SBA Communications (SBAC) 10-Q 8 May 17 2017 Q1 Quarterly report Financial data

Document And Entity Information

Document And Entity Information - shares	3 Months Ended
	Mar. 31, 2017	Apr. 30, 2017
Document And Entity Information [Abstract]
Document Type	10-Q
Amendment Flag	false
Document Period End Date	Mar. 31, 2017
Document Fiscal Year Focus	2,017
Document Fiscal Period Focus	Q1
Entity Registrant Name	SBA COMMUNICATIONS CORP
Entity Central Index Key	1,034,054
Current Fiscal Year End Date	--12-31
Entity Filer Category	Large Accelerated Filer
Entity Common Stock, Shares Outstanding		121,301,176
Trading Symbol	SBAC

Consolidated Balance Sheets

Consolidated Balance Sheets - USD ($) $ in Thousands	Mar. 31, 2017	Dec. 31, 2016
Current assets:
Cash and cash equivalents	$ 132,222	$ 146,109
Restricted cash	30,674	36,786
Accounts receivable, net	74,214	78,344
Costs and estimated earnings in excess of billings on uncompleted contracts	13,108	11,127
Prepaid expenses and other current assets	51,049	52,205
Total current assets	301,267	324,571
Property and equipment, net	2,785,944	2,792,076
Intangible assets, net	3,605,548	3,656,924
Other assets	604,691	587,374
Total assets	7,297,450	7,360,945
Current liabilities:
Accounts payable	29,628	28,320
Accrued expenses	53,956	61,129
Current maturities of long-term debt	20,000	627,157
Deferred revenue	96,039	101,098
Accrued interest	19,214	44,503
Other current liabilities	9,756	11,240
Total current liabilities	228,593	873,447
Long-term liabilities:
Long-term debt, net	8,646,174	8,148,426
Other long-term liabilities	339,177	334,993
Total long-term liabilities	8,985,351	8,483,419
Shareholders' deficit:
Preferred stock - par value $.01, 30,000 shares authorized, no shares issued or outstanding
Common stock - Class A, par value $.01, 400,000 shares authorized, 121,256 and 121,004 shares issued and outstanding at March 31, 2017and December 31, 2016, respectively	1,213	1,210
Additional paid-in capital	2,029,480	2,010,520
Accumulated deficit	(3,604,288)	(3,637,467)
Accumulated other comprehensive loss, net	(342,899)	(370,184)
Total shareholders' deficit	(1,916,494)	(1,995,921)
Total liabilities and shareholders' deficit	$ 7,297,450	$ 7,360,945

Consolidated Balance Sheets (Pa

Consolidated Balance Sheets (Parenthetical) - $ / shares	Mar. 31, 2017	Dec. 31, 2016
Preferred stock, par value	$ 0.01	$ 0.01
Preferred stock, shares authorized	30,000,000	30,000,000
Preferred stock, shares issued	0	0
Preferred stock, shares outstanding	0	0
Common Stock [Member]
Common stock - Class A, par value	$ 0.01	$ 0.01
Common stock - Class A, shares authorized	400,000,000	400,000,000
Common stock - Class A, shares issued	121,256,000	121,004,000
Common stock - Class A, shares outstanding	121,256,000	121,004,000

Consolidated Statements Of Oper

Consolidated Statements Of Operations - USD ($) shares in Thousands, $ in Thousands		3 Months Ended
		Mar. 31, 2017	Mar. 31, 2016
Revenues:
Site leasing		$ 397,550	$ 374,450
Site development		25,813	25,319
Total revenues		423,363	399,769
Cost of revenues (exclusive of depreciation, accretion, and amortization shown below):
Cost of site leasing		89,382	82,762
Cost of site development		21,588	19,833
Selling, general, and administrative	[1]	34,223	30,406
Acquisition related adjustments and expenses		2,969	3,182
Asset impairment and decommission costs		8,351	6,183
Depreciation, accretion, and amortization		159,031	159,801
Total operating expenses		315,544	302,167
Operating income		107,819	97,602
Other income (expense):
Interest income		3,234	1,866
Interest expense		(77,602)	(83,804)
Non-cash interest expense		(705)	(455)
Amortization of deferred financing fees		(6,698)	(5,265)
Other income (expense), net		14,948	45,900
Total other expense, net		(66,823)	(41,758)
Income before provision for income taxes		40,996	55,844
Provision for income taxes		(3,398)	(2,205)
Net income		$ 37,598	$ 53,639
Net income per common share
Basic		$ 0.31	$ 0.43
Diluted		$ 0.31	$ 0.43
Weighted average common shares
Basic		121,049	125,398
Diluted		121,734	126,124
[1]	Includes non-cash compensation of $8,826 and $7,686 for the three months ended March 31, 2017 and 2016, respectively.

Consolidated Statements Of Ope5

Consolidated Statements Of Operations (Parenthetical) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2017	Mar. 31, 2016
Non-cash compensation expense	$ 9,277	$ 7,785
Selling, General And Administrative [Member]
Non-cash compensation expense	$ 8,826	$ 7,686

Consolidated Statements Of Comp

Consolidated Statements Of Comprehensive Income - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2017	Mar. 31, 2016
Consolidated Statements Of Comprehensive Income [Abstract]
Net income	$ 37,598	$ 53,639
Foreign currency translation adjustments	27,285	60,693
Comprehensive income	$ 64,883	$ 114,332

Consolidated Statements Of Shar

Consolidated Statements Of Shareholders' Deficit - 3 months ended Mar. 31, 2017 - USD ($) shares in Thousands, $ in Thousands	Common Stock [Member]Class A Common Stock [Member]	Additional Paid-In Capital [Member]	Accumulated Deficit [Member]	Accumulated Other Comprehensive Loss [Member]	Total
BALANCE at Dec. 31, 2016	$ 1,210	$ 2,010,520	$ (3,637,467)	$ (370,184)	$ (1,995,921)
BALANCE, Shares at Dec. 31, 2016	121,004
Net income			37,598		37,598
Common stock issued in connection with stock purchase/option plans	$ 3	9,490			9,493
Common stock issued in connection with stock purchase/option plans, Shares	294
Non-cash compensation		9,470			9,470
Repurchase and retirement of common stock			(4,419)		(4,419)
Repurchase and retirement of common stock, Shares	(42)
Foreign currency translation adjustments				27,285	27,285
BALANCE at Mar. 31, 2017	$ 1,213	$ 2,029,480	$ (3,604,288)	$ (342,899)	$ (1,916,494)
BALANCE, Shares at Mar. 31, 2017	121,256

Consolidated Statements Of Cash

Consolidated Statements Of Cash Flows - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2017	Mar. 31, 2016
CASH FLOWS FROM OPERATING ACTIVITIES:
Net income	$ 37,598	$ 53,639
Adjustments to reconcile net income to net cash provided by operating activities:
Depreciation, accretion, and amortization	159,031	159,801
Non-cash asset impairment and decommission costs	7,047	4,196
Non-cash compensation expense	9,277	7,785
Amortization of deferred financing fees	6,698	5,265
Gain on remeasurement of U.S. dollar denominated intercompany loan	(13,659)	(44,765)
Other non-cash items reflected in the Statements of Operations	35	(121)
Changes in operating assets and liabilities, net of acquisitions:
Accounts receivable and costs and estimated earnings in excess of billings on uncompleted contracts, net	1,444	90
Prepaid expenses and other assets	(4,777)	(12,266)
Accounts payable and accrued expenses	(3,899)	(8,277)
Accrued interest	(25,290)	(14,552)
Other liabilities	(1,199)	(6,151)
Net cash provided by operating activities	172,306	144,644
CASH FLOWS FROM INVESTING ACTIVITIES:
Acquisitions	(42,651)	(91,832)
Capital expenditures	(35,747)	(36,060)
Other investing activities	(5,879)	(4,447)
Net cash used in investing activities	(84,277)	(132,339)
CASH FLOWS FROM FINANCING ACTIVITIES:
Borrowings under Revolving Credit Facility		70,000
Repayments under Revolving Credit Facility	(110,000)	(50,000)
Repayment of Term Loans	(5,000)	(5,000)
Repurchase and retirement of common stock, inclusive of fees	(4,419)	(50,012)
Other financing activities	7,147	1,689
Net cash used in financing activities	(112,272)	(33,323)
Effect of exchange rate changes on cash, cash equivalents, and restricted cash	3,744	6,032
NET CHANGE IN CASH, CASH EQUIVALENTS, AND RESTRICTED CASH	(20,499)	(14,986)
CASH, CASH EQUIVALENTS, AND RESTRICTED CASH:
Beginning of period	185,970	146,619
End of period	165,471	131,633
Cash paid during the period for:
Interest	102,875	98,434
Income taxes	$ 2,806	2,359
SUPPLEMENTAL DISCLOSURE OF NON-CASH ACTIVITIES:
Assets acquired through capital leases		$ 273

Consolidated Statements Of Cas9

Consolidated Statements Of Cash Flows (Parenthetical)	Mar. 31, 2017	Aug. 15, 2016
5.625% Senior Notes [Member]
Debt instrument, interest rate, stated percentage	5.625%	5.625%
5.75% Senior Notes [Member]
Debt instrument, interest rate, stated percentage	5.75%	5.75%

Basis Of Presentation

Basis Of Presentation	3 Months Ended
	Mar. 31, 2017
Basis Of Presentation [Abstract]
Basis Of Presentation	1. BASIS OF PRESENTATION The accompanying consolidated financial statements should be read in conjunction with the Annual Report on Form 10-K for the fiscal year ended December 31, 2016 for SBA Communications Corporation and its subsidiaries (the “Company”). These financial statements have been prepared in accordance with the instructions to Form 10-Q and Article 10 of Regulation S-X and, therefore, omit or condense certain footnotes and other information normally included in financial statements prepared in accordance with accounting principles generally accepted in the United States. In the opinion of the Company’s management, all adjustments (consisting of normal recurring accruals) considered necessary for fair financial statement presentation have been made. The results of operations for an interim period may not give a true indication of the results for the year. Certain reclassifications have been made to prior year amounts or balances to conform to the presentati on adopted in the current year. The preparation of financial statements requires management to make estimates and assumptions that affect the amounts reported in consolidated financial statements and accompanying notes. While the Company believes that such estimates are fair when considered in conjunction with the consolidated financial statements and accompanying notes, the actual amounts, when known, may vary from these estimates. Foreign Currency Translation The functional currency for the Company’s Central American subsidiaries is the U.S. dollar. Monetary assets and liabilities of such subsidiaries which are not denominated in U.S. dollars are remeasured at exchange rates in effect at the balance sheet date, and revenues and expenses are remeasured at monthly average rates prevailing during the year. Unrealized translation gains and losses are reported as other income (expense), net in the Consolidated Statement of Operations. All assets and liabilities of foreign subsidiaries that do not utilize the U.S. dollar as its functional currency are translated at period-end rates of exchange, while revenues and expenses are translated at monthly average rates of exchange prevailing during the period. Unrealized remeasurement gains and losses are reported as foreign currency translation adjustments through Accumulated Other Comprehensive Loss in the accompanying Consolidated Statement of Shareholders’ Deficit. Intercompany Loans In accordance with ASC 830, the Company remeasures foreign denominated intercompany loans with the corresponding change in the balance being recorded in O ther income (expense), ne t in the Consolidated Statement of Operations as settlement is anticipated or planned in the foreseeable future . F or the three months ended March 31, 2017 and 2016 , t he Company recorded a $13.7 million gain and a $44.8 million gain, respectively, on the remeasurement of intercompany loans. As of March 31, 2017 , the outstanding balance under this agreement was $433.3 million. Accounting Pronouncements Recently Adopted In January 2017, the FASB issued ASU 2017-01, Clarifying the Definition of a Business. The standard provides guidance to help entities determine whether transactions should be accounted for as acquisitions or disposals of assets or businesses. ASU 2017-01 provides revised guidance to determine when an acquisition meets the definition of a business or should be accounted for as an asset acquisition, likely resulting in more acquisitions being accounted for as asset acquisitions as opposed to business combinations. The Company adopted this standard prospectively effective January 1, 2017. Under this update, substantially all of the Company’s acquisitions are expected to qualify for asset acquisition treatment under ASC 360, Property, Plant, and Equipment, rather than business combination treatment under ASC 805 Business Combinations. For asset acquisitions, external, direct transaction costs will be capitalized as a component of the cost of the asset acquired, while internal costs related to the asset acquisition will continue to be expensed as incurred. Additionally, earnout liabilities will be recognized at the time when the contingency is resolved or becomes payable and will increase the cost basis of the assets acquired. The adoption of ASU 2017-01 did not have a material impact on the Company’s unaudited consolidated financial statements and related disclosures. Recent Accounting Pronouncements Not Yet Adopted In May 2014, the FASB released an updated standard regarding the recognition of revenue from contracts with customers, exclusive of those contracts within lease accounting. The core principle of the standard is that an entity should recognize revenue to depict the transfer of promised goods or services to customers in an amount that reflects the consideration to which the entity expects to be entitled in exchange for those goods or services. To achieve that core principle, an entity should apply the following steps: (1) identify the contracts with the customer; (2) identify the performance obligations in the contract; (3) determine the contract price; (4) allocate the transaction price to the performance obligations in the contract; and (5) recognize revenue when (or as) the entity satisfies a performance obligation. This standard is effective for the Company in the first quarter of 2018. Early adoption is permitted but not before the first quarter of 2017. This standard is required to be applied retrospectively to each prior reporting period presented or with the cumulative effect being recognized at the date of initial application. The Company is evaluating the standard and does not expect a material financial statement impact upon adoption since the standard only affects the Company’s site development segment which represents approximately 6% of the Company’s total revenues. In February 2016, the FASB issued ASU 2016-02, Leases. The standard requires lessees to recognize a right-of-use asset and a lease liability, initially measured at the present value of the lease payments for all leases with a term greater than 12 months. The accounting for lessors remains largely unchanged from existing guidance. This standard is effective for annual and interim periods beginning after December 15, 2018 and requires a modified retrospective transition approach for all leases existing at, or entered into after, the beginning of the earliest comparative period presented. Early adoption is permitted. The Company has established a cross functional project plan to assess the impact of the standard, expects this guidance to have a material impact on its consolidated balance sheet due to the addition of right-of-use assets and lease liabilities for all leases with a term greater than 12 months, and continues to assess additional impacts to its consolidated financial statements, including the consolidated statement of operations. 

Fair Value Measurements

Fair Value Measurements	3 Months Ended
	Mar. 31, 2017
Fair Value Measurements [Abstract]
Fair Value Measurements	2. FAIR VALUE MEASUREMENTS Items Measured at Fair Value on a Recurring Basis — The Company’s earnout liabilities related to business combinations are measured at fair value on a recurring basis using Level 3 inputs and are recorded in Accrued expenses in the accompanying Consolidated Balance Sheets. Changes in estimate are recorded in Acquisition related adjustments and expenses in the accompanying Consolidated Statement of Operations. The Company determines the fair value of earnouts (contingent consideration) and any subsequent changes in fair value using a discounted probability-weighted approach using Level 3 inputs. Level 3 valuations rely on unobservable inputs for the asset or liability, and include situations where there is little, if any, market activity for the asset or liability. The fair value of the earnouts is reviewed quarterly and is based on the payments the Company expects to make based on historical internal observations related to the anticipated performance of the underlying assets. The Company’s estimate of the fair value of its obligation contained in various acquisitions prior to January 1, 2017 was $3.7 million and $4.1 million as of March 31, 2017 and December 31, 2016 , respectively. The maximum potential obligation related to the performance targets prior to January 1, 2017 was $5.0 million and $5.8 million as of March 31, 2017 and December 31, 2016 , respectively.  Items Measured at Fair Value on a Nonrecurring Basis — The Company’s long-lived assets, intangibles, and asset retirement obligations are measured at fair value on a nonrecurring basis using Level 3 inputs. The Company considers many factors and makes certain assumptions when making this assessment, including but not limited to: general market and economic conditions, historical operating results, geographic location, lease-up potential and expected timing of lease-up. The fair value of the long-lived assets, intangibles, and asset retirement obligations is calculated using a discounted cash flow model. Asset impairment and decommission costs for all periods presented and the related impaired assets primarily relate to the Company’s site leasing operating segment. The following summarizes the activity of asset impairment and decommission costs (in thousands):     For the three months  ended March 31,  2017 2016   Asset impairment (1) $ 3,014 $ —  Write-off of carrying value of decommissioned towers 3,971 4,196  Other third party decommission costs 1,366 1,987  Total asset impairment and decommission costs $ 8,351 $ 6,183 (1) Represents impairment charges resulting from the Company’s analysis that the future cash flows from certain towers would not recover the carrying value of the investment in those towers. Fair Value of Financial Instruments — The carrying values of cash and cash equivalents, accounts receivable, restricted cash, accounts payable, and short-term investments approximate their estimated fair values due to the short maturity of these instruments. Short-term investments consisted of $0.2 million in Treasury securities as of March 31, 2017 and December 31, 2016 . The Company’s estimate of the fair value of its held-to-maturity investments in treasury and corporate bonds, including current portion, are based primarily upon Level 1 reported market values. As of March 31, 2017 and December 31, 2016 , the carrying value and fair value of the held -to-maturity investments were $0.7 million . These amounts are recorded in Other assets in the accompanying Consolidated Balance Sheets. The Company determines fair value of its debt instruments utilizing various Level 2 sources including quoted prices and indicative quotes (non-binding quotes) from brokers that require judgment to interpret market information including implied credit spreads for similar borrowings on recent trades or bid/ask prices. The fair value of the Revolving Credit Facility is considered to approximate the carrying value because the interest payments are based on Eurodollar rates that reset weekly or month ly . The Company does not believe its credit risk has changed materially from the date the applicable Eurodollar Rate plus 137.5 to 200.0 basis points was set for the Revolving Credit Facility. Refer to Note 10 for the fair values, principal balances, and carrying values of the Company’s debt instruments.

Restricted Cash

Restricted Cash	3 Months Ended
	Mar. 31, 2017
Restricted Cash [Abstract]
Restricted Cash	3. RESTRICTED CASH The cash, cash equivalents, and restricted cash balances on the consolidated statement of cash flows consists of the following:    As of As of  March 31, 2017 December 31, 2016 Included on Balance Sheet   (in thousands)  Cash and cash equivalents $ 132,222 $ 146,109  Securitization escrow accounts 30,487 36,607 Restricted cash - current asset  Payment and performance bonds 187 179 Restricted cash - current asset  Surety bonds and workers compensation 2,575 3,075 Other assets - noncurrent  Total cash, cash equivalents, and restricted cash $ 165,471 $ 185,970  Pursuant to the terms of the Tower Securities (see Note 10), the Company is required to establish a securitization escrow account, held by the indenture trustee, into which all rents and other sums due on the towers that secure the Tower Securities are directly deposited by the lessees. These restricted cash amounts are used to fund reserve accounts for the payment of (1) debt service costs, (2) ground rents, real estate and personal property taxes and insurance premiums related to towers, (3) trustee and servicing expenses, and (4) management fees. The restricted cash in the securitization escrow account in excess of required reserve balances is subsequently released to the Borrowers (as defined in Note 10) monthly, provided that the Borrowers are in compliance with their debt service coverage ratio and that no event of default has occurred. All monies held by the indenture trustee are classified as restricted cash on the Company’s Consolidated Balance Sheets. Payment and performance bonds relate primarily to collateral requirements for tower construction currently in process by the Company. Cash is pledged as collateral related to surety bonds issued for the benefit of the Company or its affiliates in the ordinary course of business and primarily relate d to the Company’s tower removal obligations. As of March 31, 2017 and December 31, 2016 , the Company had $38.8 million and $39.2 million in surety , payment and performance bonds, respectively, for which it wa s only required to post $0.0 million and $0.5 million in collateral as of March 31, 2017 and December 31, 2016, respectively . The Company periodically evaluates the collateral posted for its bonds to ensure that it meets the minimum requirements. As of March 31, 2017 and December 31, 2016 , the Company had also pledged $2.5 million as collateral related to its workers compensation policy.

Other Assets

Other Assets	3 Months Ended
	Mar. 31, 2017
Other Assets [Abstract]
Other Assets	4. OTHER ASSETS The Company’s other assets are comprised of the following:     As of As of  March 31, 2017 December 31, 2016   (in thousands)  Long-term investments $ 8,379 $ 7,884  Prepaid land rent 194,819 191,615  Straight-line rent receivable 307,535 302,893  Deferred lease costs, net 29,172 29,660  Other 64,786 55,322  Total other assets $ 604,691 $ 587,374

Acquisitions

Acquisitions	3 Months Ended
	Mar. 31, 2017
Acquisitions [Abstract]
Acquisitions	5. ACQUISITIONS The following table summarizes the Company’s cash acquisition capital expenditures:      For the three months  ended March 31,  2017 2016   (in thousands)  Towers and related intangible assets $ 31,147 $ 74,844  Land buyouts and other assets (1) 11,504 16,988  Total cash acquisition capital expenditures $ 42,651 $ 91,832  (1) In addition, the Company paid $2.7 million and $3.6 million for ground lease extensions during the three months ended March 31, 2017 and 2016 , respectively. The Company recorded these amounts in prepaid rent on its Consolidated Balance Sheets. The Company’s acquisitions generally qualify for asset acquisition treatment under ASC 360, Property, Plant, and Equipment, rather than business combination treatment under ASC 805 Business Combinations. For acquisitions which qualify as asset acquisitions, the aggregate purchase price is allocated on a relative fair value basis to non-current, non-financial assets. The fair values 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. The fair value estimates are based on available historical information and on future expectations and assumptions deemed reasonable by management at the time. 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 require acceleration of the amortization expense of intangible assets in subsequent periods. For Business Combinations, the estimates of the fair value of the assets acquired and liabilities assumed at the date of an acquisition are subject to adjustment during the measurement period (up to one year from the particular acquisition date). During the measurement period, the Company will adjust assets and/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 a revised estimated value of those assets and/or liabilities as of that date. The primary areas of the preliminary purchase price allocations that are not yet finalized relate to the fair value of certain tangible and intangible assets acquired and liabilities assumed, including contingent consideration and any related tax impact. The maximum pote ntial obligation related to performance targets for business combinations and asset acquisitions was $8.6 million and $5.8 million as of March 31, 2017 and December 31, 2016 , respectively. During the three months ended March 31, 2017 , the Company acquired 90 completed towers and related assets and liabilities for $31.1 million in cash consisting of $12.1 million of property and equipment, $17.6 million of intangible assets, and $1.4 million of working capital adjustments. Subsequent to March 31, 2017 , the Company acquired 9 towers and related assets for $5.6 million in cash.

Intangible Assets, Net

Intangible Assets, Net	3 Months Ended
	Mar. 31, 2017
Intangible Assets, Net [Abstract]
Intangible Assets, Net	6. INTANGIBLE ASSETS, NET The following table provides the gross and net carrying amounts for each major class of intangible assets:     As of March 31, 2017 As of December 31, 2016  Gross carrying Accumulated Net book Gross carrying Accumulated Net book  amount amortization value amount amortization value   (in thousands)  Current contract intangibles $ 4,179,583 $ (1,473,948) $ 2,705,635 $ 4,141,968 $ (1,401,025) $ 2,740,943  Network location intangibles 1,525,534 (625,621) 899,913 1,515,348 (599,367) 915,981  Intangible assets, net $ 5,705,117 $ (2,099,569) $ 3,605,548 $ 5,657,316 $ (2,000,392) $ 3,656,924  All intangible assets noted above are included in the Company’s site leasing segment. The Company amortizes its intangible assets using the straight-line method over 15 years. Amortization expense relating to the intangible assets above was $94.9 million and $90.2 million for the three months ended March 31, 2017 and 2016 , respectively .

Property And Equipment, Net

Property And Equipment, Net	3 Months Ended
	Mar. 31, 2017
Property And Equipment, Net [Abstract]
Property And Equipment, Net	7. PROPERTY AND EQUIPMENT, NET Property and equipment, net (including assets held under capital leases) consists of the following:     As of As of  March 31, 2017 December 31, 2016   (in thousands)  Towers and related components $ 4,601,648 $ 4,563,756  Construction-in-process 42,266 38,926  Furniture, equipment, and vehicles 51,004 50,671  Land, buildings, and improvements 590,869 578,680  Total property and equipment 5,285,787 5,232,033  Less: accumulated depreciation (2,499,843) (2,439,957)  Property and equipment, net $ 2,785,944 $ 2,792,076  Construction-in-process represents costs incurred related to towers that are under development and will be used in the Company’s operations. Depreciation expense was $64.1 million and $69.5 million for the three months ended March 31, 2017 and 2016 , respectively. At March 31, 2017 and December 31, 2016 , non-cash capital expenditures that are included in accounts payable and accrued expenses were $4.7 million and $7.0 million, respectively.

Costs And Estimated Earnings On

Costs And Estimated Earnings On Uncompleted Contracts	3 Months Ended
	Mar. 31, 2017
Costs And Estimated Earnings On Uncompleted Contracts [Abstract]
Costs And Estimated Earnings On Uncompleted Contracts	8. COSTS AND ESTIMATED EARNINGS ON UNCOMPLETED CONTRACTS Costs and estimated earnings on uncompleted contracts consist of the following:     As of As of  March 31, 2017 December 31, 2016   (in thousands)  Costs incurred on uncompleted contracts $ 29,946 $ 34,577  Estimated earnings 10,592 11,185  Billings to date (27,721) (36,027)  $ 12,817 $ 9,735  These amounts are included in the accompanying Consolidated Balance Sheets under the following captions:     As of As of  March 31, 2017 December 31, 2016   (in thousands)  Costs and estimated earnings in excess of billings on uncompleted contracts $ 13,108 $ 11,127  Billings in excess of costs and estimated earnings on  uncompleted contracts (included in Other current liabilities) (291) (1,392)  $ 12,817 $ 9,735  Eight significant customers comprised 88.2% and 81.6% of the costs and estimated earnings in excess of billings on uncompleted contracts, net of billings in excess of costs and estimated earnings at March 31, 2017 and December 31, 2016 , respectively.

Accrued Expenses

Accrued Expenses	3 Months Ended
	Mar. 31, 2017
Accrued Expenses [Abstract]
Accrued Expenses	9. ACCRUED EXPENSES The Company’s accrued expenses are comprised of the following:     As of As of  March 31, 2017 December 31, 2016   (in thousands)  Accrued earnouts $ 3,667 $ 4,128  Salaries and benefits 8,115 11,910  Real estate and property taxes 7,077 7,644  Other 35,097 37,447  Total accrued expenses $ 53,956 $ 61,129

Debt

Debt	3 Months Ended
	Mar. 31, 2017
Debt [Abstract]
Debt	 10. DEBT The principal values, fair values, and carrying values of debt consist of the following (in thousands):     As of As of  March 31, 2017 December 31, 2016  Maturity Date Principal Balance Fair Value Carrying Value Principal Balance Fair Value Carrying Value  2014 Senior Notes July 15, 2022 $ 750,000 $ 759,375 $ 737,505 $ 750,000 $ 763,125 $ 736,992  2016 Senior Notes Sep. 1, 2024 1,100,000 1,083,500 1,079,520 1,100,000 1,083,500 1,078,954  2012-1C Tower Securities Dec. 11, 2017 610,000 610,171 607,905 610,000 610,165 607,157  2013-1C Tower Securities April 10, 2018 425,000 423,827 423,192 425,000 423,381 422,768  2013-2C Tower Securities April 11, 2023 575,000 576,777 567,807 575,000 563,322 567,545  2013-1D Tower Securities April 10, 2018 330,000 330,281 328,560 330,000 334,521 328,225  2014-1C Tower Securities Oct. 8, 2019 920,000 923,183 912,889 920,000 922,199 912,219  2014-2C Tower Securities Oct. 8, 2024 620,000 619,932 612,843 620,000 608,921 612,641  2015-1C Tower Securities Oct. 8, 2020 500,000 502,555 491,828 500,000 495,145 491,289  2016-1C Tower Securities July 9, 2021 700,000 695,877 691,752 700,000 688,072 691,322  Revolving Credit Facility Feb. 5, 2020 280,000 280,000 280,000 390,000 390,000 390,000  2014 Term Loan Mar. 24, 2021 1,458,750 1,460,573 1,448,858 1,462,500 1,467,984 1,452,039  2015 Term Loan June 10, 2022 491,250 491,250 483,515 492,500 494,347 484,432  Total debt $ 8,760,000 $ 8,757,301 $ 8,666,174 $ 8,875,000 $ 8,844,682 $ 8,775,583  Less: current maturities of long-term debt (20,000) (627,157)  Total long-term debt, net of current maturities $ 8,646,174 $ 8,148,426  The table below reflects cash and non-cash interest expense amounts recognized by debt instrument for the periods presented:      For the three months ended March 31,  2017 2016  Cash Non-cash Cash Non-cash  Interest Interest Interest Interest    5.625% Senior Notes $ — $ — $ 7,031 —  5.75% Senior Notes — — 11,500 —  2014 Senior Notes 9,141 178 9,141 169  2016 Senior Notes 13,406 234 — —  2010-2C Tower Securities — — 7,058 —  2012-1C Tower Securities 4,524 — 4,534 —  2013 Tower Securities 10,804 — 10,804 —  2014 Tower Securities 12,785 — 12,785 —  2015-1C Tower Securities 3,985 — 3,985 —  2016-1C Tower Securities 5,090 — — —  Revolving Credit Facility 2,770 — 833 —  2014 Term Loan 11,284 128 12,138 125  2015 Term Loan 3,800 165 4,087 161  Capitalized interest and other 13 — (92) —  Total $ 77,602 $ 705 $ 83,804 $ 455  Revolving Credit Facility under the Senior Credit Agreement The Revolving Credit Facility is governed by the Senior Credit Agreement. T he Revolving Credit Facility consists of a revolving loan under which up to $1.0 billion aggregate principal amount may be borrowed, repaid and redrawn, based upon specific financial ratios and subject to the satisfaction of other customary conditions to borrowing. Amounts borrowed under the Revolving Credit Facility accrue interest, at SBA Senior Finance II’s election, at either (i) the Eurodollar Rate plus a margin that ranges from 137.5 basis points to 200.0 basis points or (ii) the Base Rate plus a margin that ranges from 37.5 basis points to 100.0 basis points, in each case based on the ratio of Consolidated Total Debt to Annualized Borrower EBITDA, calculated in accordance with the Senior Credit Agreement. In addition, SBA Senior Finance II is required to pay a commitment fee of 0.25% per annum on the amount of unused commitment. If not earlier terminated by SBA Senior Finance II, the Revolving Credit Facility will terminate on, and SBA Senior Finance II will repay all amounts outstanding on or before, February 5, 2020 . The proceeds available under the Revolving Credit Facility may be used for general corporate purposes. SBA Senior Finance II may, from time to time, borrow from and repay the Revolving Credit Facility. Consequently, the amount outstanding under the Revolving Credit Facility at the end of a period may not be reflective of the total amounts outstanding during such period. During the three months ended March 31, 2017 , the Company repaid $110.0 million of the outstanding balance under the Revolving Credit Facility. A s of March 31, 2017 , SBA Senior Finance II was in compliance with the financial covenants contained in the Senior Credit Agreement. Subsequent to March 31, 2017 , the Company repaid $190.0 million of the outstanding balance under the Revolving Credit Facility. Term Loans under the Senior Credit Agreement Repricing Amendment to the Senior Credit Agreement On January 20, 2017, SBA Senior Finance II amended its Senior Credit Agreement, primarily to reduce the stated rate of interest applicable to its senior secured term loans. As amended, the senior secured term loans accrue interest, at SBA Senior Finance II’s election, at either the Base Rate plus 125 basis points (with a zero Base Rate floor) or the Eurodollar Rate plus 225 basis points (with a zero Eurodollar Rate floor). 2014 Term Loan The 2014 Term Loan consists of a senior secured term loan with an initial aggregate principal amount of $1.5 billion that mature s on March 24, 2021 . Prior to the reduction in the term loan interest rates as discussed above, th e 2014 Term Loan accrue d interest, at SBA Senior Finance II’s election, at either the Base Rate plus 150 basis points (with a Base Rate floor of 1.75% ) or the Eurodollar Rate plus 250 basis points (with a Eurodollar Rate floor of 0.75% ). The 2014 Term Loan was issued at 99.75% of par value. As of March 31, 2017 , the 2014 Term Loan was accruing interest at 3.24% per annum. Principal payments on the 2014 Term Loan commenced on September 30, 2014 and are be ing made in quarterly installments on the last day of each March, June, September, and December in an amount equal to $3.8 million. SBA Senior Finance II has the ability to prepay any or all amounts under the 2014 Term Loan. To the extent not previously repaid, the 2014 Term Loan will be due and payable on the maturity date. However, to the extent the 2014 Term Loan is prepaid prior to July 20, 2017 from proceeds of certain refinancing or repricing transactions, a prepayment fee equal to 1.0% of the aggregate principal amount of such prepayment will apply. The Company incurred deferred financing fees of approximately $14.1 million in relation to this transaction which are being amort ized through the maturity date. During the three months ended March 31, 2017 , the Company repaid $ 3.8 million of principal on the 2014 Term Loan. As of March 31, 2017 , the 2014 Term Loan had a principal balance of $1.5 billion. 2015 Term Loan The 2015 Term Loan consists of a senior secured term loan with an initial aggregate principal amount of $500.0 million that matures on June 10, 2022 . Prior to the reduction in the term loan interest rates as discussed above, th e 2015 Term Loan accrue d interest, at SBA Senior Finance II’s election, at either the Base Rate plus 150 basis points (with a Base Rate floor of 1.75% ) or the Eurodollar Rate plus 250 basis points (with a Eurodollar Rate floor of 0.75% ). The 2015 Term Loan was issued at 99.0% of par value. As of March 31, 2017 , the 2015 Term Loan was accruing interest at 3.24% per annum. Principal payments on the 2015 Term Loan commence d on September 30, 2015 and are being made in quarterly installments on the last day of each March, June, September, and December in an amount equal to $1.3 million. SBA Senior Finance II has the ability to prepay any or all amounts under the 2015 Term Loan. To the extent not previously repaid, the 2015 Term Loan will be due and payable on the maturity date. However, to the extent the 2015 Term Loan is prepaid prior to July 20, 2017 from proceeds of certain refinancing or repricing transactions, a prepayment fee equal to 1.0% of the aggregate principal amount of such prepayment will apply. The Company incurred deferred financing fees of approximately $5.5 million in relation to this transaction which are being amort ized through the maturity date. During the three months ended March 31, 2017 , the Company repaid $1.3 million of principal on the 2015 Term Loan. As of March 31, 2017 , the 2015 Term Loan had a principal balance of $491.3 million. Secured Tower Revenue Securities 2012 -1C Tower Securities On August 9, 2012, the Company, through a New York common law trust (the “ Trust ”) , issued $610.0 million of Secured Tower Revenue Securities Series 2012-1C (the “2012 -1C Tower Securities”) which ha d an anticipated repayment date of December 11, 2017 and a final maturity date of December 9, 2042 . The fixed interest rate of the 2012 -1C Tower Securities wa s 2.933% per annum, payable monthly. The Company had incurred deferred financing fees of $14.9 million in relation to this transaction which we re being amortized through the anticipated repayment date of the 2012 -1C Tower Securities. On April 17, 2017, the Company repaid in full the 2012-1C Tower Securities with proceeds from the 2017-1C Tower Securities. In connection with the prepayment, the Company expensed $2.0 million of net deferred financing fees. The sole asset of the Trust consists of a non-recourse mortgage loan made in favor of those entities that are borrowers on the mortgage loan (the “Borrowers”). 2013 Tower Securities On April 18, 2013, the Company, through the Trust, issued $425.0 million of 2.240% Secured Tower Revenue Securities Series 2013-1C which have an anticipated repayment date of April 10, 2018 and a final maturity date of April 9, 2043 (the “2013-1C Tower Securities”) , $575.0 million of 3.722% Secured Tower Revenue Securities Series 2013-2C which have an anticipated repayment date of April 11, 2023 and a final maturity date of April 9, 2048 (the “ 2013-2C Tower Securities”) , and $330.0 million of 3.598% Secured Tower Revenue Securities Series 2013-1D which have an anticipated repayment date of April 10, 2018 and a final maturity date of April 9, 2043 (the “2013-1D Tower Securities”) (collectively the “2013 Tower Securities”). The aggregate $1.33 billion of 2013 Tower Securities have a blended interest rate of 3.218% per annum, payable monthly. The Company has incurred deferred financing fees of $25.5 million in relation to this transaction which are being amortized through the anticipated repayment date of each of the 2013 Tower Securities. 2014 Tower Securities On October 15, 2014, the Company, through the Trust, issued $920.0 million of 2.898% Secured Tower Revenue Securities Series 2014-1C which have an anticipated repayment date of October 8, 2019 and a final maturity date of October 11, 2044 (the “2014-1C Tower Securities”) and $620.0 million of 3.869% Secured Tower Revenue Securities Series 2014-2C which have an anticipated repayment date of October 8, 2024 and a final maturity date of October 8, 2049 (the “2014-2C Tower Securities”) (collectively the “2014 Tower Securities”). The aggregate $1.54 billion of 2014 Tower Securities have a blended interest rate of 3.289% per annum, payable monthly . The Company has incurred deferred financing fees of $22.5 million in relation to this transaction which are being amortized through the anticipated repayment date of each of the 2014 Tower Securities. 201 5-1C Tower Securities On October 1 4 , 201 5 , the Company, through the Trust, issued $500.0 million of Secured Tower Revenue Securities Series 201 5 -1C which have an anticipated repayment date of October 8, 2020 and a final maturity date of October 10, 2045 (the “201 5-1C Tower Securities”). The fixed interest rate of the 2015-1C Tower Securities is 3.156% per annum, payable monthly. The Company has incurred deferred financing fees of $11.2 million in relation to this transaction which are being amortized through the anticipated repayment date of the 201 5-1C Tower Securities. 201 6-1C Tower Securities On July 7, 2016, the Company, through the Trust , issued $700.0 million of Secured Tower R evenue Securities Series 2016-1 C which have an anticipated repayment date of July 9, 2021 and a final maturity date of July 10, 2046 (the “2016 -1C Tower Securities”). The fixed interest rate of the 2016-1C Tower Securities is 2.877% per annum, payable monthly. Net proceeds from this offering were used to prepay the full $550.0 million outstanding on the 2010 -2C Tower Securities and for general corporate purposes. The Company has incurred deferred financing fees of $9.5 million in relation to this transaction which are being amortized through the anticipated repayment date of the 2016-1C Tower Securities. 201 7-1C Tower Securities  On April 17 , 2017, the Company, through the Trust, issued $760.0 million of Secured Tower Revenue Securities Series 2017-1C which have an anticipated repayment date of April 11, 2022 and a final maturity date of April 9, 2047 (the “2017-1C Tower Securities ” ). The fixed interest rate on the 2017-1C Tower Securities is 3.168% per annum, payable monthly. Net proceeds from this offering were used to prepay the entire $610.0 million aggregate principal amount , as well as accrued and unpaid interest, of the 2012-1C Tower Securities and for general corporate purposes. The Company has incurred deferred financing fees of $9.7 million to date in relation to this transaction which are being amortized through the anticipated repayment date of the 2017-1C Tower Securities . In addition, to satisfy certain risk retention requirements of Regulation RR promulgated under the Securities Exchange Act of 1934, SBA Guarantor, LLC, a wholly owned subsidiary of the Comp any, purchased $40.0 million of Secured Tower Revenue Securities Series 2017-1R issued by the Trust which have an anticipated repayment date of April 11, 2022 and a final maturity date of April 9, 2047 (the “2017-1R Tower Securities ” ). The fixed interest rate on the 2017-1R Tower Securities is 4.459% per annum, payable monthly. Principal and interest payments made on the 2017-1R Tower Securities eliminate in consolidation. Debt Covenants As of March 31, 2017 , the Borrowers met the debt service coverage ratio required by the mortgage loan agreement and were in compliance with all other covenants as set forth in the agreement. Senior Notes 2014 Senior Notes On July 1, 2014, the Company issued $750.0 million of unsecured senior notes due July 15, 2022 (the “2014 Senior Notes”). The 2014 Senior Notes accrue interest at a rate of 4.875% per annum and were issued at 99.178% of par value. Interest on the 2014 Senior Notes is due semi-annually on January 15 and July 15 of each year. The Company incurred deferred financing fees of $11.6 million in relation to this transaction which are being amortized through the maturity date. 2016 S enior Notes On August 15, 2016, the Company issued $1.1 billion of unsecured senior notes due September 1, 2024 (the “2016 Senior Notes”). The 2016 Senior Notes accrue interest at a rate of 4.875% per annum and were issued at 99.178% of par value. Interest on the 2016 Senior Notes is due semi-annually on March 1 and September 1 of each year, beginning on March 1, 2017. The Company incurred deferred financing fees of $12.8 million in relation to this transaction which are being amortized through the maturity date. Net proceeds from this offering and cash on hand were used to redeem $800.0 million, the aggregate principal amount outstanding, of Telecommunications’ 5.75% Senior Notes and $250.0 million of the Compan y’s 5.625% Senior Notes and pay the associated call premiums.

Shareholders' Equity

Shareholders' Equity	3 Months Ended
	Mar. 31, 2017
Shareholders' Equity [Abstract]
Shareholders' Equity	11. SHAREHOLDERS’ EQUITY Common Stock equivalents The Company has potential common stock equivalents (see Note 12) related to its outstanding stock options and restricted stock units . These potential common stock equivalents were considered in the Company’s diluted earnings per share calculation (see Note 15). Stock Repurchases On June 4, 2015, the Company’s Board of Directors authorized a stock repurchase plan. This plan authorized the Company to purchase, from time to time, up to $1.0 billion of the Company’s outstanding Class A common stock through open market repurchases in compliance with Rule 10b-18 under the Securities Exchange Act of 1934, as amended, and/or in privately negotiated transactions at management’s discretion based on market and business conditions, applicable legal requirements and other factors. During the three months ended March 31, 2017 , the Company repurchased 42,163 shares of its Class A common stock for $4.4 million, at an average price per share of $104.81 under this plan. Shares purchased were retired. On January 12, 2017, the Company’s Board of Directors authorized a new stock repurchase plan, replacing the plan authorized on June 4, 2015 which had a remaining authorization of $150.0 million. This plan authorizes the Company to purchase, from time to time, up to $1.0 billion of the Company’s outstanding Class A common stock through open market repurchases in compliance with Rule 10b-18 under the Securities Exchange Act of 1934, as amended, and/or in privately negotiated transactions at management’s discretion based on market and business conditions, applicable legal requirements and other factors. Shares purchased will be retired. The new plan has no time deadline and will continue until otherwise modified or terminated by the Company’s Board of Directors at any time in its sole discretion. As of the date of this filing, the Company had the full $1.0 billion authorization remaining under the current stock repurchase program.

Stock-Based Compensation

Stock-Based Compensation	3 Months Ended
	Mar. 31, 2017
Stock-Based Compensation [Abstract]
Stock-Based Compensation	 12. STOCK-BASED COMPENSATION Stock Options The Company records compensation expense for employee stock options based on the estimated fair value of the options on the date of grant using the Black-Scholes option-pricing model with the assumptions included in the table below. The Company uses a combination of historical data and historical volatility to establish the expected volatility. Historical data is used to estimate the expected option life. The risk-free rate is based on the U.S. Treasury yield curve in effect at the time of grant for the estimated life of the option. The following assumptions were used to estimate the fair value of options granted using the Black-Scholes option-pricing model:     For the three months ended  March 31,  2017 2016   Risk free interest rate 1.91% 1.33% - 1.43%  Dividend yield 0.0% 0.0%  Expected volatility 20% 20%  Expected lives 4.6 years 4.7 years  The following table summarizes the Company’s activities with respect to its stock option plans for the three months ended March 31, 2017 as follows (dollars and number of shares in thousands, except for per share data):     Weighted-  Weighted- Average  Average Remaining  Number Exercise Price Contractual Aggregate  of Shares Per Share Life (in years) Intrinsic Value  Outstanding at December 31, 2016 4,447 $ 93.09  Granted 1,149 $ 115.17  Exercised (213) $ 62.99  Canceled (20) $ 102.89  Outstanding at March 31, 2017 5,363 $ 98.98 5.0 $ 118,838  Exercisable at March 31, 2017 2,451 $ 87.48 3.8 $ 82,673  Unvested at March 31, 2017 2,912 $ 108.66 6.0 $ 36,165  The weighted-average per share fair value of options granted during the three months ended March 31, 2017 was $23.84 . The total intrinsic value for options exercised during the three months ended March 31, 2017 was $11.0 million. Restricted Stock Units The following table summarizes the Company’s restricted stock unit activity for the three months ended March 31, 2017 :     Weighted-  Average  Grant Date  Number of Fair Value per  Shares Share  (in thousands)  Outstanding at December 31, 2016 291 $ 101.74  Granted 161 $ 115.17  Vested (115) $ 98.50  Forfeited/canceled (2) $ 105.21  Outstanding at March 31, 2017 335 $ 109.29

Income Taxes

Income Taxes	3 Months Ended
	Mar. 31, 2017
Income Taxes [Abstract]
Income Taxes	13. INCOME TAXES The primary reason for the difference in the Company’s effective tax rate and the U.S. statutory rate is a result of the Company’s REIT election and the Company having a full valuation allowance on the U.S. net deferred tax assets of the taxable REIT subsidiary. The Company has concluded that it is not more likely than not that its deferred tax assets will be realized and has recorded a full valuation allowance. A foreign tax provision is recognized because certain international subsidiaries of the Company have profitable operations or are in a net deferred tax liability position. The Company elected to be taxed as a REIT commencing with its taxable year ending December 31, 2016. As a REIT, the Company generally will be entitled to a deduction for dividends that it pays and therefore not subject to U.S. federal corporate income tax on that portion of its net income that it distributes to its shareholders. As a REIT, the Company will continue to pay U.S. federal income tax on earnings, if any, from assets and operations held through its taxable REIT subsidiaries (“TRSs”). These assets and operations currently consist primarily of the Company’s site development services and its international operations. The Company’s international operations would continue to be subject, as applicable, to foreign taxes in the jurisdictions in which those operations are located. The Company may also be subject to a variety of taxes, including payroll taxes and state, local and foreign income, property and other taxes on its assets and operations. The Company’s determination as to the timing and amount of future dividend distributions will be based on a number of factors, including REIT distribution requirements, its existing federal net operating losses (“NOLs”) of approximately $1.1 billion as of December 31, 2016, the Company’s financial condition, earnings, debt covenants, and other possible uses of such funds. The Company may use these NOLs to offset its REIT taxable income, and thus any required distributions to shareholders may be reduced or eliminated until such time as the NOLs have been fully utilized .

Segment Data

Segment Data	3 Months Ended
	Mar. 31, 2017
Segment Data [Abstract]
Segment Data	14. SEGMENT DATA The Company operates principally in two business segments : site leasing and site development . The Company’s site leasing business includes two reportable segments , domestic site leasing and international site leasing. The Company’s business segments are strategic business units that offer different services . They are managed separately based on the fundamental differences in their operations. The site leasing segment include s results of the managed and sublease businesses. The site development segment includes the results of both consulting and construction related activities. The Company’s Chief Operating Decision Maker utilizes segment operating profit and operating income as his two measures of segment profit in assessing performance and allocating resources at the reportable segment level. Revenues, cost of revenues (exclusive of depreciation, accretion and amortization), capital expenditures (including assets acquired through the issuance of shares of the Company’s Class A common stock) and identifiable assets pertaining to the segments in which the Company continues to operate are presented below.      Not  Domestic Site Int'l Site Site Identified by  Leasing Leasing Development Segment Total   For the three months ended March 31, 2017 (in thousands)  Revenues $ 321,130 $ 76,420 $ 25,813 $ — $ 423,363  Cost of revenues (2) 65,427 23,955 21,588 — 110,970  Operating profit 255,703 52,465 4,225 — 312,393  Selling, general, and administrative 19,356 5,959 3,617 5,291 34,223  Acquisition related adjustments and expenses 1,901 1,068 — — 2,969  Asset impairment and decommission costs 7,430 816 105 — 8,351  Depreciation, amortization and accretion 123,896 32,825 711 1,599 159,031  Operating income (loss) 103,120 11,797 (208) (6,890) 107,819  Other expense (principally interest expense  and other income (expense)) (66,823) (66,823)  Income before provision for income taxes 40,996  Cash capital expenditures (3) 50,433 26,890 133 942 78,398   For the three months ended March 31, 2016  Revenues $ 315,230 $ 59,220 $ 25,319 $ — $ 399,769  Cost of revenues (2) 64,475 18,287 19,833 — 102,595  Operating profit 250,755 40,933 5,486 — 297,174  Selling, general, and administrative 17,998 4,385 3,537 4,486 30,406  Acquisition related adjustments and expenses 1,842 1,340 — — 3,182  Asset impairment and decommission costs 6,021 162 — — 6,183  Depreciation, amortization and accretion 131,393 26,877 1,025 506 159,801  Operating income (loss) 93,501 8,169 924 (4,992) 97,602  Other expense (principally interest expense  and other income (expense)) (41,758) (41,758)  Income before provision for income taxes 55,844  Cash capital expenditures (3) 105,353 21,380 556 876 128,165       Domestic Site Int'l Site Site Not Identified  Leasing Leasing Development by Segment (1) Total   (in thousands)  Assets  As of March 31, 2017 $ 5,313,286 $ 1,856,435 $ 37,787 $ 89,942 $ 7,297,450  As of December 31, 2016 $ 5,396,394 $ 1,839,703 $ 43,769 $ 81,079 $ 7,360,945  (1) Assets not identified by segment consist primarily of general corporate assets. (2) Excludes depreciation, amortization, and accretion. (3) Includes cash paid for capital expenditures and acquisitions and vehicle capital lease additions.

Earnings Per Share

Earnings Per Share	3 Months Ended
	Mar. 31, 2017
Earnings Per Share [Abstract]
Earnings Per Share	15. EARNINGS PER SHARE Basic earnings per share was computed by dividing net income from continuing operations attributable to common shareholders by the weighted-average number of shares of Common Stock outstanding for each respective period. Diluted earnings per share was calculated by dividing net income from continuing operations attributable to common shareholders by the weighted-average number of shares of Common Stock outstanding adjusted for any dilutive Common Stock equivalents, including unvested restricted stock and shares issuable upon exercise of stock options as determined under the “If-Converted” method and also Common Stock warrants as determined under the “Treasury Stock” method. The following table sets forth basic and diluted net income per common share for the three months ended March 31, 2017 and 2016 (in thousands, except per share data):     For the three months  ended March 31,  2017 2016  Numerator:  Net income $ 37,598 $ 53,639  Denominator:  Basic weighted-average shares outstanding 121,049 125,398  Dilutive impact of stock options and restricted shares 685 726  Diluted weighted-average shares outstanding 121,734 126,124  Net income per common share:  Basic $ 0.31 $ 0.43  Diluted $ 0.31 $ 0.43  For the three months ended March 31, 2017 and 2016 , the diluted weighted average number of common shares outstanding excluded an additional 2.4 million shares issuable upon exercise of the Company’s stock options because th e impact would be anti-dilutive.

Basis Of Presentation (Policy)

Basis Of Presentation (Policy)	3 Months Ended
	Mar. 31, 2017
Basis Of Presentation [Abstract]
Basis Of Presentation	The accompanying consolidated financial statements should be read in conjunction with the Annual Report on Form 10-K for the fiscal year ended December 31, 2016 for SBA Communications Corporation and its subsidiaries (the “Company”). These financial statements have been prepared in accordance with the instructions to Form 10-Q and Article 10 of Regulation S-X and, therefore, omit or condense certain footnotes and other information normally included in financial statements prepared in accordance with accounting principles generally accepted in the United States. In the opinion of the Company’s management, all adjustments (consisting of normal recurring accruals) considered necessary for fair financial statement presentation have been made. The results of operations for an interim period may not give a true indication of the results for the year. Certain reclassifications have been made to prior year amounts or balances to conform to the presentati on adopted in the current year. The preparation of financial statements requires management to make estimates and assumptions that affect the amounts reported in consolidated financial statements and accompanying notes. While the Company believes that such estimates are fair when considered in conjunction with the consolidated financial statements and accompanying notes, the actual amounts, when known, may vary from these estimates.
Foreign Currency Translation	Foreign Currency Translation The functional currency for the Company’s Central American subsidiaries is the U.S. dollar. Monetary assets and liabilities of such subsidiaries which are not denominated in U.S. dollars are remeasured at exchange rates in effect at the balance sheet date, and revenues and expenses are remeasured at monthly average rates prevailing during the year. Unrealized translation gains and losses are reported as other income (expense), net in the Consolidated Statement of Operations. All assets and liabilities of foreign subsidiaries that do not utilize the U.S. dollar as its functional currency are translated at period-end rates of exchange, while revenues and expenses are translated at monthly average rates of exchange prevailing during the period. Unrealized remeasurement gains and losses are reported as foreign currency translation adjustments through Accumulated Other Comprehensive Loss in the accompanying Consolidated Statement of Shareholders’ Deficit.
Intercompany Loans	Intercompany Loans In accordance with ASC 830, the Company remeasures foreign denominated intercompany loans with the corresponding change in the balance being recorded in O ther income (expense), ne t in the Consolidated Statement of Operations as settlement is anticipated or planned in the foreseeable future . F or the three months ended March 31, 2017 and 2016 , t he Company recorded a $13.7 million gain and a $44.8 million gain, respectively, on the remeasurement of intercompany loans. As of March 31, 2017 , the outstanding balance under this agreement was $433.3 million.
Accounting Pronouncements Recently Adopted	Accounting Pronouncements Recently Adopted In January 2017, the FASB issued ASU 2017-01, Clarifying the Definition of a Business. The standard provides guidance to help entities determine whether transactions should be accounted for as acquisitions or disposals of assets or businesses. ASU 2017-01 provides revised guidance to determine when an acquisition meets the definition of a business or should be accounted for as an asset acquisition, likely resulting in more acquisitions being accounted for as asset acquisitions as opposed to business combinations. The Company adopted this standard prospectively effective January 1, 2017. Under this update, substantially all of the Company’s acquisitions are expected to qualify for asset acquisition treatment under ASC 360, Property, Plant, and Equipment, rather than business combination treatment under ASC 805 Business Combinations. For asset acquisitions, external, direct transaction costs will be capitalized as a component of the cost of the asset acquired, while internal costs related to the asset acquisition will continue to be expensed as incurred. Additionally, earnout liabilities will be recognized at the time when the contingency is resolved or becomes payable and will increase the cost basis of the assets acquired. The adoption of ASU 2017-01 did not have a material impact on the Company’s unaudited consolidated financial statements and related disclosures.
Recent Accounting Pronouncements Not Yet Adopted	Recent Accounting Pronouncements Not Yet Adopted In May 2014, the FASB released an updated standard regarding the recognition of revenue from contracts with customers, exclusive of those contracts within lease accounting. The core principle of the standard is that an entity should recognize revenue to depict the transfer of promised goods or services to customers in an amount that reflects the consideration to which the entity expects to be entitled in exchange for those goods or services. To achieve that core principle, an entity should apply the following steps: (1) identify the contracts with the customer; (2) identify the performance obligations in the contract; (3) determine the contract price; (4) allocate the transaction price to the performance obligations in the contract; and (5) recognize revenue when (or as) the entity satisfies a performance obligation. This standard is effective for the Company in the first quarter of 2018. Early adoption is permitted but not before the first quarter of 2017. This standard is required to be applied retrospectively to each prior reporting period presented or with the cumulative effect being recognized at the date of initial application. The Company is evaluating the standard and does not expect a material financial statement impact upon adoption since the standard only affects the Company’s site development segment which represents approximately 6% of the Company’s total revenues. In February 2016, the FASB issued ASU 2016-02, Leases. The standard requires lessees to recognize a right-of-use asset and a lease liability, initially measured at the present value of the lease payments for all leases with a term greater than 12 months. The accounting for lessors remains largely unchanged from existing guidance. This standard is effective for annual and interim periods beginning after December 15, 2018 and requires a modified retrospective transition approach for all leases existing at, or entered into after, the beginning of the earliest comparative period presented. Early adoption is permitted. The Company has established a cross functional project plan to assess the impact of the standard, expects this guidance to have a material impact on its consolidated balance sheet due to the addition of right-of-use assets and lease liabilities for all leases with a term greater than 12 months, and continues to assess additional impacts to its consolidated financial statements, including the consolidated statement of operations.

Fair Value Measurements (Tables

Fair Value Measurements (Tables)	3 Months Ended
	Mar. 31, 2017
Fair Value Measurements [Abstract]
Summary Of Asset Impairment And Decommission Costs	   For the three months  ended March 31,  2017 2016   Asset impairment (1) $ 3,014 $ —  Write-off of carrying value of decommissioned towers 3,971 4,196  Other third party decommission costs 1,366 1,987  Total asset impairment and decommission costs $ 8,351 $ 6,183 (1) Represents impairment charges resulting from the Company’s analysis that the future cash flows from certain towers would not recover the carrying value of the investment in those towers.

Restricted Cash (Tables)

Restricted Cash (Tables)	3 Months Ended
	Mar. 31, 2017
Restricted Cash [Abstract]
Schedule Of Cash, Cash Equivalents And Restricted Cash	   As of As of  March 31, 2017 December 31, 2016 Included on Balance Sheet   (in thousands)  Cash and cash equivalents $ 132,222 $ 146,109  Securitization escrow accounts 30,487 36,607 Restricted cash - current asset  Payment and performance bonds 187 179 Restricted cash - current asset  Surety bonds and workers compensation 2,575 3,075 Other assets - noncurrent  Total cash, cash equivalents, and restricted cash $ 165,471 $ 185,970 

Other Assets (Tables)

Other Assets (Tables)	3 Months Ended
	Mar. 31, 2017
Other Assets [Abstract]
Schedule Of Other Assets	   As of As of  March 31, 2017 December 31, 2016   (in thousands)  Long-term investments $ 8,379 $ 7,884  Prepaid land rent 194,819 191,615  Straight-line rent receivable 307,535 302,893  Deferred lease costs, net 29,172 29,660  Other 64,786 55,322  Total other assets $ 604,691 $ 587,374 

Acquisitions (Tables)

Acquisitions (Tables)	3 Months Ended
	Mar. 31, 2017
Acquisitions [Abstract]
Schedule Of Acquisition Capital Expenditures	   For the three months  ended March 31,  2017 2016   (in thousands)  Towers and related intangible assets $ 31,147 $ 74,844  Land buyouts and other assets (1) 11,504 16,988  Total cash acquisition capital expenditures $ 42,651 $ 91,832  (1) In addition, the Company paid $2.7 million and $3.6 million for ground lease extensions during the three months ended March 31, 2017 and 2016 , respectively. The Company recorded these amounts in prepaid rent on its Consolidated Balance Sheets. The Company’s acquisitions generally qualify for asset acquisition treatment under ASC 360, Property, Plant, and Equipment, rather than business combination treatment under ASC 805 Business Combinations. For acquisitions which qualify as asset acquisitions, the aggregate purchase price is allocated on a relative fair value basis to non-current, non-financial assets.

Intangible Assets, Net (Tables)

Intangible Assets, Net (Tables)	3 Months Ended
	Mar. 31, 2017
Intangible Assets, Net [Abstract]
Gross And Net Carrying Amounts For Each Major Class Of Intangible Assets	   As of March 31, 2017 As of December 31, 2016  Gross carrying Accumulated Net book Gross carrying Accumulated Net book  amount amortization value amount amortization value   (in thousands)  Current contract intangibles $ 4,179,583 $ (1,473,948) $ 2,705,635 $ 4,141,968 $ (1,401,025) $ 2,740,943  Network location intangibles 1,525,534 (625,621) 899,913 1,515,348 (599,367) 915,981  Intangible assets, net $ 5,705,117 $ (2,099,569) $ 3,605,548 $ 5,657,316 $ (2,000,392) $ 3,656,924 

Property And Equipment, Net (Ta

Property And Equipment, Net (Tables)	3 Months Ended
	Mar. 31, 2017
Property And Equipment, Net [Abstract]
Property And Equipment, Net (Including Assets Held Under Capital Leases)	   As of As of  March 31, 2017 December 31, 2016   (in thousands)  Towers and related components $ 4,601,648 $ 4,563,756  Construction-in-process 42,266 38,926  Furniture, equipment, and vehicles 51,004 50,671  Land, buildings, and improvements 590,869 578,680  Total property and equipment 5,285,787 5,232,033  Less: accumulated depreciation (2,499,843) (2,439,957)  Property and equipment, net $ 2,785,944 $ 2,792,076 

Costs And Estimated Earnings 32

Costs And Estimated Earnings On Uncompleted Contracts (Tables)	3 Months Ended
	Mar. 31, 2017
Costs And Estimated Earnings On Uncompleted Contracts [Abstract]
Summary Of Costs And Estimated Earnings On Uncompleted Contracts	   As of As of  March 31, 2017 December 31, 2016   (in thousands)  Costs incurred on uncompleted contracts $ 29,946 $ 34,577  Estimated earnings 10,592 11,185  Billings to date (27,721) (36,027)  $ 12,817 $ 9,735 
Costs And Estimated Earnings On Uncompleted Contracts Accompanying Consolidated Balance Sheets	   As of As of  March 31, 2017 December 31, 2016   (in thousands)  Costs and estimated earnings in excess of billings on uncompleted contracts $ 13,108 $ 11,127  Billings in excess of costs and estimated earnings on  uncompleted contracts (included in Other current liabilities) (291) (1,392)  $ 12,817 $ 9,735 

Accrued Expenses (Tables)

Accrued Expenses (Tables)	3 Months Ended
	Mar. 31, 2017
Accrued Expenses [Abstract]
Schedule Of Accrued Expenses	   As of As of  March 31, 2017 December 31, 2016   (in thousands)  Accrued earnouts $ 3,667 $ 4,128  Salaries and benefits 8,115 11,910  Real estate and property taxes 7,077 7,644  Other 35,097 37,447  Total accrued expenses $ 53,956 $ 61,129 

Debt (Tables)

Debt (Tables)	3 Months Ended
	Mar. 31, 2017
Debt [Abstract]
Schedule Of Carrying And Principal Values Of Debt	   As of As of  March 31, 2017 December 31, 2016  Maturity Date Principal Balance Fair Value Carrying Value Principal Balance Fair Value Carrying Value  2014 Senior Notes July 15, 2022 $ 750,000 $ 759,375 $ 737,505 $ 750,000 $ 763,125 $ 736,992  2016 Senior Notes Sep. 1, 2024 1,100,000 1,083,500 1,079,520 1,100,000 1,083,500 1,078,954  2012-1C Tower Securities Dec. 11, 2017 610,000 610,171 607,905 610,000 610,165 607,157  2013-1C Tower Securities April 10, 2018 425,000 423,827 423,192 425,000 423,381 422,768  2013-2C Tower Securities April 11, 2023 575,000 576,777 567,807 575,000 563,322 567,545  2013-1D Tower Securities April 10, 2018 330,000 330,281 328,560 330,000 334,521 328,225  2014-1C Tower Securities Oct. 8, 2019 920,000 923,183 912,889 920,000 922,199 912,219  2014-2C Tower Securities Oct. 8, 2024 620,000 619,932 612,843 620,000 608,921 612,641  2015-1C Tower Securities Oct. 8, 2020 500,000 502,555 491,828 500,000 495,145 491,289  2016-1C Tower Securities July 9, 2021 700,000 695,877 691,752 700,000 688,072 691,322  Revolving Credit Facility Feb. 5, 2020 280,000 280,000 280,000 390,000 390,000 390,000  2014 Term Loan Mar. 24, 2021 1,458,750 1,460,573 1,448,858 1,462,500 1,467,984 1,452,039  2015 Term Loan June 10, 2022 491,250 491,250 483,515 492,500 494,347 484,432  Total debt $ 8,760,000 $ 8,757,301 $ 8,666,174 $ 8,875,000 $ 8,844,682 $ 8,775,583  Less: current maturities of long-term debt (20,000) (627,157)  Total long-term debt, net of current maturities $ 8,646,174 $ 8,148,426 
Schedule Of Cash And Non-Cash Interest Expense	   For the three months ended March 31,  2017 2016  Cash Non-cash Cash Non-cash  Interest Interest Interest Interest    5.625% Senior Notes $ — $ — $ 7,031 —  5.75% Senior Notes — — 11,500 —  2014 Senior Notes 9,141 178 9,141 169  2016 Senior Notes 13,406 234 — —  2010-2C Tower Securities — — 7,058 —  2012-1C Tower Securities 4,524 — 4,534 —  2013 Tower Securities 10,804 — 10,804 —  2014 Tower Securities 12,785 — 12,785 —  2015-1C Tower Securities 3,985 — 3,985 —  2016-1C Tower Securities 5,090 — — —  Revolving Credit Facility 2,770 — 833 —  2014 Term Loan 11,284 128 12,138 125  2015 Term Loan 3,800 165 4,087 161  Capitalized interest and other 13 — (92) —  Total $ 77,602 $ 705 $ 83,804 $ 455 

Stock-Based Compensation (Table

Stock-Based Compensation (Tables)	3 Months Ended
	Mar. 31, 2017
Stock-Based Compensation [Abstract]
Schedule Of Assumptions Used To Estimate Fair Value Of Stock Options	   For the three months ended  March 31,  2017 2016   Risk free interest rate 1.91% 1.33% - 1.43%  Dividend yield 0.0% 0.0%  Expected volatility 20% 20%  Expected lives 4.6 years 4.7 years 
Company's Activities With Respect To Its Stock Options	   Weighted-  Weighted- Average  Average Remaining  Number Exercise Price Contractual Aggregate  of Shares Per Share Life (in years) Intrinsic Value  Outstanding at December 31, 2016 4,447 $ 93.09  Granted 1,149 $ 115.17  Exercised (213) $ 62.99  Canceled (20) $ 102.89  Outstanding at March 31, 2017 5,363 $ 98.98 5.0 $ 118,838  Exercisable at March 31, 2017 2,451 $ 87.48 3.8 $ 82,673  Unvested at March 31, 2017 2,912 $ 108.66 6.0 $ 36,165 
Company's Restricted Stock Unit Activity	   Weighted-  Average  Grant Date  Number of Fair Value per  Shares Share  (in thousands)  Outstanding at December 31, 2016 291 $ 101.74  Granted 161 $ 115.17  Vested (115) $ 98.50  Forfeited/canceled (2) $ 105.21  Outstanding at March 31, 2017 335 $ 109.29 

Segment Data (Tables)

Segment Data (Tables)	3 Months Ended
	Mar. 31, 2017
Segment Data [Abstract]
Segment Reporting Information Disclosure	    Not  Domestic Site Int'l Site Site Identified by  Leasing Leasing Development Segment Total   For the three months ended March 31, 2017 (in thousands)  Revenues $ 321,130 $ 76,420 $ 25,813 $ — $ 423,363  Cost of revenues (2) 65,427 23,955 21,588 — 110,970  Operating profit 255,703 52,465 4,225 — 312,393  Selling, general, and administrative 19,356 5,959 3,617 5,291 34,223  Acquisition related adjustments and expenses 1,901 1,068 — — 2,969  Asset impairment and decommission costs 7,430 816 105 — 8,351  Depreciation, amortization and accretion 123,896 32,825 711 1,599 159,031  Operating income (loss) 103,120 11,797 (208) (6,890) 107,819  Other expense (principally interest expense  and other income (expense)) (66,823) (66,823)  Income before provision for income taxes 40,996  Cash capital expenditures (3) 50,433 26,890 133 942 78,398   For the three months ended March 31, 2016  Revenues $ 315,230 $ 59,220 $ 25,319 $ — $ 399,769  Cost of revenues (2) 64,475 18,287 19,833 — 102,595  Operating profit 250,755 40,933 5,486 — 297,174  Selling, general, and administrative 17,998 4,385 3,537 4,486 30,406  Acquisition related adjustments and expenses 1,842 1,340 — — 3,182  Asset impairment and decommission costs 6,021 162 — — 6,183  Depreciation, amortization and accretion 131,393 26,877 1,025 506 159,801  Operating income (loss) 93,501 8,169 924 (4,992) 97,602  Other expense (principally interest expense  and other income (expense)) (41,758) (41,758)  Income before provision for income taxes 55,844  Cash capital expenditures (3) 105,353 21,380 556 876 128,165       Domestic Site Int'l Site Site Not Identified  Leasing Leasing Development by Segment (1) Total   (in thousands)  Assets  As of March 31, 2017 $ 5,313,286 $ 1,856,435 $ 37,787 $ 89,942 $ 7,297,450  As of December 31, 2016 $ 5,396,394 $ 1,839,703 $ 43,769 $ 81,079 $ 7,360,945  (1) Assets not identified by segment consist primarily of general corporate assets. (2) Excludes depreciation, amortization, and accretion. (3) Includes cash paid for capital expenditures and acquisitions and vehicle capital lease additions.

Earnings Per Share (Tables)

Earnings Per Share (Tables)	3 Months Ended
	Mar. 31, 2017
Earnings Per Share [Abstract]
Weighted-Average Shares Of Common Stock Outstanding Used In Calculation Of Basic And Diluted Earnings Per Share	   For the three months  ended March 31,  2017 2016  Numerator:  Net income $ 37,598 $ 53,639  Denominator:  Basic weighted-average shares outstanding 121,049 125,398  Dilutive impact of stock options and restricted shares 685 726  Diluted weighted-average shares outstanding 121,734 126,124  Net income per common share:  Basic $ 0.31 $ 0.43  Diluted $ 0.31 $ 0.43 

Basis of Presentation (Narrativ

Basis of Presentation (Narrative) (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2017	Mar. 31, 2016	Dec. 31, 2016
Basis Of Presentation [Line Items]
Gain (loss) on remeasurement of U.S. dollar denominated intercompany loan	$ 13,659	$ 44,765
Debt instrument, carrying value	8,666,174		$ 8,775,583
Subsidiaries [Member] | Intercompany Loan with Brazil Shareholder I, LLC. [Member]
Basis Of Presentation [Line Items]
Debt instrument, carrying value	$ 433,300
Site Development [Member] | Revenue [Member]
Basis Of Presentation [Line Items]
Concentration risk percentage of revenue	6.00%

Fair Value Measurements (Narrat

Fair Value Measurements (Narrative) (Details) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2017	Dec. 31, 2016
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Performance targets, maximum potential obligation	$ 5	$ 5.8
Treasury securities	0.2	0.2
Held-to-maturity investments, carrying value	0.7	0.7
Held-to-maturity investments, fair value	$ 0.7	$ 0.7
Revolving Credit Facility [Member] | Minimum [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Basis spread on variable interest rate	1.375%
Revolving Credit Facility [Member] | Maximum [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Basis spread on variable interest rate	2.00%

Fair Value Measurements (Summar

Fair Value Measurements (Summary Of Asset Impairment And Decommission Costs) (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2017	Mar. 31, 2016
Asset impairment	$ 3,014
Total asset impairment and decommission costs	8,351	$ 6,183
Not Identified by Segment [Member]
Write-offs relating to long-lived assets and intangibles	1,366	1,987
Decommissioned Towers [Member]
Write-offs relating to long-lived assets and intangibles	$ 3,971	$ 4,196

Restricted Cash (Narrative) (De

Restricted Cash (Narrative) (Details) - USD ($) $ in Millions	Mar. 31, 2017	Dec. 31, 2016
Restricted Cash [Abstract]
Surety, payment and performance bonds	$ 38.8	$ 39.2
Collateral payment for performance bonds	0	0.5
Collateral related to workers compensation policy	$ 2.5	$ 2.5

Restricted Cash (Schedule Of Ca

Restricted Cash (Schedule Of Cash, Cash Equivalents And Restricted Cash) (Details) - USD ($) $ in Thousands	Mar. 31, 2017	Dec. 31, 2016	Mar. 31, 2016	Dec. 31, 2015
Restricted Cash And Cash Equivalents Items [Line Items]
Cash and cash equivalents	$ 132,222	$ 146,109
Restricted cash - short term	30,674	36,786
Total cash, cash equivalents, and restricted cash	165,471	185,970	$ 131,633	$ 146,619
Securitization Escrow Accounts [Member] | Restricted Cash - Current Asset [Member]
Restricted Cash And Cash Equivalents Items [Line Items]
Restricted cash - short term	30,487	36,607
Payment and Performance Bonds [Member] | Restricted Cash - Current Asset [Member]
Restricted Cash And Cash Equivalents Items [Line Items]
Restricted cash - short term	187	179
Surety Bonds and Workers Compensation [Member] | Other Assets - Noncurrent [Member]
Restricted Cash And Cash Equivalents Items [Line Items]
Restricted cash - long term	$ 2,575	$ 3,075

Other Assets (Schedule Of Other

Other Assets (Schedule Of Other Assets) (Details) - USD ($) $ in Thousands	Mar. 31, 2017	Dec. 31, 2016
Other Assets [Abstract]
Long-term investments	$ 8,379	$ 7,884
Prepaid land rent	194,819	191,615
Straight-line rent receivable	307,535	302,893
Deferred lease costs, net	29,172	29,660
Other	64,786	55,322
Total other assets	$ 604,691	$ 587,374

Acquisitions (Narrative) (Detai

Acquisitions (Narrative) (Details) $ in Millions	1 Months Ended	3 Months Ended
	Apr. 30, 2017USD ($)item	Mar. 31, 2017USD ($)item	Dec. 31, 2016USD ($)
Business Acquisition [Line Items]
Potential obligation recorded in accrued expenses		$ 8.6	$ 5.8
Other Acquisitions [Member]
Business Acquisition [Line Items]
Number of towers acquired | item		90
Cash paid for acquisition		$ 31.1
Property and equipment		12.1
Intangible assets		17.6
Working capital adjustments		$ 1.4
Subsequent Event [Member]
Business Acquisition [Line Items]
Number of towers acquired | item	9
Cash paid for acquisition	$ 5.6

Acquisitions (Schedule Of Acqui

Acquisitions (Schedule Of Acquisition Capital Expenditures) (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2017	Mar. 31, 2016
Acquisitions [Abstract]
Towers and related intangible assets	$ 31,147	$ 74,844
Land buyouts and other assets	11,504	16,988
Total cash acquisition capital expenditures	42,651	91,832
Ground lease extensions	$ 2,700	$ 3,600

Intangible Assets, Net (Narrati

Intangible Assets, Net (Narrative) (Details) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2017	Mar. 31, 2016
Intangible Assets, Net [Abstract]
Intangible assets, useful life	15 years
Amortization expense	$ 94.9	$ 90.2

Intangible Assets, Net (Gross A

Intangible Assets, Net (Gross And Net Carrying Amounts For Each Major Class Of Intangible Assets) (Details) - USD ($) $ in Thousands	Mar. 31, 2017	Dec. 31, 2016
Finite-Lived Intangible Assets [Line Items]
Gross carrying amount	$ 5,705,117	$ 5,657,316
Accumulated amortization	(2,099,569)	(2,000,392)
Net book value	3,605,548	3,656,924
Current Contract Intangibles [Member]
Finite-Lived Intangible Assets [Line Items]
Gross carrying amount	4,179,583	4,141,968
Accumulated amortization	(1,473,948)	(1,401,025)
Net book value	2,705,635	2,740,943
Network Location Intangibles [Member]
Finite-Lived Intangible Assets [Line Items]
Gross carrying amount	1,525,534	1,515,348
Accumulated amortization	(625,621)	(599,367)
Net book value	$ 899,913	$ 915,981

Property And Equipment, Net (Na

Property And Equipment, Net (Narrative) (Details) - USD ($) $ in Millions	3 Months Ended		12 Months Ended
	Mar. 31, 2017	Mar. 31, 2016	Dec. 31, 2016
Property And Equipment, Net [Abstract]
Depreciation expense	$ 64.1	$ 69.5
Non-cash capital expenditures	$ 4.7		$ 7

Property And Equipment, Net (Pr

Property And Equipment, Net (Property And Equipment, Net (Including Assets Held Under Capital Leases)) (Details) - USD ($) $ in Thousands	Mar. 31, 2017	Dec. 31, 2016
Property, Plant and Equipment [Line Items]
Total property and equipment	$ 5,285,787	$ 5,232,033
Less: accumulated depreciation	(2,499,843)	(2,439,957)
Property and equipment, net	2,785,944	2,792,076
Towers And Related Components [Member]
Property, Plant and Equipment [Line Items]
Total property and equipment	4,601,648	4,563,756
Construction-In-Process [Member]
Property, Plant and Equipment [Line Items]
Total property and equipment	42,266	38,926
Furniture, Equipment And Vehicles [Member]
Property, Plant and Equipment [Line Items]
Total property and equipment	51,004	50,671
Land, Buildings, and Improvements [Member]
Property, Plant and Equipment [Line Items]
Total property and equipment	$ 590,869	$ 578,680

Costs And Estimated Earnings 50

Costs And Estimated Earnings On Uncompleted Contracts (Narrative) (Details) - customer	3 Months Ended	12 Months Ended
	Mar. 31, 2017	Dec. 31, 2016
Costs And Estimated Earnings On Uncompleted Contracts [Abstract]
Costs and estimated earnings in excess of billings on uncompleted contracts, net of billings in excess of costs and estimated earnings on uncompleted contracts, percentage comprised by significant customers	88.20%	81.60%
Number of significant customers	8	8

Costs And Estimated Earnings 51

Costs And Estimated Earnings On Uncompleted Contracts (Summary Of Costs And Estimated Earnings On Uncompleted Contracts) (Details) - USD ($) $ in Thousands	Mar. 31, 2017	Dec. 31, 2016
Costs And Estimated Earnings On Uncompleted Contracts [Abstract]
Costs incurred on uncompleted contracts	$ 29,946	$ 34,577
Estimated earnings	10,592	11,185
Billings to date	(27,721)	(36,027)
Costs and estimated earnings on uncompleted contracts	$ 12,817	$ 9,735

Costs And Estimated Earnings 52

Costs And Estimated Earnings On Uncompleted Contracts (Costs And Estimated Earnings On Uncompleted Contracts Accompanying Consolidated Balance Sheets) (Details) - USD ($) $ in Thousands	Mar. 31, 2017	Dec. 31, 2016
Costs And Estimated Earnings On Uncompleted Contracts [Abstract]
Costs and estimated earnings in excess of billings on uncompleted contracts	$ 13,108	$ 11,127
Billings in excess of costs and estimated earnings on uncompleted contracts (included in Other current liabilities)	(291)	(1,392)
Costs and estimated earnings on uncompleted contracts	$ 12,817	$ 9,735

Accrued Expenses (Schedule Of A

Accrued Expenses (Schedule Of Accrued Expenses) (Details) - USD ($) $ in Thousands	Mar. 31, 2017	Dec. 31, 2016
Accrued Expenses [Abstract]
Accrued earnouts	$ 3,667	$ 4,128
Salaries and benefits	8,115	11,910
Real estate and property taxes	7,077	7,644
Other	35,097	37,447
Total accrued expenses	$ 53,956	$ 61,129

Debt (Revolving Credit Facility

Debt (Revolving Credit Facility Under The Senior Credit Agreement) (Narrative) (Details) - USD ($) $ in Thousands	1 Months Ended	3 Months Ended
	Apr. 30, 2017	Mar. 31, 2017	Mar. 31, 2016
Line of Credit Facility [Line Items]
Repayments of revolving credit facility		$ 110,000	$ 50,000
Revolving Credit Facility [Member]
Line of Credit Facility [Line Items]
Line of credit facility, maximum borrowing capacity		$ 1,000,000
Line of credit facility, commitment fee		0.25%
Revolving credit facility, maturity date		Feb. 5, 2020
Repayments of revolving credit facility		$ 110,000
Revolving Credit Facility [Member] | Subsequent Event [Member]
Line of Credit Facility [Line Items]
Repayments of revolving credit facility	$ 190,000
Minimum [Member] | Revolving Credit Facility [Member]
Line of Credit Facility [Line Items]
Basis spread on variable interest rate		1.375%
Minimum [Member] | Revolving Credit Facility [Member] | Base Rate [Member]
Line of Credit Facility [Line Items]
Basis spread on variable interest rate		0.375%
Maximum [Member] | Revolving Credit Facility [Member]
Line of Credit Facility [Line Items]
Basis spread on variable interest rate		2.00%
Maximum [Member] | Revolving Credit Facility [Member] | Base Rate [Member]
Line of Credit Facility [Line Items]
Basis spread on variable interest rate		1.00%

Debt (Term Loans Under The Seni

Debt (Term Loans Under The Senior Credit Agreement) (Narrative) (Details) - USD ($)	Jan. 20, 2017	Mar. 31, 2017	Mar. 31, 2016	Dec. 31, 2016
Debt Instrument [Line Items]
Repayment of term loans		$ 5,000,000	$ 5,000,000
Debt instrument, principal balance		8,760,000,000		$ 8,875,000,000
2014 Term Loan [Member]
Debt Instrument [Line Items]
Debt instrument, face amount		$ 1,500,000,000
Debt instrument, maturity date		Mar. 24, 2021
Term Loan, percentage of par value		99.75%
Coupon rate of notes		3.24%
Deferred financing fees		$ 14,100,000
Quarterly payments		3,800,000
Repayment of term loans		3,800,000
Debt instrument, principal balance		$ 1,458,750,000		1,462,500,000
Date after which no prepayment fee will be assessed		Jul. 20, 2017
Percentage fee charged for prepayment equal to aggregate principal amount		1.00%
2015 Term Loan [Member]
Debt Instrument [Line Items]
Debt instrument, face amount		$ 500,000,000
Debt instrument, maturity date		Jun. 10, 2022
Term Loan, percentage of par value		99.00%
Coupon rate of notes		3.24%
Deferred financing fees		$ 5,500,000
Quarterly payments		1,300,000
Repayment of term loans		1,300,000
Debt instrument, principal balance		$ 491,250,000		$ 492,500,000
Date after which no prepayment fee will be assessed		Jul. 20, 2017
Percentage fee charged for prepayment equal to aggregate principal amount		1.00%
Base Rate [Member] | 2014 Term Loan [Member]
Debt Instrument [Line Items]
Basis spread on variable interest rate		1.50%
Base rate floor		1.75%
Base Rate [Member] | 2015 Term Loan [Member]
Debt Instrument [Line Items]
Basis spread on variable interest rate		1.50%
Base rate floor		1.75%
Base Rate [Member] | Term Loan under the Senior Credit Agreement [Member]
Debt Instrument [Line Items]
Basis spread on variable interest rate	1.25%
Base rate floor	0.00%
Eurodollar [Member] | 2014 Term Loan [Member]
Debt Instrument [Line Items]
Basis spread on variable interest rate		2.50%
Eurodollar rate floor		0.75%
Eurodollar [Member] | 2015 Term Loan [Member]
Debt Instrument [Line Items]
Basis spread on variable interest rate		2.50%
Eurodollar rate floor		0.75%
Eurodollar [Member] | Term Loan under the Senior Credit Agreement [Member]
Debt Instrument [Line Items]
Basis spread on variable interest rate	2.25%
Eurodollar rate floor	0.00%

Debt (Secured Tower Revenue Sec

Debt (Secured Tower Revenue Securities) (Narrative) (Details) - USD ($)	Apr. 17, 2017	Jul. 07, 2016	Oct. 14, 2015	Oct. 15, 2014	Apr. 18, 2013	Aug. 09, 2012	Mar. 31, 2017	Dec. 31, 2016
Debt Instrument [Line Items]
Long-term debt							$ 8,666,174,000	$ 8,775,583,000
2010-2C Tower Securities [Member]
Debt Instrument [Line Items]
Repayments of long-term debt		$ 550,000,000
2012-1C Tower Securities [Member]
Debt Instrument [Line Items]
Debt instrument, face amount						$ 610,000,000
Debt instrument, interest rate, stated percentage						2.933%
Repayment date of debt instrument						Dec. 11, 2017
Debt instrument, maturity date						Dec. 9, 2042	Dec. 11, 2017
Deferred financing fees						$ 14,900,000
Long-term debt							$ 607,905,000	607,157,000
2013 Tower Securities [Member]
Debt Instrument [Line Items]
Deferred financing fees					$ 25,500,000
Debt instrument, weighted average interest rate					3.218%
Long-term debt					$ 1,330,000,000
2013-1C Tower Securities [Member]
Debt Instrument [Line Items]
Debt instrument, face amount					$ 425,000,000
Debt instrument, interest rate, stated percentage					2.24%
Repayment date of debt instrument					Apr. 10, 2018
Debt instrument, maturity date					Apr. 9, 2043		Apr. 10, 2018
Long-term debt							$ 423,192,000	422,768,000
2013-2C Tower Securities [Member]
Debt Instrument [Line Items]
Debt instrument, face amount					$ 575,000,000
Debt instrument, interest rate, stated percentage					3.722%
Repayment date of debt instrument					Apr. 11, 2023
Debt instrument, maturity date					Apr. 9, 2048		Apr. 11, 2023
Long-term debt							$ 567,807,000	567,545,000
2013-1D Tower Securities [Member]
Debt Instrument [Line Items]
Debt instrument, face amount					$ 330,000,000
Debt instrument, interest rate, stated percentage					3.598%
Repayment date of debt instrument					Apr. 10, 2018
Debt instrument, maturity date					Apr. 9, 2043		Apr. 10, 2018
Long-term debt							$ 328,560,000	328,225,000
2014 Tower Securities [Member]
Debt Instrument [Line Items]
Deferred financing fees				$ 22,500,000
Debt instrument, weighted average interest rate				3.289%
Long-term debt				$ 1,540,000,000
2014-1C Tower Securities [Member]
Debt Instrument [Line Items]
Debt instrument, face amount				$ 920,000,000
Debt instrument, interest rate, stated percentage				2.898%
Repayment date of debt instrument				Oct. 8, 2019
Debt instrument, maturity date				Oct. 11, 2044			Oct. 8, 2019
Long-term debt							$ 912,889,000	912,219,000
2014-2C Tower Securities [Member]
Debt Instrument [Line Items]
Debt instrument, face amount				$ 620,000,000
Debt instrument, interest rate, stated percentage				3.869%
Repayment date of debt instrument				Oct. 8, 2024
Debt instrument, maturity date				Oct. 8, 2049			Oct. 8, 2024
Long-term debt							$ 612,843,000	612,641,000
2015-1C Tower Securities [Member]
Debt Instrument [Line Items]
Debt instrument, face amount			$ 500,000,000
Debt instrument, interest rate, stated percentage			3.156%
Repayment date of debt instrument			Oct. 8, 2020
Debt instrument, maturity date			Oct. 10, 2045				Oct. 8, 2020
Deferred financing fees			$ 11,200,000
Long-term debt							$ 491,828,000	491,289,000
2016-1C Tower Securities [Member]
Debt Instrument [Line Items]
Debt instrument, face amount		$ 700,000,000
Debt instrument, interest rate, stated percentage		2.877%
Repayment date of debt instrument		Jul. 9, 2021
Debt instrument, maturity date		Jul. 10, 2046					Jul. 9, 2021
Deferred financing fees							$ 9,500,000
Long-term debt							$ 691,752,000	$ 691,322,000
Subsequent Event [Member] | 2012-1C Tower Securities [Member]
Debt Instrument [Line Items]
Net deferred finance costs expensed	$ 2,000,000
Repayments of long-term debt	610,000,000
Subsequent Event [Member] | 2017-1C Tower Securities [Member]
Debt Instrument [Line Items]
Debt instrument, face amount	$ 760,000,000
Debt instrument, interest rate, stated percentage	3.168%
Repayment date of debt instrument	Apr. 11, 2022
Debt instrument, maturity date	Apr. 9, 2047
Deferred financing fees	$ 9,700,000
Subsequent Event [Member] | SBA Guarantor, LLC [Member] | 2017-1R Tower Securities [Member]
Debt Instrument [Line Items]
Debt instrument, face amount	$ 40,000,000
Debt instrument, interest rate, stated percentage	4.459%
Repayment date of debt instrument	Apr. 11, 2022
Debt instrument, maturity date	Apr. 9, 2047

Debt (Senior Notes) (Narrative)

Debt (Senior Notes) (Narrative) (Details) - USD ($) $ in Millions	Aug. 15, 2016	Jul. 01, 2014	Mar. 31, 2017
5.75% Senior Notes [Member]
Debt Instrument [Line Items]
Debt instrument, interest rate, stated percentage	5.75%		5.75%
Repayments of unsecured debt	$ 800
5.625% Senior Notes [Member]
Debt Instrument [Line Items]
Debt instrument, interest rate, stated percentage	5.625%		5.625%
Repayments of unsecured debt	$ 250
2014 Senior Notes [Member]
Debt Instrument [Line Items]
Unsecured senior notes		$ 750
Debt instrument, maturity date			Jul. 15, 2022
Debt instrument, interest rate, stated percentage		4.875%
Percentage of face value price for issuance of senior notes		99.178%
Interest payable dates			January 15 and July 15
Deferred financing fees		$ 11.6
2016 Senior Notes [Member]
Debt Instrument [Line Items]
Unsecured senior notes	$ 1,100
Debt instrument, maturity date			Sep. 1, 2024
Debt instrument, interest rate, stated percentage	4.875%
Percentage of face value price for issuance of senior notes	99.178%
Interest payable dates			March 1 and September 1
Deferred financing fees	$ 12.8

Debt (Schedule Of Carrying And

Debt (Schedule Of Carrying And Principal Values Of Debt) (Details) - USD ($)	Jul. 07, 2016	Oct. 14, 2015	Oct. 15, 2014	Apr. 18, 2013	Aug. 09, 2012	Mar. 31, 2017	Dec. 31, 2016
Debt Instrument [Line Items]
Principal Balance						$ 8,760,000,000	$ 8,875,000,000
Fair Value						8,757,301,000	8,844,682,000
Carrying Value						8,666,174,000	8,775,583,000
Less: current maturities of long-term debt						(20,000,000)	(627,157,000)
Total long-term debt, net of current maturities						8,646,174,000	8,148,426,000
Revolving Credit Facility [Member]
Debt Instrument [Line Items]
Principal Balance						280,000,000	390,000,000
Fair Value						280,000,000	390,000,000
Carrying Value						$ 280,000,000	390,000,000
Debt instrument, maturity date						Feb. 5, 2020
2014 Senior Notes [Member]
Debt Instrument [Line Items]
Principal Balance						$ 750,000,000	750,000,000
Fair Value						759,375,000	763,125,000
Carrying Value						$ 737,505,000	736,992,000
Debt instrument, maturity date						Jul. 15, 2022
2016 Senior Notes [Member]
Debt Instrument [Line Items]
Principal Balance						$ 1,100,000,000	1,100,000,000
Fair Value						1,083,500,000	1,083,500,000
Carrying Value						$ 1,079,520,000	1,078,954,000
Debt instrument, maturity date						Sep. 1, 2024
2012-1C Tower Securities [Member]
Debt Instrument [Line Items]
Principal Balance						$ 610,000,000	610,000,000
Fair Value						610,171,000	610,165,000
Carrying Value						$ 607,905,000	607,157,000
Debt instrument, maturity date					Dec. 9, 2042	Dec. 11, 2017
2013-1C Tower Securities [Member]
Debt Instrument [Line Items]
Principal Balance						$ 425,000,000	425,000,000
Fair Value						423,827,000	423,381,000
Carrying Value						$ 423,192,000	422,768,000
Debt instrument, maturity date				Apr. 9, 2043		Apr. 10, 2018
2013-2C Tower Securities [Member]
Debt Instrument [Line Items]
Principal Balance						$ 575,000,000	575,000,000
Fair Value						576,777,000	563,322,000
Carrying Value						$ 567,807,000	567,545,000
Debt instrument, maturity date				Apr. 9, 2048		Apr. 11, 2023
2013-1D Tower Securities [Member]
Debt Instrument [Line Items]
Principal Balance						$ 330,000,000	330,000,000
Fair Value						330,281,000	334,521,000
Carrying Value						$ 328,560,000	328,225,000
Debt instrument, maturity date				Apr. 9, 2043		Apr. 10, 2018
2014-1C Tower Securities [Member]
Debt Instrument [Line Items]
Principal Balance						$ 920,000,000	920,000,000
Fair Value						923,183,000	922,199,000
Carrying Value						$ 912,889,000	912,219,000
Debt instrument, maturity date			Oct. 11, 2044			Oct. 8, 2019
2014-2C Tower Securities [Member]
Debt Instrument [Line Items]
Principal Balance						$ 620,000,000	620,000,000
Fair Value						619,932,000	608,921,000
Carrying Value						$ 612,843,000	612,641,000
Debt instrument, maturity date			Oct. 8, 2049			Oct. 8, 2024
2015-1C Tower Securities [Member]
Debt Instrument [Line Items]
Principal Balance						$ 500,000,000	500,000,000
Fair Value						502,555,000	495,145,000
Carrying Value						$ 491,828,000	491,289,000
Debt instrument, maturity date		Oct. 10, 2045				Oct. 8, 2020
2016-1C Tower Securities [Member]
Debt Instrument [Line Items]
Principal Balance						$ 700,000,000	700,000,000
Fair Value						695,877,000	688,072,000
Carrying Value						$ 691,752,000	691,322,000
Debt instrument, maturity date	Jul. 10, 2046					Jul. 9, 2021
2014 Term Loan [Member]
Debt Instrument [Line Items]
Principal Balance						$ 1,458,750,000	1,462,500,000
Fair Value						1,460,573,000	1,467,984,000
Carrying Value						$ 1,448,858,000	1,452,039,000
Debt instrument, maturity date						Mar. 24, 2021
2015 Term Loan [Member]
Debt Instrument [Line Items]
Principal Balance						$ 491,250,000	492,500,000
Fair Value						491,250,000	494,347,000
Carrying Value						$ 483,515,000	$ 484,432,000
Debt instrument, maturity date						Jun. 10, 2022

Debt (Schedule Of Cash And Non-

Debt (Schedule Of Cash And Non-Cash Interest Expense) (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2017	Mar. 31, 2016	Aug. 15, 2016	Jul. 07, 2016	Oct. 14, 2015	Jul. 01, 2014	Aug. 09, 2012
Debt Instrument [Line Items]
Cash Interest	$ 77,602	$ 83,804
Non-cash Interest	705	455
Revolving Credit Facility [Member]
Debt Instrument [Line Items]
Cash Interest	$ 2,770	833
5.625% Senior Notes [Member]
Debt Instrument [Line Items]
Cash Interest		7,031
Debt instrument, interest rate, stated percentage	5.625%		5.625%
5.75% Senior Notes [Member]
Debt Instrument [Line Items]
Cash Interest		11,500
Debt instrument, interest rate, stated percentage	5.75%		5.75%
2014 Senior Notes [Member]
Debt Instrument [Line Items]
Cash Interest	$ 9,141	9,141
Non-cash Interest	178	169
Debt instrument, interest rate, stated percentage						4.875%
2016 Senior Notes [Member]
Debt Instrument [Line Items]
Cash Interest	13,406
Non-cash Interest	234
Debt instrument, interest rate, stated percentage			4.875%
2010-2C Tower Securities [Member]
Debt Instrument [Line Items]
Cash Interest		7,058
2012-1C Tower Securities [Member]
Debt Instrument [Line Items]
Cash Interest	4,524	4,534
Debt instrument, interest rate, stated percentage							2.933%
2013 Tower Securities [Member]
Debt Instrument [Line Items]
Cash Interest	10,804	10,804
2014 Tower Securities [Member]
Debt Instrument [Line Items]
Cash Interest	12,785	12,785
2015-1C Tower Securities [Member]
Debt Instrument [Line Items]
Cash Interest	3,985	3,985
Debt instrument, interest rate, stated percentage					3.156%
2016-1C Tower Securities [Member]
Debt Instrument [Line Items]
Cash Interest	5,090
Debt instrument, interest rate, stated percentage				2.877%
2014 Term Loan [Member]
Debt Instrument [Line Items]
Cash Interest	11,284	12,138
Non-cash Interest	128	125
2015 Term Loan [Member]
Debt Instrument [Line Items]
Cash Interest	3,800	4,087
Non-cash Interest	165	161
Capitalized Interest And Other [Member]
Debt Instrument [Line Items]
Cash Interest	$ 13	$ (92)

Shareholders' Equity (Narrative

Shareholders' Equity (Narrative) (Details) - Class A Common Stock [Member] - USD ($) $ / shares in Units, $ in Millions	3 Months Ended
	Mar. 31, 2017	May 04, 2017	Jan. 12, 2017	Jun. 04, 2015
Previous Stock Repurchase Program [Member]
Class of Stock [Line Items]
Stock repurchase program, authorized				$ 1,000
Stock repurchased, shares	42,163
Stock repurchased, value	$ 4.4
Weighted average price per share	$ 104.81
Stock repurchase program, remaining authorization			$ 150
New Stock Repurchase Program [Member]
Class of Stock [Line Items]
Stock repurchase program, authorized			$ 1,000
New Stock Repurchase Program [Member] | Subsequent Event [Member]
Class of Stock [Line Items]
Stock repurchase program, remaining authorization		$ 1,000

Stock-Based Compensation (Narra

Stock-Based Compensation (Narrative) (Details) $ / shares in Units, $ in Millions	3 Months Ended
	Mar. 31, 2017USD ($)$ / shares
Stock-Based Compensation [Abstract]
Weighted-average fair value of options granted | $ / shares	$ 23.84
Total intrinsic value for options exercised | $	$ 11

Stock-Based Compensation (Sched

Stock-Based Compensation (Schedule Of Assumptions Used To Estimate Fair Value Of Stock Options) (Details)	3 Months Ended
	Mar. 31, 2017	Mar. 31, 2016
Stock-Based Compensation [Abstract]
Risk free interest rate	1.91%
Risk free interest rate, Minimum		1.33%
Risk free interest rate, Maximum		1.43%
Dividend yield	0.00%	0.00%
Expected volatility	20.00%	20.00%
Expected lives	4 years 7 months 6 days	4 years 8 months 12 days

Stock-Based Compensation (Compa

Stock-Based Compensation (Company's Activities With Respect To Its Stock Options) (Details) $ / shares in Units, shares in Thousands, $ in Thousands	3 Months Ended
	Mar. 31, 2017USD ($)$ / sharesshares
Stock-Based Compensation [Abstract]
Number of Shares Outstanding, Beginning Balance | shares	4,447
Number of Shares, Granted | shares	1,149
Number of Shares, Exercised | shares	(213)
Number of Shares, Canceled | shares	(20)
Number of Shares Outstanding, Ending Balance | shares	5,363
Number of Shares Exercisable, Ending Balance | shares	2,451
Number of Shares Unvested, Ending Balance | shares	2,912
Weighted-Average Exercise Price Per Share, Outstanding, Beginning Balance | $ / shares	$ 93.09
Weighted-Average Exercise Price Per Share, Granted | $ / shares	115.17
Weighted-Average Exercise Price Per Share, Exercised | $ / shares	62.99
Weighted-Average Exercise Price Per Share, Canceled | $ / shares	102.89
Weighted-Average Exercise Price Per Share, Outstanding, Ending Balance | $ / shares	98.98
Weighted-Average Exercise Price Per Share, Exercisable, Ending Balance | $ / shares	87.48
Weighted-Average Exercise Price Per Share, Unvested, Ending Balance | $ / shares	$ 108.66
Weighted-Average Remaining Contractual Life (in years), Outstanding at March 31, 2017	5 years
Weighted-Average Remaining Contractual Life (in years), Exercisable at March 31, 2017	3 years 9 months 18 days
Weighted-Average Remaining Contractual Life (in years), Unvested at March 31, 2017	6 years
Aggregate Intrinsic Value, Outstanding at March 31, 2017 | $	$ 118,838
Aggregate Intrinsic Value, Exercisable at March 31, 2017 | $	82,673
Aggregate Intrinsic Value, Unvested at March 31, 2017 | $	$ 36,165

Stock-Based Compensation (Restr

Stock-Based Compensation (Restricted Stock Unit Activity) (Details) shares in Thousands	3 Months Ended
	Mar. 31, 2017$ / sharesshares
Stock-Based Compensation [Abstract]
Number of Shares, Outstanding, at December 31, 2016 | shares	291
Number of Shares, Granted | shares	161
Number of Shares, Vested | shares	(115)
Number of Shares, Forfeited/canceled | shares	(2)
Number of Shares, Outstanding, at March 31, 2017 | shares	335
Weighted-Average Grant Date Fair Value per Share, Outstanding, at December 31, 2016 | $ / shares	$ 101.74
Weighted-Average Grant Date Fair Value per Share, Granted | $ / shares	115.17
Weighted-Average Grant Date Fair Value per Share, Vested | $ / shares	98.50
Weighted-Average Grant Date Fair Value per Share, Forfeited/canceled | $ / shares	105.21
Weighted-Average Grant Date Fair Value per Share, Outstanding, at March 31, 2017 | $ / shares	$ 109.29

Income Taxes (Narrative) (Detai

Income Taxes (Narrative) (Details) $ in Billions	Dec. 31, 2016USD ($)
Income Taxes [Abstract]
Foreign net operating loss carry-forward	$ 1.1

Segment Data (Narrative) (Detai

Segment Data (Narrative) (Details)	3 Months Ended
	Mar. 31, 2017segment
Segment Data [Abstract]
Number of business segments	2

Segment Data (Segment Reporting

Segment Data (Segment Reporting Information Disclosure) (Details) - USD ($) $ in Thousands		3 Months Ended
		Mar. 31, 2017	Mar. 31, 2016	Dec. 31, 2016
Segment Reporting Information [Line Items]
Revenues		$ 423,363	$ 399,769
Cost of revenues		110,970	102,595
Operating profit		312,393	297,174
Selling, general, and administrative	[1]	34,223	30,406
Acquisition related adjustments and expenses		2,969	3,182
Asset impairment and decommission costs		8,351	6,183
Depreciation, amortization and accretion		159,031	159,801
Operating income		107,819	97,602
Other expense (principally interest expense and other expense)		(66,823)	(41,758)
Income before provision for income taxes		40,996	55,844
Cash capital expenditures		78,398	128,165
Assets		7,297,450		$ 7,360,945
Domestic Site Leasing [Member]
Segment Reporting Information [Line Items]
Revenues		321,130	315,230
Cost of revenues		65,427	64,475
Operating profit		255,703	250,755
Selling, general, and administrative		19,356	17,998
Acquisition related adjustments and expenses		1,901	1,842
Asset impairment and decommission costs		7,430	6,021
Depreciation, amortization and accretion		123,896	131,393
Operating income		103,120	93,501
Cash capital expenditures		50,433	105,353
Assets		5,313,286		5,396,394
International Site Leasing [Member]
Segment Reporting Information [Line Items]
Revenues		76,420	59,220
Cost of revenues		23,955	18,287
Operating profit		52,465	40,933
Selling, general, and administrative		5,959	4,385
Acquisition related adjustments and expenses		1,068	1,340
Asset impairment and decommission costs		816	162
Depreciation, amortization and accretion		32,825	26,877
Operating income		11,797	8,169
Cash capital expenditures		26,890	21,380
Assets		1,856,435		1,839,703
Site Development [Member]
Segment Reporting Information [Line Items]
Revenues		25,813	25,319
Cost of revenues		21,588	19,833
Operating profit		4,225	5,486
Selling, general, and administrative		3,617	3,537
Asset impairment and decommission costs		105
Depreciation, amortization and accretion		711	1,025
Operating income		(208)	924
Cash capital expenditures		133	556
Assets		37,787		43,769
Not Identified by Segment [Member]
Segment Reporting Information [Line Items]
Selling, general, and administrative		5,291	4,486
Depreciation, amortization and accretion		1,599	506
Operating income		(6,890)	(4,992)
Other expense (principally interest expense and other expense)		(66,823)	(41,758)
Cash capital expenditures		942	$ 876
Assets		$ 89,942		$ 81,079
[1]	Includes non-cash compensation of $8,826 and $7,686 for the three months ended March 31, 2017 and 2016, respectively.

Earnings Per Share (Narrative)

Earnings Per Share (Narrative) (Details) - shares shares in Millions	3 Months Ended
	Mar. 31, 2017	Mar. 31, 2016
Stock Options [Member]
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Securities excluded from earnings per share calculation	2.4	2.4

Earnings Per Share (Weighted-Av

Earnings Per Share (Weighted-Average Shares of Common Stock Outstanding Used in Calculation of Basic and Diluted Earnings Per Share) (Details) - USD ($) $ / shares in Units, shares in Thousands, $ in Thousands	3 Months Ended
	Mar. 31, 2017	Mar. 31, 2016
Earnings Per Share [Abstract]
Net income	$ 37,598	$ 53,639
Basic weighted-average shares outstanding	121,049	125,398
Dilutive impact of stock options and restricted shares	685	726
Diluted weighted-average shares outstanding	121,734	126,124
Net income per common share:
Basic	$ 0.31	$ 0.43
Diluted	$ 0.31	$ 0.43