and development expense attributable to the segment, excluding stock-based compensation expense and corporate expenses. For reporting purposes, the Latin America property segment gross margin and segment operating profit also include Interest income, TV Azteca, net. These measures of segment gross margin and segment operating profit are also before Interest income, Interest expense, Gain (loss) on retirement of long-term obligations, Other income (expense), Net income (loss) attributable to noncontrolling interest, Income (loss) on equity method investments, and Income tax benefit (provision). The categories of expenses indicated above, such as depreciation, have been excluded from segment operating performance as they are not considered in the review of information or the evaluation of results by management. There are no significant revenues resulting from transactions between the Company’s operating segments. All intercompany transactions are eliminated to reconcile segment results and assets to the consolidated statements of operations and consolidated balance sheets. Summarized financial information concerning the Company’s reportable segments for the years ended December 31, 2015 , 2014 and 2013 is shown in the following tables. The “Other” column (i) represents amounts excluded from specific segments, such as business development operations, stock-based compensation expense and corporate expenses included in Selling, general, administrative and development expense; Other operating expenses; Interest income; Interest expense; Gain (loss) on retirement of long-term obligations; and Other income (expense), and (ii) reconciles segment operating profit to Income from continuing operations before income taxes, as the amounts are not utilized in assessing each segment’s performance. Property Total Property Services Other Total Year ended December 31, 2015 U.S. Asia EMEA Latin America (in thousands) Segment revenues $ 3,157,501 $ 242,223 $ 395,092 $ 885,572 $ 4,680,388 $ 91,128 $ 4,771,516 Segment operating expenses (1) 678,499 126,874 163,820 304,629 1,273,822 32,993 1,306,815 Interest income, TV Azteca, net — — — 11,209 11,209 — 11,209 Segment gross margin 2,479,002 115,349 231,272 592,152 3,417,775 58,135 3,475,910 Segment selling, general, administrative and development expense (1) 138,617 22,771 48,672 62,111 272,171 15,724 287,895 Segment operating profit $ 2,340,385 $ 92,578 $ 182,600 $ 530,041 $ 3,145,604 $ 42,411 $ 3,188,015 Stock-based compensation expense $ 90,537 90,537 Other selling, general, administrative and development expense 121,456 121,456 Depreciation, amortization and accretion 1,285,328 1,285,328 Other expense (2) 860,732 860,732 Income from continuing operations before income taxes $ 829,962 Capital expenditures $ 367,663 $ 75,407 $ 66,625 $ 201,806 $ 711,501 $ — $ 17,252 $ 728,753 _______________ (1) Segment operating expenses and segment selling, general, administrative and development expenses exclude stock-based compensation expense of $2.1 million and $88.5 million , respectively. (2) Primarily includes interest expense. Property Total Property Services Other Total Year ended December 31, 2014 U.S. Asia EMEA Latin America (in thousands) Segment revenues $ 2,639,790 $ 219,566 $ 315,053 $ 832,445 $ 4,006,854 $ 93,194 $ 4,100,048 Segment operating expenses (1) 515,742 121,797 126,714 290,527 1,054,780 37,648 1,092,428 Interest income, TV Azteca, net — — — 10,547 10,547 — 10,547 Segment gross margin 2,124,048 97,769 188,339 552,465 2,962,621 55,546 3,018,167 Segment selling, general, administrative and development expense (1) 124,944 19,632 39,553 66,890 251,019 12,469 263,488 Segment operating profit $ 1,999,104 $ 78,137 $ 148,786 $ 485,575 $ 2,711,602 $ 43,077 $ 2,754,679 Stock-based compensation expense $ 80,153 80,153 Other selling, general, administrative and development expense (2) 104,738 104,738 Depreciation, amortization and accretion 1,003,802 1,003,802 Other expense (3) 700,282 700,282 Income from continuing operations before income taxes $ 865,704 Capital expenditures $ 576,153 $ 74,334 $ 70,126 $ 229,645 $ 950,258 $ — $ 24,146 $ 974,404 _______________ (1) Segment operating expenses and segment selling, general, administrative and development expenses exclude stock-based compensation expense of $1.8 million and $78.3 million , respectively. (2) Includes $7.9 million of expense previously recorded as segment selling, general, administrative and development expense. (3) Primarily includes interest expense. Property Total Property Other Total Year ended December 31, 2013 U.S. Asia EMEA Latin America (in thousands) Segment revenues $ 2,189,365 $ 191,355 $ 295,681 $ 610,689 $ 3,287,090 $ 74,317 $ 3,361,407 Segment operating expenses (1) 405,419 109,645 121,122 191,579 827,765 30,564 858,329 Interest income, TV Azteca, net — — — 22,235 22,235 — 22,235 Segment gross margin 1,783,946 81,710 174,559 441,345 2,481,560 43,753 2,525,313 Segment selling, general, administrative and development expense (1) 103,989 15,630 39,076 62,756 221,451 9,257 230,708 Segment operating profit $ 1,679,957 $ 66,080 $ 135,483 $ 378,589 $ 2,260,109 $ 34,496 $ 2,294,605 Stock-based compensation expense $ 68,138 68,138 Other selling, general, administrative and development expense (2) 118,243 118,243 Depreciation, amortization and accretion 800,145 800,145 Other expense (3) 766,330 766,330 Income from continuing operations before income taxes $ 541,749 Capital expenditures $ 416,239 $ 55,914 $ 67,462 $ 154,534 $ 694,149 $ — $ 30,383 $ 724,532 _______________ (1) Segment operating expenses and segment selling, general, administrative and development expenses exclude stock-based compensation expense of $1.5 million and $66.6 million , respectively. (2) Includes $5.9 million of expense previously recorded as segment selling, general, administrative and development expense. (3) Primarily includes interest expense. Additional information relating to the total assets of the Company’s operating segments for the years ended December 31, is as follows (in thousands): 2015 2014 (1) (2) 2013 (2) U.S. property $ 19,286,465 $ 14,335,731 $ 13,608,818 Asia property (3) 736,149 738,290 743,671 EMEA property (3) 2,249,634 1,275,253 1,472,143 Latin America property (3) 4,401,258 4,700,357 4,184,135 Services 68,388 57,367 47,607 Other (4) 162,378 156,567 157,563 Total assets $ 26,904,272 $ 21,263,565 $ 20,213,937 _______________ (1) Balances have been revised to reflect purchase accounting measurement period adjustments. (2) Balances have been revised to reflect debt issuance cost adjustments. (3) Balances are translated at the applicable period end exchange rate and therefore may impact comparability between periods. (4) Balances include corporate assets such as cash and cash equivalents, certain tangible and intangible assets and income tax accounts which have not been allocated to specific segments. Summarized geographic information related to the Company’s operating revenues for the years ended December 31, 2015 , 2014 and 2013 and long-lived assets as of December 31, 2015 and 2014, is as follows (in thousands): 2015 2014 2013 Operating Revenues: United States $ 3,248,629 $ 2,732,984 $ 2,263,682 Asia (1): India 242,223 219,566 191,355 EMEA (1): Germany 55,965 64,946 62,756 Ghana 94,549 95,486 92,114 Nigeria 109,701 — — South Africa 80,510 98,334 91,906 Uganda 54,367 56,287 48,905 Latin America (1): Brazil 408,644 331,089 212,201 Chile 29,650 31,756 28,978 Colombia 78,351 89,421 70,901 Costa Rica 17,244 16,742 4,055 Mexico 340,461 354,116 288,306 Panama (2) — 1,243 424 Peru 11,222 8,078 5,824 Total operating revenues $ 4,771,516 $ 4,100,048 $ 3,361,407 _______________ (1) Balances are translated at the applicable exchange rate and therefore may impact comparability between periods. (2) In September 2014, the Company completed the sale of the operations in Panama. 2015 2014 (1) Long-Lived Assets (2): United States $ 17,516,535 $ 12,771,089 Asia (3): India 619,370 616,266 EMEA (3): Germany 388,727 456,698 Ghana 217,530 235,523 Nigeria 1,018,980 — South Africa 133,088 184,292 Uganda 162,346 185,956 Latin America (3): Brazil 2,204,494 2,152,953 Chile 121,938 147,413 Colombia 256,892 319,260 Costa Rica 120,292 127,436 Mexico 976,707 1,188,183 Peru 59,206 61,490 Total long-lived assets $ 23,796,105 $ 18,446,559 _______________ (1) Balances have been revised to reflect purchase accounting measurement period adjustments and debt issuance costs related to the Company’s credit facilities (see note 1). (2) Includes Property and equipment, net, Goodwill and Other intangible assets, net. (3) Balances are translated at the applicable period end exchange rate and therefore may impact comparability between periods. The following tenants within the property segments and services segment individually accounted for 10% or more of the Company’s consolidated operating revenues for the years ended December 31, is as follows: 2015 2014 2013 AT&T 24 % 20 % 18 % Verizon Wireless 16 % 11 % 11 % Sprint 13 % 15 % 16 % T-Mobile 10 % 10 % 11 %

Related Party Transactions

Related Party Transactions	12 Months Ended
	Dec. 31, 2015
Related Party Transaction, Due from (to) Related Party [Abstract]
Related Party Transactions	RELATED PARTY TRANSACTIONS During the years ended December 31, 2015 , 2014 , and 2013 , the Company had no significant related party transactions.

Selected Quarterly Financial Da

Selected Quarterly Financial Data	12 Months Ended
	Dec. 31, 2015
Selected Quarterly Financial Information [Abstract]
Selected Quarterly Financial Data (Unaudited)	SELECTED QUARTERLY FINANCIAL DATA (UNAUDITED) Selected quarterly financial data for the years ended December 31, 2015 and 2014 is as follows (in thousands, except per share data): Three Months Ended Year Ended December 31, March 31, June 30, September 30, December 31, 2015: Operating revenues $ 1,079,190 $ 1,174,375 $ 1,237,910 $ 1,280,041 $ 4,771,516 Costs of operations (1) 264,640 322,458 365,389 356,381 1,308,868 Operating income 419,966 389,774 400,925 402,124 1,612,789 Net income 195,492 157,180 97,740 221,595 672,007 Net income attributable to American Tower Corporation stockholders 193,317 156,056 102,999 232,702 685,074 Dividends on preferred stock (9,819 ) (26,782 ) (26,781 ) (26,781 ) (90,163 ) Net income attributable to American Tower Corporation common stockholders 183,498 129,274 76,218 205,921 594,911 Basic net income per share attributable to American Tower Corporation common stockholders 0.45 0.31 0.18 0.49 1.42 Diluted net income per share attributable to American Tower Corporation common stockholders 0.45 0.30 0.18 0.48 1.41 Three Months Ended Year Ended December 31, March 31, June 30, September 30, December 31, 2014: Operating revenues $ 984,089 $ 1,031,457 $ 1,038,188 $ 1,046,314 $ 4,100,048 Costs of operations (1) 260,769 272,275 284,202 277,019 1,094,265 Operating income 353,637 402,499 384,807 345,979 1,486,922 Net income 193,313 221,659 206,630 181,597 803,199 Net income attributable to American Tower Corporation stockholders 202,499 234,431 207,593 180,387 824,910 Dividends on preferred stock — (4,375 ) (7,700 ) (11,813 ) (23,888 ) Net income attributable to American Tower Corporation common stockholders 202,499 230,056 199,893 168,574 801,022 Basic net income per share attributable to American Tower Corporation common stockholders 0.51 0.58 0.50 0.43 2.02 Diluted net income per share attributable to American Tower Corporation common stockholders 0.51 0.58 0.50 0.42 2.00 _______________ (1) Represents Operating expenses, exclusive of Depreciation, amortization and accretion, Selling, general, administrative and development expense, and Other operating expenses.

Subsequent Events

Subsequent Events	12 Months Ended
	Dec. 31, 2015
Subsequent Events [Abstract]
Subsequent Events	SUBSEQUENT EVENTS 3.300% Senior Notes and 4.400% Senior Notes Offering— On January 12, 2016, the Company completed a registered public offering of $750.0 million aggregate principal amount of 3.300% senior unsecured notes due 2021 (the “ 3.300% Notes”) and $500.0 million aggregate principal amount of 4.400% senior unsecured notes due 2026 (the “ 4.400% Notes”). The net proceeds from this offering were approximately $1,237.2 million , after deducting commissions and estimated expenses. The Company used the proceeds to repay existing indebtedness under the 2013 Credit Facility and for general corporate purposes. The 3.300% Notes will mature on February 15, 2021 and bear interest at a rate of 3.300% per annum. The 4.400% Notes will mature on February 15, 2026 and bear interest at a rate of 4.400% per annum. Accrued and unpaid interest on the notes will be payable in U.S. Dollars semi-annually in arrears on February 15 and August 15 of each year, beginning on August 15, 2016. Interest on the notes is computed on the basis of a 360-day year comprised of twelve 30-day months and commenced accruing on January 12, 2016.

Schedule III - Real Estate and

Schedule III - Real Estate and Accumulated Depreciation	12 Months Ended
	Dec. 31, 2015
SEC Schedule III, Real Estate and Accumulated Depreciation Disclosure [Abstract]
Real Estate and Accumulated Depreciation Disclosure	SCHEDULE III—SCHEDULE OF REAL ESTATE AND ACCUMULATED DEPRECIATION (dollars in thousands) Description Encumbrances Initial cost to company Cost capitalized subsequent to acquisition Gross amount carried at close of current period Accumulated depreciation at close of current period Date of construction Date acquired Life on which depreciation in latest income statements is computed 100,131 sites (1) $3,364,202 (2) (3) (3) $ 13,046,291 (4) $ (3,994,874 ) Various Various Up to 20 years _______________ (1) No single site exceeds 5% of the total amounts indicated in the table above. (2) Certain assets secure debt of $3.4 billion . (3) The Company has omitted this information, as it would be impracticable to compile such information on a site-by-site basis. (4) Does not include those sites under construction. 2015 2014 2013 Gross amount at beginning (1) $ 10,434,326 $ 9,921,276 $ 8,290,313 Additions during period: Acquisitions 2,620,778 397,837 1,415,171 Discretionary capital projects (2) 210,421 437,720 314,126 Discretionary ground lease purchases (3) 144,695 159,637 102,991 Redevelopment capital expenditures (4) 114,089 96,782 89,960 Capital improvements (5) 42,417 41,967 58,960 Start-up capital expenditures (6) 35,561 21,173 15,757 Other (7) 201,118 22,069 8,764 Total additions 3,369,079 1,177,185 2,005,729 Deductions during period: Cost of real estate sold or disposed (60,975 ) (60,147 ) (48,467 ) Other (8) (696,139 ) (569,107 ) (243,958 ) Total deductions: (757,114 ) (629,254 ) (292,425 ) Balance at end $ 13,046,291 $ 10,469,207 $ 10,003,617 2015 2014 2013 Gross amount of accumulated depreciation at beginning $ (3,613,078 ) $ (3,297,033 ) $ (2,968,230 ) Additions during period: Depreciation (557,052 ) (457,135 ) (408,693 ) Other — (761 ) (264 ) Total additions (557,052 ) (457,896 ) (408,957 ) Deductions during period: Amount of accumulated depreciation for assets sold or disposed 30,083 20,953 17,462 Other (8) 145,173 120,898 62,692 Total deductions 175,256 141,851 80,154 Balance at end $ (3,994,874 ) $ (3,613,078 ) $ (3,297,033 ) _______________ (1) Balance has been revised to reflect purchase accounting measurement period adjustments. (2) Includes amounts incurred primarily for the construction of new sites. (3) Includes amounts incurred to purchase or otherwise secure the land under communications sites. (4) Includes amounts incurred to increase the capacity of existing sites, which results in new incremental tenant revenue. (5) Includes amounts incurred to maintain existing sites. (6) Includes amounts incurred in connection with acquisitions and new market launches and costs that are contemplated in the business cases for these investments. (7) Primarily includes regional improvements and other additions. (8) Primarily includes foreign currency exchange rate fluctuations.

Business and Summary of Signi33

Business and Summary of Significant Accounting Policies (Policies)	12 Months Ended
	Dec. 31, 2015
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Nature of Operations Policy [Policy Text Block]	American Tower Corporation (together with its subsidiaries, “ATC” or the “Company”) is one of the largest global real estate investment trusts and a leading independent owner, operator and developer of multitenant communications real estate. The Company’s primary business is the leasing of space on communications sites to wireless service providers, radio and television broadcast companies, wireless data providers, government agencies and municipalities and tenants in a number of other industries, which the Company refers to as its property operations. Additionally, the Company offers tower-related services in the United States, including site acquisition, zoning and permitting and structural analysis, which primarily support its site leasing business, including the addition of new tenants and equipment on its sites, which the Company refers to as its services operations. The Company’s portfolio primarily consists of towers it owns and towers it operates pursuant to long-term lease arrangements, as well as distributed antenna system (“DAS”) networks, which provide seamless coverage solutions in certain in-building and outdoor wireless environments. In addition to the communications sites in its portfolio, the Company manages rooftop and tower sites for property owners under various contractual arrangements. The Company also holds property interests that it leases to communications service providers and third-party tower operators. ATC is a holding company that conducts its operations through its directly and indirectly owned subsidiaries and its joint ventures. ATC’s principal domestic operating subsidiaries are American Towers LLC and SpectraSite Communications, LLC. ATC conducts its international operations primarily through its subsidiary, American Tower International, Inc., which in turn conducts operations through its various international holding and operating subsidiaries and joint ventures. The Company operates as a real estate investment trust for U.S. federal income tax purposes (“REIT”). Accordingly, the Company generally is not subject to U.S. federal income taxes on income generated by its U.S. REIT operations, including the income derived from leasing space on its towers, as the Company receives a dividends paid deduction for distributions to stockholders that generally offsets its income and gains. However, the Company remains obligated to pay U.S. federal income taxes on earnings from its domestic taxable REIT subsidiaries (“TRSs”). In addition, the Company’s international assets and operations, regardless of their designation for U.S. tax purposes, continue to be subject to taxation in the foreign jurisdictions where those assets are held or those operations are conducted. The use of TRSs enables the Company to continue to engage in certain businesses while complying with REIT qualification requirements. The Company may, from time to time, change the election of previously designated TRSs to be included as part of the REIT. As of December 31, 2015 , the Company’s U.S. REIT qualified business included its U.S. tower leasing business, most of its operations in Costa Rica, Germany and Mexico and a majority of its services segment and indoor DAS networks business.
Principles of Consolidation and Basis of Presentation	The accompanying consolidated financial statements include the accounts of the Company and those entities in which it has a controlling interest. Investments in entities that the Company does not control are accounted for using the equity or cost method, depending upon the Company’s ability to exercise significant influence over operating and financial policies. All intercompany accounts and transactions have been eliminated. As of December 31, 2015, the Company has a controlling interest in two joint ventures. The Company established joint ventures in Ghana and Uganda with MTN Group Limited (“MTN Group”). The joint ventures are controlled by a holding company of which a wholly owned subsidiary of the Company holds a 51% interest and a wholly owned subsidiary of MTN Group holds a 49% interest. In addition, the Company holds an approximate 75% controlling interest in a subsidiary of the Company in South Africa and the South African investors hold an approximate 25% noncontrolling interest.
Significant Accounting Policies and Use of Estimates	The preparation of financial statements in conformity with accounting principles generally accepted in the United States (“GAAP”) requires management to make estimates and assumptions that affect the amounts reported in the consolidated financial statements and accompanying notes. Actual results may differ from those estimates, and such differences could be material to the accompanying consolidated financial statements. The significant estimates in the accompanying consolidated financial statements include impairment of long-lived assets (including goodwill), asset retirement obligations, revenue recognition, rent expense, stock-based compensation, income taxes and accounting for business combinations and acquisitions of assets. The Company considers events or transactions that occur after the balance sheet date but before the financial statements are issued as additional evidence for certain estimates or to identify matters that require additional disclosure.
Accounts Receivable and Deferred Rent Asset	The Company derives the largest portion of its revenues, corresponding accounts receivable and the related deferred rent asset from a relatively small number of tenants in the telecommunications industry, and 63% of its current year revenues are derived from four tenants. The Company’s deferred rent asset is associated with non-cancellable tenant leases that contain fixed escalation clauses over the terms of the applicable lease in which revenue is recognized on a straight-line basis over the lease term. The Company mitigates its concentrations of credit risk with respect to notes and trade receivables and the related deferred rent assets by actively monitoring the creditworthiness of its borrowers and tenants. In recognizing customer revenue, the Company assesses the collectibility of both the amounts billed and the portion recognized in advance of billing on a straight-line basis. This assessment takes tenant credit risk and business and industry conditions into consideration to ultimately determine the collectibility of the amounts billed. To the extent the amounts, based on management’s estimates, may not be collectible, recognition is deferred until such point as collectibility is determined to be reasonably assured. Any amounts that were previously recognized as revenue and subsequently determined to be uncollectible are charged to bad debt expense included in Selling, general, administrative and development expense in the accompanying consolidated statements of operations. Accounts receivable is reported net of allowances for doubtful accounts related to estimated losses resulting from a tenant’s inability to make required payments and allowances for amounts invoiced whose collectibility is not reasonably assured. These allowances are generally estimated based on payment patterns, days past due and collection history, and incorporate changes in economic conditions that may not be reflected in historical trends, such as tenants in bankruptcy, liquidation or reorganization. Receivables are written-off against the allowances when they are determined to be uncollectible. Such determination includes analysis and consideration of the particular conditions of the account.
Functional Currency	The functional currency of each of the Company’s foreign operating subsidiaries is the respective local currency, except for Costa Rica, where the functional currency is the U.S. Dollar. All foreign currency assets and liabilities held by the subsidiaries are translated into U.S. Dollars at the exchange rate in effect at the end of the applicable fiscal reporting period and all foreign currency revenues and expenses are translated at the average monthly exchange rates. Translation adjustments are reflected in equity as a component of Accumulated other comprehensive (loss) income (“AOCI”) in the consolidated balance sheets and included as a component of comprehensive loss (income) in the consolidated statements of comprehensive (loss) income. Transactional gains and losses on foreign currency transactions are reflected in Other expense in the consolidated statements of operations. However, the effect from fluctuations in foreign currency exchange rates on intercompany debt that is considered to be permanently reinvested is reflected in AOCI in the consolidated balance sheets and included as a component of comprehensive income.
Cash and Cash Equivalents	Cash and cash equivalents include cash on hand, demand deposits and short-term investments with original maturities of three months or less. The Company maintains its deposits at high quality financial institutions and monitors the credit ratings of those institutions.
Restricted Cash	Restricted cash includes cash pledged as collateral to secure obligations and all cash whose use is otherwise limited by contractual provisions
Property and Equipment	Property and equipment is recorded at cost or, in the case of acquired properties at estimated fair value on the date acquired. Cost for self-constructed towers includes direct materials and labor, capitalized interest and certain indirect costs associated with construction of the tower, such as transportation costs, employee benefits and payroll taxes. The Company begins the capitalization of costs during the pre-construction period, which is the period during which costs are incurred to evaluate the site, and continues to capitalize costs until the tower is substantially completed and ready for occupancy by a tenant. Labor costs capitalized for the years ended December 31, 2015 , 2014 and 2013 were $44.7 million , $48.5 million and $44.1 million , respectively. Interest costs capitalized for the years ended December 31, 2015 , 2014 and 2013 were $1.8 million , $2.8 million and $1.8 million , respectively. Expenditures for repairs and maintenance are expensed as incurred. Augmentation and improvements that extend an asset’s useful life or enhance capacity are capitalized. Depreciation expense is recorded using the straight-line method over the assets’ estimated useful lives. Towers and related assets on leased land are depreciated over the shorter of the estimated useful life of the asset or the term of the corresponding ground lease, taking into consideration lease renewal options and residual value. Towers or assets acquired through capital leases are recorded net at the present value of future minimum lease payments or the fair value of the leased asset at the inception of the lease. Property and equipment and assets held under capital leases are amortized over the shorter of the applicable lease term or the estimated useful life of the respective assets for periods generally not exceeding twenty years. The Company reviews its tower portfolio for indicators of impairment on an individual tower basis. Impairments primarily result from a tower not having current tenant leases or from having expenses in excess of revenues. The Company reviews other long-lived assets for impairment whenever events, changes in circumstances or other evidence indicate that the carrying amount of the Company’s assets may not be recoverable. The Company records impairment charges in Other operating expenses in the consolidated statement of operations in the period in which the Company identifies such impairment.
Goodwill and Other Intangible Assets	The Company reviews goodwill for impairment at least annually (as of December 31) or whenever events or circumstances indicate the carrying value of an asset may not be recoverable. Goodwill is recorded in the applicable segment and assessed for impairment at the reporting unit level. The Company utilizes the two-step impairment test when testing goodwill for impairment and employs a discounted cash flow analysis. The key assumptions utilized in the discounted cash flow analysis include current operating performance, terminal sales growth rate, management’s expectations of future operating results and cash requirements, the current weighted average cost of capital and an expected tax rate. Under the first step of this test, the Company compares the fair value of the reporting unit, as calculated under an income approach using future discounted cash flows, to the carrying amount of the applicable reporting unit. If the carrying amount exceeds the fair value, the Company conducts the second step of this test, in which the implied fair value of the applicable reporting unit’s goodwill is compared to the carrying amount of that goodwill. If the carrying amount of goodwill exceeds its implied fair value, an impairment loss would be recognized for the amount of the excess. During the years ended December 31, 2015 , 2014 and 2013 , no potential impairment was identified under the first step of the test, as the fair value of each of the reporting units was in excess of its carrying amount. Intangible assets that are separable from goodwill and are deemed to have a definite life are amortized over their useful lives, generally ranging from three to twenty years and are evaluated separately for impairment at least annually or whenever events or circumstances indicate that the carrying amount of an asset may not be recoverable. The Company reviews its network location intangible assets for indicators of impairment on an individual tower basis. Impairments primarily result from a tower not having current tenant leases or from having expenses in excess of revenues. The Company monitors its customer-related intangible assets on a customer by customer basis for indicators of impairment, such as high levels of turnover or attrition, non-renewal of a significant number of contracts, or the cancellation or termination of a relationship. The Company assesses recoverability by determining whether the carrying amount of the related assets will be recovered, either through projected undiscounted future cash flows or anticipated proceeds from sales of the assets. If the Company determines that the carrying amount of an asset may not be recoverable, the Company measures any impairment loss based on the projected future discounted cash flows to be provided from the asset or available market information relative to the asset’s fair value, as compared to the asset’s carrying amount. The Company records impairment charges in Other operating expenses in the consolidated statement of operations in the period in which the Company identifies such impairment.
Derivatives Financial Instruments	Derivatives are recorded on the consolidated balance sheet at fair value. If a derivative is designated as a cash flow hedge, the effective portions of changes in the fair value of the derivative are recorded in AOCI, as well as a component of comprehensive income, and are recognized in the results of operations when the hedged item affects earnings. Changes in fair value of the ineffective portions of cash flow hedges are recognized in the results of operations. For derivative instruments not designated as hedging instruments, changes in fair value are recognized in the results of operations in the period that the change occurs. The primary risk managed through the use of derivative instruments is interest rate risk. From time to time, the Company enters into interest rate protection agreements to manage exposure to variability in cash flows relating to forecasted interest payments. Under these agreements, the Company is exposed to credit risk to the extent that a counterparty fails to meet the terms of a contract. The Company’s credit risk exposure is limited to the current value of the contract at the time the counterparty fails to perform. The Company assesses, both at the inception of the hedge and on an ongoing basis, whether the derivatives that are used in hedging transactions are highly effective in offsetting changes in cash flows of hedged items. The Company does not hold derivatives for trading purposes.
Fair Value Measurements	The Company determines the fair value of its financial instruments based on the fair value hierarchy, which requires an entity to maximize the use of observable inputs and minimize the use of unobservable inputs when measuring fair value.
Asset Retirement Obligations	When required, the Company recognizes the fair value of obligations to remove its tower assets and remediate the leased land upon which certain of its tower assets are located. Generally, the associated retirement costs are capitalized as part of the carrying amount of the related tower assets and depreciated over their estimated useful lives and the liability is accreted through the obligation’s estimated settlement date. Fair value estimates of asset retirement obligations generally involve discounting of estimated future cash flows. Periodic accretion of such liabilities due to the passage of time is included in Depreciation, amortization and accretion expense in the consolidated statements of operations. Adjustments are also made to the asset retirement obligation liability to reflect changes in the estimates of timing and amount of expected cash flows, with an offsetting adjustment made to the related tangible long-lived asset. The significant assumptions used in estimating the Company’s aggregate asset retirement obligation are: timing of tower removals; cost of tower removals; timing and number of land lease renewals; expected inflation rates; and credit-adjusted, risk-free interest rates that approximate the Company’s incremental borrowing rate.
Income Taxes	As a REIT, the Company generally is not subject to U.S. federal income taxes on income generated by its U.S. REIT operations. However, the Company remains obligated to pay U.S. federal income taxes on certain earnings and continues to be subject to taxation in its foreign jurisdictions. Accordingly, the consolidated financial statements reflect provisions for federal, state, local and foreign income taxes. The Company recognizes deferred tax assets and liabilities for the future tax consequences attributable to differences between the financial statement carrying amounts of existing assets and liabilities and their respective tax basis, as well as operating loss and tax credit carryforwards. The Company measures deferred tax assets and liabilities using enacted tax rates expected to apply to taxable income in the years in which those temporary differences and carryforwards are expected to be recovered or settled. The effect on deferred tax assets and liabilities as a result of a change in tax rates is recognized in income in the period that includes the enactment date. The Company periodically reviews its deferred tax assets, and provides valuation allowances if, based on the available evidence, it is more likely than not that some or all of the deferred tax assets will not be realized. Management assesses the available positive and negative evidence to estimate if sufficient future taxable income will be generated to use the existing deferred tax assets. Valuation allowances would be reversed as a reduction to the provision for income taxes if related deferred tax assets are deemed realizable based on changes in facts and circumstances relevant to the assets’ recoverability. The Company classifies uncertain tax positions as non-current income tax liabilities unless expected to be paid within one year. The Company reports penalties and tax-related interest expense as a component of the income tax provision and interest income from tax refunds as a component of Other income (expense) in the consolidated statements of operations.
Other Comprehensive Income (Loss)	Other comprehensive income (loss) refers to items excluded from net income that are recorded as an adjustment to equity, net of tax. The Company’s other comprehensive income (loss) is primarily comprised of changes in fair value of effective derivative cash flow hedges, foreign currency translation adjustments and reclassification of unrealized losses on effective derivative cash flow hedges.
Distributions	As a REIT, the Company must annually distribute to its stockholders an amount equal to at least 90% of its REIT taxable income (determined before the deduction for distributed earnings and excluding any net capital gain). Generally, the Company has distributed, and expects to continue to distribute all or substantially all of its REIT taxable income after taking into consideration its utilization of net operating losses (“NOLs”). The amount, timing and frequency of future distributions will be at the sole discretion of the Board of Directors and will be dependent upon various factors, a number of which may be beyond the Company’s control, including the Company’s financial condition and operating cash flows, the amount required to maintain its qualification for taxation as a REIT and reduce any income and excise taxes that the Company otherwise would be required to pay, limitations on distributions in the Company’s existing and future debt and preferred equity instruments, the Company’s ability to utilize NOLs to offset the Company’s distribution requirements, limitations on its ability to fund distributions using cash generated through its TRSs and other factors that the Board of Directors may deem relevant.
Acquisitions	For acquisitions that meet the definition of a business combination, the Company applies the acquisition method of accounting where assets acquired and liabilities assumed are recorded at fair value at the date of each acquisition, and the results of operations are included with those of the Company from the dates of the respective acquisitions. Any excess of the purchase price paid by the Company over the amounts recognized for assets acquired and liabilities assumed is recorded as goodwill. The Company continues to evaluate acquisitions for a period not to exceed one year after the applicable acquisition date of each transaction to determine whether any additional adjustments are needed to the allocation of the purchase price paid for the assets acquired and liabilities assumed. The fair value of the assets acquired and liabilities assumed is typically determined by using either estimates of replacement costs or discounted cash flow valuation methods. When determining the fair value of tangible assets acquired, the Company must estimate the cost to replace the asset with a new asset taking into consideration such factors as age, condition and the economic useful life of the asset. When determining the fair value of intangible assets acquired, the Company must estimate the applicable discount rate and the timing and amount of future customer cash flows, including rate and terms of renewal and attrition.
Revenue Recognition	The Company’s revenue from leasing arrangements, including fixed escalation clauses present in non-cancellable lease agreements, is reported on a straight-line basis over the term of the respective leases when collectibility is reasonably assured. Escalation clauses tied to the Consumer Price Index (“CPI”) or other inflation-based indices, and other incentives present in lease agreements with the Company’s tenants are excluded from the straight-line calculation. Total property straight-line revenues for the years ended December 31, 2015 , 2014 and 2013 was $155.0 million , $123.7 million and $147.7 million , respectively. Amounts billed upfront in connection with the execution of lease agreements are initially deferred and reflected in Unearned revenue in the accompanying consolidated balance sheets and recognized as revenue over the terms of the applicable leases. Amounts billed or received for services prior to being earned are deferred and reflected in Unearned revenue in the accompanying consolidated balance sheets until the criteria for recognition have been met. Services revenues are derived under contracts or arrangements with customers that provide for billings either on a fixed price basis or a variable price basis, which includes factors such as time and expenses. Revenues are recognized as services are performed, and include estimates for percentage completed. Amounts billed or received for services prior to being earned are deferred and reflected in Unearned revenue in the accompanying consolidated balance sheets until the criteria for recognition have been met.
Rent Expense	Many of the leases underlying the Company’s tower sites have fixed rent escalations, which provide for periodic increases in the amount of ground rent payable by the Company over time. In addition, certain of the Company’s tenant leases require the Company to exercise available renewal options pursuant to the underlying ground lease if the tenant exercises its renewal option. The Company calculates straight-line ground rent expense for these leases based on the fixed non-cancellable term of the underlying ground lease plus all periods, if any, for which failure to renew the lease imposes an economic penalty to the Company such that renewal appears to be reasonably assured. Total property straight-line ground rent expense for the years ended December 31, 2015 , 2014 and 2013 was $56.1 million , $38.4 million and $29.7 million , respectively. The Company records a liability for straight-line ground rent expense in Other non-current liabilities. The Company records prepaid ground rent in Prepaid and other current assets and Notes receivable and other non-current assets in the accompanying consolidated balance sheets according to the anticipated period of benefit.
Selling, General, Administrative and Development Expense	Selling, general and administrative expense consists of overhead expenses related to the Company’s property and services operations and corporate overhead costs not specifically allocable to any of the Company’s individual business operations. Development expense consists of costs related to the Company’s acquisition efforts, costs associated with new business initiatives and project cancellation costs.
Stock-based Compensation	Stock-based compensation expense is measured at the accounting measurement date based on the fair value of the award and is generally recognized as an expense over the service period, which generally represents the vesting period. The Company’s Compensation Committee adopted a death, disability and retirement benefits program in connection with equity awards granted on or after January 1, 2013, which provides for accelerated vesting and extended exercise periods of stock options and restricted stock units upon an employee’s death or permanent disability, or upon an employee’s qualified retirement, provided certain eligibility criteria are met. Accordingly, for grants made on or after January 1, 2013, the Company recognizes compensation expense for stock options and time-based restricted stock units (“RSUs”) over the shorter of (i) the four -year vesting period or (ii) the period from the date of grant to the date the employee becomes eligible for such retirement benefits, which may occur upon grant. The expense recognized includes an estimate of awards that will not fully vest and be forfeited. In March 2015, the Company granted performance-based restricted stock units (“PSUs”) to its executive officers. Threshold, target and maximum parameters were established for the metric for each year in the three -year performance period, and will be used to calculate the number of shares that will be issuable when the award vests, which may range from zero to 200% of the target amount. The Company recognizes compensation expense for PSUs over the three -year vesting period, subject to adjustment based on the date the employee becomes eligible for such retirement benefits. The fair value of stock options is determined using the Black-Scholes option-pricing model and the fair value of restricted stock units is based on the fair value of the Company’s common stock on the date of grant. The Company recognizes all stock-based compensation expense in either Selling, general, administrative and development expense, costs of operations or as part of the costs associated with the construction of the tower assets. Compensation expense for PSUs may be adjusted based on the Compensation Committee’s assessment of performance relative to grant parameters.
Litigation Costs	The Company periodically becomes involved in various claims and lawsuits that are incidental to its business. The Company regularly monitors the status of pending legal actions to evaluate both the magnitude and likelihood of any potential loss. The Company accrues for these potential losses when it is probable that a liability has been incurred and the amount of loss, or possible range of loss, can be reasonably estimated. Should the ultimate losses on contingencies or litigation vary from estimates, adjustments to those liabilities may be required. The Company also incurs legal costs in connection with these matters and records estimates of these expenses, which are reflected in Selling, general, administrative and development expense in the accompanying consolidated statements of operations.
Earnings Per Common Share-Basic and Diluted	Basic net income per common share represents net income attributable to American Tower Corporation common stockholders divided by the weighted average number of common shares outstanding during the period. Diluted net income per common share represents net income attributable to American Tower Corporation common stockholders divided by the weighted average number of common shares outstanding during the period and any dilutive common share equivalents, including (A) shares issuable upon (i) the vesting of RSUs, (ii) exercise of stock options, and (iii) conversion of the Company’s mandatory convertible preferred stock and (B) shares earned upon the achievement of the parameters established for the PSUs, each to the extent not anti-dilutive. Dilutive common share equivalents also include the dilutive impact of the shares issuable in the ALLTEL transaction, which is described in note 17. The Company uses the treasury stock method to calculate the effect of its outstanding RSUs, PSUs and stock options and uses the if-converted method to calculate the effect of its outstanding mandatory convertible preferred stock.
Retirement Plan	The Company has a 401(k) plan covering substantially all employees who meet certain age and employment requirements. For the years ended December 31, 2015, 2014 and 2013, the Company matched 75% of the first 6% of a participant’s contributions. For the years ended December 31, 2015 , 2014 and 2013 , the Company contributed $7.4 million , $6.5 million and $6.0 million to the plan, respectively.
Accounting Standards Updates	In May 2014, the Financial Accounting Standards Board (the “FASB”) issued new revenue recognition guidance, which requires an entity to recognize revenue in an amount that reflects the consideration to which the entity expects to be entitled in exchange for the transfer of promised goods or services to customers. The standard will replace most existing revenue recognition guidance in GAAP and will become effective for the Company on January 1, 2018. Early adoption is permitted for fiscal years, and interim periods within those years, beginning after December 15, 2016. The standard permits the use of either the retrospective or cumulative effect transition method and leases are not included in the scope of this standard. The Company is evaluating the impact this standard will have on its financial statements. In June 2014, the FASB issued stock-based compensation guidance, which requires a performance target that could be achieved after the requisite service period be treated as a performance condition that affects vesting, rather than a condition that affects the grant-date fair value. The Company early adopted this guidance on a prospective basis during the year ended December 31, 2015, and it did not have a material effect on the Company’s financial statements. In February 2015, the FASB issued consolidation guidance, which changes the guidance with respect to the analysis that a reporting entity must perform to determine whether it should consolidate certain types of legal entities. All legal entities are subject to reevaluation under the revised consolidation model. This guidance is effective for fiscal years, and for interim periods within those fiscal years, beginning after December 15, 2015. The Company is evaluating the impact this standard will have on its financial statements. In April 2015, the FASB issued new guidance on the presentation of debt issuance costs. The guidance requires debt issuance costs be presented in the balance sheet as a direct deduction from the carrying amount of the related debt liability, consistent with debt discounts and premiums. In August 2015, the FASB clarified that debt issuance costs associated with line of credit arrangements may continue to be presented as an asset, regardless of whether there are any outstanding borrowings on the line of credit arrangement. The Company early adopted this guidance during the year ended December 31, 2015 and applied the guidance retrospectively. As a result, the Company reclassified $75.9 million of deferred financing costs at December 31, 2014 from Other intangible assets, net. The Company recorded $68.2 million and $0.2 million as a direct reduction to Long-term obligations and Current portion of long-term obligations, respectively. Debt issuance costs of $7.5 million related to the Company’s credit facilities have been reclassified from Other intangible assets, net and are recorded in Notes receivable and other non-current assets in the consolidated balance sheet for the year ended December 31, 2014. In September 2015, the FASB issued new guidance on the accounting for measurement-period adjustments related to business combinations. The guidance requires that an acquirer recognize adjustments to provisional amounts that are identified during the measurement period in the reporting period in which the adjustment amounts are determined rather than retrospectively. The effect on earnings as a result of the change to the provisional amounts is calculated as if the accounting had been completed as of the acquisition date. The update requires prospective application and the update is effective for fiscal years, and interim periods within those years, beginning after December 15, 2015, with early adoption permitted. The Company does not expect the adoption of this guidance to have a material effect on the Company’s financial statements. In November 2015, the FASB issued new guidance on the balance sheet classification of all deferred income taxes. The guidance requires that deferred tax assets and liabilities, along with the related valuation allowance, be classified as noncurrent in a classified balance sheet. The Company has early adopted this guidance for the year ended December 31, 2015, and it did not have a material effect on the Company’s financial statements. Prior periods were not retrospectively adjusted. In January 2016, the FASB issued new guidance on the recognition and measurement of financial assets and financial liabilities. The guidance amends certain aspects of recognition, measurement, presentation and disclosure of financial instruments. This standard is effective for fiscal years, and for interim periods within those fiscal years, beginning after December 15, 2017. The Company does not expect the adoption of this guidance to have a material effect on the Company’s financial statements. In February 2016, the FASB issued new guidance on the accounting for leases. The guidance amends the existing accounting standards for lease accounting, including the requirement that lessees recognize assets and liabilities for lease terms greater than twelve months in the statement of financial position. This guidance is effective for fiscal years, including interim periods within those fiscal years, beginning after December 15, 2018. The Company is evaluating the impact this standard will have on its financial statements.

Business and Summary of Signi34

Business and Summary of Significant Accounting Policies (Tables)	12 Months Ended
	Dec. 31, 2015
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Changes in allowances	Changes in the allowances were as follows for the years ended December 31, (in thousands): 2015 2014 2013 Balance as of January 1 $ 17,306 $ 19,895 $ 20,406 Current year increases 19,878 8,243 7,025 Write-offs, net of recoveries and other (14,088 ) (10,832 ) (7,536 ) Balance as of December 31 $ 23,096 $ 17,306 $ 19,895

Prepaid And Other Current Ass35

Prepaid And Other Current Assets (Tables)	12 Months Ended
	Dec. 31, 2015
Prepaid Expense and Other Assets, Current [Abstract]
Prepaid and other current assets	Prepaid and other current assets consisted of the following as of December 31, (in thousands): 2015 2014 (1) Prepaid operating ground leases $ 128,542 $ 88,053 Prepaid income tax 45,056 34,512 Unbilled receivables 34,173 25,352 Prepaid assets 32,892 23,848 Value added tax and other consumption tax receivables 30,239 23,228 Other miscellaneous current assets 35,333 69,800 Balance $ 306,235 $ 264,793 _______________ (1) December 31, 2014 balances have been revised to reflect purchase accounting measurement period adjustments.

Property and Equipment (Tables)

Property and Equipment (Tables)	12 Months Ended
	Dec. 31, 2015
Property, Plant and Equipment [Abstract]
Property and equipment	Property and equipment (including assets held under capital leases) consisted of the following as of December 31, (in thousands): Estimated Useful Lives (years) (1) 2015 2014 (2) Towers Up to 20 $ 10,726,656 $ 8,265,732 Equipment 2 - 15 1,095,906 995,667 Buildings and improvements 3 - 32 607,661 617,064 Land and improvements (3) Up to 20 1,728,115 1,565,871 Construction-in-progress 238,960 214,760 Total 14,397,298 11,659,094 Less accumulated depreciation (4,530,874 ) (4,068,982 ) Property and equipment, net $ 9,866,424 $ 7,590,112 _______________ (1) Assets on leased land are depreciated over the shorter of the estimated useful life of the asset or the term of the corresponding ground lease taking into consideration lease renewal options and residual value. (2) December 31, 2014 balances have been revised to reflect purchase accounting measurement period adjustments. (3) Estimated useful lives apply to land improvements only.

Goodwill and Other Intangible37

Goodwill and Other Intangible Assets (Tables)	12 Months Ended
	Dec. 31, 2015
Goodwill and Intangible Assets Disclosure [Abstract]
Changes in the carrying value of goodwill	The changes in the carrying value of goodwill for the Company’s business segments were as follows (in thousands): Property Services Total U.S. Asia EMEA Latin America Balance as of January 1, 2014 $ 3,293,899 $ 182,114 $ 90,035 $ 286,754 $ 2,000 $ 3,854,802 Additions (1) 62,197 — 40 170,068 — 232,305 Effect of foreign currency translation — (3,593 ) (11,428 ) (36,259 ) — (51,280 ) Other (2) — — — (3,641 ) (12 ) (3,653 ) Balance as of December 31, 2014 (1) $ 3,356,096 $ 178,521 $ 78,647 $ 416,922 $ 1,988 $ 4,032,174 Additions 23,067 610 68,663 122,345 — 214,685 Effect of foreign currency translation — (8,412 ) (14,740 ) (131,902 ) — (155,054 ) Balance as of December 31, 2015 $ 3,379,163 $ 170,719 $ 132,570 $ 407,365 $ 1,988 $ 4,091,805 _______________ (1) Balances have been revised to reflect purchase accounting measurement period adjustments. (2) Other represents the goodwill associated with the Company’s operations in Panama and the Company’s third-party structural analysis business. Both businesses were sold during the year ended December 31, 2014 (see note 11).
Finite Intangible Assets	The Company’s other intangible assets subject to amortization consisted of the following (in thousands): As of December 31, 2015 As of December 31, 2014 (1) Estimated Useful Lives Gross Carrying Value Accumulated Amortization Net Book Value Gross Carrying Value Accumulated Amortization Net Book Value (years) (in thousands) Acquired network location intangibles (2) Up to 20 $ 3,980,281 $ (1,052,393 ) $ 2,927,888 $ 2,513,788 $ (901,903 ) $ 1,611,885 Acquired customer-related intangibles 15-20 8,640,554 (1,763,853 ) 6,876,701 6,594,469 (1,429,572 ) 5,164,897 Acquired licenses and other intangibles 3-20 28,293 (5,486 ) 22,807 38,443 (3,514 ) 34,929 Economic Rights, TV Azteca 70 21,688 (11,208 ) 10,480 25,522 (12,960 ) 12,562 Total other intangible assets $ 12,670,816 $ (2,832,940 ) $ 9,837,876 $ 9,172,222 $ (2,347,949 ) $ 6,824,273 _______________ (1) December 31, 2014 balances have been revised to reflect purchase accounting measurement period adjustments. (2) Acquired network location intangibles are amortized over the shorter of the term of the corresponding ground lease taking into consideration lease renewal options and residual value or up to 20 years, as the Company considers these intangibles to be directly related to the tower assets.
Expected future amortization expenses	Based on current exchange rates, the Company expects to record amortization expense as follows over the next five subsequent years (in millions): Year Ending December 31, 2016 $ 598.8 2017 597.1 2018 596.0 2019 593.7 2020 576.0

Notes Receivable and Other No38

Notes Receivable and Other Non-current Assets (Tables)	12 Months Ended
	Dec. 31, 2015
Notes Receivable And Other Long Term Assets [Abstract]
Notes receivable and other non-current assets	Notes receivable and other non-current assets consisted of the following as of December 31, (in thousands): 2015 2014 (1) Long-term prepaid ground rent $ 388,790 $ 311,502 Notes receivable 83,658 87,515 Other miscellaneous assets 260,455 176,229 Balance $ 732,903 $ 575,246 _______________ (1) December 31, 2014 balances have been revised to reflect purchase accounting measurement period adjustments and debt issuance costs.

Acquisitions (Tables)

Acquisitions (Tables)	12 Months Ended
	Dec. 31, 2015
Business Combination, Description [Abstract]
Schedule of merger and acquisition related costs	During the years ended December 31, 2015 , 2014 and 2013 the Company recorded the following acquisition and merger related expenses and integration costs (in thousands): Year Ended December 31, 2015 2014 2013 Acquisition and merger related expenses (1) $ 18,799 $ 26,969 $ 36,172 Integration costs $ 18,097 $ 13,057 $ 1,424 _______________ (1) Acquisition and merger related expenses for the year ended December 31, 2015 does not reflect transaction costs related to the Verizon Transaction, as these costs have been capitalized as part of the assets’ fair value.
Schedule of recognized identified assets acquired and liabilities assumed	The following table summarizes the final allocation of consideration transferred for the 11,286 communications sites under the Master Prepaid Lease (in thousands). Balances are reflected in the accompanying consolidated balance sheets as of December 31, 2015 and represent the asset balances of the capital lease. Current assets $ 14,132 Non-current assets 53,339 Property and equipment 2,094,678 Intangible assets (1): Customer-related intangible assets 1,886,443 Network location intangible assets 1,186,428 Current liabilities (31,012 ) Other non-current liabilities (2) (236,965 ) Fair value of consideration transferred $ 4,967,043 _______________ (1) Customer-related intangible assets and network location intangible assets are amortized on a straight-line basis over periods of up to 20 years . (2) Primarily represents liabilities recorded for asset retirement obligations. The following table summarizes the preliminary and final allocations of the purchase prices paid and the amounts of assets acquired and liabilities assumed for the fiscal year 2014 acquisitions based upon their estimated fair value at the date of acquisition (in thousands). Preliminary balances are reflected in the consolidated balance sheets in the Company’s Annual Report on Form 10-K for the year ended December 31, 2014 . Final balances are reflected in the accompanying consolidated balance sheets herein. Preliminary Allocation Final Allocation (1) U.S. Latin America Other U.S. Latin America Other Richland BR Towers Richland BR Towers Current assets $ 8,583 $ 31,832 $ 7,869 $ 8,583 $ 31,568 $ 7,404 Non-current assets — 9,135 1,521 — 9,365 2,562 Property and equipment 185,777 141,422 70,638 154,899 135,916 70,317 Intangible assets (2): Customer-related intangible assets 169,452 495,279 110,207 186,455 495,151 108,707 Network location intangible assets 1,700 136,233 50,199 3,409 135,549 49,199 Other intangible assets — 37,664 — — 33,095 — Current liabilities (3,635 ) (23,930 ) (2,860 ) (3,635 ) (24,012 ) (2,860 ) Other non-current liabilities (2,922 ) (101,508 ) (7,938 ) (2,922 ) (101,814 ) (7,938 ) Net assets acquired 358,955 726,127 229,636 346,789 714,818 227,391 Goodwill (3) 32,423 164,955 19,835 44,128 166,097 22,080 Fair value of net assets acquired 391,378 891,082 249,471 390,917 880,915 249,471 Debt assumed (4) (201,999 ) (261,136 ) — (201,999 ) (261,136 ) — Preferred stock outstanding — (61,056 ) — — (61,056 ) — Purchase Price $ 189,379 $ 568,890 $ 249,471 $ 188,918 $ 558,723 $ 249,471 _______________ (1) The allocation of the purchase price was finalized during the year ended December 31, 2015 . (2) Customer-related intangible assets and network location intangible assets are amortized on a straight-line basis over periods of up to 20 years . Other intangible assets are amortized on a straight-line basis over the life of the lease, which is a period of 11 years . (3) Goodwill was allocated to the Company’s property operating segments, as applicable, and the Company expects goodwill recorded will be deductible for local tax purposes except for goodwill associated with BR Towers, where goodwill is expected to be partially deductible. (4) Assumed BR Towers debt approximated fair value at the date of acquisition and included $11.5 million of current indebtedness. Assumed Richland debt included $196.5 million of Richland’s indebtedness and a fair value adjustment of $5.5 million . The fair value adjustments were based primarily on reported market values using Level 2 inputs. The following table summarizes the preliminary allocation of the purchase price for the fiscal year 2015 acquisitions based upon their estimated fair value at the date of acquisition (in thousands). Balances are reflected in the accompanying consolidated balance sheet as of December 31, 2015 . EMEA Latin America Other Airtel TIM Current assets $ 15,828 $ — $ 1,113 Non-current assets 69,277 — 995 Property and equipment 415,246 275,630 42,716 Intangible assets (1): Customer-related intangible assets 231,788 361,822 63,001 Network location intangible assets 328,334 115,562 37,691 Current liabilities (4,246 ) (3,192 ) (624 ) Other non-current liabilities (12,534 ) (74,966 ) (4,028 ) Net assets acquired 1,043,693 674,856 140,864 Goodwill (2) 68,663 122,011 24,011 Fair value of net assets acquired 1,112,356 796,867 164,875 Debt assumed — — — Purchase Price $ 1,112,356 $ 796,867 $ 164,875 _______________ (1) Customer-related intangible assets and network location intangible assets are amortized on a straight-line basis over periods of up to 20 years . (2) Goodwill was allocated to the Company’s property segments. The Company expects goodwill recorded in its U.S. and Asia property segments will be deductible for local tax purposes. The Company expects goodwill recorded in its Europe, Middle East and Africa (“EMEA”) property segment will not be deductible for local tax purposes and goodwill recorded in its Latin America property segment will be deductible in certain jurisdictions for local tax purposes. The consideration for the Verizon Transaction consisted of the following (in thousands): Cash consideration for sites under the Master Prepaid Lease $ 4,959,006 Capitalized transaction costs 8,037 Total consideration for sites under the Master Prepaid Lease 4,967,043 Cash consideration for acquired sites 99,000 Total consideration for the Verizon Transaction (1) $ 5,066,043 _______________ (1) Includes $6.6 million of accrued costs that have not been paid as of December 31, 2015.
Schedule of pro forma information	The following table presents the unaudited pro forma financial results as if the 2015 acquisitions, as well as the Verizon Transaction described above, had occurred on January 1, 2014 and the 2014 acquisitions had occurred on January 1, 2013 (in thousands, except per share data). Management relied on various estimates and assumptions due to the fact that some of the transactions never operated as a business and were utilized solely by the seller as a component of their network infrastructure. As a result, historical operating results may not be available. The pro forma results do not include any anticipated cost synergies, costs or other integration impacts. Accordingly, such pro forma amounts are not necessarily indicative of the results that actually would have occurred had the transactions been completed on the dates indicated, nor are they indicative of the future operating results of the Company. Year Ended December 31, 2015 2014 Pro forma revenues $ 5,034,746 $ 5,000,208 Pro forma net income attributable to American Tower Corporation common stockholders $ 564,579 $ 587,999 Pro forma net income per common share amounts: Basic net income attributable to American Tower Corporation common stockholders $ 1.33 $ 1.39 Diluted net income attributable to American Tower Corporation common stockholders $ 1.32 $ 1.38
Schedule of contingent consideration changes	A summary of the value of the Company’s contingent consideration is as follows (in thousands): Year Ended December 31, 2015 Maximum potential value (1) Estimated value at December 31, 2015 (2) Additions (3) Settlements Change in Fair Value Colombia $ 22,444 $ 9,829 $ — $ — $ (5,011 ) Costa Rica — — — (1,898 ) — Ghana 569 569 — — 99 India 1,164 163 315 (139 ) — United States 1,875 1,875 1,311 (5,906 ) 131 Total $ 26,052 $ 12,436 $ 1,626 $ (7,943 ) $ (4,781 ) _______________ (1) The maximum potential value is based on exchange rates at December 31, 2015 . The minimum value could be zero. (2) Estimate is determined using a probability weighted average of expected outcomes as of December 31, 2015 . (3) Based on preliminary acquisition accounting upon closing of certain acquisitions during the year ended December 31, 2015 . The changes in fair value of the contingent consideration were as follows during the years ended December 31, (in thousands): 2015 2014 Balance as of January 1 $ 28,524 $ 31,890 Additions 1,626 6,412 Settlements (7,943 ) (3,889 ) Change in fair value (4,781 ) (225 ) Foreign currency translation adjustment (4,990 ) (4,934 ) Other (1) — (730 ) Balance as of December 31 $ 12,436 $ 28,524 _______________ (1) In connection with the sale of operations in Panama in September 2014, the buyer assumed the Company’s potential obligations related to additional purchase price consideration.

Accrued Expenses (Tables)

Accrued Expenses (Tables)	12 Months Ended
	Dec. 31, 2015
Accrued Liabilities, Current [Abstract]
Schedule of accrued expenses	Accrued expenses consisted of the following as of December 31, (in thousands): 2015 2014 (1) Accrued property and real estate taxes $ 75,827 $ 61,206 Payroll and related withholdings 62,334 57,110 Accrued rent 54,732 34,074 Accrued construction costs 19,857 46,024 Other accrued expenses 303,663 219,422 Balance $ 516,413 $ 417,836 _______________ (1) December 31, 2014 balances have been revised to reflect purchase accounting measurement period adjustments.

Long-Term Obligations (Tables)

Long-Term Obligations (Tables)	12 Months Ended
	Dec. 31, 2015
Long-term Debt, Excluding Current Maturities [Abstract]
Long-term financing arrangements	Outstanding amounts under the Company’s long-term obligations, reflecting discounts, premiums and debt issuance costs, consisted of the following as of December 31, (in thousands): 2015 2014 (1) Contractual Interest Rate (2) Maturity Date (2) Series 2013-1A Securities (3) $ 497,478 $ 496,314 1.551 % March 15, 2018 Series 2013-2A Securities (4) 1,288,689 1,287,110 3.070 % March 15, 2023 Series 2015-1 Notes (5) 346,262 — 2.350 % June 15, 2020 Series 2015-2 Notes (6) 518,776 — 3.482 % June 16, 2025 GTP AP Notes (7) — 973,397 N/A N/A 2012 GTP Notes (7)(8) 281,902 290,586 3.721% - 7.358% Various Unison Notes (9) 201,930 203,683 5.349% - 9.522% Various BR Towers Debentures (10) 85,219 118,688 7.400 % October 15, 2023 Shareholder loans (11) 145,540 137,655 Various Various South African Facility (12) 53,175 73,156 8.575 % December 17, 2020 Colombian Credit Facility (13) 59,640 82,501 9.853 % April 24, 2021 Brazil Credit Facility (14) 21,868 — Various January 15, 2022 Indian Working Capital Facility (15) 8,752 — 9.700 % January 31, 2016 Mexican Loan — 263,426 N/A N/A BR Towers Credit Facility — 16,389 N/A N/A Total American Tower subsidiary debt 3,509,231 3,942,905 2013 Credit Facility (16) 1,225,000 — 1.652 % June 28, 2019 Term Loan (16) 1,993,601 1,495,284 1.680 % January 29, 2021 2014 Credit Facility (16) 1,980,000 1,100,000 1.680 % January 29, 2021 4.625% Notes — 599,720 N/A N/A 7.000% Notes — 497,750 N/A N/A 4.500% Notes 997,693 996,571 4.500 % January 15, 2018 3.40% Notes 999,769 999,607 3.400 % February 15, 2019 7.25% Notes 296,242 295,229 7.250 % May 15, 2019 2.800% Notes 743,557 — 2.800 % June 1, 2020 5.050% Notes 697,216 696,560 5.050 % September 1, 2020 3.450% Notes 642,786 641,579 3.450 % September 15, 2021 5.900% Notes 497,188 496,715 5.900 % November 1, 2021 4.70% Notes 695,374 694,694 4.700 % March 15, 2022 3.50% Notes 987,966 986,389 3.500 % January 31, 2023 5.00% Notes 1,003,453 1,003,628 5.000 % February 15, 2024 4.000% Notes 739,057 — 4.000 % June 1, 2025 Total American Tower Corporation debt 13,498,902 10,503,726 Other debt, including capital lease obligations 110,876 93,710 Total 17,119,009 14,540,341 Less current portion long-term obligations (50,202 ) (897,386 ) Long-term obligations $ 17,068,807 $ 13,642,955 _______________ (1) December 31, 2014 balances have been revised to reflect debt issuance costs as a direct deduction from the carrying amounts, with the exception of debt issuance costs associated with the 2013 Credit Facility and the 2014 Credit Facility (as defined below) which are reflected in Notes receivable and other non-current assets on the consolidated balance sheets. Amortization of deferred financing costs is included in interest expense on the consolidated statements of operations. (2) Represents the interest rate or maturity date as of December 31, 2015 and does not reflect the impact of interest rate swap agreements. (3) Maturity date reflects the anticipated repayment date; final legal maturity is March 15, 2043. (4) Maturity date reflects the anticipated repayment date; final legal maturity is March 15, 2048. (5) Maturity date reflects the anticipated repayment date; final legal maturity is June 15, 2045. (6) Maturity date reflects the anticipated repayment date; final legal maturity is June 15, 2050. (7) Secured debt assumed in connection with the acquisition of MIP Tower Holdings LLC (“MIPT”). (8) Anticipated repayment dates begin March 15, 2017. (9) Secured debt assumed in connection with the acquisition of certain legal entities holding a portfolio of property interests from Unison Holdings, LLC and Unison Site Management II, L.L.C. (together, “Unison”). Anticipated repayment dates begin April 15, 2017; final legal maturity date is April 15, 2040. (10) Publicly issued debentures assumed in connection with the acquisition of BR Towers and denominated in BRL. Debt accrues interest at a variable rate. (11) Reflects balances owed to the Company’s joint venture partners in Ghana and Uganda. The Ghana loan is denominated in Ghanaian Cedi (“GHS”) and the Uganda loan is denominated in U.S. Dollars (“USD”). The Uganda loan accrues interest at a variable rate. (12) Denominated in South African Rand (“ZAR”). Debt accrues interest at a variable rate. (13) Denominated in Colombian Pesos (“COP”). Debt accrues interest at a variable rate. (14) Denominated in BRL. Debt accrues interest at variable rate. (15) Denominated in INR. This agreement provides that the maturity date may be extended for additional 30-day periods. (16) Debt accrues interest at a variable rate.
Schedule of shareholder loans	Outstanding amounts under each of the Company’s shareholder loans consisted of the following as of December 31, (in thousands): 2015 2014 Contractual Interest Rate Maturity Date Ghana loan (1) $ 70,314 $ 68,651 21.87 % December 31, 2019 Uganda loan (2)(3) 75,226 69,004 6.066 % June 29, 2019 _______________ (1) Denominated in GHS. As of December 31, 2015, the aggregate principal amount outstanding under the Ghana loan was 267.5 million GHS, which included 46.7 million GHS ( $12.3 million ) of interest which was capitalized during the year ended December 31, 2015. (2) Interest rate as of December 31, 2015. Interest accrues at a variable rate. (3) Includes $6.3 million of interest which was capitalized during the year ended December 31, 2015.
Schedule of Brazil Credit Facility Sublimits	Outstanding amounts and key terms under the Brazil Credit Facility consisted of the following as of December 31, 2015 (in millions): Amounts Outstanding (BRL) Amounts Outstanding (USD at December 31, 2015) Maximum Borrowing Amount (BRL) Maximum Borrowing Amount (USD at December 31, 2015) Contractual Interest Rate Tranche A 23.4 $ 6.0 34.8 $ 8.9 TJLP + 4.25% Tranche B 24.5 $ 6.3 34.8 $ 8.9 SELIC + 4.25% Tranche C 37.5 $ 9.6 200.0 $ 51.2 6.00 % Tranche D — $ — 1.4 $ 0.4 TJLP
Schedule of debt discounts	The following table outlines key terms related to the Company ’ s outstanding senior notes as of December 31, 2015 : Adjustments to Principal Amount (1) Aggregate Principal Amount 2015 2014 (2) Semi-annual interest payments due Issue Date Maturity Date (in thousands) 4.500% Notes $ 1,000,000 $ (2,307 ) $ (3,429 ) January 15 and July 15 December 7, 2010 January 15, 2018 3.40 % Notes (3) 1,000,000 (231 ) (393 ) February 15 and August 15 August 19, 2013 February 15, 2019 7.25% Notes 300,000 (3,758 ) (4,771 ) May 15 and November 15 June 10, 2009 May 15, 2019 2.800% Notes 750,000 (6,443 ) — June 1 and December 1 May 7, 2015 June 1, 2020 5.050% Notes 700,000 (2,784 ) (3,440 ) March 1 and September 1 August 16, 2010 September 1, 2020 3.450% Notes 650,000 (7,214 ) (8,421 ) March 15 and September 15 August 7, 2014 September 15, 2021 5.900% Notes 500,000 (2,812 ) (3,285 ) May 1 and November 1 October 6, 2011 November 1, 2021 4.70% Notes 700,000 (4,626 ) (5,306 ) March 15 and September 15 March 12, 2012 March 15, 2022 3.50% Notes 1,000,000 (12,034 ) (13,611 ) January 31 and July 31 January 8, 2013 January 31, 2023 5.00% Notes (3) 1,000,000 3,453 3,628 February 15 and August 15 August 19, 2013 February 15, 2024 4.000% Notes 750,000 (10,943 ) — June 1 and December 1 May 7, 2015 June 1, 2025 _______________ (1) Includes unamortized discounts, premiums, and debt issuance costs. (2) December 31, 2014 balances have been revised to reflect debt issuance costs. (3) The original issue date for the 3.40% Notes and the 5.00% Notes was August 19, 2013. The issue date for the reopened 3.40% Notes and the reopened 5.00% Notes was January 10, 2014.
Aggregate carrying value of long-term debt, including capital leases	As of December 31, 2015 , aggregate principal maturities of long-term debt, including capital leases, for the next five years and thereafter are expected to be (in thousands): Year Ending December 31, 2016 $ 50,202 2017 195,536 2018 1,537,659 2019 2,883,615 2020 1,970,026 Thereafter 10,549,061 Total cash obligations 17,186,099 Unamortized discounts, premiums and debt issuance costs, net (67,090 ) Balance as of December 31, 2015 $ 17,119,009

Other Non-Current Liabilities (

Other Non-Current Liabilities (Tables)	12 Months Ended
	Dec. 31, 2015
Other Liabilities, Noncurrent [Abstract]
Other non-current liabilities	Other non-current liabilities consisted of the following as of December 31, (in thousands): 2015 2014 (1) Unearned revenue $ 451,844 $ 415,809 Deferred rent liability 348,532 303,442 Other miscellaneous liabilities 265,306 309,436 Balance $ 1,065,682 $ 1,028,687 _______________ (1) December 31, 2014 balances have been revised to reflect purchase accounting measurement period adjustments.

Asset Retirement Obligations (T

Asset Retirement Obligations (Tables)	12 Months Ended
	Dec. 31, 2015
Asset Retirement Obligation [Abstract]
Carrying value of asset retirement obligations	The changes in the carrying amount of the Company’s asset retirement obligations were as follows (in thousands): 2015 2014 Beginning balance as of January 1, $ 609,035 $ 549,548 Additions 277,982 52,623 Accretion expense 55,592 40,325 Revisions in estimates (1) (83,636 ) (32,311 ) Settlements (2,037 ) (1,150 ) Balance as of December 31, $ 856,936 $ 609,035 _______________ (1) Revisions in estimates include the negative impact of $81.7 million and $38.5 million of foreign currency translation for the years ended December 31, 2015 and 2014, respectively.

Fair Value Measurements (Tables

Fair Value Measurements (Tables)	12 Months Ended
	Dec. 31, 2015
Fair Value Disclosures [Abstract]
Schedule of fair value	The fair value of the Company’s financial assets and liabilities that are required to be measured on a recurring basis at fair value was as follows (in thousands): December 31, 2015 December 31, 2014 Fair Value Measurements Using Assets/Liabilities at Fair Value Fair Value Measurements Using Assets/Liabilities Level 1 Level 2 Level 3 Level 1 Level 2 Level 3 Assets: Short-term investments (1) — — — — — $ 6,302 — $ 6,302 Interest rate swap agreements — $ 692 — $ 692 — $ 88 — $ 88 Embedded derivative in lease agreement — — $ 14,176 $ 14,176 — — — — Liabilities: Acquisition-related contingent consideration — — $ 12,436 $ 12,436 — — $ 28,524 $ 28,524 Interest rate swap agreements — — — — — $ 647 — $ 647 _______________ (1) Consists of highly liquid investments with original maturities in excess of three months.
Schedule of derivative financial instruments	The notional amount and fair value of the interest rate swap agreements were as follows as of December 31, (in thousands): 2015 (1) 2014 (2) Local USD Local USD South Africa (ZAR) Notional — — 440,614 38,080 Fair Value — — 1,016 88 Colombia (COP) Notional 95,000,000 30,164 100,000,000 41,798 Fair Value 2,179,374 692 (1,548,688 ) (647 ) _______________ (1) As of December 31, 2015, the interest rate swap agreement in Colombia was included in Notes receivable and other non-current assets on the consolidated balance sheet. (2) As of December 31, 2014, the interest rate swap agreement in Colombia was included in Other non-current liabilities on the consolidated balance sheet and the interest rate swap agreements in South Africa were included in Notes receivable and other non-current assets on the consolidated balance sheet.
Schedule of contingent consideration changes	A summary of the value of the Company’s contingent consideration is as follows (in thousands): Year Ended December 31, 2015 Maximum potential value (1) Estimated value at December 31, 2015 (2) Additions (3) Settlements Change in Fair Value Colombia $ 22,444 $ 9,829 $ — $ — $ (5,011 ) Costa Rica — — — (1,898 ) — Ghana 569 569 — — 99 India 1,164 163 315 (139 ) — United States 1,875 1,875 1,311 (5,906 ) 131 Total $ 26,052 $ 12,436 $ 1,626 $ (7,943 ) $ (4,781 ) _______________ (1) The maximum potential value is based on exchange rates at December 31, 2015 . The minimum value could be zero. (2) Estimate is determined using a probability weighted average of expected outcomes as of December 31, 2015 . (3) Based on preliminary acquisition accounting upon closing of certain acquisitions during the year ended December 31, 2015 . The changes in fair value of the contingent consideration were as follows during the years ended December 31, (in thousands): 2015 2014 Balance as of January 1 $ 28,524 $ 31,890 Additions 1,626 6,412 Settlements (7,943 ) (3,889 ) Change in fair value (4,781 ) (225 ) Foreign currency translation adjustment (4,990 ) (4,934 ) Other (1) — (730 ) Balance as of December 31 $ 12,436 $ 28,524 _______________ (1) In connection with the sale of operations in Panama in September 2014, the buyer assumed the Company’s potential obligations related to additional purchase price consideration.

Income Taxes (Tables)

Income Taxes (Tables)	12 Months Ended
	Dec. 31, 2015
Income Tax Expense (Benefit), Continuing Operations [Abstract]
Income tax provision from continuing operations	The income tax provision from continuing operations consisted of the following for the years ended December 31, (in thousands): 2015 2014 2013 Current: Federal $ (73,930 ) $ (2,390 ) $ (30,322 ) State (21,216 ) (797 ) (13,731 ) Foreign (55,045 ) (57,934 ) (44,973 ) Deferred: Federal 9,131 (4,180 ) (16,318 ) State 8 (973 ) (5,139 ) Foreign (16,903 ) 3,769 50,942 Income tax provision $ (157,955 ) $ (62,505 ) $ (59,541 )
Reconciliation between the U.S. statutory rate and the effective rate from continuing operations	Reconciliation between the U.S. statutory rate and the effective rate from continuing operations is as follows for the years ended December 31: 2015 2014 2013 Statutory tax rate 35 % 35 % 35 % Tax adjustment related to REIT (1) (35 ) (35 ) (35 ) State taxes, net of federal benefit — 1 3 Foreign taxes 3 2 (5 ) Foreign withholding taxes 3 3 6 Domestic TRS restructuring — — 4 Change in tax law 2 — — MIPT tax election (2) 11 — — Other — 1 3 Effective tax rate 19 % 7 % 11 % _______________ (1) Includes 36% , 24% and 28% from dividend paid deductions in 2015, 2014 and 2013, respectively. (2) Includes federal and state taxes, net of federal benefit.
Components of income from continuing operations before income taxes and income on equity method investments	The domestic and foreign components of income from continuing operations before income taxes are as follows for the years ended December 31, (in thousands): 2015 2014 2013 United States $ 785,201 $ 857,457 $ 766,772 Foreign 44,761 8,247 (225,023 ) Total $ 829,962 $ 865,704 $ 541,749
Components of the net deferred tax asset and related valuation allowance	The components of the net deferred tax asset and related valuation allowance were as follows as of December 31, (in thousands): 2015 (1) 2014 (2) Current assets: Allowances, accruals and other items not currently deductible $ — $ 19,893 Current deferred liabilities — (2,799 ) Subtotal — 17,094 Valuation allowance — (3,094 ) Net current deferred tax assets $ — $ 14,000 Non-current items: Assets: Net operating loss carryforwards 277,977 242,788 Accrued asset retirement obligations 92,295 103,975 Stock-based compensation 3,889 693 Unearned revenue 25,654 18,947 Unrealized loss on foreign currency 37,440 15,952 Items not currently deductible and other 31,432 22,142 Liabilities: Depreciation and amortization (194,230 ) (131,678 ) Deferred rent (20,720 ) (18,355 ) Other (11,077 ) (1,791 ) Subtotal 242,660 252,673 Valuation allowance (136,952 ) (138,147 ) Net non-current deferred tax assets $ 105,708 $ 114,526 _______________ (1) Change in accounting pronouncement, as described below. (2) December 31, 2014 balances have been revised to reflect purchase accounting measurement period adjustments.
Summary of valuation allowance	A summary of the activity in the valuation allowance is as follows (in thousands): 2015 2014 2013 Balance as of January 1, $ 141,241 $ 136,006 $ 95,558 Additions (1) 19,512 40,124 48,411 Reversals — (10,769 ) — Foreign currency translation (23,801 ) (24,120 ) (7,963 ) Balance as of December 31, $ 136,952 $ 141,241 $ 136,006 _______________ (1) Includes net charges to expense and allowances established through goodwill at acquisition.
Net operating loss carryforwards expire	If not utilized, the Company’s net operating loss carryforwards expire as follows (in thousands): Years ended December 31, Federal State Foreign 2016 to 2020 $ — $ 79,928 $ 14,727 2021 to 2025 — 281,061 195,694 2026 to 2030 51,596 188,030 — 2031 to 2035 23,670 10,853 — Indefinite carryforward — — 695,052 Total $ 75,266 $ 559,872 $ 905,473
Change in unrecognized tax benefit	A reconciliation of the beginning and ending amount of unrecognized tax benefits are as follows for the years ended December 31, (in thousands): 2015 2014 2013 Balance at January 1 $ 31,947 $ 32,545 $ 34,337 Additions based on tax positions related to the current year 5,042 4,187 1,427 Additions for tax positions of prior years — 3,780 — Reductions for tax positions of prior years — — (320 ) Foreign currency (5,371 ) (3,216 ) (1,681 ) Reduction as a result of the lapse of statute of limitations and effective settlements (3,504 ) (5,349 ) (1,218 ) Balance at December 31 $ 28,114 $ 31,947 $ 32,545

Stock-Based Compensation (Table

Stock-Based Compensation (Tables)	12 Months Ended
	Dec. 31, 2015
Share-based Compensation, Allocation and Classification in Financial Statements [Abstract]
Assumptions used to determine the grant date fair value for options granted	Key assumptions used to apply this pricing model were as follows: 2015 2014 2013 Range of risk-free interest rate 1.32% - 1.62% 1.46% - 1.74% 0.75% - 1.42% Weighted average risk-free interest rate 1.61% 1.64% 0.91% Expected life of stock options 4.5 years 4.5 years 4.4 years Range of expected volatility of the underlying stock price 21.09% - 21.24% 21.94% - 23.35% 24.43% - 36.09% Weighted average expected volatility of underlying stock price 21.09% 23.08% 33.37% Range of expected annual dividend yield 1.50% - 1.85% 1.50% 1.50%
Summary of the company's option activity	The Company’s option activity for the year ended December 31, 2015 was as follows: Options Weighted Average Exercise Price Weighted Average Remaining Life (Years) Aggregate Intrinsic Value (in millions) Outstanding as of January 1, 2015 6,508,435 $62.14 Granted 2,059,600 94.43 Exercised (779,615 ) 56.56 Forfeited (105,226 ) 82.47 Expired (2,375 ) 23.74 Outstanding as of December 31, 2015 7,680,819 $71.10 6.72 $198.6 Exercisable as of December 31, 2015 3,549,709 $54.13 4.76 $152.0 Vested or expected to vest as of December 31, 2015 7,674,324 $71.08 6.72 $198.6
Schedule of options outstanding	The following table sets forth information regarding options outstanding at December 31, 2015 : Options Outstanding Options Exercisable Outstanding Number of Options Range of Exercise Price Per Share Weighted Average Exercise Price Per Share Weighted Average Remaining Life (Years) Options Exercisable Weighted Average Exercise Price Per Share 2,064,426 $25.43 - $50.78 $40.73 3.21 2,064,426 $40.73 852,265 51.03 - 74.06 61.88 6.16 578,340 61.43 1,091,181 76.90 - 79.45 76.94 7.17 467,735 76.92 1,707,519 81.18 - 94.23 81.63 8.21 376,025 81.35 1,965,428 94.57 - 99.67 94.60 9.12 63,183 94.57 7,680,819 $25.43 - $99.67 $71.10 6.72 3,549,709 $54.13
Summary of the company's restricted stock unit activity	The Company’s RSU and PSU activity for the year ended December 31, 2015 was as follows: RSUs Weighted Average Grant Date Fair Value PSUs (1) Weighted Average Grant Date Fair Value Outstanding as of January 1, 2015 1,758,817 $73.80 — $— Granted 715,379 94.55 33,377 94.57 Vested (703,955 ) 69.24 — — Forfeited (113,248 ) 82.20 — — Outstanding as of December 31, 2015 1,656,993 $84.12 33,377 $94.57 Expected to vest, net of estimated forfeitures, as of December 31, 2015 1,578,040 $83.87 33,377 $94.57 _______________ (1) Represents the target number of shares issuable at the end of the three-year performance cycle attributable to the first year’s performance period and incremental shares issuable based on exceeding the performance metric for the first year’s performance period.

Equity (Tables)

Equity (Tables)	12 Months Ended
	Dec. 31, 2015
Common Stock
Class of Stock [Line Items]
Schedule of Stock by Class	The following table characterizes the tax treatment of distributions declared per share of common stock and Mandatory Convertible Preferred Stock. For the year ended December 31, 2015 2014 (1) 2013 (1) Per Share % Per Share % Per Share % Common Stock Ordinary dividend $ 1.2694 70.13 % $ 1.4000 100.00 % $ 1.1000 100.00 % Capital gains distribution 0.5406 29.87 — — — — Total $ 1.8100 100.00 % $ 1.4000 100.00 % $ 1.1000 100.00 % Series A Preferred Stock Ordinary dividend $ 3.6818 (2) 70.13 % $ 2.6688 100.00 % $ — — % Capital gains distribution 1.5682 29.87 — — — — Total $ 5.2500 100.00 % $ 2.6688 100.00 % $ — — % Series B Preferred Stock (3) Ordinary dividend $ 2.7107 70.13 % $ — — % $ — — % Capital gains distribution 1.1546 29.87 — — — — Total $ 3.8653 100.00 % $ — — % $ — — % _______________ (1) The Company had no Series A Preferred Stock outstanding during the year ended December 31, 2013 and no Series B Preferred Stock outstanding during the years ended December 31, 2014 and 2013. (2) Includes dividend declared on December 2, 2014 of $1.3125 per share, payable on February 16, 2015 to preferred stockholders of record at the close of business on February 1, 2015. (3) Represents the tax treatment on dividends per depositary share, each of which represents a 1/10th interest in a share of Series B Preferred Stock.

Earnings Per Common Share (Tabl

Earnings Per Common Share (Tables)	12 Months Ended
	Dec. 31, 2015
Earnings Per Share [Abstract]
Schedule of earnings per basic and diluted by common class	The following table sets forth basic and diluted net income per common share computational data for the years ended December 31, (in thousands, except per share data): 2015 2014 2013 Net income attributable to American Tower Corporation stockholders $ 685,074 $ 824,910 $ 551,333 Dividends on preferred stock (90,163 ) (23,888 ) — Net income attributable to American Tower Corporation common stockholders 594,911 801,022 551,333 Basic weighted average common shares outstanding 418,907 395,958 395,040 Dilutive securities 4,108 4,128 4,106 Diluted weighted average common shares outstanding 423,015 400,086 399,146 Basic net income attributable to American Tower Corporation common stockholders per common share $ 1.42 $ 2.02 $ 1.40 Diluted net income attributable to American Tower Corporation common stockholders per common share $ 1.41 $ 2.00 $ 1.38
Schedule of antidilutive securities excluded from computation of earnings per share	The following shares were not included in the computation of diluted earnings per share because the effect would be anti-dilutive for the years ended December 31, (in thousands, on a weighted average basis): 2015 2014 2013 Restricted stock awards — 5 — Stock options 1,606 1,290 1,161 Preferred stock 15,408 4,303 —

Commitments and Contingencies (

Commitments and Contingencies (Tables)	12 Months Ended
	Dec. 31, 2015
Commitments and Contingencies Disclosure [Abstract]
Future minimum rental payments under non-cancelable operating leases	Future minimum rental payments under non-cancellable operating leases include payments for certain renewal periods at the Company’s option because failure to renew could result in a loss of the applicable communications sites and related revenues from tenant leases, thereby making it reasonably assured that the Company will renew the leases. Such payments at December 31, 2015 are as follows (in millions): Year Ending December 31, 2016 $ 722 2017 709 2018 690 2019 670 2020 643 Thereafter 6,416 Total $ 9,850
Future minimum payments under capital leases	Future minimum payments under capital leases in effect at December 31, 2015 were as follows (in millions): Year Ending December 31, 2016 $ 21 2017 18 2018 17 2019 15 2020 12 Thereafter 173 Total minimum lease payments 256 Less amounts representing interest (143 ) Present value of capital lease obligations $ 113
Future minimum rental receipts under operating lease agreements	Future minimum rental receipts expected from tenants under non-cancellable operating lease agreements in effect at December 31, 2015 were as follows (in millions): Year Ending December 31, 2016 $ 4,082 2017 4,004 2018 3,874 2019 3,654 2020 3,369 Thereafter 11,294 Total $ 30,277

Supplemental Cash Flow Inform50

Supplemental Cash Flow Information (Tables)	12 Months Ended
	Dec. 31, 2015
Supplemental Cash Flow Information [Abstract]
Supplemental cash flow information and non-cash investing and financing activities	Supplemental cash flow information and non-cash investing and financing activities are as follows for the years ended December 31, (in thousands): 2015 2014 2013 Supplemental cash flow information: Cash paid for interest $ 577,952 $ 548,089 $ 397,366 Cash paid for income taxes (net of refunds of $7,053, $8,476 and $19,701, respectively) 157,058 69,212 51,676 Non-cash investing and financing activities: Increase in accounts payable and accrued expenses for purchases of property and equipment and construction activities 2,780 1,121 9,147 Purchases of property and equipment under capital leases 36,851 36,486 27,416 Fair value of debt assumed through acquisitions — 463,135 1,576,186 Settlement of accounts receivable related to acquisitions 899 31,849 — Conversion of third-party debt to equity — 111,181 —

Business Segments (Tables)

Business Segments (Tables)	12 Months Ended
	Dec. 31, 2015
Segment Reporting, Measurement Disclosures [Abstract]
Summarized financial information concerning the company's reportable segments	Property Total Property Other Total Year ended December 31, 2013 U.S. Asia EMEA Latin America (in thousands) Segment revenues $ 2,189,365 $ 191,355 $ 295,681 $ 610,689 $ 3,287,090 $ 74,317 $ 3,361,407 Segment operating expenses (1) 405,419 109,645 121,122 191,579 827,765 30,564 858,329 Interest income, TV Azteca, net — — — 22,235 22,235 — 22,235 Segment gross margin 1,783,946 81,710 174,559 441,345 2,481,560 43,753 2,525,313 Segment selling, general, administrative and development expense (1) 103,989 15,630 39,076 62,756 221,451 9,257 230,708 Segment operating profit $ 1,679,957 $ 66,080 $ 135,483 $ 378,589 $ 2,260,109 $ 34,496 $ 2,294,605 Stock-based compensation expense $ 68,138 68,138 Other selling, general, administrative and development expense (2) 118,243 118,243 Depreciation, amortization and accretion 800,145 800,145 Other expense (3) 766,330 766,330 Income from continuing operations before income taxes $ 541,749 Capital expenditures $ 416,239 $ 55,914 $ 67,462 $ 154,534 $ 694,149 $ — $ 30,383 $ 724,532 _______________ (1) Segment operating expenses and segment selling, general, administrative and development expenses exclude stock-based compensation expense of $1.5 million and $66.6 million , respectively. (2) Includes $5.9 million of expense previously recorded as segment selling, general, administrative and development expense. (3) Primarily includes interest expense. Summarized financial information concerning the Company’s reportable segments for the years ended December 31, 2015 , 2014 and 2013 is shown in the following tables. The “Other” column (i) represents amounts excluded from specific segments, such as business development operations, stock-based compensation expense and corporate expenses included in Selling, general, administrative and development expense; Other operating expenses; Interest income; Interest expense; Gain (loss) on retirement of long-term obligations; and Other income (expense), and (ii) reconciles segment operating profit to Income from continuing operations before income taxes, as the amounts are not utilized in assessing each segment’s performance. Property Total Property Services Other Total Year ended December 31, 2015 U.S. Asia EMEA Latin America (in thousands) Segment revenues $ 3,157,501 $ 242,223 $ 395,092 $ 885,572 $ 4,680,388 $ 91,128 $ 4,771,516 Segment operating expenses (1) 678,499 126,874 163,820 304,629 1,273,822 32,993 1,306,815 Interest income, TV Azteca, net — — — 11,209 11,209 — 11,209 Segment gross margin 2,479,002 115,349 231,272 592,152 3,417,775 58,135 3,475,910 Segment selling, general, administrative and development expense (1) 138,617 22,771 48,672 62,111 272,171 15,724 287,895 Segment operating profit $ 2,340,385 $ 92,578 $ 182,600 $ 530,041 $ 3,145,604 $ 42,411 $ 3,188,015 Stock-based compensation expense $ 90,537 90,537 Other selling, general, administrative and development expense 121,456 121,456 Depreciation, amortization and accretion 1,285,328 1,285,328 Other expense (2) 860,732 860,732 Income from continuing operations before income taxes $ 829,962 Capital expenditures $ 367,663 $ 75,407 $ 66,625 $ 201,806 $ 711,501 $ — $ 17,252 $ 728,753 _______________ (1) Segment operating expenses and segment selling, general, administrative and development expenses exclude stock-based compensation expense of $2.1 million and $88.5 million , respectively. (2) Primarily includes interest expense. Property Total Property Services Other Total Year ended December 31, 2014 U.S. Asia EMEA Latin America (in thousands) Segment revenues $ 2,639,790 $ 219,566 $ 315,053 $ 832,445 $ 4,006,854 $ 93,194 $ 4,100,048 Segment operating expenses (1) 515,742 121,797 126,714 290,527 1,054,780 37,648 1,092,428 Interest income, TV Azteca, net — — — 10,547 10,547 — 10,547 Segment gross margin 2,124,048 97,769 188,339 552,465 2,962,621 55,546 3,018,167 Segment selling, general, administrative and development expense (1) 124,944 19,632 39,553 66,890 251,019 12,469 263,488 Segment operating profit $ 1,999,104 $ 78,137 $ 148,786 $ 485,575 $ 2,711,602 $ 43,077 $ 2,754,679 Stock-based compensation expense $ 80,153 80,153 Other selling, general, administrative and development expense (2) 104,738 104,738 Depreciation, amortization and accretion 1,003,802 1,003,802 Other expense (3) 700,282 700,282 Income from continuing operations before income taxes $ 865,704 Capital expenditures $ 576,153 $ 74,334 $ 70,126 $ 229,645 $ 950,258 $ — $ 24,146 $ 974,404 _______________ (1) Segment operating expenses and segment selling, general, administrative and development expenses exclude stock-based compensation expense of $1.8 million and $78.3 million , respectively. (2) Includes $7.9 million of expense previously recorded as segment selling, general, administrative and development expense. (3) Primarily includes interest expense.
Reconciliation of assets from segments to consolidated	Additional information relating to the total assets of the Company’s operating segments for the years ended December 31, is as follows (in thousands): 2015 2014 (1) (2) 2013 (2) U.S. property $ 19,286,465 $ 14,335,731 $ 13,608,818 Asia property (3) 736,149 738,290 743,671 EMEA property (3) 2,249,634 1,275,253 1,472,143 Latin America property (3) 4,401,258 4,700,357 4,184,135 Services 68,388 57,367 47,607 Other (4) 162,378 156,567 157,563 Total assets $ 26,904,272 $ 21,263,565 $ 20,213,937 _______________ (1) Balances have been revised to reflect purchase accounting measurement period adjustments. (2) Balances have been revised to reflect debt issuance cost adjustments. (3) Balances are translated at the applicable period end exchange rate and therefore may impact comparability between periods. (4) Balances include corporate assets such as cash and cash equivalents, certain tangible and intangible assets and income tax accounts which have not been allocated to specific segments.
Schedule of revenue from external customers attributed to foreign countries by geographic area	Summarized geographic information related to the Company’s operating revenues for the years ended December 31, 2015 , 2014 and 2013 and long-lived assets as of December 31, 2015 and 2014, is as follows (in thousands): 2015 2014 2013 Operating Revenues: United States $ 3,248,629 $ 2,732,984 $ 2,263,682 Asia (1): India 242,223 219,566 191,355 EMEA (1): Germany 55,965 64,946 62,756 Ghana 94,549 95,486 92,114 Nigeria 109,701 — — South Africa 80,510 98,334 91,906 Uganda 54,367 56,287 48,905 Latin America (1): Brazil 408,644 331,089 212,201 Chile 29,650 31,756 28,978 Colombia 78,351 89,421 70,901 Costa Rica 17,244 16,742 4,055 Mexico 340,461 354,116 288,306 Panama (2) — 1,243 424 Peru 11,222 8,078 5,824 Total operating revenues $ 4,771,516 $ 4,100,048 $ 3,361,407 _______________ (1) Balances are translated at the applicable exchange rate and therefore may impact comparability between periods. (2) In September 2014, the Company completed the sale of the operations in Panama.
Schedule of disclosure on geographic areas, long-lived assets	2015 2014 (1) Long-Lived Assets (2): United States $ 17,516,535 $ 12,771,089 Asia (3): India 619,370 616,266 EMEA (3): Germany 388,727 456,698 Ghana 217,530 235,523 Nigeria 1,018,980 — South Africa 133,088 184,292 Uganda 162,346 185,956 Latin America (3): Brazil 2,204,494 2,152,953 Chile 121,938 147,413 Colombia 256,892 319,260 Costa Rica 120,292 127,436 Mexico 976,707 1,188,183 Peru 59,206 61,490 Total long-lived assets $ 23,796,105 $ 18,446,559 _______________ (1) Balances have been revised to reflect purchase accounting measurement period adjustments and debt issuance costs related to the Company’s credit facilities (see note 1). (2) Includes Property and equipment, net, Goodwill and Other intangible assets, net. (3) Balances are translated at the applicable period end exchange rate and therefore may impact comparability between periods.
Schedule of revenue by major customers	The following tenants within the property segments and services segment individually accounted for 10% or more of the Company’s consolidated operating revenues for the years ended December 31, is as follows: 2015 2014 2013 AT&T 24 % 20 % 18 % Verizon Wireless 16 % 11 % 11 % Sprint 13 % 15 % 16 % T-Mobile 10 % 10 % 11 %

Selected Quarterly Financial 52

Selected Quarterly Financial Data (Tables)	12 Months Ended
	Dec. 31, 2015
Selected Quarterly Financial Information [Abstract]
Schedule of quarterly financial information	Selected quarterly financial data for the years ended December 31, 2015 and 2014 is as follows (in thousands, except per share data): Three Months Ended Year Ended December 31, March 31, June 30, September 30, December 31, 2015: Operating revenues $ 1,079,190 $ 1,174,375 $ 1,237,910 $ 1,280,041 $ 4,771,516 Costs of operations (1) 264,640 322,458 365,389 356,381 1,308,868 Operating income 419,966 389,774 400,925 402,124 1,612,789 Net income 195,492 157,180 97,740 221,595 672,007 Net income attributable to American Tower Corporation stockholders 193,317 156,056 102,999 232,702 685,074 Dividends on preferred stock (9,819 ) (26,782 ) (26,781 ) (26,781 ) (90,163 ) Net income attributable to American Tower Corporation common stockholders 183,498 129,274 76,218 205,921 594,911 Basic net income per share attributable to American Tower Corporation common stockholders 0.45 0.31 0.18 0.49 1.42 Diluted net income per share attributable to American Tower Corporation common stockholders 0.45 0.30 0.18 0.48 1.41 Three Months Ended Year Ended December 31, March 31, June 30, September 30, December 31, 2014: Operating revenues $ 984,089 $ 1,031,457 $ 1,038,188 $ 1,046,314 $ 4,100,048 Costs of operations (1) 260,769 272,275 284,202 277,019 1,094,265 Operating income 353,637 402,499 384,807 345,979 1,486,922 Net income 193,313 221,659 206,630 181,597 803,199 Net income attributable to American Tower Corporation stockholders 202,499 234,431 207,593 180,387 824,910 Dividends on preferred stock — (4,375 ) (7,700 ) (11,813 ) (23,888 ) Net income attributable to American Tower Corporation common stockholders 202,499 230,056 199,893 168,574 801,022 Basic net income per share attributable to American Tower Corporation common stockholders 0.51 0.58 0.50 0.43 2.02 Diluted net income per share attributable to American Tower Corporation common stockholders 0.51 0.58 0.50 0.42 2.00 _______________ (1) Represents Operating expenses, exclusive of Depreciation, amortization and accretion, Selling, general, administrative and development expense, and Other operating expenses.

Business and Summary of Signi53

Business and Summary of Significant Accounting Policies (Narrative) (Details) $ in Thousands	12 Months Ended
	Dec. 31, 2015USD ($)customers	Dec. 31, 2014USD ($)		Dec. 31, 2013USD ($)
Concentration Risk [Line Items]
Number of customers, concentration of credit risk | customers	4
Foreign currency transaction gain (loss), in AOCI and Income Statement	$ (867,600)
Foreign currency transaction gain (loss), reclassified as AOCI	(732,900)
Foreign currency transaction loss	(134,700)
Labor costs capitalized	44,700	$ 48,500		$ 44,100
Interest costs capitalized	1,800	2,800		1,800
Accumulated other comprehensive loss	(1,836,996)	(794,221)
Straight line revenue	155,000	123,700		147,700
Straight-line ground rent expense	$ 56,100	38,400		29,700
Employers percentage of employees first 6 percent	75.00%
Employee maximum annual contribution eligible for match	6.00%
Company's contribution	$ 7,400	6,500		6,000
Prior Period Adjustment [Abstract]
Long-term debt	17,119,009
Current portion of long-term obligations	$ 50,202	897,386	[1]
Adjustments for New Accounting Pronouncement
Prior Period Adjustment [Abstract]
Other intangible assets, net		75,900
Long-term debt		68,200
Current portion of long-term obligations		200
Deferred financing costs, net		7,500
2007 Plan
Concentration Risk [Line Items]
Vesting period	4 years
Performance Shares
Concentration Risk [Line Items]
Vesting period	3 years
Performance Shares | 2007 Plan
Concentration Risk [Line Items]
Vesting period	3 years
Foreign Currency Items
Concentration Risk [Line Items]
Accumulated other comprehensive loss	$ 1,837,300	$ 790,600		$ 306,300
Maximum
Concentration Risk [Line Items]
Estimated useful life of respective assets	20 years
Maximum | Performance Shares
Concentration Risk [Line Items]
Percentage of potential target shares	200.00%
Minimum
Concentration Risk [Line Items]
Estimated useful life of respective assets	3 years
Minimum | Performance Shares
Concentration Risk [Line Items]
Percentage of potential target shares	0.00%
Customer Concentration Risk
Concentration Risk [Line Items]
Concentration risk, percentage	10.00%	10.00%		10.00%
Sales Revenue, Net | Customer Concentration Risk
Concentration Risk [Line Items]
Concentration risk, percentage	63.00%
Uganda | Corporate Joint Venture
Concentration Risk [Line Items]
Company's ownership percentage	51.00%
Noncontrolling owners, ownership percentage	49.00%
Ghana | Corporate Joint Venture
Concentration Risk [Line Items]
Company's ownership percentage	51.00%
Noncontrolling owners, ownership percentage	49.00%
South Africa | Corporate Joint Venture
Concentration Risk [Line Items]
Company's ownership percentage	75.00%
Noncontrolling owners, ownership percentage	25.00%
[1]	December 31, 2014 balances have been revised to reflect debt issuance costs as a direct deduction from the carrying amounts, with the exception of debt issuance costs associated with the 2013 Credit Facility and the 2014 Credit Facility (as defined below) which are reflected in Notes receivable and other non-current assets on the consolidated balance sheets. Amortization of deferred financing costs is included in interest expense on the consolidated statements of operations.

Business and Summary of Signi54

Business and Summary of Significant Accounting Policies (Changes in Allowances) (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Allowance for Doubtful Accounts Receivable [Roll Forward]
Balance as of January 1	$ 17,306	$ 19,895	$ 20,406
Current year increases	19,878	8,243	7,025
Write-offs, net of recoveries and other	(14,088)	(10,832)	(7,536)
Balance as of December 31	$ 23,096	$ 17,306	$ 19,895

Prepaid and Other Current Ass55

Prepaid and Other Current Assets (Details) - USD ($) $ in Thousands	Dec. 31, 2015	Dec. 31, 2014	[1]
Prepaid Expense and Other Assets, Current [Abstract]
Prepaid operating ground leases	$ 128,542	$ 88,053
Prepaid income tax	45,056	34,512
Unbilled receivables	34,173	25,352
Prepaid assets	32,892	23,848
Value added tax and other consumption tax receivables	30,239	23,228
Other miscellaneous current assets	35,333	69,800
Balance	$ 306,235	$ 264,793
[1]	December 31, 2014 balances have been revised to reflect purchase accounting measurement period adjustments.

Property and Equipment (Propert

Property and Equipment (Property and Equipment) (Details) - USD ($) $ in Thousands		12 Months Ended
		Dec. 31, 2015	Dec. 31, 2014	[1]
Property, Plant and Equipment [Line Items]
Towers		$ 10,726,656	$ 8,265,732
Equipment		1,095,906	995,667
Buildings and improvements		607,661	617,064
Land and improvements	[2]	1,728,115	1,565,871
Construction-in-progress		238,960	214,760
Total		14,397,298	11,659,094
Less accumulated depreciation		(4,530,874)	(4,068,982)
Property and equipment, net		$ 9,866,424	$ 7,590,112
Minimum
Property, Plant and Equipment [Line Items]
Estimated useful lives		3 years
Maximum
Property, Plant and Equipment [Line Items]
Estimated useful lives		20 years
Tower | Minimum
Property, Plant and Equipment [Line Items]
Estimated useful lives	[3]	0 years
Tower | Maximum
Property, Plant and Equipment [Line Items]
Estimated useful lives	[3]	20 years
Equipment | Minimum
Property, Plant and Equipment [Line Items]
Estimated useful lives	[3]	2 years
Equipment | Maximum
Property, Plant and Equipment [Line Items]
Estimated useful lives	[3]	15 years
Buildings and Improvements | Minimum
Property, Plant and Equipment [Line Items]
Estimated useful lives	[3]	3 years
Buildings and Improvements | Maximum
Property, Plant and Equipment [Line Items]
Estimated useful lives	[3]	32 years
Land and Improvements | Minimum
Property, Plant and Equipment [Line Items]
Estimated useful lives	[2],[3]	0 years
Land and Improvements | Maximum
Property, Plant and Equipment [Line Items]
Estimated useful lives	[2],[3]	20 years
[1]	December 31, 2014 balances have been revised to reflect purchase accounting measurement period adjustments.
[2]	Estimated useful lives apply to land improvements only.
[3]	Assets on leased land are depreciated over the shorter of the estimated useful life of the asset or the term of the corresponding ground lease taking into consideration lease renewal options and residual value.

Property and Equipment (Narrati

Property and Equipment (Narrative) (Details) $ in Millions	12 Months Ended
	Dec. 31, 2015USD ($)communications_site	Dec. 31, 2014USD ($)	Dec. 31, 2013USD ($)	Mar. 27, 2015communications_site
Property, Plant and Equipment [Line Items]
Depreciation expense	$ 661.4	$ 551.8	$ 483.6
Verizon Transaction | Leased Sites
Property, Plant and Equipment [Line Items]
Capital leased assets, number of units | communications_site	11,286			11,286
Assets Held under Capital Leases
Property, Plant and Equipment [Line Items]
Capital leases, which are primarily classified as towers or land and improvements	$ 5,112.4	2,921.4
Accumulated depreciation on capital lease assets	$ 1,414.6	$ 1,256.3

Goodwill and Other Intangible58

Goodwill and Other Intangible Assets (Narrative) (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Acquired Finite-Lived Intangible Assets [Line Items]
Amortization of intangible assets	$ 568.3	$ 411.7	$ 282.5
Weighted Average
Acquired Finite-Lived Intangible Assets [Line Items]
Finite-lived intangible assets, remaining amortization period	16 years

Goodwill and Other Intangible59

Goodwill and Other Intangible Assets (Rollforward) (Details) - USD ($) $ in Thousands		12 Months Ended
		Dec. 31, 2015		Dec. 31, 2014
Goodwill [Roll Forward]
Goodwill, beginning balance		$ 4,032,174	[1]	$ 3,854,802
Additions		214,685		232,305	[1]
Effect of foreign currency translation		(155,054)		(51,280)
Other	[2]			(3,653)
Goodwill, ending balance		4,091,805		4,032,174	[1]
Network Development Services
Goodwill [Roll Forward]
Goodwill, beginning balance		1,988	[1]	2,000
Additions		0		0	[1]
Effect of foreign currency translation		0		0
Other	[2]			(12)
Goodwill, ending balance		1,988		1,988	[1]
United States | Rental And Management
Goodwill [Roll Forward]
Goodwill, beginning balance		3,356,096	[1]	3,293,899
Additions		23,067		62,197	[1]
Effect of foreign currency translation		0		0
Other	[2]			0
Goodwill, ending balance		3,379,163		3,356,096	[1]
Asia | Rental And Management
Goodwill [Roll Forward]
Goodwill, beginning balance		178,521	[1]	182,114
Additions		610		0	[1]
Effect of foreign currency translation		(8,412)		(3,593)
Other	[2]			0
Goodwill, ending balance		170,719		178,521	[1]
EMEA | Rental And Management
Goodwill [Roll Forward]
Goodwill, beginning balance		78,647	[1]	90,035
Additions		68,663		40	[1]
Effect of foreign currency translation		(14,740)		(11,428)
Other	[2]			0
Goodwill, ending balance		132,570		78,647	[1]
Latin America | Rental And Management
Goodwill [Roll Forward]
Goodwill, beginning balance		416,922	[1]	286,754
Additions		122,345		170,068	[1]
Effect of foreign currency translation		(131,902)		(36,259)
Other	[2]			(3,641)
Goodwill, ending balance		$ 407,365		$ 416,922	[1]
[1]	Balances have been revised to reflect purchase accounting measurement period adjustments.
[2]	Other represents the goodwill associated with the Company’s operations in Panama and the Company’s third-party structural analysis business. Both businesses were sold during the year ended December 31, 2014 (see note 11).

Goodwill and Other Intangible60

Goodwill and Other Intangible Assets (Changes in the Carrying Value of Goodwill) (Details) - USD ($) $ in Thousands		12 Months Ended
		Dec. 31, 2015	Dec. 31, 2014
Finite-Lived Intangible Assets [Line Items]
Gross Carrying Value		$ 12,670,816	$ 9,172,222	[1]
Accumulated Amortization		(2,832,940)	(2,347,949)	[1]
Net Book Value		9,837,876	$ 6,824,273	[1]
Finite-lived intangible asset, useful life			11 years
Acquired Network Location
Finite-Lived Intangible Assets [Line Items]
Gross Carrying Value	[2]	3,980,281	$ 2,513,788	[1]
Accumulated Amortization	[2]	(1,052,393)	(901,903)	[1]
Net Book Value	[2]	$ 2,927,888	1,611,885	[1]
Acquired Network Location | Minimum
Finite-Lived Intangible Assets [Line Items]
Finite-lived intangible asset, useful life	[2]	0 years
Acquired Network Location | Maximum
Finite-Lived Intangible Assets [Line Items]
Finite-lived intangible asset, useful life	[2]	20 years
Customer Relationships
Finite-Lived Intangible Assets [Line Items]
Gross Carrying Value		$ 8,640,554	6,594,469	[1]
Accumulated Amortization		(1,763,853)	(1,429,572)	[1]
Net Book Value		$ 6,876,701	5,164,897	[1]
Customer Relationships | Minimum
Finite-Lived Intangible Assets [Line Items]
Finite-lived intangible asset, useful life		15 years
Customer Relationships | Maximum
Finite-Lived Intangible Assets [Line Items]
Finite-lived intangible asset, useful life		20 years
Acquired Licenses And Other Intangibles
Finite-Lived Intangible Assets [Line Items]
Gross Carrying Value		$ 28,293	38,443	[1]
Accumulated Amortization		(5,486)	(3,514)	[1]
Net Book Value		$ 22,807	34,929	[1]
Acquired Licenses And Other Intangibles | Minimum
Finite-Lived Intangible Assets [Line Items]
Finite-lived intangible asset, useful life		3 years
Acquired Licenses And Other Intangibles | Maximum
Finite-Lived Intangible Assets [Line Items]
Finite-lived intangible asset, useful life		20 years
Economic Rights, TV Azteca
Finite-Lived Intangible Assets [Line Items]
Gross Carrying Value		$ 21,688	25,522	[1]
Accumulated Amortization		(11,208)	(12,960)	[1]
Net Book Value		$ 10,480	$ 12,562	[1]
Finite-lived intangible asset, useful life		70 years
[1]	December 31, 2014 balances have been revised to reflect purchase accounting measurement period adjustments.
[2]	Acquired network location intangibles are amortized over the shorter of the term of the corresponding ground lease taking into consideration lease renewal options and residual value or up to 20 years, as the Company considers these intangibles to be directly related to the tower assets.

Goodwill and Other Intangible61

Goodwill and Other Intangible Assets (Expected Future Amortization Expenses) (Details) $ in Millions	Dec. 31, 2015USD ($)
Goodwill and Intangible Assets Disclosure [Abstract]
2,016	$ 598.8
2,017	597.1
2,018	596
2,019	593.7
2,020	$ 576

Notes Receivable and Other No62

Notes Receivable and Other Non-Current Assets (Narrative) (Details) $ in Millions	1 Months Ended	12 Months Ended
	Dec. 31, 2000USD ($)	Dec. 31, 2000USD ($)communications_site	Dec. 31, 2015USD ($)	Dec. 31, 2014USD ($)
Economic Rights, TV Azteca
Notes Receivable And Other NonCurrent Assets [Line Items]
Term of the loan, years		70 years
Loan prepayment without penalty, period, years	50 years
Number of broadcast towers | communications_site		190
Commercial rights, annual payment	$ 1.5	$ 1.5
Percentage of the revenues from leasing of towers		100.00%
Capital lease, liability	18.6	$ 18.6
Capital lease, asset	18.6	18.6
Capital lease asset and discount on note	30.2	30.2
TV Azteca
Notes Receivable And Other NonCurrent Assets [Line Items]
Loans receivable	$ 119.8	$ 119.8	$ 91.8	$ 91.8
Loan interest rate		13.11%
Term of the loan, years		70 years
Loan prepayment without penalty, period, years		50 years
Loans receivable, net of discount			82.9	$ 82.9
Repayment of Principal | TV Azteca
Notes Receivable And Other NonCurrent Assets [Line Items]
Loans receivable			$ 28

Notes Receivable and Other No63

Notes Receivable and Other Non-Current Assets (Notes Receivable and Other Non-Current Assets) (Details) - USD ($) $ in Thousands	Dec. 31, 2015	Dec. 31, 2014	[1]
Notes Receivable And Other Long Term Assets [Abstract]
Long-term prepaid ground rent	$ 388,790	$ 311,502
Notes receivable	83,658	87,515
Other miscellaneous assets	260,455	176,229
Balance	$ 732,903	$ 575,246
[1]	December 31, 2014 balances have been revised to reflect purchase accounting measurement period adjustments and debt issuance costs.

Acquisitions (Narrative) (Detai

Acquisitions (Narrative) (Details) $ / shares in Units, BRL in Millions, ₨ in Billions

Dec. 16, 2015USD ($)communications_site

Dec. 16, 2015BRLcommunications_site

Oct. 21, 2015USD ($)sitesystem

Oct. 21, 2015INR (₨)sitesystem

Sep. 30, 2015USD ($)communications_site

Sep. 30, 2015BRLcommunications_site

Jul. 01, 2015USD ($)communications_site

Apr. 29, 2015USD ($)communications_site

Apr. 29, 2015BRLcommunications_site

Mar. 27, 2015USD ($)communications_sitesiterenewal_period

Nov. 19, 2014USD ($)towerproperty_interest

Apr. 03, 2014USD ($)communications_siteproperty_interest

Dec. 31, 2015USD ($)communications_siteproperty_interest$ / shares

Dec. 31, 2014USD ($)communications_siteproperty_interest

Dec. 31, 2013USD ($)

Dec. 31, 2015BRLcommunications_siteproperty_interest

Business Acquisition [Line Items]

Business combination, acquisition and merger related expenses

[1]

$ 18,799,000

$ 26,969,000

$ 36,172,000

Integration related costs

18,097,000

13,057,000

1,424,000

Contingent consideration

12,436,000

[2]

28,524,000

$ 31,890,000

Long-term debt

17,119,009,000

Value added tax and other consumption tax receivables

30,239,000

23,228,000

[3]

Secured Debt | BR Towers Debentures

Business Acquisition [Line Items]

Long-term debt

$ 85,219,000

[4],[5]

118,688,000

[5],[6]

BRL 332.8

[4]

Series B Preferred Stock

Business Acquisition [Line Items]

Dividend rate, percentage

5.50%

Preferred stock, par value | $ / shares

$ 0.01

Verizon Transaction

Business Acquisition [Line Items]

Number of communications sites acquired | site

11,449

Verizon Transaction | Adjusted Purchase Price Allocation

Business Acquisition [Line Items]

Aggregate purchase price

[7]

$ 5,066,043,000

Verizon Transaction | Leased Sites

Business Acquisition [Line Items]

Capital leased assets, number of units | communications_site

11,286

11,286

11,286

Right to lease, weighted average term

28 years

Initial Lease Term

10 years

Successive terms to renew lease | renewal_period

8

Renewal term

5 years

Future monthly sublease rent per tower

$ 1,900

Fixed annual rent escalation percentage

2.00%

Verizon Transaction | Leased Sites | Adjusted Purchase Price Allocation

Business Acquisition [Line Items]

Aggregate purchase price

$ 4,959,006,000

Verizon Transaction | Owned Sites

Business Acquisition [Line Items]

Number of communications sites acquired | communications_site

163

Verizon Transaction | Owned Sites | Adjusted Purchase Price Allocation

Business Acquisition [Line Items]

Aggregate purchase price

$ 99,000,000

Airtel Acquisition

Business Acquisition [Line Items]

Number of communications sites acquired | communications_site

4,699

17

17

Airtel Acquisition | Preliminary Purchase Price Allocation

Business Acquisition [Line Items]

Aggregate purchase price

$ 1,112,000,000

$ 1,112,356,000

TIM Acquisition

Business Acquisition [Line Items]

Number of communications sites acquired | communications_site

182

182

1,125

1,125

4,176

4,176

Letters of credit, amount outstanding

10,400,000

BRL 40.6

TIM Acquisition | Preliminary Purchase Price Allocation

Business Acquisition [Line Items]

Aggregate purchase price

$ 21,700,000

BRL 84.1

$ 130,900,000

BRL 516.9

$ 644,300,000

BRL 1,900

$ 796,867,000

Other International Acquisitions 2015

Business Acquisition [Line Items]

Number of communications sites acquired | communications_site

439

439

Other International Acquisitions 2015 | Preliminary Purchase Price Allocation

Business Acquisition [Line Items]

Aggregate purchase price

$ 22,500,000

Contingent consideration

$ 300,000

Other Us Acquisition 2015

Business Acquisition [Line Items]

Number of communications sites acquired | communications_site

210

210

Number of property interests acquired | property_interest

4

4

Other Us Acquisition 2015 | Preliminary Purchase Price Allocation

Business Acquisition [Line Items]

Aggregate purchase price

$ 142,400,000

Contingent consideration

1,300,000

BR Towers

Business Acquisition [Line Items]

Number of communications sites acquired | tower

2,504

Number of property interests acquired | property_interest

4

Additional sites to be acquired | tower

2,113

right to use property interests acquired | property_interest

43

BR Towers | Preliminary Purchase Price Allocation

Business Acquisition [Line Items]

Aggregate purchase price

$ 568,900,000

568,890,000

Preferred stock assumed through acquisitions

61,056,000

Noncash or part noncash acquisition, value of liabilities assumed

[8]

$ 261,100,000

261,136,000

BR Towers | Adjusted Purchase Price Allocation

Business Acquisition [Line Items]

Aggregate purchase price

[9]

558,723,000

Preferred stock assumed through acquisitions

[9]

61,056,000

Noncash or part noncash acquisition, value of liabilities assumed

[8],[9]

261,136,000

Richland Acquisition

Business Acquisition [Line Items]

Number of communications sites acquired | communications_site

59

Number of property interests acquired | property_interest

4

Noncash or part noncash acquisition, value of liabilities assumed

$ 196,500,000

Richland Acquisition | Preliminary Purchase Price Allocation

Business Acquisition [Line Items]

Aggregate purchase price

$ 189,400,000

189,379,000

Preferred stock assumed through acquisitions

0

Noncash or part noncash acquisition, value of liabilities assumed

[8]

$ 201,999,000

Richland Acquisition | Adjusted Purchase Price Allocation

Business Acquisition [Line Items]

Aggregate purchase price

[9]

188,918,000

Preferred stock assumed through acquisitions

[9]

0

Noncash or part noncash acquisition, value of liabilities assumed

[8],[9]

201,999,000

Other International Acquisitions 2014

Business Acquisition [Line Items]

Number of communications sites acquired | communications_site

159

Aggregate purchase price

$ 28,300,000

Value added tax and other consumption tax receivables

$ 1,200,000

Other International Acquisitions 2014 | Mexico

Business Acquisition [Line Items]

Number of communications sites acquired | communications_site

299

Aggregate purchase price

$ 40,300,000

Noncash or part noncash acquisition, value of liabilities assumed

3,400,000

Value added tax and other consumption tax receivables

5,600,000

Consideration transferred, other

36,300,000

Partial cash consideration transferred

$ 4,000,000

Other US Acquisition 2014

Business Acquisition [Line Items]

Number of communications sites acquired | communications_site

184

Aggregate purchase price

$ 180,800,000

Contingent consideration

$ 6,300,000

Number of property interests acquired | property_interest

6

Viom Transaction

Business Acquisition [Line Items]

Number of communications sites acquired | site

42,000

42,000

Aggregate purchase price

$ 1,200,000,000

₨ 76

Distributed antenna systems acquired | system

200

200

Percentage of voting interest acquired

51.00%

51.00%

2015 Acquisitions

Business Acquisition [Line Items]

Business combination, pro forma information, revenue of acquiree since acquisition date, actual

455,800,000

Business combination pro forma information gross margin of acquiree since acquisition date actual

$ 218,900,000

[1]

Acquisition and merger related expenses for the year ended December 31, 2015 does not reflect transaction costs related to the Verizon Transaction, as these costs have been capitalized as part of the assets’ fair value.

[2]

Estimate is determined using a probability weighted average of expected outcomes as of December 31, 2015.

[3]

December 31, 2014 balances have been revised to reflect purchase accounting measurement period adjustments.

[4]

Maturity date reflects the anticipated repayment date; final legal maturity is March 15, 2043.

[5]

Publicly issued debentures assumed in connection with the acquisition of BR Towers and denominated in BRL. Debt accrues interest at a variable rate.

[6]

December 31, 2014 balances have been revised to reflect debt issuance costs as a direct deduction from the carrying amounts, with the exception of debt issuance costs associated with the 2013 Credit Facility and the 2014 Credit Facility (as defined below) which are reflected in Notes receivable and other non-current assets on the consolidated balance sheets. Amortization of deferred financing costs is included in interest expense on the consolidated statements of operations.

[7]

Includes $6.6 million of accrued costs that have not been paid as of December 31, 2015.

[8]

Assumed BR Towers debt approximated fair value at the date of acquisition and included $11.5 million of current indebtedness. Assumed Richland debt included $196.5 million of Richland’s indebtedness and a fair value adjustment of $5.5 million. The fair value adjustments were based primarily on reported market values using Level 2 inputs.

[9]

The allocation of the purchase price was finalized during the year ended December 31, 2015.

Acquisitions (Schedule of Aggre

Acquisitions (Schedule of Aggregate Purchase Consideration Paid and the Amount of Assets Acquired) (Details) $ in Thousands, BRL in Millions

Dec. 16, 2015USD ($)

Dec. 16, 2015BRL

Sep. 30, 2015USD ($)

Sep. 30, 2015BRL

Jul. 01, 2015USD ($)

Apr. 29, 2015USD ($)

Apr. 29, 2015BRL

Nov. 19, 2014USD ($)

Apr. 03, 2014USD ($)

Dec. 31, 2015USD ($)

Dec. 31, 2014USD ($)

Dec. 31, 2013USD ($)

Business Acquisition [Line Items]

Goodwill

$ 4,091,805

$ 4,032,174

[1]

$ 3,854,802

Fair value of debt assumed through acquisitions

$ 0

$ 463,135

$ 1,576,186

Finite-lived intangible asset, useful life

11 years

Maximum | Customer Relationships

Business Acquisition [Line Items]

Finite-lived intangible asset, useful life

20 years

Maximum | Acquired Network Location

Business Acquisition [Line Items]

Finite-lived intangible asset, useful life

[2]

20 years

Preliminary Purchase Price Allocation | Maximum | Customer Relationships

Business Acquisition [Line Items]

Finite-lived intangible asset, useful life

20 years

20 years

Verizon Transaction | Adjusted Purchase Price Allocation

Business Acquisition [Line Items]

Aggregate purchase price

[3]

$ 5,066,043

Verizon Transaction | Leased Sites

Business Acquisition [Line Items]

Business acquisition, transaction costs, amount not yet paid

6,600

Verizon Transaction | Leased Sites | Adjusted Purchase Price Allocation

Business Acquisition [Line Items]

Aggregate purchase price

4,959,006

Business acquisition, transaction costs

8,037

Fair value of net assets acquired

4,967,043

Current assets

14,132

Non-current assets

53,339

Property and equipment

2,094,678

Customer-related intangible assets

[4]

1,886,443

Network location intangible assets

[4]

1,186,428

Current liabilities

(31,012)

Other non-current liabilities

[5]

(236,965)

Verizon Transaction | Owned Sites | Adjusted Purchase Price Allocation

Business Acquisition [Line Items]

Aggregate purchase price

99,000

Airtel Acquisition | Preliminary Purchase Price Allocation

Business Acquisition [Line Items]

Aggregate purchase price

$ 1,112,000

1,112,356

Fair value of net assets acquired

1,112,356

Current assets

15,828

Non-current assets

69,277

Property and equipment

415,246

Customer-related intangible assets

[6]

231,788

Network location intangible assets

[6]

328,334

Current liabilities

(4,246)

Other non-current liabilities

(12,534)

Fair value of net assets acquired

1,043,693

Goodwill

[7]

68,663

Fair value of debt assumed through acquisitions

0

TIM Acquisition | Preliminary Purchase Price Allocation

Business Acquisition [Line Items]

Aggregate purchase price

$ 21,700

BRL 84.1

$ 130,900

BRL 516.9

$ 644,300

BRL 1,900

796,867

Fair value of net assets acquired

796,867

Current assets

0

Non-current assets

0

Property and equipment

275,630

Customer-related intangible assets

[6]

361,822

Network location intangible assets

[6]

115,562

Current liabilities

(3,192)

Other non-current liabilities

(74,966)

Fair value of net assets acquired

674,856

Goodwill

[7]

122,011

Fair value of debt assumed through acquisitions

0

Other Acquisition 2015 | Preliminary Purchase Price Allocation

Business Acquisition [Line Items]

Aggregate purchase price

164,875

Fair value of net assets acquired

164,875

Current assets

1,113

Non-current assets

995

Property and equipment

42,716

Customer-related intangible assets

[6]

63,001

Network location intangible assets

[6]

37,691

Current liabilities

(624)

Other non-current liabilities

(4,028)

Fair value of net assets acquired

140,864

Goodwill

[7]

24,011

Fair value of debt assumed through acquisitions

0

Richland Acquisition

Business Acquisition [Line Items]

Noncash or part noncash acquisition, value of liabilities assumed

$ (196,500)

Liabilities, fair value adjustment

5,500

Richland Acquisition | Preliminary Purchase Price Allocation

Business Acquisition [Line Items]

Aggregate purchase price

$ 189,400

$ 189,379

Fair value of net assets acquired

391,378

Current assets

8,583

Non-current assets

0

Property and equipment

185,777

Customer-related intangible assets

[8]

169,452

Current liabilities

(3,635)

Other non-current liabilities

(2,922)

Fair value of net assets acquired

358,955

Goodwill

[9]

32,423

Noncash or part noncash acquisition, value of liabilities assumed

[10]

(201,999)

Preferred stock assumed through acquisitions

0

Richland Acquisition | Preliminary Purchase Price Allocation | Acquired Network Location

Business Acquisition [Line Items]

Network location intangible assets

[8]

1,700

Other intangible assets, net

[8]

0

Richland Acquisition | Adjusted Purchase Price Allocation

Business Acquisition [Line Items]

Aggregate purchase price

[11]

188,918

Fair value of net assets acquired

[11]

390,917

Current assets

[11]

8,583

Non-current assets

[11]

0

Property and equipment

[11]

154,899

Customer-related intangible assets

[8],[11]

186,455

Current liabilities

[11]

(3,635)

Other non-current liabilities

[11]

(2,922)

Fair value of net assets acquired

[11]

346,789

Goodwill

[9],[11]

44,128

Noncash or part noncash acquisition, value of liabilities assumed

[10],[11]

(201,999)

Preferred stock assumed through acquisitions

[11]

0

Richland Acquisition | Adjusted Purchase Price Allocation | Acquired Network Location

Business Acquisition [Line Items]

Network location intangible assets

[8],[11]

3,409

Other intangible assets, net

[8],[11]

0

BR Towers

Business Acquisition [Line Items]

Noncash or part noncash acquisition, value of liabilities assumed, current portion

$ 11,500

BR Towers | Preliminary Purchase Price Allocation

Business Acquisition [Line Items]

Aggregate purchase price

568,900

568,890

Fair value of net assets acquired

891,082

Current assets

31,832

Non-current assets

9,135

Property and equipment

141,422

Customer-related intangible assets

[8]

495,279

Current liabilities

(23,930)

Other non-current liabilities

(101,508)

Fair value of net assets acquired

726,127

Goodwill

[9]

164,955

Noncash or part noncash acquisition, value of liabilities assumed

[10]

$ (261,100)

(261,136)

Preferred stock assumed through acquisitions

(61,056)

BR Towers | Preliminary Purchase Price Allocation | Acquired Network Location

Business Acquisition [Line Items]

Network location intangible assets

[8]

136,233

Other intangible assets, net

[8]

37,664

BR Towers | Adjusted Purchase Price Allocation

Business Acquisition [Line Items]

Aggregate purchase price

[11]

558,723

Fair value of net assets acquired

[11]

880,915

Current assets

[11]

31,568

Non-current assets

[11]

9,365

Property and equipment

[11]

135,916

Customer-related intangible assets

[8],[11]

495,151

Current liabilities

[11]

(24,012)

Other non-current liabilities

[11]

(101,814)

Fair value of net assets acquired

[11]

714,818

Goodwill

[9],[11]

166,097

Noncash or part noncash acquisition, value of liabilities assumed

[10],[11]

(261,136)

Preferred stock assumed through acquisitions

[11]

(61,056)

BR Towers | Adjusted Purchase Price Allocation | Acquired Network Location

Business Acquisition [Line Items]

Network location intangible assets

[8],[11]

135,549

Other intangible assets, net

[8],[11]

33,095

Other Acquisition 2014 | Preliminary Purchase Price Allocation

Business Acquisition [Line Items]

Aggregate purchase price

249,471

Fair value of net assets acquired

249,471

Current assets

7,869

Non-current assets

1,521

Property and equipment

70,638

Customer-related intangible assets

[8]

110,207

Current liabilities

(2,860)

Other non-current liabilities

(7,938)

Fair value of net assets acquired

229,636

Goodwill

[9]

19,835

Noncash or part noncash acquisition, value of liabilities assumed

[10]

0

Preferred stock assumed through acquisitions

0

Other Acquisition 2014 | Preliminary Purchase Price Allocation | Acquired Network Location

Business Acquisition [Line Items]

Network location intangible assets

[8]

50,199

Other intangible assets, net

[8]

0

Other Acquisition 2014 | Adjusted Purchase Price Allocation

Business Acquisition [Line Items]

Aggregate purchase price

[11]

249,471

Fair value of net assets acquired

[11]

249,471

Current assets

[11]

7,404

Non-current assets

[11]

2,562

Property and equipment

[11]

70,317

Customer-related intangible assets

[8],[11]

108,707

Current liabilities

[11]

(2,860)

Other non-current liabilities

[11]

(7,938)

Fair value of net assets acquired

[11]

227,391

Goodwill

[9],[11]

22,080

Noncash or part noncash acquisition, value of liabilities assumed

[10],[11]

0

Preferred stock assumed through acquisitions

[11]

0

Other Acquisition 2014 | Adjusted Purchase Price Allocation | Acquired Network Location

Business Acquisition [Line Items]

Network location intangible assets

[8],[11]

49,199

Other intangible assets, net

[8],[11]

$ 0

Other International Acquisitions 2014

Business Acquisition [Line Items]

Aggregate purchase price

28,300

Other US Acquisition 2014

Business Acquisition [Line Items]

Aggregate purchase price

$ 180,800

[1]

Balances have been revised to reflect purchase accounting measurement period adjustments.

[2]

Acquired network location intangibles are amortized over the shorter of the term of the corresponding ground lease taking into consideration lease renewal options and residual value or up to 20 years, as the Company considers these intangibles to be directly related to the tower assets.

[3]

Includes $6.6 million of accrued costs that have not been paid as of December 31, 2015.

[4]

Customer-related intangible assets and network location intangible assets are amortized on a straight-line basis over periods of up to 20 years.

[5]

Primarily represents liabilities recorded for asset retirement obligations.

[6]

Customer-related intangible assets and network location intangible assets are amortized on a straight-line basis over periods of up to 20 years.

[7]

Goodwill was allocated to the Company’s property segments. The Company expects goodwill recorded in its U.S. and Asia property segments will be deductible for local tax purposes. The Company expects goodwill recorded in its Europe, Middle East and Africa (“EMEA”) property segment will not be deductible for local tax purposes and goodwill recorded in its Latin America property segment will be deductible in certain jurisdictions for local tax purposes.

[8]

Customer-related intangible assets and network location intangible assets are amortized on a straight-line basis over periods of up to 20 years. Other intangible assets are amortized on a straight-line basis over the life of the lease, which is a period of 11 years.

[9]

Goodwill was allocated to the Company’s property operating segments, as applicable, and the Company expects goodwill recorded will be deductible for local tax purposes except for goodwill associated with BR Towers, where goodwill is expected to be partially deductible.

[10]

Assumed BR Towers debt approximated fair value at the date of acquisition and included $11.5 million of current indebtedness. Assumed Richland debt included $196.5 million of Richland’s indebtedness and a fair value adjustment of $5.5 million. The fair value adjustments were based primarily on reported market values using Level 2 inputs.

[11]

The allocation of the purchase price was finalized during the year ended December 31, 2015.

Acquisitions (Pro Forma Informa

Acquisitions (Pro Forma Information) (Details) - USD ($) $ / shares in Units, $ in Thousands	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014
Business Acquisition, Pro Forma Information [Abstract]
Pro forma operating revenues	$ 5,034,746	$ 5,000,208
Pro forma net income attributable to American Tower Corporation	$ 564,579	$ 587,999
Basic net income attributable to American Tower Corporation (in dollars per share)	$ 1.33	$ 1.39
Diluted net income attributable to American Tower Corporation (in dollars per share)	$ 1.32	$ 1.38

Acquisitions - Schedule Of Busi

Acquisitions - Schedule Of Business Acquisitions By Acquisition Contingent Consideration (Details) - USD ($) $ in Thousands		12 Months Ended
		Dec. 31, 2015		Dec. 31, 2014	Dec. 31, 2013
Business Acquisition [Line Items]
Fair value of debt assumed through acquisitions		$ 0		$ 463,135	$ 1,576,186
Contingent consideration, maximum potential value	[1]	26,052
Contingent consideration		12,436	[2]	28,524	$ 31,890
Contingent consideration, additions	[3]	1,626
Contingent consideration, settlements		(7,943)
Change in fair value		(4,781)		$ (225)
Colombia
Business Acquisition [Line Items]
Contingent consideration, maximum potential value	[1]	22,444
Contingent consideration	[2]	9,829
Contingent consideration, additions	[3]	0
Contingent consideration, settlements		0
Change in fair value		(5,011)
Costa Rica
Business Acquisition [Line Items]
Contingent consideration, maximum potential value	[1]	0
Contingent consideration	[2]	0
Contingent consideration, additions	[3]	0
Contingent consideration, settlements		(1,898)
Change in fair value		0
Ghana
Business Acquisition [Line Items]
Contingent consideration, maximum potential value	[1]	569
Contingent consideration	[2]	569
Contingent consideration, additions	[3]	0
Contingent consideration, settlements		0
Change in fair value		99
India
Business Acquisition [Line Items]
Contingent consideration, maximum potential value	[1]	1,164
Contingent consideration	[2]	163
Contingent consideration, additions	[3]	315
Contingent consideration, settlements		(139)
Change in fair value		0
United States
Business Acquisition [Line Items]
Contingent consideration, maximum potential value	[1]	1,875
Contingent consideration	[2]	1,875
Contingent consideration, additions	[3]	1,311
Contingent consideration, settlements		(5,906)
Change in fair value		$ 131
[1]	The maximum potential value is based on exchange rates at December 31, 2015. The minimum value could be zero.
[2]	Estimate is determined using a probability weighted average of expected outcomes as of December 31, 2015.
[3]	Based on preliminary acquisition accounting upon closing of certain acquisitions during the year ended December 31, 2015.

Accrued Expenses (Details)

Accrued Expenses (Details) - USD ($) $ in Thousands	Dec. 31, 2015	Dec. 31, 2014	[1]
Accrued Liabilities, Current [Abstract]
Accrued property and real estate taxes	$ 75,827	$ 61,206
Payroll and related withholdings	62,334	57,110
Accrued rent	54,732	34,074
Accrued construction costs	19,857	46,024
Other accrued expenses	303,663	219,422
Balance	$ 516,413	$ 417,836
[1]	December 31, 2014 balances have been revised to reflect purchase accounting measurement period adjustments.

Long-Term Obligations (Narrativ

Long-Term Obligations (Narrative) (Details) ₨ in Millions, GHS in Millions, MXN in Billions, COP in Billions		Dec. 23, 2015USD ($)	Dec. 23, 2015ZAR	May. 29, 2015USD ($)	May. 07, 2015USD ($)	Apr. 29, 2015USD ($)	Feb. 11, 2015USD ($)	May. 31, 2015USD ($)	May. 31, 2015MXN	Nov. 30, 2014BRL	Oct. 31, 2014USD ($)	Mar. 31, 2013USD ($)site	Dec. 31, 2015USD ($)sitequarterproperty_interest		Dec. 31, 2015INR (₨)	Dec. 31, 2015GHS	Dec. 31, 2014USD ($)		Dec. 31, 2013USD ($)	Dec. 31, 2015COPsitequarterproperty_interest		Dec. 31, 2015GHSsitequarterproperty_interest		Dec. 31, 2015BRLsitequarterproperty_interest		Dec. 31, 2015ZARsitequarterproperty_interest		Dec. 19, 2015ZAR	Oct. 28, 2015USD ($)	Oct. 27, 2015USD ($)	Sep. 30, 2015USD ($)	Feb. 28, 2015USD ($)	Feb. 20, 2015USD ($)	Dec. 31, 2014BRL	Oct. 31, 2014COP	Apr. 30, 2013USD ($)
Debt Instrument [Line Items]
Long-term debt													$ 17,119,009,000
Fair value of debt assumed through acquisitions													0				$ 463,135,000		$ 1,576,186,000
Interest costs capitalized													1,800,000				2,800,000		1,800,000
Borrowings under credit facilities													6,126,618,000				2,187,000,000		3,507,000,000
Extinguishment of Debt, Gain (Loss), Net of Tax													(79,750,000)				(3,379,000)		(35,288,000)
Accrued interest													115,672,000				130,265,000
Loss on retirement of long-term obligations													(79,606,000)				(3,473,000)		$ (38,701,000)
Capital lease obligations													$ 110,900,000				93,700,000
Capital lease obligation and notes payable, interest rates, minimum													2.40%							2.40%		2.40%		2.40%		2.40%
Capital lease obligation and notes payable, interest rate, maximum													9.25%							9.25%		9.25%		9.25%		9.25%
Capital lease obligation and notes payable, interest maturity, minimum													1 year		1 year	1 year
Capital lease obligation and notes payable, maturity, maximum													70 years		70 years	70 years
Senior Notes
Debt Instrument [Line Items]
Extinguishment of Debt, Gain (Loss), Net of Tax													$ (3,700,000)
Senior Notes
Debt Instrument [Line Items]
Maximum Adjusted EBITDA													3.5							3.5		3.5		3.5		3.5
Commercial Mortgage Pass Through Certificates Series 2013 | Secured Debt
Debt Instrument [Line Items]
Long-term debt												$ 1,800,000,000
Proceeds from the issuance of debt												$ 1,780,000,000
Number of communications sites | site												5,186
Weighted average life, years												8 years 7 months
Weighted average, interest rate												2.648%
Cash Trap Debt Service Credit Ratio													1.3							1.3		1.3		1.3		1.3
Debt Instrument, Covenant, Number of Consecutive Quarters Required For Release of Funds | quarter													2							2		2		2		2
Minimum, DSCR													1.15							1.15		1.15		1.15		1.15
Debt Instrument, Covenant, Threshold For Majority Of Holders In Event Of Default													50.00%		50.00%	50.00%
Restricted cash													$ 95,000,000
Series 2015-1 Class A | Secured Debt
Debt Instrument [Line Items]
Long-term debt				$ 350,000,000									$ 346,262,000	[1]			0	[1],[2]
Long-term debt, stated interest rate	[1],[3]												2.35%							2.35%		2.35%		2.35%		2.35%
Series 2015-2 Class A | Secured Debt
Debt Instrument [Line Items]
Long-term debt				$ 525,000,000									$ 518,776,000	[4]			0	[2],[4]
Long-term debt, stated interest rate	[3],[4]												3.482%							3.482%		3.482%		3.482%		3.482%
Commercial Mortgage Pass Through Certificates Series 2015 | Secured Debt
Debt Instrument [Line Items]
Number of communications sites | site													3,609							3,609		3,609		3,609		3,609
Weighted average life, years				8 years 1 month
Weighted average, interest rate				3.029%
Cash Trap Debt Service Credit Ratio													1.3							1.3		1.3		1.3		1.3
Debt Instrument, Covenant, Number of Consecutive Quarters Required For Release of Funds | quarter													2							2		2		2		2
Minimum, DSCR													1.15							1.15		1.15		1.15		1.15
Debt Instrument, Covenant, Threshold For Majority Of Holders In Event Of Default													50.00%		50.00%	50.00%
Restricted cash													$ 16,300,000
GTP Notes | Secured Debt
Debt Instrument [Line Items]
Long-term debt	[5],[6]												$ 281,902,000				290,586,000	[2]
Number of communications sites | site													105							105		105		105		105
Restricted cash													$ 5,300,000
Principal amount	[7]												272,100,000
Debt Instrument, Unamortized Premium	[7]												$ 9,800,000
Property interests under communications sites | property_interest													1,064							1,064		1,064		1,064		1,064
GTP Notes | Secured Debt | Minimum
Debt Instrument [Line Items]
Long-term debt, stated interest rate	[2]												3.721%							3.721%		3.721%		3.721%		3.721%
GTP Notes | Secured Debt | Maximum
Debt Instrument [Line Items]
Long-term debt, stated interest rate	[2]												7.358%							7.358%		7.358%		7.358%		7.358%
GTP Notes | Secured Debt | Series 2012-1 Class A Notes
Debt Instrument [Line Items]
Long-term debt, stated interest rate													3.721%							3.721%		3.721%		3.721%		3.721%
GTP Notes | Secured Debt | Series 2012-2 Class A Notes
Debt Instrument [Line Items]
Long-term debt, stated interest rate													4.336%							4.336%		4.336%		4.336%		4.336%
GTP Notes | Secured Debt | Series 2012-2 Class B Notes
Debt Instrument [Line Items]
Long-term debt, stated interest rate													6.413%							6.413%		6.413%		6.413%		6.413%
GTP Notes | Secured Debt | Series 2012-2 Class C Notes
Debt Instrument [Line Items]
Long-term debt, stated interest rate													7.358%							7.358%		7.358%		7.358%		7.358%
Secured Cellular Site Revenue Notes | Secured Debt
Debt Instrument [Line Items]
Long-term debt	[8]												$ 201,930,000				203,683,000	[2]
Restricted cash													4,900,000
Principal amount	[1]												196,000,000
Debt Instrument, Unamortized Premium	[1]												$ 5,900,000
Property interests under communications sites | property_interest													1,516							1,516		1,516		1,516		1,516
Secured Cellular Site Revenue Notes | Secured Debt | Minimum
Debt Instrument [Line Items]
Long-term debt, stated interest rate	[2]												5.349%							5.349%		5.349%		5.349%		5.349%
Secured Cellular Site Revenue Notes | Secured Debt | Maximum
Debt Instrument [Line Items]
Long-term debt, stated interest rate	[2]												9.522%							9.522%		9.522%		9.522%		9.522%
Secured Cellular Site Revenue Notes | Secured Debt | Series 2010-1 Class C
Debt Instrument [Line Items]
Long-term debt, stated interest rate													5.349%							5.349%		5.349%		5.349%		5.349%
Secured Cellular Site Revenue Notes | Secured Debt | Series 2010-2 Class C
Debt Instrument [Line Items]
Long-term debt, stated interest rate													6.392%							6.392%		6.392%		6.392%		6.392%
Secured Cellular Site Revenue Notes | Secured Debt | Series 2010-2 Class F
Debt Instrument [Line Items]
Long-term debt, stated interest rate													9.522%							9.522%		9.522%		9.522%		9.522%
BR Towers Debentures | Secured Debt
Debt Instrument [Line Items]
Long-term debt													$ 85,219,000	[7],[9]			118,688,000	[2],[9]						BRL 332,800,000	[7]
Debt Instrument, Interest Rate, Effective Percentage	[3],[9]												7.40%							7.40%		7.40%		7.40%		7.40%
BR Towers Debentures | Unsecured Debt
Debt Instrument [Line Items]
Long-term debt | BRL										BRL 300,000,000
Fair value of debt assumed through acquisitions										313,100,000			$ 80,200,000
BR Towers Credit Facility | Unsecured Debt
Debt Instrument [Line Items]
Long-term Debt, Fair Value | BRL										BRL 48,100,000
BR Towers Credit Facility | Unsecured Debt | Revolving Credit Facility | Minimum
Debt Instrument [Line Items]
Long-term debt, stated interest rate	[2]												3.50%							3.50%		3.50%		3.50%		3.50%
BR Towers Credit Facility | Unsecured Debt | Revolving Credit Facility | Maximum
Debt Instrument [Line Items]
Long-term debt, stated interest rate	[2]												10.80%							10.80%		10.80%		10.80%		10.80%
BR Towers Credit Facility | Revolving Credit Facility
Debt Instrument [Line Items]
Long-term debt													$ 0				16,389,000	[2]
Ghana Loan | Unsecured Debt
Debt Instrument [Line Items]
Long-term debt													$ 70,314,000	[10]			68,651,000					GHS 267.5
Long-term debt, stated interest rate													21.87%							21.87%		21.87%		21.87%		21.87%
Interest costs capitalized													$ 12,300,000			GHS 46.7
Uganda Loan | Unsecured Debt
Debt Instrument [Line Items]
Long-term debt													75,226,000	[11],[12]			69,004,000
Interest costs capitalized													$ 6,300,000
Debt Instrument, Interest Rate, Effective Percentage	[12]												6.066%							6.066%		6.066%		6.066%		6.066%
South African Facility | Revolving Credit Facility
Debt Instrument [Line Items]
Long-term debt	[13]												$ 53,175,000				73,156,000	[2]
Principal amount	[4],[5]												$ 53,700,000													ZAR 830,000,000
Long-term Line of Credit | ZAR																												ZAR 830,000,000
Borrowings under credit facilities	[4],[5]	$ 54,500,000	ZAR 830,000,000
Line of credit facility, optional additional commitments | ZAR																										ZAR 830,000,000
Base rate borrowing margin													1.95%							1.95%		1.95%		1.95%		1.95%
Debt Instrument, Interest Rate, Effective Percentage	[3],[13]												8.575%							8.575%		8.575%		8.575%		8.575%
2014 Colombian Long Term Credit Facility | Revolving Credit Facility
Debt Instrument [Line Items]
Principal amount													$ 60,300,000							COP 190
Line of credit facility, maximum borrowing capacity											$ 63,500,000																								COP 200
Basis spread on variable rate											4.00%
Derivative, Variable Interest Rate													9.80%							9.80%		9.80%		9.80%		9.80%
Brazil Credit Facility
Debt Instrument [Line Items]
Long-term debt	[14]												$ 21,868,000				0	[2]
Brazil Credit Facility | Unsecured Debt
Debt Instrument [Line Items]
Line of credit facility, maximum borrowing capacity													$ 69,400,000																					BRL 271,000,000
Indian Facility | Revolving Credit Facility
Debt Instrument [Line Items]
Long-term debt, stated interest rate	[3],[15]												9.70%							9.70%		9.70%		9.70%		9.70%
Borrowings under credit facilities													$ 8,800,000		₨ 579
Line of credit facility, maximum borrowing capacity																																				$ 10,000,000
Mexican loan | Secured Debt
Debt Instrument [Line Items]
Long-term debt													0				263,426,000	[2]
Mexican loan | Unsecured Debt
Debt Instrument [Line Items]
Bridge Loan | MXN									MXN 5.2
Repayments of Unsecured Debt								$ 251,200,000	MXN 3.9
Credit Facility 2014 | Revolving Credit Facility
Debt Instrument [Line Items]
Long-term Line of Credit	[16]												1,980,000,000				1,100,000,000	[2]
Borrowings under credit facilities													2,100,000,000
Line of credit facility, optional additional commitments																																	$ 500,000,000
Line of credit facility, maximum borrowing capacity																																	2,000,000,000
Maximum revolving loan commitments																																$ 2,500,000,000
Repayment of indebtedness under credit facility													1,300,000,000
Letters of credit, amount outstanding													$ 7,400,000
Annual renewal periods, number													2		2	2
Line of credit facility, commitment fee percentage													0.15%		0.15%	0.15%
Debt Instrument, Interest Rate, Effective Percentage	[3],[16]												1.68%							1.68%		1.68%		1.68%		1.68%
Credit Facility 2014 | Revolving Credit Facility | London Interbank Offered Rate (LIBOR)
Debt Instrument [Line Items]
Basis spread on variable rate													1.25%		1.25%	1.25%
Credit Facility 2014 | Revolving Credit Facility | Minimum
Debt Instrument [Line Items]
Line of credit facility, commitment fee percentage													0.10%		0.10%	0.10%
Credit Facility 2014 | Revolving Credit Facility | Maximum
Debt Instrument [Line Items]
Line of credit facility, commitment fee percentage													0.40%		0.40%	0.40%
Credit Facility 2014 | Revolving Credit Facility | Letter of Credit
Debt Instrument [Line Items]
Line of credit facility, capacity available																																	200,000,000
Credit Facility 2014 | Revolving Credit Facility | Swingline Loan
Debt Instrument [Line Items]
Line of credit facility, capacity available																																	50,000,000
Credit Facility 2014 | Revolving Credit Facility | Third measurement period
Debt Instrument [Line Items]
Ratio of total debt to EBITDA																																7
Credit Facility 2014 | Revolving Credit Facility | Fourth measurement period
Debt Instrument [Line Items]
Ratio of total debt to EBITDA																																6
Credit Facility 2014 | Unsecured Debt | Minimum | London Interbank Offered Rate (LIBOR)
Debt Instrument [Line Items]
Basis spread on variable rate													1.00%		1.00%	1.00%
Credit Facility 2014 | Unsecured Debt | Maximum | London Interbank Offered Rate (LIBOR)
Debt Instrument [Line Items]
Basis spread on variable rate													2.00%		2.00%	2.00%
Credit Facility 2014 | Unsecured Debt | Maximum | Base Rate
Debt Instrument [Line Items]
Basis spread on variable rate													1.00%		1.00%	1.00%
Credit Facility 2014 | Revolving Credit Facility
Debt Instrument [Line Items]
Debt covenant, threshold on indebtedness													$ 250																$ 300
Term Loan 2013 | Revolving Credit Facility | London Interbank Offered Rate (LIBOR)
Debt Instrument [Line Items]
Basis spread on variable rate													1.25%		1.25%	1.25%
Term Loan 2013 | Unsecured Debt
Debt Instrument [Line Items]
Long-term debt	[16]												$ 1,993,601,000				1,495,284,000	[3]
Long-term Line of Credit													$ 2,000,000,000
Debt covenant, threshold on indebtedness																													300		$ 250
Term Loan, optional additional commitments																																	500,000,000
Debt Instrument, Interest Rate, Effective Percentage	[3],[16]												1.68%							1.68%		1.68%		1.68%		1.68%
Term Loan 2013 | Unsecured Debt | Minimum | London Interbank Offered Rate (LIBOR)
Debt Instrument [Line Items]
Basis spread on variable rate													1.00%		1.00%	1.00%
Term Loan 2013 | Unsecured Debt | Maximum | London Interbank Offered Rate (LIBOR)
Debt Instrument [Line Items]
Basis spread on variable rate													2.00%		2.00%	2.00%
Term Loan 2013 | Unsecured Debt | Maximum | Base Rate
Debt Instrument [Line Items]
Basis spread on variable rate													1.00%		1.00%	1.00%
Term Loan 2013 | Unsecured Debt | Third measurement period
Debt Instrument [Line Items]
Ratio of total debt to EBITDA													7							7		7		7		7
Term Loan 2013 | Unsecured Debt | Fourth measurement period
Debt Instrument [Line Items]
Ratio of total debt to EBITDA													6							6		6		6		6
Term Loan 2013 | Term Loan 2013
Debt Instrument [Line Items]
Maximum revolving loan commitments																																$ 1,000,000,000
Credit Facility 2013 | Revolving Credit Facility
Debt Instrument [Line Items]
Long-term Line of Credit	[16]												$ 1,225,000,000				0	[3]
Borrowings under credit facilities													4,000,000,000
Line of credit facility, optional additional commitments																																	750,000,000
Line of credit facility, maximum borrowing capacity																																	2,750,000,000
Maximum revolving loan commitments																																$ 3,500,000,000
Repayment of indebtedness under credit facility													2,700,000,000
Letters of credit, amount outstanding													$ 3,200,000
Annual renewal periods, number													2		2	2
Line of credit facility, commitment fee percentage													0.15%		0.15%	0.15%
Debt Instrument, Interest Rate, Effective Percentage	[3],[16]												1.652%							1.652%		1.652%		1.652%		1.652%
Credit Facility 2013 | Revolving Credit Facility | London Interbank Offered Rate (LIBOR)
Debt Instrument [Line Items]
Basis spread on variable rate													1.25%		1.25%	1.25%
Credit Facility 2013 | Revolving Credit Facility | Minimum
Debt Instrument [Line Items]
Line of credit facility, commitment fee percentage													0.10%		0.10%	0.10%
Credit Facility 2013 | Revolving Credit Facility | Maximum
Debt Instrument [Line Items]
Line of credit facility, commitment fee percentage													0.40%		0.40%	0.40%
Credit Facility 2013 | Revolving Credit Facility | Multicurrency Borrowings
Debt Instrument [Line Items]
Line of credit facility, capacity available																																	1,000,000,000
Credit Facility 2013 | Revolving Credit Facility | Letter of Credit
Debt Instrument [Line Items]
Line of credit facility, capacity available																																	200,000,000
Credit Facility 2013 | Revolving Credit Facility | Swingline Loan
Debt Instrument [Line Items]
Line of credit facility, capacity available																																	$ 50,000,000
Credit Facility 2013 | Unsecured Debt | Minimum | London Interbank Offered Rate (LIBOR)
Debt Instrument [Line Items]
Basis spread on variable rate													1.00%		1.00%	1.00%
Credit Facility 2013 | Unsecured Debt | Maximum | London Interbank Offered Rate (LIBOR)
Debt Instrument [Line Items]
Basis spread on variable rate													2.00%		2.00%	2.00%
Credit Facility 2013 | Unsecured Debt | Maximum | Base Rate
Debt Instrument [Line Items]
Basis spread on variable rate													1.00%		1.00%	1.00%
Credit Facility 2013 | Revolving Credit Facility
Debt Instrument [Line Items]
Debt covenant, threshold on indebtedness																													$ 300,000,000	$ 250,000,000
Credit Facility 2013 | Revolving Credit Facility | Third measurement period
Debt Instrument [Line Items]
Ratio of total debt to EBITDA													7							7		7		7		7
Credit Facility 2013 | Revolving Credit Facility | Fourth measurement period
Debt Instrument [Line Items]
Ratio of total debt to EBITDA													6							6		6		6		6
2.80% Senior Notes | Senior Notes
Debt Instrument [Line Items]
Long-term debt													$ 743,557,000				0	[2]
Proceeds from the issuance of debt					$ 1,480,100,000
Long-term debt, stated interest rate					2.80%								2.80%	[3]						2.80%	[3]	2.80%	[3]	2.80%	[3]	2.80%	[3]
Principal amount					$ 750,000,000								$ 750,000,000
4.00% Senior Notes | Senior Notes
Debt Instrument [Line Items]
Long-term debt													$ 739,057,000				0	[2]
Long-term debt, stated interest rate					4.00%								4.00%	[3]						4.00%	[3]	4.00%	[3]	4.00%	[3]	4.00%	[3]
Principal amount					$ 750,000,000								$ 750,000,000
3.40% Senior Notes | Senior Notes
Debt Instrument [Line Items]
Long-term debt													$ 999,769,000				999,607,000	[2]
Long-term debt, stated interest rate	[2],[3]												3.40%							3.40%		3.40%		3.40%		3.40%
Principal amount	[17]												$ 1,000,000,000
5.00% Senior Notes | Senior Notes
Debt Instrument [Line Items]
Long-term debt													$ 1,003,453,000				1,003,628,000	[2]
Long-term debt, stated interest rate	[2],[3]												5.00%							5.00%		5.00%		5.00%		5.00%
Principal amount	[17]												$ 1,000,000,000
Senior Notes | Senior Notes
Debt Instrument [Line Items]
Debt Instrument, Redemption Price, Percentage													100.00%		100.00%	100.00%
Repurchase price as a percentage of principal													101.00%							101.00%		101.00%		101.00%		101.00%
4.625% Senior Notes | Senior Notes
Debt Instrument [Line Items]
Long-term debt, stated interest rate							4.625%
4.625% Senior Notes | Senior Notes
Debt Instrument [Line Items]
Long-term debt													$ 0				599,720,000	[2]
Debt Instrument, Redemption Price, Percentage							100.5898%
Repayments of Senior Debt							$ 613,600,000
Accrued interest							10,000,000
7.00% Senior Notes | Senior Notes
Debt Instrument [Line Items]
Long-term debt													0				$ 497,750,000	[2]
Long-term debt, stated interest rate						7.00%
Debt Instrument, Redemption Price, Percentage						114.0629%
Repayments of Senior Debt						$ 571,700,000
Accrued interest							$ 1,400,000
Loss on retirement of long-term obligations													$ (74,300,000)
[1]	Maturity date reflects the anticipated repayment date; final legal maturity is June 15, 2045.
[2]	December 31, 2014 balances have been revised to reflect debt issuance costs as a direct deduction from the carrying amounts, with the exception of debt issuance costs associated with the 2013 Credit Facility and the 2014 Credit Facility (as defined below) which are reflected in Notes receivable and other non-current assets on the consolidated balance sheets. Amortization of deferred financing costs is included in interest expense on the consolidated statements of operations.
[3]	Represents the interest rate or maturity date as of December 31, 2015 and does not reflect the impact of interest rate swap agreements.
[4]	Maturity date reflects the anticipated repayment date; final legal maturity is June 15, 2050.
[5]	Anticipated repayment dates begin March 15, 2017.
[6]	Secured debt assumed in connection with the acquisition of MIP Tower Holdings LLC (“MIPT”).
[7]	Maturity date reflects the anticipated repayment date; final legal maturity is March 15, 2043.
[8]	Secured debt assumed in connection with the acquisition of certain legal entities holding a portfolio of property interests from Unison Holdings, LLC and Unison Site Management II, L.L.C. (together, “Unison”). Anticipated repayment dates begin April 15, 2017; final legal maturity date is April 15, 2040.
[9]	Publicly issued debentures assumed in connection with the acquisition of BR Towers and denominated in BRL. Debt accrues interest at a variable rate.
[10]	Denominated in GHS. As of December 31, 2015, the aggregate principal amount outstanding under the Ghana loan was 267.5 million GHS, which included 46.7 million GHS ($12.3 million) of interest which was capitalized during the year ended December 31, 2015.
[11]	Includes $6.3 million of interest which was capitalized during the year ended December 31, 2015.
[12]	Interest rate as of December 31, 2015. Interest accrues at a variable rate.
[13]	Denominated in South African Rand (“ZAR”). Debt accrues interest at a variable rate.
[14]	Denominated in BRL. Debt accrues interest at variable rate.
[15]	Denominated in INR. This agreement provides that the maturity date may be extended for additional 30-day periods.
[16]	Debt accrues interest at a variable rate.
[17]	The original issue date for the 3.40% Notes and the 5.00% Notes was August 19, 2013. The issue date for the reopened 3.40% Notes and the reopened 5.00% Notes was January 10, 2014.

Long-Term Obligations (Long-Ter

Long-Term Obligations (Long-Term Financing Arrangements) (Details) $ in Thousands, ZAR in Millions

Dec. 31, 2015USD ($)

Dec. 31, 2015BRL

Dec. 19, 2015ZAR

May. 29, 2015USD ($)

May. 07, 2015

Apr. 29, 2015

Dec. 31, 2014USD ($)

Nov. 30, 2014BRL

Mar. 31, 2013USD ($)

Debt Instrument [Line Items]

Long-term debt

$ 17,119,009

Other debt, including capital lease obligations

110,876

$ 93,710

[1]

Debt, long-term and short-term, combined amount

17,119,009

14,540,341

[1]

Less current portion long-term obligations

(50,202)

(897,386)

[1]

Long-term debt, excluding current maturities

17,068,807

13,642,955

[1]

Subsidiaries

Debt Instrument [Line Items]

Long-term debt

3,509,231

3,942,905

[1]

Parent

Debt Instrument [Line Items]

Long-term debt

13,498,902

10,503,726

[1]

South African Facility | Revolving Credit Facility

Debt Instrument [Line Items]

Long-term debt

[2]

$ 53,175

73,156

[1]

Long-term Line of Credit | ZAR

ZAR 830

Interest rate at period end

[2],[3]

8.575%

8.575%

Brazil Credit Facility

Debt Instrument [Line Items]

Long-term debt

[4]

$ 21,868

0

[1]

Indian Facility | Revolving Credit Facility

Debt Instrument [Line Items]

Short-term Debt

[5]

$ 8,752

0

[1]

Long-term debt, stated interest rate

[3],[5]

9.70%

9.70%

Credit Facility 2013 | Revolving Credit Facility

Debt Instrument [Line Items]

Long-term Line of Credit

[6]

$ 1,225,000

0

[3]

Interest rate at period end

[3],[6]

1.652%

1.652%

Credit Facility 2014 | Revolving Credit Facility

Debt Instrument [Line Items]

Long-term Line of Credit

[6]

$ 1,980,000

1,100,000

[1]

Interest rate at period end

[3],[6]

1.68%

1.68%

Secured Debt | Commercial Mortgage Pass Through Certificates Series 2013

Debt Instrument [Line Items]

Long-term debt

$ 1,800,000

Secured Debt | Commercial Mortgage Pass Through Certificates Series 2013 | Secured Tower Revenue Securities, Series 2013-1A

Debt Instrument [Line Items]

Long-term debt

[7]

$ 497,478

496,314

[1]

Long-term debt, stated interest rate

[3],[7]

1.551%

1.551%

Secured Debt | Commercial Mortgage Pass Through Certificates Series 2013 | Secured Tower Revenue Securities, Series 2013-2A

Debt Instrument [Line Items]

Long-term debt

[8]

$ 1,288,689

1,287,110

[1]

Long-term debt, stated interest rate

[3],[8]

3.07%

3.07%

Secured Debt | Series 2015-1 Class A

Debt Instrument [Line Items]

Long-term debt

$ 346,262

[9]

$ 350,000

0

[1],[9]

Long-term debt, stated interest rate

[3],[9]

2.35%

2.35%

Secured Debt | Series 2015-2 Class A

Debt Instrument [Line Items]

Long-term debt

$ 518,776

[10]

$ 525,000

0

[1],[10]

Long-term debt, stated interest rate

[3],[10]

3.482%

3.482%

Secured Debt | GTP AP

Debt Instrument [Line Items]

Long-term debt

[11]

$ 0

973,397

[1]

Secured Debt | GTP Notes

Debt Instrument [Line Items]

Long-term debt

[11],[12]

$ 281,902

290,586

[1]

Secured Debt | GTP Notes | Minimum

Debt Instrument [Line Items]

Long-term debt, stated interest rate

[1]

3.721%

3.721%

Secured Debt | GTP Notes | Maximum

Debt Instrument [Line Items]

Long-term debt, stated interest rate

[1]

7.358%

7.358%

Secured Debt | Secured Cellular Site Revenue Notes

Debt Instrument [Line Items]

Long-term debt

[13]

$ 201,930

203,683

[1]

Secured Debt | Secured Cellular Site Revenue Notes | Minimum

Debt Instrument [Line Items]

Long-term debt, stated interest rate

[1]

5.349%

5.349%

Secured Debt | Secured Cellular Site Revenue Notes | Maximum

Debt Instrument [Line Items]

Long-term debt, stated interest rate

[1]

9.522%

9.522%

Secured Debt | BR Towers Debentures

Debt Instrument [Line Items]

Long-term debt

$ 85,219

[7],[14]

BRL 332,800,000

[7]

118,688

[1],[14]

Interest rate at period end

[3],[14]

7.40%

7.40%

Secured Debt | Mexican loan

Debt Instrument [Line Items]

Long-term debt

$ 0

263,426

[1]

Unsecured Debt | BR Towers Debentures

Debt Instrument [Line Items]

Long-term debt | BRL

BRL 300,000,000

Unsecured Debt | Shareholder Loans

Debt Instrument [Line Items]

Long-term debt

[15]

$ 145,540

137,655

[1]

Unsecured Debt | BR Towers Credit Facility | Revolving Credit Facility | Minimum

Debt Instrument [Line Items]

Long-term debt, stated interest rate

[1]

3.50%

3.50%

Unsecured Debt | BR Towers Credit Facility | Revolving Credit Facility | Maximum

Debt Instrument [Line Items]

Long-term debt, stated interest rate

[1]

10.80%

10.80%

Unsecured Debt | Term Loan 2013

Debt Instrument [Line Items]

Long-term debt

[6]

$ 1,993,601

1,495,284

[3]

Long-term Line of Credit

$ 2,000,000

Interest rate at period end

[3],[6]

1.68%

1.68%

Revolving Credit Facility | Colombian Long Term Credit Facility

Debt Instrument [Line Items]

Long-term debt

[16]

$ 59,640

82,501

[1]

Long-term debt, stated interest rate

[3],[16]

9.853%

9.853%

Revolving Credit Facility | BR Towers Credit Facility

Debt Instrument [Line Items]

Long-term debt

$ 0

16,389

[1]

Senior Notes | 4.625% Senior Notes

Debt Instrument [Line Items]

Long-term debt

0

599,720

[1]

Senior Notes | 7.00% Senior Notes

Debt Instrument [Line Items]

Long-term debt

0

497,750

[1]

Long-term debt, stated interest rate

7.00%

Senior Notes | 4.50% Senior Notes

Debt Instrument [Line Items]

Long-term debt

$ 997,693

996,571

[1]

Long-term debt, stated interest rate

[3]

4.50%

4.50%

Senior Notes | 3.40% Senior Notes

Debt Instrument [Line Items]

Long-term debt

$ 999,769

999,607

[1]

Long-term debt, stated interest rate

[1],[3]

3.40%

3.40%

Senior Notes | 7.25% Senior Notes

Debt Instrument [Line Items]

Long-term debt

$ 296,242

295,229

[1]

Long-term debt, stated interest rate

[3]

7.25%

7.25%

Senior Notes | 2.80% Senior Notes

Debt Instrument [Line Items]

Long-term debt

$ 743,557

0

[1]

Long-term debt, stated interest rate

2.80%

[3]

2.80%

[3]

2.80%

Senior Notes | 5.05% Senior Notes

Debt Instrument [Line Items]

Long-term debt

$ 697,216

696,560

[1]

Long-term debt, stated interest rate

[3]

5.05%

5.05%

Senior Notes | 3.450% Senior Notes

Debt Instrument [Line Items]

Long-term debt

$ 642,786

641,579

[1]

Long-term debt, stated interest rate

[3]

3.45%

3.45%

Senior Notes | 5.90% Senior Notes

Debt Instrument [Line Items]

Long-term debt

$ 497,188

496,715

[1]

Long-term debt, stated interest rate

[3]

5.90%

5.90%

Senior Notes | 4.70% Senior Notes

Debt Instrument [Line Items]

Long-term debt

$ 695,374

694,694

[1]

Long-term debt, stated interest rate

[3]

4.70%

4.70%

Senior Notes | 3.50% Senior Notes

Debt Instrument [Line Items]

Long-term debt

$ 987,966

986,389

[1]

Long-term debt, stated interest rate

[3]

3.50%

3.50%

Senior Notes | 5.00% Senior Notes

Debt Instrument [Line Items]

Long-term debt

$ 1,003,453

1,003,628

[1]

Long-term debt, stated interest rate

[1],[3]

5.00%

5.00%

Senior Notes | 4.00% Senior Notes

Debt Instrument [Line Items]

Long-term debt

$ 739,057

$ 0

[1]

Long-term debt, stated interest rate

4.00%

[3]

4.00%

[3]

4.00%

[1]

December 31, 2014 balances have been revised to reflect debt issuance costs as a direct deduction from the carrying amounts, with the exception of debt issuance costs associated with the 2013 Credit Facility and the 2014 Credit Facility (as defined below) which are reflected in Notes receivable and other non-current assets on the consolidated balance sheets. Amortization of deferred financing costs is included in interest expense on the consolidated statements of operations.

[2]

Denominated in South African Rand (“ZAR”). Debt accrues interest at a variable rate.

[3]

Represents the interest rate or maturity date as of December 31, 2015 and does not reflect the impact of interest rate swap agreements.

[4]

Denominated in BRL. Debt accrues interest at variable rate.

[5]

Denominated in INR. This agreement provides that the maturity date may be extended for additional 30-day periods.

[6]

Debt accrues interest at a variable rate.

[7]

Maturity date reflects the anticipated repayment date; final legal maturity is March 15, 2043.

[8]

Maturity date reflects the anticipated repayment date; final legal maturity is March 15, 2048.

[9]

Maturity date reflects the anticipated repayment date; final legal maturity is June 15, 2045.

[10]

Maturity date reflects the anticipated repayment date; final legal maturity is June 15, 2050.

[11]

Secured debt assumed in connection with the acquisition of MIP Tower Holdings LLC (“MIPT”).

[12]

Anticipated repayment dates begin March 15, 2017.

[13]

Secured debt assumed in connection with the acquisition of certain legal entities holding a portfolio of property interests from Unison Holdings, LLC and Unison Site Management II, L.L.C. (together, “Unison”). Anticipated repayment dates begin April 15, 2017; final legal maturity date is April 15, 2040.

[14]

Publicly issued debentures assumed in connection with the acquisition of BR Towers and denominated in BRL. Debt accrues interest at a variable rate.

[15]

Reflects balances owed to the Company’s joint venture partners in Ghana and Uganda. The Ghana loan is denominated in Ghanaian Cedi (“GHS”) and the Uganda loan is denominated in U.S. Dollars (“USD”). The Uganda loan accrues interest at a variable rate.

[16]

Denominated in Colombian Pesos (“COP”). Debt accrues interest at a variable rate.

Long-Term Obligations Long Term

Long-Term Obligations Long Term Obligations (Schedule of Brazil credit facility) (Details)	12 Months Ended
	Dec. 31, 2015USD ($)	Dec. 31, 2015BRL
Debt Instrument [Line Items]
Long-term debt	$ 17,119,009,000
Brazil Credit Facility Tranche A
Debt Instrument [Line Items]
Long-term debt	6,000,000	BRL 23,400,000
Line of credit facility, maximum borrowing capacity	$ 8,900,000	34,800,000
Basis spread on variable rate	4.25%
Brazil Credit Facility Tranche B
Debt Instrument [Line Items]
Long-term debt	$ 6,300,000	24,500,000
Line of credit facility, maximum borrowing capacity	$ 8,900,000	34,800,000
Basis spread on variable rate	4.25%
Brazil Credit Facility Tranche C
Debt Instrument [Line Items]
Long-term debt	$ 9,600,000	37,500,000
Line of credit facility, maximum borrowing capacity	$ 51,200,000	BRL 200,000,000
Long-term debt, stated interest rate	6.00%	6.00%
Brazil Credit Facility Tranche D
Debt Instrument [Line Items]
Long-term debt	$ 0	BRL 0
Line of credit facility, maximum borrowing capacity	$ 400,000	BRL 1,400,000

Long Term Obligations (Schedule

Long Term Obligations (Schedule of shareholder loans) (Details) $ in Thousands, GHS in Millions		12 Months Ended
		Dec. 31, 2015USD ($)		Dec. 31, 2015GHS	Dec. 31, 2014USD ($)	Dec. 31, 2013USD ($)	Dec. 31, 2015GHS
Debt Instrument [Line Items]
Long-term debt		$ 17,119,009
Interest costs capitalized		1,800			$ 2,800	$ 1,800
Unsecured Debt | Ghana Loan
Debt Instrument [Line Items]
Long-term debt		$ 70,314	[1]		68,651		GHS 267.5
Debt Instrument, Interest Rate, Stated Percentage		21.87%					21.87%
Interest costs capitalized		$ 12,300		GHS 46.7
Unsecured Debt | Uganda Loan
Debt Instrument [Line Items]
Long-term debt		$ 75,226	[2],[3]		$ 69,004
Debt Instrument, Interest Rate, Effective Percentage	[3]	6.066%					6.066%
Interest costs capitalized		$ 6,300
[1]	Denominated in GHS. As of December 31, 2015, the aggregate principal amount outstanding under the Ghana loan was 267.5 million GHS, which included 46.7 million GHS ($12.3 million) of interest which was capitalized during the year ended December 31, 2015.
[2]	Includes $6.3 million of interest which was capitalized during the year ended December 31, 2015.
[3]	Interest rate as of December 31, 2015. Interest accrues at a variable rate.

Long-Term Obligations (Aggregat

Long-Term Obligations (Aggregate Carrying Value of Long-Term Debt) (Details) $ in Thousands	Dec. 31, 2015USD ($)
Long-term Debt, Excluding Current Maturities [Abstract]
2,016	$ 50,202
2,017	195,536
2,018	1,537,659
2,019	2,883,615
2,020	1,970,026
Thereafter	10,549,061
Total cash obligations	17,186,099
Unamortized discounts, premiums and debt issuance costs, net	(67,090)
Balance as of December 31, 2015	$ 17,119,009

Long-Term Obligations (Schedule

Long-Term Obligations (Schedule of Debt Discounts) (Details) - Senior Notes - USD ($) $ in Thousands		Dec. 31, 2015	May. 07, 2015	Dec. 31, 2014	[2]
4.50% Senior Notes
Debt Instrument [Line Items]
Principal amount		$ 1,000,000
Adjustments to Principal Amount	[1]	(2,307)		$ (3,429)
3.40% Senior Notes
Debt Instrument [Line Items]
Principal amount	[3]	1,000,000
Adjustments to Principal Amount	[1],[3]	(231)		(393)
7.25% Senior Notes
Debt Instrument [Line Items]
Principal amount		300,000
Adjustments to Principal Amount	[1]	(3,758)		(4,771)
2.80% Senior Notes
Debt Instrument [Line Items]
Principal amount		750,000	$ 750,000
Adjustments to Principal Amount	[1]	(6,443)		0
5.05% Senior Notes
Debt Instrument [Line Items]
Principal amount		700,000
Adjustments to Principal Amount	[1]	(2,784)		(3,440)
3.450% Senior Notes
Debt Instrument [Line Items]
Principal amount		650,000
Adjustments to Principal Amount	[1]	(7,214)		(8,421)
5.90% Senior Notes
Debt Instrument [Line Items]
Principal amount		500,000
Adjustments to Principal Amount	[1]	(2,812)		(3,285)
4.70% Senior Notes
Debt Instrument [Line Items]
Principal amount		700,000
Adjustments to Principal Amount	[1]	(4,626)		(5,306)
3.50% Notes
Debt Instrument [Line Items]
Principal amount		1,000,000
Adjustments to Principal Amount	[1]	(12,034)		(13,611)
5.00% Senior Notes
Debt Instrument [Line Items]
Principal amount	[3]	1,000,000
Adjustments to Principal Amount	[1],[3]	3,453		3,628
4.00% Senior Notes
Debt Instrument [Line Items]
Principal amount		750,000	$ 750,000
Adjustments to Principal Amount	[1]	$ (10,943)		$ 0
[1]	Includes unamortized discounts, premiums, and debt issuance costs.
[2]	December 31, 2014 balances have been revised to reflect debt issuance costs.
[3]	The original issue date for the 3.40% Notes and the 5.00% Notes was August 19, 2013. The issue date for the reopened 3.40% Notes and the reopened 5.00% Notes was January 10, 2014.

Other Non-Current Liabilities75

Other Non-Current Liabilities (Other Non-Current Liabilities) (Details) - USD ($) $ in Thousands	Dec. 31, 2015	Dec. 31, 2014	[1]
Other Liabilities, Noncurrent [Abstract]
Unearned revenue	$ 451,844	$ 415,809
Deferred rent liability	348,532	303,442
Other miscellaneous liabilities	265,306	309,436
Balance	$ 1,065,682	$ 1,028,687
[1]	December 31, 2014 balances have been revised to reflect purchase accounting measurement period adjustments.

Asset Retirement Obligations (N

Asset Retirement Obligations (Narrative) (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014
Asset Retirement Obligation [Abstract]
Asset retirement obligation, foreign currency translation	$ 81.7	$ 38.5
Estimated undiscounted future cash outlay for asset retirement obligations	$ 2,600

Asset Retirement Obligations (C

Asset Retirement Obligations (Carrying Value of Asset Retirement Obligations) (Details) - USD ($) $ in Thousands		12 Months Ended
		Dec. 31, 2015	Dec. 31, 2014
Asset Retirement Obligation, Roll Forward Analysis [Roll Forward]
Beginning balance as of January 1,		$ 609,035	$ 549,548
Additions		277,982	52,623
Accretion expense		55,592	40,325
Revisions in estimates	[1]	(83,636)	(32,311)
Settlements		(2,037)	(1,150)
Balance as of December 31,		$ 856,936	$ 609,035
[1]	Revisions in estimates include the negative impact of $81.7 million and $38.5 million of foreign currency translation for the years ended December 31, 2015 and 2014, respectively.

Fair Value Measurements (Narrat

Fair Value Measurements (Narrative) (Details)		12 Months Ended
		Dec. 31, 2015USD ($)	Dec. 31, 2014USD ($)		Dec. 31, 2015COP	Jul. 01, 2015USD ($)
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair value of embedded derivative asset		$ 14,176,000				$ 14,600,000
Loss on derivative		400,000
Business combination, contingent consideration arrangements, range of outcomes, value, low		0
Business combination, contingent consideration arrangements, range of outcomes, value, high	[1]	26,052,000
Impairment of long-lived assets held for use		15,100,000	$ 11,200,000
Assets held and used, original carrying value		12,600,000,000	8,900,000,000
Debt, long-term and short-term, combined amount		17,119,009,000	14,540,341,000	[2]
Estimate of Fair Value Measurement
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Long-term debt, fair value		17,400,000,000	15,000,000,000
Estimate of Fair Value Measurement | Fair Value, Inputs, Level 1
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Long-term debt, fair value		8,700,000,000	9,700,000,000
Estimate of Fair Value Measurement | Fair Value, Inputs, Level 2
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Long-term debt, fair value		8,700,000,000	5,300,000,000
Operations In Panama and Portion of Engineering Business
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Aggregate sale price			17,900,000
Property, plant and equipment			8,100,000
Intangible noncurrent assets			7,800,000
Goodwill			3,600,000
Goodwill and intangible asset impairment			$ 2,200,000
Revolving Credit Facility | Colombian Long Term Credit Facility
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative asset, notional amount		$ 31,800,000			COP 100,000,000,000
Derivative, fixed interest rate		5.74%			5.74%
[1]	The maximum potential value is based on exchange rates at December 31, 2015. The minimum value could be zero.
[2]	December 31, 2014 balances have been revised to reflect debt issuance costs as a direct deduction from the carrying amounts, with the exception of debt issuance costs associated with the 2013 Credit Facility and the 2014 Credit Facility (as defined below) which are reflected in Notes receivable and other non-current assets on the consolidated balance sheets. Amortization of deferred financing costs is included in interest expense on the consolidated statements of operations.

Fair Value Measurements (Assets

Fair Value Measurements (Assets and Liabilities Measured at Fair Value on a Recurring Basis) (Details) COP in Thousands, $ in Thousands		Dec. 31, 2015USD ($)		Dec. 31, 2015COP	Jul. 01, 2015USD ($)	Dec. 31, 2014USD ($)		Dec. 31, 2014COP	Dec. 31, 2013USD ($)
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Short-term investments		$ 0				$ 6,302	[1]
Interest rate swap agreements		692				88
Fair value of embedded derivative asset		14,176			$ 14,600
Acquisition-related contingent consideration		12,436	[2]			28,524			$ 31,890
Interest rate swap agreements						647
Colombian Long Term Credit Facility | Interest Rate Swap
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Interest rate swap agreements | COP				COP (2,179,374)
Interest rate swap agreements						647		COP 1,548,688
Fair Value, Inputs, Level 2
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Interest rate swap agreements						647
Fair Value, Inputs, Level 2 | Colombian Long Term Credit Facility | Interest Rate Swap
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Short-term investments	[1]					6,302
Interest rate swap agreements		692				88
Fair Value, Inputs, Level 3
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair value of embedded derivative asset		14,176
Acquisition-related contingent consideration		$ 12,436				$ 28,524
[1]	Consists of highly liquid investments with original maturities in excess of three months.
[2]	Estimate is determined using a probability weighted average of expected outcomes as of December 31, 2015.

Fair Value Measurements Fair Va

Fair Value Measurements Fair Value Measurements (Schedule of derivative financial instruments) (Details) ZAR in Thousands, COP in Thousands, $ in Thousands	Dec. 31, 2015USD ($)	Dec. 31, 2015COP	Dec. 31, 2015ZAR	Dec. 31, 2014USD ($)	Dec. 31, 2014COP	Dec. 31, 2014ZAR
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Interest rate swap agreements	$ 692			$ 88
Interest rate swap agreements				(647)
Fair Value, Inputs, Level 2
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Interest rate swap agreements				(647)
Interest Rate Swap | South African Facility
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative asset, notional amount	0		ZAR 0	38,080		ZAR 440,614
Interest rate swap agreements	0		ZAR 0	88		ZAR 1,016
Interest Rate Swap | Colombian Long Term Credit Facility
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative asset, notional amount	30,164	COP 95,000,000
Interest rate swap agreements | COP		COP (2,179,374)
Derivative liability, notional amount				41,798	COP 100,000,000
Interest rate swap agreements				(647)	COP (1,548,688)
Interest Rate Swap | Colombian Long Term Credit Facility | Fair Value, Inputs, Level 2
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Interest rate swap agreements	$ 692			$ 88

Fair Value Measurements (Contin

Fair Value Measurements (Contingent Consideration) (Details) - USD ($) $ in Thousands		12 Months Ended
		Dec. 31, 2015		Dec. 31, 2014
Fair Value, Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Balance as of January 1		$ 28,524		$ 31,890
Additions		1,626		6,412
Settlements		(7,943)		(3,889)
Change in fair value		(4,781)		(225)
Foreign currency translation adjustment		(4,990)		(4,934)
Other	[1]	0		(730)
Balance as of December 31		12,436	[2]	28,524
Fair Value, Inputs, Level 3
Fair Value, Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Balance as of January 1		28,524
Balance as of December 31		$ 12,436		$ 28,524
[1]	In connection with the sale of operations in Panama in September 2014, the buyer assumed the Company’s potential obligations related to additional purchase price consideration.
[2]	Estimate is determined using a probability weighted average of expected outcomes as of December 31, 2015.

Income Taxes (Narrative) (Detai

Income Taxes (Narrative) (Details) - USD ($)	12 Months Ended
	Dec. 31, 2015		Dec. 31, 2014		Dec. 31, 2013	Dec. 31, 2012
Income Tax Contingency [Line Items]
REIT liquidation tax charge	$ 93,000,000
REIT Liquidiation deferred tax benefit	5,800,000
Deferred tax assets, other	$ 31,432,000	[1]	$ 22,142,000	[2]
Income tax expense, restructuring domestic TRS			$ 2,600,000		$ 21,500,000
Dividend paid deduction, percentage	36.00%		24.00%		28.00%
Valuation allowance	$ 136,952,000		$ 141,241,000		$ 136,006,000	$ 95,558,000
Undistributed earnings of foreign subsidiaries	490,600,000
Excess tax benefit from the exercise of employee stock options	51,600,000
Decrease in unrecognized tax benefits, lapse of applicable statute of limitations	3,504,000		5,349,000		1,218,000
Unrecognized tax benefits, income tax penalties and interest	100,000		(3,400,000)		$ 3,400,000
Unrecognized tax benefits, income tax penalties and interest accrued	20,200,000		24,900,000
Minimum
Income Tax Contingency [Line Items]
Decrease in unrecognized tax benefits is reasonably possible	0
Maximum
Income Tax Contingency [Line Items]
Decrease in unrecognized tax benefits is reasonably possible	14,300,000
Other Noncurrent Liabilities
Income Tax Contingency [Line Items]
Unrecognized tax benefits that would impact the ETR	28,100,000		31,900,000
Mexican Tax Authority
Income Tax Contingency [Line Items]
Tax credit carryforward	$ 1,800,000
MIPT
Income Tax Contingency [Line Items]
Deferred tax assets, other			$ 13,100,000
[1]	Change in accounting pronouncement, as described below.
[2]	December 31, 2014 balances have been revised to reflect purchase accounting measurement period adjustments.

Income Taxes (Income Tax Provis

Income Taxes (Income Tax Provision from Continuing Operations) (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Income Tax Expense (Benefit), Continuing Operations [Abstract]
Federal, current	$ (73,930)	$ (2,390)	$ (30,322)
State, current	(21,216)	(797)	(13,731)
Foreign, current	(55,045)	(57,934)	(44,973)
Federal, deferred	9,131	(4,180)	(16,318)
State, deferred	8	(973)	(5,139)
Foreign, deferred	(16,903)	3,769	50,942
Income tax provision	$ (157,955)	$ (62,505)	$ (59,541)

Income Taxes (Components of Inc

Income Taxes (Components of Income from Continuing Operations Before Income Taxes and Income on Equity Method Investments) (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Income Tax Expense (Benefit), Continuing Operations [Abstract]
United States	$ 785,201	$ 857,457	$ 766,772
Foreign	44,761	8,247	(225,023)
INCOME FROM CONTINUING OPERATIONS BEFORE INCOME TAXES	$ 829,962	$ 865,704	$ 541,749

Income Taxes (Reconciliation Be

Income Taxes (Reconciliation Between the U.S. Statutory Rate and the Effective Rate from Continuing Operations) (Details)		12 Months Ended
		Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Income Tax Expense (Benefit), Continuing Operations [Abstract]
Statutory tax rate		35.00%	35.00%	35.00%
Tax adjustment related to REIT	[1]	(35.00%)	(35.00%)	(35.00%)
State taxes, net of federal benefit		0.00%	1.00%	3.00%
Foreign taxes		3.00%	2.00%	(5.00%)
Foreign withholding taxes		3.00%	3.00%	6.00%
Domestic TRS restructuring		0.00%	0.00%	4.00%
Change in tax law		2.00%	0.00%	0.00%
MIPT tax election	[2]	11.00%	0.00%	0.00%
Other		0.00%	1.00%	3.00%
Effective tax rate		19.00%	7.00%	11.00%
[1]	Includes 36%, 24% and 28% from dividend paid deductions in 2015, 2014 and 2013, respectively.
[2]	Includes federal and state taxes, net of federal benefit.

Income Taxes (Components of the

Income Taxes (Components of the Net Deferred Tax Asset and Related Valuation Allowance) (Details) - USD ($) $ in Thousands	Dec. 31, 2015	[1]	Dec. 31, 2014	[2]
Income Tax Expense (Benefit), Continuing Operations [Abstract]
Allowances, accruals and other items not currently deductible	$ 0		$ 19,893
Current deferred liabilities	0		(2,799)
Subtotal	0		17,094
Valuation allowance	0		(3,094)
Net current deferred tax assets	0		14,000
Net operating loss carryforwards	277,977		242,788
Accrued asset retirement obligations	92,295		103,975
Stock-based compensation	3,889		693
Unearned revenue	25,654		18,947
Unrealized loss on foreign currency	37,440		15,952
Items not currently deductible and other	31,432		22,142
Depreciation and amortization	(194,230)		(131,678)
Deferred rent	(20,720)		(18,355)
Other	(11,077)		(1,791)
Subtotal	242,660		252,673
Valuation allowance	(136,952)		(138,147)
Net non-current deferred tax assets	$ 105,708		$ 114,526
[1]	Change in accounting pronouncement, as described below.
[2]	December 31, 2014 balances have been revised to reflect purchase accounting measurement period adjustments.

Income Taxes Valuation allowanc

Income Taxes Valuation allowance activity (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Movement in Valuation Allowances and Reserves [Roll Forward]
Balance as of January 1,	$ 141,241	$ 136,006	$ 95,558
Additions (1)	19,512	40,124	48,411
Reversals	0	(10,769)	0
Foreign currency translation	(23,801)	(24,120)	(7,963)
Balance as of December 31,	$ 136,952	$ 141,241	$ 136,006

Income Taxes (Net Operating Los

Income Taxes (Net Operating Loss Carryforwards Expire) (Details) $ in Thousands	Dec. 31, 2015USD ($)
Federal
Operating Loss Carryforwards [Line Items]
2016 to 2020	$ 0
2021 to 2025	0
2026 to 2030	51,596
2031 to 2035	23,670
Indefinite Carryforward	0
Total	75,266
State
Operating Loss Carryforwards [Line Items]
2016 to 2020	79,928
2021 to 2025	281,061
2026 to 2030	188,030
2031 to 2035	10,853
Indefinite Carryforward	0
Total	559,872
Foreign
Operating Loss Carryforwards [Line Items]
2016 to 2020	14,727
2021 to 2025	195,694
2026 to 2030	0
2031 to 2035	0
Indefinite Carryforward	695,052
Total	$ 905,473

Income Taxes (Reconciliation of

Income Taxes (Reconciliation of the Beginning and Ending Amount of Unrecognized Tax Benefits) (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Reconciliation of Unrecognized Tax Benefits, Excluding Amounts Pertaining to Examined Tax Returns [Roll Forward]
Balance at January 1	$ 31,947	$ 32,545	$ 34,337
Additions based on tax positions related to the current year	5,042	4,187	1,427
Additions for tax positions of prior years	0	3,780	0
Reductions for tax positions of prior years	0	0	(320)
Foreign currency	(5,371)	(3,216)	(1,681)
Reduction as a result of the lapse of statute of limitations and effective settlements	(3,504)	(5,349)	(1,218)
Balance at December 31	$ 28,114	$ 31,947	$ 32,545

Stock-Based Compensation (Narra

Stock-Based Compensation (Narrative) (Details) - USD ($) $ / shares in Units, $ in Thousands	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Stock-based compensation expense	$ 90,537	$ 80,153	$ 68,138
Capitalized stock-based compensation expense	$ 2,100	$ 1,600
Performance Shares
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Vesting period	3 years
Stock-based compensation expense	$ 2,500
Total unrecognized compensation expense	$ 700
Expected recognition of stock award compensation expense weighted average period in years	1 year
Three year performance grant, shares granted	70,135
Shares granted, grant date fair value not yet established	46,756
Performance Shares | Minimum
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Percentage of potential target shares	0.00%
Performance Shares | Maximum
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Percentage of potential target shares	200.00%
Employee Stock
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Employee purchase shares not exceeding of gross compensation	15.00%
Employee Stock Option
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Weighted average grant date fair value (in dollars per share)	$ 15.06	$ 14.86	$ 19.05
Intrinsic value of stock options exercised	$ 32,100	$ 58,000	$ 42,100
Total unrecognized compensation expense	$ 29,200
Expected recognition of stock award compensation expense weighted average period in years	2 years
Employee service share-based compensation, cash received from exercise of stock options	$ 44,100
Restricted Stock
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Total unrecognized compensation expense	$ 77,000
Expected recognition of stock award compensation expense weighted average period in years	2 years
Total fair value of restricted stock units vested during period	$ 67,000
2007 Plan
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Vesting period	4 years
Expiration period	10 years
Number of shares issuable under stock incentive plan	11,600,000
2007 Plan | Performance Shares
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Vesting period	3 years

Stock-Based Compensation (Assum

Stock-Based Compensation (Assumptions Used to Determine the Grant Date Fair Value for Options Granted) (Details) - Employee Stock Option	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Minimum range of risk-free interest rate	1.32%	1.46%	0.75%
Maximum range of risk-free interest rate	1.62%	1.74%	1.42%
Weighted average risk-free interest rate	1.61%	1.64%	0.91%
Expected life of stock options	4 years 4 months 52 days	4 years 6 months	4 years 4 months 28 days
Minimum range of expected volatility of underlying stock price	21.09%	21.94%	24.43%
Maximum range of expected volatility of underlying stock price	21.24%	23.35%	36.09%
Weighted average expected volatility of underlying stock price	21.09%	23.08%	33.37%
Range of expected annual dividend yield		1.50%	1.50%
Minimum
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Range of expected annual dividend yield	1.50%
Maximum
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Range of expected annual dividend yield	1.85%

Stock-Based Compensation (Summa

Stock-Based Compensation (Summary of the Company's Option Activity) (Details) - Employee Stock Option $ / shares in Units, $ in Millions	12 Months Ended
	Dec. 31, 2015USD ($)$ / sharesshares
Share-based Compensation Arrangement by Share-based Payment Award, Options, Outstanding [Roll Forward]
Outstanding as of January 1, 2015 (in shares) | shares	6,508,435
Granted (in shares) | shares	2,059,600
Exercised (in shares) | shares	(779,615)
Forfeited (in shares) | shares	(105,226)
Expired (in shares) | shares	(2,375)
Outstanding as of December 31, 2015 (in shares) | shares	7,680,819
Exercisable as of December 31, 2015 (in shares) | shares	3,549,709
Vested or expected to vest as of December 31, 2015 (in shares) | shares	7,674,324
Share-based Compensation Arrangement by Share-based Payment Award, Options, Outstanding, Weighted Average Exercise Price [Roll Forward]
Outstanding as of January 1, 2015 (in dollars per share) | $ / shares	$ 62.14
Granted (in dollars per share) | $ / shares	94.43
Exercised (in dollars per share) | $ / shares	56.56
Forfeited (in dollars per share) | $ / shares	82.47
Expired (in dollars per share) | $ / shares	23.74
Outstanding as of December 31, 2015 (in dollars per share) | $ / shares	71.10
Exercisable as of December 31, 2015 (in dollars per share) | $ / shares	54.13
Vested or expected to vest as of December 31, 2015 (in dollars per share) | $ / shares	$ 71.08
Share-based Compensation Arrangement by Share-based Payment Award, Options, Additional Disclosures [Abstract]
Weighted average contractual term, outstanding (in years)	6 years 8 months 20 days
Weighted average contractual term, exercisable (in years)	4 years 7 months 65 days
Weighted average contractual term, vested or expected to vest (in years)	6 years 8 months 20 days
Aggregate intrinsic value, outstanding | $	$ 198.6
Aggregate intrinsic value, exercisable | $	152
Aggregate intrinsic value, vested or expected to vest | $	$ 198.6

Stock-Based Compensation (Sched

Stock-Based Compensation (Schedule of Options Outstanding) (Details)	12 Months Ended
	Dec. 31, 2015$ / sharesshares
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range [Line Items]
Outstanding Number of Options | shares	7,680,819
Exercise price per share, minimum	$ 25.43
Exercise price per share, maximum	99.67
Weighted Average Exercise Price Per Share	$ 71.10
Weighted Average Remaining Life (Years)	6 years 8 months 18 days
Options Exercisable | shares	3,549,709
Weighted Average Exercise Price Per Share	$ 54.13
$25.43 - $50.78
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range [Line Items]
Outstanding Number of Options | shares	2,064,426
Exercise price per share, minimum	$ 25.43
Exercise price per share, maximum	50.78
Weighted Average Exercise Price Per Share	$ 40.73
Weighted Average Remaining Life (Years)	3 years 2 months 15 days
Options Exercisable | shares	2,064,426
Weighted Average Exercise Price Per Share	$ 40.73
51.03 - 74.06
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range [Line Items]
Outstanding Number of Options | shares	852,265
Exercise price per share, minimum	$ 51.03
Exercise price per share, maximum	74.06
Weighted Average Exercise Price Per Share	$ 61.88
Weighted Average Remaining Life (Years)	6 years 1 month 27 days
Options Exercisable | shares	578,340
Weighted Average Exercise Price Per Share	$ 61.43
76.90 - 79.45
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range [Line Items]
Outstanding Number of Options | shares	1,091,181
Exercise price per share, minimum	$ 76.90
Exercise price per share, maximum	79.45
Weighted Average Exercise Price Per Share	$ 76.94
Weighted Average Remaining Life (Years)	7 years 1 month 30 days
Options Exercisable | shares	467,735
Weighted Average Exercise Price Per Share	$ 76.92
81.18 - 94.23
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range [Line Items]
Outstanding Number of Options | shares	1,707,519
Exercise price per share, minimum	$ 81.18
Exercise price per share, maximum	94.23
Weighted Average Exercise Price Per Share	$ 81.63
Weighted Average Remaining Life (Years)	8 years 2 months 15 days
Options Exercisable | shares	376,025
Weighted Average Exercise Price Per Share	$ 81.35
94.57 - 99.67
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range [Line Items]
Outstanding Number of Options | shares	1,965,428
Exercise price per share, minimum	$ 94.57
Exercise price per share, maximum	99.67
Weighted Average Exercise Price Per Share	$ 94.60
Weighted Average Remaining Life (Years)	9 years 1 month 12 days
Options Exercisable | shares	63,183
Weighted Average Exercise Price Per Share	$ 94.57

Stock-Based Compensation (Sum94

Stock-Based Compensation (Summary of the Company's Restricted Stock Unit Activity) (Details) - $ / shares		12 Months Ended
		Dec. 31, 2015	Dec. 31, 2015
Restricted Stock
Share-based Compensation Arrangement by Share-based Payment Award, Non-Option Equity Instruments, Outstanding [Roll Forward]
Outstanding as of January 1, 2015 (in shares)		1,758,817
Granted (in shares)		715,379
Vested (in shares)		(703,955)
Forfeited (in shares)		(113,248)
Outstanding as of December 31, 2015 (in shares)		1,758,817	1,656,993
Expected to vest, net of estimated forfeitures, as of December 31, 2015 (in shares)			1,578,040
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Nonvested, Weighted Average Grant Date Fair Value [Roll Forward]
Outstanding as of January 1, 2015 (in dollars per share)		$ 73.80
Granted (in dollars per share)		94.55
Vested (in dollars per share)		69.24
Forfeitures (in dollars per share)		82.20
Outstanding as of December 31, 2015 (in dollars per share)		$ 84.12
Expected to vest, net of estimated forfeitures, as of December 31, 2015 (in dollars per share)			$ 83.87
Performance Shares
Share-based Compensation Arrangement by Share-based Payment Award, Non-Option Equity Instruments, Outstanding [Roll Forward]
Outstanding as of January 1, 2015 (in shares)	[1]	0
Granted (in shares)	[1]	33,377
Vested (in shares)	[1]	0
Forfeited (in shares)	[1]	0
Outstanding as of December 31, 2015 (in shares)	[1]	0	33,377
Expected to vest, net of estimated forfeitures, as of December 31, 2015 (in shares)	[1]		33,377
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Nonvested, Weighted Average Grant Date Fair Value [Roll Forward]
Outstanding as of January 1, 2015 (in dollars per share)		$ 0
Granted (in dollars per share)		94.57
Vested (in dollars per share)		0
Forfeitures (in dollars per share)		0
Outstanding as of December 31, 2015 (in dollars per share)		$ 94.57
Expected to vest, net of estimated forfeitures, as of December 31, 2015 (in dollars per share)			$ 94.57
[1]	Represents the target number of shares issuable at the end of the three-year performance cycle attributable to the first year’s performance period and incremental shares issuable based on exceeding the performance metric for the first year’s performance period.

Equity (Narrative) (Details)

Equity (Narrative) (Details) - USD ($)		12 Months Ended
		Dec. 31, 2015	Dec. 31, 2014		Dec. 31, 2013		Mar. 05, 2015	Mar. 03, 2015	Mar. 31, 2011
Class of Stock [Line Items]
Common stock, shares issued		426,695,279	399,508,751
Common stock, par value (in dollars per share)		$ 0.01	$ 0.01
Proceeds from the issuance of common stock, net		$ 2,440,327,000	$ 0		$ 0
Proceeds from the issuance of preferred stock, net		1,337,946,000	583,105,000		0
Authorized repurchase of common stock									$ 1,500,000,000
Remaining stock value of buyback									$ 1,100,000,000
Distributions paid on common stock		710,852,000	404,631,000		$ 434,687,000
Preferred stock dividends declared		76,772,000	$ 23,888,000
Accrued dividend RSU		5,100,000
Common Stock
Class of Stock [Line Items]
Common stock, shares issued								23,500,000
Common stock, par value (in dollars per share)								$ 0.01
Shares issued, price per share								97
Additional shares issued							2,350,000
Proceeds from the issuance of common stock, net		$ 2,440,000,000
Dividends declared per share		$ 1.81	$ 1.4	[1]	$ 1.1	[1]
Series B Preferred Stock
Class of Stock [Line Items]
Preferred Stock, Depositary Shares, Percentage of Preferred Shares		0.1
Preferred stock, aggregate liquidation value		5.50%
Preferred stock, par value		$ 0.01
Convertible Preferred Stock Subject to Mandatory Redemption | Series B Preferred Stock
Class of Stock [Line Items]
Shares issued, price per share								$ 100
Preferred stock, shares issued								12,500,000
Preferred stock, additional shares issued							1,250,000
Proceeds from the issuance of preferred stock, net		$ 1,340,000,000
Preferred stock, aggregate liquidation value		5.50%
Preferred stock, liquidation preference per share		$ 1,000
Preferred stock, liquidation preference, depositary shares		100
Preferred stock, dividends per share, declared	[2]	$ 3.8653	0	[1]	0	[1]
Convertible Preferred Stock Subject to Mandatory Redemption | Series B Preferred Stock | Minimum
Class of Stock [Line Items]
Conversion factor, preferred stock		8.5911
Convertible Preferred Stock Subject to Mandatory Redemption | Series B Preferred Stock | Maximum
Class of Stock [Line Items]
Conversion factor, preferred stock		10.3093
Convertible Preferred Stock Subject to Mandatory Redemption | Series A Preferred Stock
Class of Stock [Line Items]
Preferred stock, shares issued		6,000,000
Preferred stock, aggregate liquidation value		5.25%
Preferred stock, liquidation preference per share		$ 100
Preferred stock, par value		0.01
Preferred stock, dividends per share, declared		$ 5.25	$ 2.6688	[1]	$ 0	[1]
Convertible Preferred Stock Subject to Mandatory Redemption | Series A Preferred Stock | Minimum
Class of Stock [Line Items]
Conversion factor, preferred stock		0.9174
Convertible Preferred Stock Subject to Mandatory Redemption | Series A Preferred Stock | Maximum
Class of Stock [Line Items]
Conversion factor, preferred stock		1.1468
Dividends Declared and Paid
Class of Stock [Line Items]
Paid dividend RSU		$ 1,300,000
Dividends Declared and Paid | Common Stock
Class of Stock [Line Items]
Distributions paid on common stock		766,400,000	$ 554,600,000		$ 434,500,000
Dividends Declared and Paid | Convertible Preferred Stock Subject to Mandatory Redemption | Series B Preferred Stock
Class of Stock [Line Items]
Preferred stock dividends declared		$ 53,100,000
Preferred stock, dividends per share, declared		$ 38.65
Dividends Declared and Paid | Convertible Preferred Stock Subject to Mandatory Redemption | Series A Preferred Stock
Class of Stock [Line Items]
Preferred stock dividends declared		$ 23,700,000	$ 23,900,000
Preferred stock, dividends per share, declared		$ 3.94	$ 3.98
[1]	The Company had no Series A Preferred Stock outstanding during the year ended December 31, 2013 and no Series B Preferred Stock outstanding during the years ended December 31, 2014 and 2013.
[2]	Represents the tax treatment on dividends per depositary share, each of which represents a 1/10th interest in a share of Series B Preferred Stock.

Equity (Distributions) (Detail)

Equity (Distributions) (Detail) - $ / shares		Dec. 02, 2015	Dec. 31, 2015		Dec. 31, 2014		Dec. 31, 2013	[1]
Common Stock
Dividends Payable [Line Items]
Dividends declared per share			$ 1.81		$ 1.4	[1]	$ 1.1
Dividends declared, common stock, percent of total			100.00%		100.00%	[1]	100.00%
Common Stock | Ordinary Income
Dividends Payable [Line Items]
Dividends declared per share			$ 1.269352		$ 1.40	[1]	$ 1.1
Dividends declared, common stock, percent of total			70.13%		100.00%	[1]	100.00%
Common Stock | Capital Gain
Dividends Payable [Line Items]
Dividends declared per share			$ 0.540648		$ 0	[1]	$ 0
Dividends declared, common stock, percent of total			29.87%		0.00%	[1]	0.00%
Series A Preferred Stock | Convertible Preferred Stock Subject to Mandatory Redemption
Dividends Payable [Line Items]
Preferred stock, dividends per share, declared			$ 5.25		$ 2.6688	[1]	$ 0
Dividends declared, preferred stock, declared			100.00%		100.00%	[1]	0.00%
Dividends per share, preferred stock		$ 1.3125
Series A Preferred Stock | Convertible Preferred Stock Subject to Mandatory Redemption | Ordinary Income
Dividends Payable [Line Items]
Preferred stock, dividends per share, declared			$ 3.68182	[2]	$ 2.6688	[1]	$ 0
Dividends declared, preferred stock, declared			70.13%		100.00%	[1]	0.00%
Series A Preferred Stock | Convertible Preferred Stock Subject to Mandatory Redemption | Capital Gain
Dividends Payable [Line Items]
Preferred stock, dividends per share, declared			$ 1.56818		$ 0	[1]	$ 0
Dividends declared, preferred stock, declared			29.87%		0.00%	[1]	0.00%
Series A Preferred Stock | Dividends Declared and Paid | Convertible Preferred Stock Subject to Mandatory Redemption
Dividends Payable [Line Items]
Preferred stock, dividends per share, declared			$ 3.94		$ 3.98
Series B Preferred Stock | Convertible Preferred Stock Subject to Mandatory Redemption
Dividends Payable [Line Items]
Preferred stock, dividends per share, declared	[3]		$ 3.8653		$ 0	[1]	$ 0
Dividends declared, preferred stock, declared	[3]		100.00%		0.00%	[1]	0.00%
Series B Preferred Stock | Convertible Preferred Stock Subject to Mandatory Redemption | Ordinary Income
Dividends Payable [Line Items]
Preferred stock, dividends per share, declared	[3]		$ 2.710717		$ 0	[1]	$ 0
Dividends declared, preferred stock, declared	[3]		70.13%		0.00%	[1]	0.00%
Series B Preferred Stock | Convertible Preferred Stock Subject to Mandatory Redemption | Capital Gain
Dividends Payable [Line Items]
Preferred stock, dividends per share, declared	[3]		$ 1.154563		$ 0	[1]	$ 0
Dividends declared, preferred stock, declared	[3]		29.87%		0.00%	[1]	0.00%
Series B Preferred Stock | Dividends Declared and Paid | Convertible Preferred Stock Subject to Mandatory Redemption
Dividends Payable [Line Items]
Preferred stock, dividends per share, declared			$ 38.65
[1]	The Company had no Series A Preferred Stock outstanding during the year ended December 31, 2013 and no Series B Preferred Stock outstanding during the years ended December 31, 2014 and 2013.
[2]	Includes dividend declared on December 2, 2014 of $1.3125 per share, payable on February 16, 2015 to preferred stockholders of record at the close of business on February 1, 2015.
[3]	Represents the tax treatment on dividends per depositary share, each of which represents a 1/10th interest in a share of Series B Preferred Stock.

Impairments, Net Loss on Sale97

Impairments, Net Loss on Sale of Long-Lived Assets (Narrative) (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Property, Plant and Equipment Impairment or Disposal [Abstract]
Impairment charges and net losses on sales or disposals of long-lived assets	$ 29.8	$ 28.5	$ 32.5
Impairment charges	15.1	15.3	15.9
Losses associated with the sale or disposal of certain non-core towers, other assets and other miscellaneous items	$ 14.7	$ 13.2	$ 16.6

Earnings Per Common Share (Sche

Earnings Per Common Share (Schedule of Earnings Per Basic And Diluted by Common Class) (Details) - USD ($) $ / shares in Units, shares in Thousands, $ in Thousands	3 Months Ended								12 Months Ended
	Dec. 31, 2015	Sep. 30, 2015	Jun. 30, 2015	Mar. 31, 2015	Dec. 31, 2014	Sep. 30, 2014	Jun. 30, 2014	Mar. 31, 2014	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Earnings Per Share [Abstract]
NET INCOME ATTRIBUTABLE TO AMERICAN TOWER CORPORATION STOCKHOLDERS	$ 232,702	$ 102,999	$ 156,056	$ 193,317	$ 180,387	$ 207,593	$ 234,431	$ 202,499	$ 685,074	$ 824,910	$ 551,333
Dividends on preferred stock	(26,781)	(26,781)	(26,782)	(9,819)	(11,813)	(7,700)	(4,375)	0	(90,163)	(23,888)	0
NET INCOME ATTRIBUTABLE TO AMERICAN TOWER CORPORATION COMMON STOCKHOLDERS	$ 205,921	$ 76,218	$ 129,274	$ 183,498	$ 168,574	$ 199,893	$ 230,056	$ 202,499	$ 594,911	$ 801,022	$ 551,333
Basic weighted average common shares outstanding									418,907	395,958	395,040
Dilutive securities									4,108	4,128	4,106
Diluted weighted average common shares outstanding									423,015	400,086	399,146
Basic net income attributable to American Tower Corporation common stockholders (in dollars per share)	$ 0.49	$ 0.18	$ 0.31	$ 0.45	$ 0.43	$ 0.50	$ 0.58	$ 0.51	$ 1.42	$ 2.02	$ 1.40
Diluted net income attributable to American Tower Corporation common stockholders (in dollars per share)	$ 0.48	$ 0.18	$ 0.30	$ 0.45	$ 0.42	$ 0.50	$ 0.58	$ 0.51	$ 1.41	$ 2	$ 1.38

Earnings Per Common Share (Sc99

Earnings Per Common Share (Schedule of Shares Excluded From Computation of Earnings Per Share) (Details) - shares shares in Thousands	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Restricted Stock
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Shares issuable upon conversion of the stock-based awards and convertible notes	0	5	0
Equity Option
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Shares issuable upon conversion of the stock-based awards and convertible notes	1,606	1,290	1,161
Preferred Stock
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Shares issuable upon conversion of the stock-based awards and convertible notes	15,408	4,303	0

Commitments And Contingencie100

Commitments And Contingencies (Narrative) (Details)	Mar. 27, 2015USD ($)communications_siterenewal_period	Dec. 31, 2000USD ($)tower	Dec. 31, 2015USD ($)towerrenewal_periodshares	Dec. 31, 2014USD ($)	Dec. 31, 2013USD ($)
Loss Contingencies [Line Items]
Aggregate rent expense			$ 804,800,000	$ 655,000,000	$ 495,200,000
Verizon Transaction
Loss Contingencies [Line Items]
Capital leased assets, number of units | communications_site	11,286
Right to lease, weighted average term	28 years
Aggregate purchase option price for towers	$ 5,000,000,000
Customer lease, initial term	10 years
Successive terms to renew lease | renewal_period	8
Renewal term	5 years
At T Transaction
Loss Contingencies [Line Items]
Capital leased assets, number of units | tower			2,370
Aggregate purchase option price for towers			$ 697,200,000
Successive terms to renew lease | renewal_period			4
Operating lease, term of contract			27 years
Number of communications sites acquired | tower			60
Purchase price accretion rate (per year)			10.00%
At T Transaction | Commitments prior to June 30, 2020
Loss Contingencies [Line Items]
Renewal term			5 years
At T Transaction | Commitments subsequent to June 30, 2020
Loss Contingencies [Line Items]
Renewal term			1 year
ALLTEL Transaction
Loss Contingencies [Line Items]
Capital leased assets, number of units | tower		1,800
Aggregate purchase option price for towers			$ 75,300,000
Purchase price accretion rate (per year)		3.00%
Average lease term (in years)		15 years
Cash purchase price per tower		$ 27,500
Purchase price of tower in shares of common stock | shares			769
Television And Radio Broadcast
Loss Contingencies [Line Items]
Operating lease, term			10 years

Commitments and Contingencie101

Commitments and Contingencies (Future Minimum Rental Payments Under Non-Cancelable Operating Leases) (Details) $ in Millions	Dec. 31, 2015USD ($)
Commitments and Contingencies Disclosure [Abstract]
2,016	$ 722
2,017	709
2,018	690
2,019	670
2,020	643
Thereafter	6,416
Total	$ 9,850

Commitments and Contingencie102

Commitments and Contingencies (Future Minimum Payments Under Capital Leases) (Details) $ in Millions	Dec. 31, 2015USD ($)
Commitments and Contingencies Disclosure [Abstract]
2,016	$ 21
2,017	18
2,018	17
2,019	15
2,020	12
Thereafter	173
Total minimum lease payments	256
Less amounts representing interest	(143)
Present value of capital lease obligations	$ 113

Commitments and Contingencie103

Commitments and Contingencies (Future Minimum Rental Receipts Under Operating Lease Agreements) (Details) $ in Millions	Dec. 31, 2015USD ($)
Commitments and Contingencies Disclosure [Abstract]
2,016	$ 4,082
2,017	4,004
2,018	3,874
2,019	3,654
2,020	3,369
Thereafter	11,294
Total	$ 30,277

Supplemental Cash Flow Infor104

Supplemental Cash Flow Information (Supplemental Cash Flow Information and Non-Cash Investing and Financing Activities) (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Supplemental Cash Flow Information [Abstract]
Cash paid for interest	$ 577,952	$ 548,089	$ 397,366
Cash paid for income taxes (net of refunds of $7,053, $8,476 and $19,701, respectively)	157,058	69,212	51,676
Increase in accounts payable and accrued expenses for purchases of property and equipment and construction activities	2,780	1,121	9,147
Purchases of property and equipment under capital leases	36,851	36,486	27,416
Fair value of debt assumed through acquisitions	0	463,135	1,576,186
Settlement of accounts receivable related to acquisitions	899	31,849	0
Conversion of third-party debt to equity	0	111,181	0
Proceeds from income tax refunds	$ 7,053	$ 8,476	$ 19,701

Business Segments (Narrative) (

Business Segments (Narrative) (Details) - segment	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Segment Reporting Information [Line Items]
Number of reportable segments	5
Customer Concentration Risk
Segment Reporting Information [Line Items]
Concentration risk, percentage	10.00%	10.00%	10.00%
Property | Total international
Segment Reporting Information [Line Items]
Number of reportable segments	3

Business Segments (Summarized F

Business Segments (Summarized Financial Information Concerning the Company's Reportable Segments) (Details) - USD ($) $ in Thousands	3 Months Ended								12 Months Ended
	Dec. 31, 2015	Sep. 30, 2015	Jun. 30, 2015	Mar. 31, 2015	Dec. 31, 2014	Sep. 30, 2014	Jun. 30, 2014	Mar. 31, 2014	Dec. 31, 2015		Dec. 31, 2014		Dec. 31, 2013
Segment Reporting Information [Line Items]
Segment revenues	$ 1,280,041	$ 1,237,910	$ 1,174,375	$ 1,079,190	$ 1,046,314	$ 1,038,188	$ 1,031,457	$ 984,089	$ 4,771,516		$ 4,100,048		$ 3,361,407
Segment operating expenses									1,306,815	[1]	1,092,428	[2]	858,329	[3]
Segment gross margin									3,475,910		3,018,167		2,525,313
Segment selling, general, administrative and development expense									287,895	[1]	263,488	[2]	230,708	[3]
Segment operating profit									3,188,015		2,754,679		2,294,605
Stock-based compensation expense									90,537		80,153		68,138
Depreciation, amortization and accretion									1,285,328		1,003,802		800,145
Other expense (2)									860,732	[4]	700,282	[5]	766,330	[6]
INCOME FROM CONTINUING OPERATIONS BEFORE INCOME TAXES									829,962		865,704		541,749
Other selling, general, administrative and development expense									121,456		104,738	[7]	118,243	[8]
Capital expenditures									728,753		974,404		724,532
United States
Segment Reporting Information [Line Items]
Segment revenues									3,248,629		2,732,984		2,263,682
Corporate, Non-Segment
Segment Reporting Information [Line Items]
Stock-based compensation expense									90,537		80,153		68,138
Depreciation, amortization and accretion									1,285,328		1,003,802		800,145
Other expense (2)									860,732	[4]	700,282	[5]	766,330	[6]
Other selling, general, administrative and development expense									121,456		104,738	[7]	118,243	[8]
Capital expenditures									17,252		24,146		30,383
Amount previously recorded as segment selling, general and administrative expense									7,900		5,900
Operating Expense
Segment Reporting Information [Line Items]
Stock-based compensation expense									2,100		1,800		1,500
Operating Segments | Network Development Services
Segment Reporting Information [Line Items]
Segment revenues									91,128		93,194		74,317
Segment operating expenses									32,993	[1]	37,648	[2]	30,564	[3]
Segment gross margin									58,135		55,546		43,753
Segment selling, general, administrative and development expense									15,724	[1]	12,469	[2]	9,257	[3]
Segment operating profit									42,411		43,077		34,496
Capital expenditures									0		0		0
Operating Segments | Property
Segment Reporting Information [Line Items]
Segment revenues									4,680,388		4,006,854		3,287,090
Segment operating expenses									1,273,822	[1]	1,054,780	[2]	827,765	[3]
Segment gross margin									3,417,775		2,962,621		2,481,560
Segment selling, general, administrative and development expense									272,171	[1]	251,019	[2]	221,451	[3]
Segment operating profit									3,145,604		2,711,602		2,260,109
Capital expenditures									711,501		950,258		694,149
Operating Segments | Property | United States
Segment Reporting Information [Line Items]
Segment revenues									3,157,501		2,639,790		2,189,365
Segment operating expenses									678,499	[1]	515,742	[2]	405,419	[3]
Segment gross margin									2,479,002		2,124,048		1,783,946
Segment selling, general, administrative and development expense									138,617	[1]	124,944	[2]	103,989	[3]
Segment operating profit									2,340,385		1,999,104		1,679,957
Capital expenditures									367,663		576,153		416,239
Operating Segments | Property | Asia
Segment Reporting Information [Line Items]
Segment revenues									242,223		219,566		191,355
Segment operating expenses									126,874	[1]	121,797	[2]	109,645	[3]
Segment gross margin									115,349		97,769		81,710
Segment selling, general, administrative and development expense									22,771	[1]	19,632	[2]	15,630	[3]
Segment operating profit									92,578		78,137		66,080
Capital expenditures									75,407		74,334		55,914
Operating Segments | Property | EMEA
Segment Reporting Information [Line Items]
Segment revenues									395,092		315,053		295,681
Segment operating expenses									163,820	[1]	126,714	[2]	121,122	[3]
Segment gross margin									231,272		188,339		174,559
Segment selling, general, administrative and development expense									48,672	[1]	39,553	[2]	39,076	[3]
Segment operating profit									182,600		148,786		135,483
Capital expenditures									66,625		70,126		67,462
Operating Segments | Property | Latin America
Segment Reporting Information [Line Items]
Segment revenues									885,572		832,445		610,689
Segment operating expenses									304,629	[1]	290,527	[2]	191,579	[3]
Segment gross margin									592,152		552,465		441,345
Segment selling, general, administrative and development expense									62,111	[1]	66,890	[2]	62,756	[3]
Segment operating profit									530,041		485,575		378,589
Capital expenditures									201,806		229,645		154,534
Selling General Administrative And Development Expense
Segment Reporting Information [Line Items]
Stock-based compensation expense									88,484		78,316		66,594
TV Azteca
Segment Reporting Information [Line Items]
Interest income, TV Azteca, net of interest expense of $820, $1,482 and $1,483, respectively									11,209		10,547		22,235
TV Azteca | Operating Segments | Network Development Services
Segment Reporting Information [Line Items]
Interest income, TV Azteca, net of interest expense of $820, $1,482 and $1,483, respectively									0		0		0
TV Azteca | Operating Segments | Property
Segment Reporting Information [Line Items]
Interest income, TV Azteca, net of interest expense of $820, $1,482 and $1,483, respectively									11,209		10,547		22,235
TV Azteca | Operating Segments | Property | United States
Segment Reporting Information [Line Items]
Interest income, TV Azteca, net of interest expense of $820, $1,482 and $1,483, respectively									0		0		0
TV Azteca | Operating Segments | Property | Asia
Segment Reporting Information [Line Items]
Interest income, TV Azteca, net of interest expense of $820, $1,482 and $1,483, respectively									0		0		0
TV Azteca | Operating Segments | Property | EMEA
Segment Reporting Information [Line Items]
Interest income, TV Azteca, net of interest expense of $820, $1,482 and $1,483, respectively									0		0		0
TV Azteca | Operating Segments | Property | Latin America
Segment Reporting Information [Line Items]
Interest income, TV Azteca, net of interest expense of $820, $1,482 and $1,483, respectively									$ 11,209		$ 10,547		$ 22,235
[1]	Segment operating expenses and segment selling, general, administrative and development expenses exclude stock-based compensation expense of $2.1 million and $88.5 million, respectively
[2]	Segment operating expenses and segment selling, general, administrative and development expenses exclude stock-based compensation expense of $1.8 million and $78.3 million, respectively.
[3]	Segment operating expenses and segment selling, general, administrative and development expenses exclude stock-based compensation expense of $1.5 million and $66.6 million, respectively.
[4]	Primarily includes interest expense.
[5]	Primarily includes interest expense.
[6]	Primarily includes interest expense.
[7]	Includes $7.9 million of expense previously recorded as segment selling, general, administrative and development expense.
[8]	Includes $5.9 million of expense previously recorded as segment selling, general, administrative and development expense.

Business Segments (Additional I

Business Segments (Additional Information Relating to the Company's Operating Segments) (Details) - USD ($) $ in Thousands		Dec. 31, 2015	Dec. 31, 2014	[1],[2]	Dec. 31, 2013	[1]
Segment Reporting, Asset Reconciling Item [Line Items]
Assets		$ 26,904,272	$ 21,263,565		$ 20,213,937
Corporate, Non-Segment
Segment Reporting, Asset Reconciling Item [Line Items]
Assets	[3]	162,378	156,567		157,563
Operating Segments | Property | United States
Segment Reporting, Asset Reconciling Item [Line Items]
Assets		19,286,465	14,335,731		13,608,818
Operating Segments | Property | Asia
Segment Reporting, Asset Reconciling Item [Line Items]
Assets	[4]	736,149	738,290		743,671
Operating Segments | Property | EMEA
Segment Reporting, Asset Reconciling Item [Line Items]
Assets	[4]	2,249,634	1,275,253		1,472,143
Operating Segments | Property | Latin America
Segment Reporting, Asset Reconciling Item [Line Items]
Assets	[4]	4,401,258	4,700,357		4,184,135
Operating Segments | Network Development Services
Segment Reporting, Asset Reconciling Item [Line Items]
Assets		$ 68,388	$ 57,367		$ 47,607
[1]	Balances have been revised to reflect debt issuance cost adjustments.
[2]	Balances have been revised to reflect purchase accounting measurement period adjustments.
[3]	Balances include corporate assets such as cash and cash equivalents, certain tangible and intangible assets and income tax accounts which have not been allocated to specific segments.
[4]	Balances are translated at the applicable period end exchange rate and therefore may impact comparability between periods.

Business Segments (Summarized G

Business Segments (Summarized Geographic Information Related to the Company's Operating Revenues) (Details) - USD ($) $ in Thousands		3 Months Ended								12 Months Ended
		Dec. 31, 2015	Sep. 30, 2015	Jun. 30, 2015	Mar. 31, 2015	Dec. 31, 2014	Sep. 30, 2014	Jun. 30, 2014	Mar. 31, 2014	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Segment Reporting, Other Significant Reconciling Item [Line Items]
Segment revenues		$ 1,280,041	$ 1,237,910	$ 1,174,375	$ 1,079,190	$ 1,046,314	$ 1,038,188	$ 1,031,457	$ 984,089	$ 4,771,516	$ 4,100,048	$ 3,361,407
United States
Segment Reporting, Other Significant Reconciling Item [Line Items]
Segment revenues										3,248,629	2,732,984	2,263,682
India
Segment Reporting, Other Significant Reconciling Item [Line Items]
Segment revenues	[1]									242,223	219,566	191,355
Germany
Segment Reporting, Other Significant Reconciling Item [Line Items]
Segment revenues	[1]									55,965	64,946	62,756
Ghana
Segment Reporting, Other Significant Reconciling Item [Line Items]
Segment revenues	[1]									94,549	95,486	92,114
Nigeria
Segment Reporting, Other Significant Reconciling Item [Line Items]
Segment revenues	[1]									109,701	0	0
South Africa
Segment Reporting, Other Significant Reconciling Item [Line Items]
Segment revenues	[1]									80,510	98,334	91,906
Uganda
Segment Reporting, Other Significant Reconciling Item [Line Items]
Segment revenues	[1]									54,367	56,287	48,905
Brazil
Segment Reporting, Other Significant Reconciling Item [Line Items]
Segment revenues	[1]									408,644	331,089	212,201
Chile
Segment Reporting, Other Significant Reconciling Item [Line Items]
Segment revenues	[1]									29,650	31,756	28,978
Colombia
Segment Reporting, Other Significant Reconciling Item [Line Items]
Segment revenues	[1]									78,351	89,421	70,901
Costa Rica
Segment Reporting, Other Significant Reconciling Item [Line Items]
Segment revenues	[1]									17,244	16,742	4,055
Mexico
Segment Reporting, Other Significant Reconciling Item [Line Items]
Segment revenues	[1]									340,461	354,116	288,306
Panama
Segment Reporting, Other Significant Reconciling Item [Line Items]
Segment revenues	[1],[2]									0	1,243	424
Peru
Segment Reporting, Other Significant Reconciling Item [Line Items]
Segment revenues	[1]									$ 11,222	$ 8,078	$ 5,824
[1]	Balances are translated at the applicable exchange rate and therefore may impact comparability between periods.
[2]	In September 2014, the Company completed the sale of the operations in Panama.

Business Segments (Summarize109

Business Segments (Summarized Geographic Information Related to the Company's Long-lived Assets) (Details) - USD ($) $ in Thousands		Dec. 31, 2015	Dec. 31, 2014	[1]
Segment Reporting, Other Significant Reconciling Item [Line Items]
Long-Lived Assets		$ 23,796,105	$ 18,446,559
United States
Segment Reporting, Other Significant Reconciling Item [Line Items]
Long-Lived Assets	[2]	17,516,535	12,771,089
Brazil
Segment Reporting, Other Significant Reconciling Item [Line Items]
Long-Lived Assets	[3]	2,204,494	2,152,953
Chile
Segment Reporting, Other Significant Reconciling Item [Line Items]
Long-Lived Assets	[3]	121,938	147,413
Colombia
Segment Reporting, Other Significant Reconciling Item [Line Items]
Long-Lived Assets	[3]	256,892	319,260
Costa Rica
Segment Reporting, Other Significant Reconciling Item [Line Items]
Long-Lived Assets	[3]	120,292	127,436
Germany
Segment Reporting, Other Significant Reconciling Item [Line Items]
Long-Lived Assets	[3]	388,727	456,698
Ghana
Segment Reporting, Other Significant Reconciling Item [Line Items]
Long-Lived Assets	[3]	217,530	235,523
Nigeria
Segment Reporting, Other Significant Reconciling Item [Line Items]
Long-Lived Assets	[3]	1,018,980	0
India
Segment Reporting, Other Significant Reconciling Item [Line Items]
Long-Lived Assets	[3]	619,370	616,266
Mexico
Segment Reporting, Other Significant Reconciling Item [Line Items]
Long-Lived Assets	[3]	976,707	1,188,183
Peru
Segment Reporting, Other Significant Reconciling Item [Line Items]
Long-Lived Assets	[3]	59,206	61,490
South Africa
Segment Reporting, Other Significant Reconciling Item [Line Items]
Long-Lived Assets	[3]	133,088	184,292
Uganda
Segment Reporting, Other Significant Reconciling Item [Line Items]
Long-Lived Assets	[3]	$ 162,346	$ 185,956
[1]	Balances have been revised to reflect purchase accounting measurement period adjustments and debt issuance costs related to the Company’s credit facilities (see note 1).
[2]	Includes Property and equipment, net, Goodwill and Other intangible assets, net.
[3]	Balances are translated at the applicable period end exchange rate and therefore may impact comparability between periods.

Business Segments (Major Custom

Business Segments (Major Customers) (Details) - Customer Concentration Risk	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Revenue, Major Customer [Line Items]
Concentration risk, percentage	10.00%	10.00%	10.00%
Sales Revenue, Net
Revenue, Major Customer [Line Items]
Concentration risk, percentage	63.00%
Sales Revenue, Net | AT&T Mobility
Revenue, Major Customer [Line Items]
Concentration risk, percentage	24.00%	20.00%	18.00%
Sales Revenue, Net | Verizon Wireless
Revenue, Major Customer [Line Items]
Concentration risk, percentage	16.00%	11.00%	11.00%
Sales Revenue, Net | Sprint Nextel
Revenue, Major Customer [Line Items]
Concentration risk, percentage	13.00%	15.00%	16.00%
Sales Revenue, Net | T-Mobile
Revenue, Major Customer [Line Items]
Concentration risk, percentage	10.00%	10.00%	11.00%

Selected Quarterly Financial111

Selected Quarterly Financial Data (Schedule Of Quarterly Financial Information) (Details) - USD ($) $ / shares in Units, $ in Thousands		3 Months Ended								12 Months Ended
		Dec. 31, 2015	Sep. 30, 2015	Jun. 30, 2015	Mar. 31, 2015	Dec. 31, 2014	Sep. 30, 2014	Jun. 30, 2014	Mar. 31, 2014	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Selected Quarterly Financial Information [Abstract]
Operating revenues		$ 1,280,041	$ 1,237,910	$ 1,174,375	$ 1,079,190	$ 1,046,314	$ 1,038,188	$ 1,031,457	$ 984,089	$ 4,771,516	$ 4,100,048	$ 3,361,407
Cost of operations	[1]	356,381	365,389	322,458	264,640	277,019	284,202	272,275	260,769	1,308,868	1,094,265
Operating income		402,124	400,925	389,774	419,966	345,979	384,807	402,499	353,637	1,612,789	1,486,922	1,214,305
Net income		221,595	97,740	157,180	195,492	181,597	206,630	221,659	193,313	672,007	803,199	482,208
NET INCOME ATTRIBUTABLE TO AMERICAN TOWER CORPORATION STOCKHOLDERS		232,702	102,999	156,056	193,317	180,387	207,593	234,431	202,499	685,074	824,910	551,333
Dividends on preferred stock		(26,781)	(26,781)	(26,782)	(9,819)	(11,813)	(7,700)	(4,375)	0	(90,163)	(23,888)	0
Net income attributable to American Tower Corporation common stockholders		$ 205,921	$ 76,218	$ 129,274	$ 183,498	$ 168,574	$ 199,893	$ 230,056	$ 202,499	$ 594,911	$ 801,022	$ 551,333
Basic net income per common share (in dollars per share)		$ 0.49	$ 0.18	$ 0.31	$ 0.45	$ 0.43	$ 0.50	$ 0.58	$ 0.51	$ 1.42	$ 2.02	$ 1.40
Diluted net income per common share (in dollars per share)		$ 0.48	$ 0.18	$ 0.30	$ 0.45	$ 0.42	$ 0.50	$ 0.58	$ 0.51	$ 1.41	$ 2	$ 1.38
[1]	Represents Operating expenses, exclusive of Depreciation, amortization and accretion, Selling, general, administrative and development expense, and Other operating expenses.

Subsequent Events Narrative (De

Subsequent Events Narrative (Details) - Subsequent Event - Senior Notes $ in Millions	Jan. 12, 2016USD ($)
3.30% Senior Notes
Subsequent Event [Line Items]
Long-term debt, stated interest rate	3.30%
Principal amount	$ 750
4.40% Senior Notes
Subsequent Event [Line Items]
Long-term debt, stated interest rate	4.40%
Principal amount	$ 500
3.30% and 4.40% senior notes
Subsequent Event [Line Items]
Proceeds from the issuance of debt	$ 1,237.2

Schedule III - Real Estate A113

Schedule III - Real Estate And Accumulated Depreciation (Schedule Of Real Estate And Accumulated Depreciation) (Details) $ in Thousands		12 Months Ended
		Dec. 31, 2015USD ($)site	Dec. 31, 2014USD ($)	Dec. 31, 2013USD ($)	Dec. 31, 2012USD ($)
SEC Schedule III, Real Estate and Accumulated Depreciation [Line Items]
Number of units | site	[1]	100,131
Amount of Encumbrances	[2]	$ 3,364,202
SEC Schedule III, Real Estate, Gross		13,046,291	$ 10,469,207	$ 10,003,617
Accumulated Depreciation		$ (3,994,874)	$ (3,613,078)	$ (3,297,033)	$ (2,968,230)
Date of construction		Various
Date Acquired		Various
Percentage Of Gross Amounts Maximum		5.00%
Maximum
SEC Schedule III, Real Estate and Accumulated Depreciation [Line Items]
SEC Schedule III, Real Estate and Accumulated Depreciation, Life Used for Depreciation	[3]	20 years
[1]	No single site exceeds 5% of the total amounts indicated in the table above.
[2]	Certain assets secure debt of $3.4 billion.
[3]	Does not include those sites under construction.

Schedule III - Real Estate A114

Schedule III - Real Estate And Accumulated Depreciation (Activity Of Real Estate And Accumulated Depreciation) (Details) - USD ($) $ in Thousands		12 Months Ended
		Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
SEC Schedule III, Real Estate and Accumulated Depreciation Disclosure [Abstract]
Adjusted Real Estate Gross At Carrying Value	[1]		$ 10,434,326	$ 9,921,276	$ 8,290,313
SEC Schedule III, Reconciliation of Carrying Amount of Real Estate Investments [Roll Forward]
Gross amount at beginning		$ 10,469,207	10,003,617
Acquisitions		2,620,778	397,837	1,415,171
Discretionary capital projects	[2]	210,421	437,720	314,126
Discretionary ground lease purchases	[3]	144,695	159,637	102,991
Redevelopment capital expenditures	[4]	114,089	96,782	89,960
Capital improvements	[5]	42,417	41,967	58,960
Start-up capital expenditures	[6]	35,561	21,173	15,757
Other additions	[7]	201,118	22,069	8,764
Total additions		3,369,079	1,177,185	2,005,729
Cost of real estate sold or disposed		(60,975)	(60,147)	(48,467)
Other deductions	[8]	(696,139)	(569,107)	(243,958)
Total deductions		(757,114)	(629,254)	(292,425)
Balance at end		13,046,291	10,469,207	10,003,617
SEC Schedule III, Reconciliation of Real Estate Accumulated Depreciation [Roll Forward]
Gross amount of accumulated depreciation at beginning		(3,613,078)	(3,297,033)	(2,968,230)
Depreciation		(557,052)	(457,135)	(408,693)
Other additions		0	(761)	(264)
Total additions		(557,052)	(457,896)	(408,957)
Amount of accumulated depreciation for assets sold or disposed		30,083	20,953	17,462
Other deductions	[8]	145,173	120,898	62,692
Total deductions		175,256	141,851	80,154
Balance at end		$ (3,994,874)	$ (3,613,078)	$ (3,297,033)
[1]	Balance has been revised to reflect purchase accounting measurement period adjustments.
[2]	Includes amounts incurred primarily for the construction of new sites.
[3]	Includes amounts incurred to purchase or otherwise secure the land under communications sites.
[4]	Includes amounts incurred to increase the capacity of existing sites, which results in new incremental tenant revenue.
[5]	Includes amounts incurred to maintain existing sites.
[6]	Includes amounts incurred in connection with acquisitions and new market launches and costs that are contemplated in the business cases for these investments.
[7]	Primarily includes regional improvements and other additions.
[8]	Primarily includes foreign currency exchange rate fluctuations.