Inteliquent (IQNT) 10-K 18 Feb 16 2015 FY Annual report Financial data

Document and Entity Information

Document and Entity Information - USD ($)	12 Months Ended
	Dec. 31, 2015	Jan. 31, 2016	Jun. 30, 2015
Document And Entity Information [Abstract]
Document Type	10-K
Amendment Flag	false
Document Period End Date	Dec. 31, 2015
Document Fiscal Year Focus	2,015
Document Fiscal Period Focus	FY
Trading Symbol	IQNT
Entity Registrant Name	INTELIQUENT, INC.
Entity Central Index Key	1,292,653
Current Fiscal Year End Date	--12-31
Entity Well-known Seasoned Issuer	No
Entity Current Reporting Status	Yes
Entity Voluntary Filers	No
Entity Filer Category	Accelerated Filer
Entity Common Stock, Shares Outstanding		33,913,161
Entity Public Float			$ 581,683,763

Consolidated Balance Sheets

Consolidated Balance Sheets - USD ($) $ in Thousands	Dec. 31, 2015	Dec. 31, 2014
Current assets:
Cash and cash equivalents	$ 109,050	$ 104,737
Receivables — net of allowance of $2,365 and $2,336, respectively	39,589	32,766
Deferred income taxes-current		836
Prepaid expenses	9,376	2,198
Other current assets	219	1,320
Total current assets	158,234	141,857
Property and equipment—net	37,336	23,678
Restricted cash	345	345
Deferred income taxes-noncurrent	1,059	3,284
Other assets	1,075	1,007
Total assets	198,049	170,171
Current liabilities:
Accounts payable	424	1,607
Accrued liabilities:
Taxes payable	624	1,263
Network and facilities	10,984	7,266
Rent	1,969	2,015
Payroll and related items	2,918	3,079
Other	1,297	897
Total current liabilities	$ 18,216	$ 16,127
Commitments and contingencies (Note 9)
Shareholders’ equity:
Preferred stock—par value of $.001; 50,000 authorized shares; no shares issued and outstanding at December 31, 2015 and December 31, 2014
Common stock—par value of $.001; 150,000 authorized shares; 33,891 shares and 33,458 shares issued and outstanding at December 31, 2015 and December 31, 2014, respectively	$ 34	$ 33
Less treasury stock, at cost; 3,351 shares at December 31, 2015 and December 31, 2014	(51,668)	(51,668)
Additional paid-in capital	225,474	217,628
Retained earnings (accumulated deficit)	5,993	(11,949)
Total shareholders’ equity	179,833	154,044
Total liabilities and shareholders' equity	$ 198,049	$ 170,171

Consolidated Balance Sheets (Pa

Consolidated Balance Sheets (Parenthetical) - USD ($) $ in Thousands	Dec. 31, 2015	Dec. 31, 2014
Statement Of Financial Position [Abstract]
Receivables, allowance	$ 2,365	$ 2,336
Preferred stock, par value	$ 0.001	$ 0.001
Preferred stock, authorized shares	50,000,000	50,000,000
Preferred stock, shares issued	0	0
Preferred stock, shares outstanding	0	0
Common stock, par value	$ 0.001	$ 0.001
Common stock, authorized shares	150,000,000	150,000,000
Common stock, shares issued	33,891,000	33,891,000
Common stock, shares outstanding	33,458,000	33,458,000
Treasury stock, shares, at cost	3,351,000	3,351,000

Consolidated Statements of Inco

Consolidated Statements of Income - USD ($) $ in Thousands	Apr. 30, 2013	Dec. 31, 2015	Sep. 30, 2015	Jun. 30, 2015	Mar. 31, 2015	Dec. 31, 2014	Sep. 30, 2014	Jun. 30, 2014	Mar. 31, 2014	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Income Statement [Abstract]
Revenue		$ 76,963	$ 63,716	$ 52,886	$ 55,054	$ 55,365	$ 54,045	$ 54,881	$ 56,217	$ 248,619	$ 220,508	$ 211,661
Operating expense:
Network and facilities expense (excluding depreciation and amortization)		46,427	34,858	21,295	22,765	23,960	23,016	23,129	24,890	125,345	94,995	94,867
Operations		8,204	7,955	7,391	7,620	7,355	7,432	7,202	7,307	31,170	29,296	28,595
Sales and marketing		776	690	765	643	722	1,048	818	676	2,874	3,264	5,554
General and administrative		4,363	4,648	4,942	4,555	4,141	3,645	5,254	3,800	18,508	16,840	18,772
Depreciation and amortization		3,255	2,894	2,600	2,643	2,681	2,985	3,010	3,141	11,392	11,817	14,652
(Gain) loss on sale of property and equipment		10	(4)	(149)	33	(31)	2	(31)		(110)	(60)	192
Loss (gain) on sale of Americas data assets	$ (28,800)								1,081		1,081	(28,791)
Total operating expense		63,035	51,041	36,844	38,259	38,828	38,128	39,382	40,895	189,179	157,233	133,841
Income from operations		13,928	12,675	16,042	16,795	16,537	15,917	15,499	15,322	59,440	63,275	77,820
Other (income) expense:
Interest expense (income)		(7)	9	11	16	14	18	17	2	29	51	(6)
Other (income) expense					(1,290)			(2)		(1,290)	(2)	4
Total other (income) expense		(7)	9	11	(1,274)	14	18	15	2	(1,261)	49	(2)
Income before provision for income taxes		13,935	12,666	16,031	18,069	16,523	15,899	15,484	15,320	60,701	63,226	77,822
Provision for income taxes		5,255	4,399	6,031	6,887	6,417	6,123	6,036	6,127	22,572	24,703	13,524
Income from continuing operations										38,129	38,523	64,298
Loss from discontinued operations, net of provision for income taxes												(3,808)
Loss on sale of discontinued operations, net of provision for income taxes	$ 4,800											(4,837)
Net income		$ 8,680	$ 8,267	$ 10,000	$ 11,182	$ 10,106	$ 9,776	$ 9,448	$ 9,193	$ 38,129	$ 38,523	$ 55,653
Earnings per share- continuing operations:
Basic										$ 1.13	$ 1.17	$ 1.99
Diluted										1.12	1.15	1.97
Loss per share- discontinued operations:
Basic												(0.27)
Diluted												(0.27)
Earnings per share- net income:
Basic		$ 0.26	$ 0.25	$ 0.30	$ 0.33	$ 0.30	$ 0.30	$ 0.29	$ 0.28	1.13	1.17	1.72
Diluted		$ 0.25	$ 0.24	$ 0.29	$ 0.33	$ 0.30	$ 0.29	$ 0.28	$ 0.28	$ 1.12	$ 1.15	$ 1.71
Weighted average number of shares outstanding:
Basic		33,843	33,620	33,568	33,496	33,316	33,115	32,832	32,273	33,633,000	32,887,000	32,306,000
Diluted		34,213	34,138	34,033	33,970	33,785	33,343	33,369	32,616	34,070,000	33,384,000	32,557,000

Consolidated Statements of Comp

Consolidated Statements of Comprehensive Income - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Statement Of Income And Comprehensive Income [Abstract]
Net income	$ 38,129	$ 38,523	$ 55,653
Other comprehensive income:
Foreign currency adjustments			4,904
Total other comprehensive income			4,904
Comprehensive income	$ 38,129	$ 38,523	$ 60,557

Consolidated Statements of Shar

Consolidated Statements of Shareholders' Equity - USD ($) shares in Thousands, $ in Thousands	Total	Common Shares Outstanding	Treasury Shares	Additional Paid-In Capital	Retained Earnings (Accumulated Deficit)	Accumulated Other Comprehensive Income (Loss)
Beginning Balance at Dec. 31, 2012	$ 99,093	$ 32	$ (50,103)	$ 199,331	$ (45,263)	$ (4,904)
Beginning Balance (in shares) at Dec. 31, 2012		32,345
Net income	55,653				55,653
Dividend payment	(45,922)				(45,922)
Foreign currency translation	4,904					$ 4,904
Tax benefit (deficiency) associated with share-based payments	(1,165)			(1,165)
Exercise of stock options (in shares)		206
Exercise of stock options	468			468
Repurchase of common stock (in shares)		(268)
Repurchase of common stock	(1,565)		(1,565)
Non-cash share based compensation expense	6,163			6,163
Activity related to non-vested shares (in shares)		(68)
Activity related to non-vested shares	(808)			(808)
Ending Balance at Dec. 31, 2013	116,821	$ 32	(51,668)	203,989	(35,532)
Ending Balance (in shares) at Dec. 31, 2013		32,215
Net income	38,523				38,523
Dividend payment	(14,940)				(14,940)
Tax benefit (deficiency) associated with share-based payments	$ (1,992)			(1,992)
Exercise of stock options (in shares)	1,096	1,096
Exercise of stock options	$ 12,476	$ 1		12,475
Non-cash share based compensation expense	4,269			4,269
Activity related to non-vested shares (in shares)		147
Activity related to non-vested shares	(1,113)			(1,113)
Ending Balance at Dec. 31, 2014	$ 154,044	$ 33	(51,668)	217,628	(11,949)
Ending Balance (in shares) at Dec. 31, 2014	33,458	33,458
Net income	$ 38,129				38,129
Dividend payment	(20,187)				(20,187)
Tax benefit (deficiency) associated with share-based payments	$ 1,601			1,601
Exercise of stock options (in shares)	320	320
Exercise of stock options	$ 2,211	$ 1		2,210
Non-cash share based compensation expense	5,222			5,222
Activity related to non-vested shares (in shares)		113
Activity related to non-vested shares	(1,187)			(1,187)
Ending Balance at Dec. 31, 2015	$ 179,833	$ 34	$ (51,668)	$ 225,474	$ 5,993
Ending Balance (in shares) at Dec. 31, 2015	33,458	33,891

Consolidated Statements of Cash

Consolidated Statements of Cash Flows - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Operating
Net income	$ 38,129	$ 38,523	$ 55,653
Adjustments to reconcile net income to net cash flows provided by operating activities:
Depreciation and amortization	11,392	11,817	15,894
Deferred income taxes	3,061	8	(2,295)
(Gain) loss on sale of property and equipment	(110)	(60)	458
Loss (gain) on sale of Americas data assets		1,081	(28,791)
Gain on settlement of Tinet escrow	(1,290)
Loss on sale of discontinued operations			4,837
Non-cash share-based compensation	5,222	4,269	6,163
Gain on intercompany foreign exchange transactions			56
Provision for uncollectible accounts	197	1,925	900
Excess tax benefit associated with share-based payments	(1,852)	(1,090)	(262)
Changes in assets and liabilities:
Receivables	(7,020)	(12,491)	4,281
Other current assets	(6,095)	(247)	180
Other noncurrent assets	(68)	2,614	199
Accounts payable	146	(175)	(3,830)
Accrued liabilities	6,163	(5,716)	3,922
Net cash provided by operating activities	47,875	40,458	57,365
Investing
Purchase of property and equipment	(26,439)	(10,090)	(12,470)
Proceeds from sale of property and equipment	188	72	28
Sale of other investments			534
Proceeds from sale of discontinued operations, net of transaction costs			42,587
Proceeds from sale of Americas data assets, net of transaction costs			4,203
(Increase) decrease in restricted cash		(220)	837
Net cash (used for) provided by investing activities	(26,251)	(10,238)	35,719
Financing
Proceeds from the exercise of stock options	2,211	12,476	468
Restricted shares withheld to cover employee taxes paid	(1,187)	(1,113)	(808)
Dividends paid	(20,187)	(14,940)	(45,922)
Payments made for repurchase of common stock			(1,565)
Excess tax benefit associated with share-based payments	1,852	1,090	262
Net cash used for financing activities	(17,311)	(2,487)	(47,565)
Effect of exchange rate changes on cash			6
Net increase in cash and cash equivalents	4,313	27,733	45,525
Cash and cash equivalents — Beginning	104,737	77,004	31,479
Cash and cash equivalents — Ending	109,050	104,737	77,004
Supplemental disclosure of cash flow information:
Cash paid for taxes	24,477	25,759	12,695
Supplemental disclosure of noncash flow items:
Investing activity — Accrued purchases of property and equipment	$ 19	$ 1,348	$ 1,742

DESCRIPTION OF THE BUSINESS

DESCRIPTION OF THE BUSINESS	12 Months Ended
	Dec. 31, 2015
Business Combinations [Abstract]
DESCRIPTION OF THE BUSINESS	1. DESCRIPTION OF THE BUSINESS Organization —Inteliquent, Inc. (the “Company”) provides voice telecommunications services primarily on a wholesale basis. The Company offers these services using an all-IP network, which enables the Company to deliver global connectivity for a variety of media, including voice and, historically, data and video. The Company’s solutions enable carriers and other providers to deliver voice traffic or other services where they do not have their own network or elect not to use their own network. These solutions are sometimes called “off-net” services. We also provide our solutions to customers, such as OTT providers, who also typically do not have their own network. On April 30, 2013, the Company sold its global data business to Global Telecom & Technology, Inc. (GTT) for $54.5 million, subject to certain adjustments. The total consideration consisted of $52.5 million in cash, subject to net working capital adjustments, and $2.0 million of non-cash commercial IP Transit and point-to-point Ethernet data network services to be provided to the Company by GTT free-of-charge for a three-year period. The $2.0 million of non-cash commercial services was calculated based upon the discounted present value of the market cost of such services as of the date on which the commercial services agreement was signed with GTT. In addition, the Company recorded in its 2013 consolidated statement of operations, as part of its gain amount on the sale of its global data business, approximately $2.4 million for divestiture-related costs, including legal and advisory services. Refer to Note 3 “Business Disposition” for a description of the sale of our global data business. During the three months ended March 31, 2015, the Company received a $1.3 million payment from an escrow fund that had been established in connection with the Company’s purchase of the Tinet global data business in 2010. The Company received this payment as a result of a settlement with the sellers of Tinet. The settlement related to a dispute regarding the Company’s claim that certain tax liabilities were not properly represented to the Company at the time the transaction closed. This payment was recorded as other income in the Company’s Consolidated Statements of Income for year ended December 31, 2015 and as an operating cash inflow in the Consolidated Statements of Cash Flows for the year ended December 31, 2015.

SUMMARY OF SIGNIFICANT ACCOUNTI

SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES	12 Months Ended
	Dec. 31, 2015
Accounting Policies [Abstract]
SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES	2. SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES Principles of Consolidation —The consolidated financial statements include the accounts of the Company and its wholly owned subsidiaries. All intercompany balances and transactions have been eliminated in consolidation. Changes in Presentation —On April 30, 2013, the Company sold its global data business to GTT for $54.5 million, subject to certain adjustments. The Company determined that the appropriate level in which to assess discontinued operations was at its reporting unit level. As such, the Company’s Europe, Middle East and Africa (EMEA) and Asia Pacific (APAC) reporting units of the global data business consist of results of operations and cash flows that can be clearly distinguished from the rest of the entity and are therefore reflected in the consolidated statements of operations and in the consolidated balance sheets as discontinued operations. Historical information related to these reporting units have been reclassified accordingly. The Americas reporting unit of the global data business does not consist of results of operations and cash flows that can be clearly distinguished, operationally and for financial reporting purposes, from the rest of the entity. This reporting unit does not qualify for discontinued operations accounting treatment. Therefore, the Americas reporting unit of the global data business is reported in continuing operations in the consolidated statements of operations and in the consolidated balance sheets. Refer to Note 3 “Business Disposition” in the Notes to Consolidated Financial Statements of this Annual Report on Form 10-K for more information regarding the sale of the global data business. Use of Estimates —The Company’s consolidated financial statements are prepared in accordance with accounting principles generally accepted in the United States of America. These accounting principles require management to make certain estimates and assumptions that can affect the reported amounts of assets and liabilities and disclosure of contingent liabilities at the date of the consolidated financial statements, as well as the reported amounts of revenues and expenses during the periods presented. The Company believes that the estimates and assumptions upon which it relies are reasonable based upon information available to it at the time that these estimates and assumptions are made. To the extent there are material differences between these estimates and actual results, the Company’s consolidated financial statements will be affected. Cash and Cash Equivalents —The Company considers all highly liquid investments with an original maturity of 90 days or less to be cash equivalents. The carrying values of our cash and cash equivalents approximate fair value. At December 31, 2015, the Company had $22.2 million of cash in banks and $86.9 million in three money market funds. At December 31, 2014, the Company had $32.9 million of cash in banks and $71.8 million in three money market funds. Fair Value Measurements —Certain assets and liabilities are required to be recorded at fair value on a recurring basis. Fair value is determined based on the exchange price that would be received for an asset or paid to transfer a liability (an exit price) in the principal or most advantageous market for the asset or liability in an orderly transaction between market participants. Assets measured at fair value on a nonrecurring basis include long-lived assets held and used. The fair value of cash and cash equivalents, accounts receivable, accounts payable and accrued liabilities approximate their carrying values. The three-tier value hierarchy, which prioritizes valuation methodologies based on the reliability of the inputs, is: Level 1—Valuations based on quoted prices for identical assets and liabilities in active markets. Level 2—Valuations based on observable inputs other than quoted prices included in Level 1, such as quoted prices for similar assets and liabilities in active markets, quoted prices for identical or similar assets and liabilities in markets that are not active, or other inputs that are observable or can be corroborated by observable market data. Level 3—Valuations based on unobservable inputs reflecting the Company’s own assumptions, consistent with reasonably available assumptions made by other market participants. Accounts Receivable and Allowance for Doubtful Accounts —Accounts receivable consist of trade receivables recorded upon recognition of revenue from sales of voice services, reduced by reserves for estimated bad debts. Trade accounts receivable are generally recorded at the invoiced amount and do not bear interest. Credit is extended based on evaluation of the customer’s financial condition. We make judgments as to our ability to collect outstanding receivables and provide allowances for a portion of receivables when collection becomes doubtful. The specific identification method is applied to all significant outstanding invoices to determine this provision. At December 31, 2015 and December 31, 2014, our allowance for doubtful accounts was $2.4 million and $2.3 million, respectively. Property and Equipment — Property and equipment is recorded at cost. These values are depreciated over the estimated useful lives of the individual assets using the straight-line method. Any gains and losses from the disposition of property and equipment are included in operations as incurred. The estimated useful life for network equipment, wireless equipment and tools and test equipment is five years. The estimated useful life for computer equipment, computer software and furniture and fixtures is three years. Leasehold improvements are amortized on a straight-line basis over an estimated useful life of five years or the life of the lease, whichever is less. As discussed in further detail below, the impairment of long-lived assets is evaluated when events or changes in circumstances indicate that a potential impairment has occurred. Long-lived Assets —The carrying value of long-lived assets, including property and equipment, are reviewed whenever events or changes in circumstances indicate that the related carrying amounts may not be recoverable. Impairment of assets with definite lives is generally determined by comparing projected undiscounted cash flows to be generated by the asset, or appropriate grouping of assets, to its carrying value. If an impairment is identified, a loss is recorded equal to the excess of the asset’s net book value over its fair value. The fair value becomes the new cost basis of the asset. Determining the extent of an impairment, if any, typically requires various estimates and assumptions including using management’s judgment, cash flows directly attributable to the asset, the useful life of the asset and residual value, if any. In addition, the remaining useful life of the impaired asset is revised, if necessary. There were no property and equipment impairment charges in 2015, 2014 or 2013. Revenue Recognition — The Company generates revenue from sales of its voice services. The Company maintains tariffs and executed service agreements with each of its customers in which specific fees and rates are determined. One customer agreement contains multiple voice service elements and is accounted for as a multiple-element arrangement under ASC topic 605-25, Revenue Recognition-Multiple Element Arrangements. Following the requirements of ASC 605-25, the Company evaluated the multiple-element arrangement to determine which deliverables represented separate units of accounting and then allocated consideration to each unit of accounting based on their selling prices using relative fair values. Some of these deliverables are treated as non-monetary transactions which are also recorded at fair value. Voice revenue is recorded each month on an accrual basis, when collection is probable, based upon minutes of traffic switched by the Company’s network by each customer, which is referred to as minutes of use. Prior to the sale of the Company’s global data business in April 2013, IP Transit and Ethernet services revenues that related to the Company’s Americas reporting were recorded each month on an accrual basis based upon bandwidth used by each customer. The rates charged were the total of a monthly fee for bandwidth (the Committed Traffic Rate) plus additional charges for the sustained peak bandwidth used monthly in excess of the Committed Traffic Rate. Earnings (Loss) Per Share —Basic earnings (loss) per share is computed based on the weighted average number of common shares and participating securities outstanding. Diluted earnings (loss) per share is computed based on the weighted average number of common shares and participating securities outstanding adjusted by the number of additional shares that would have been outstanding during the period had the potentially dilutive securities been issued. The following table presents a reconciliation of the numerators and denominators of basic and diluted earnings (loss) per share of common stock: Years Ended December 31, (In thousands, except per share amounts) 2015 2014 2013 Numerator: Income from continuing operations $ 38,129 $ 38,523 $ 64,298 Loss from discontinued operations, net of provision for income taxes — — (3,808 ) Loss on sale of discontinued operations, net of provision for income taxes — — (4,837 ) Net income $ 38,129 $ 38,523 $ 55,653 Denominator: Weighted average common shares outstanding 33,633 32,887 32,306 Effect of dilutive securities: Stock options and performance stock units 437 497 251 Denominator for diluted earnings per share 34,070 33,384 32,557 Earnings per share - continuing operations: Basic $ 1.13 $ 1.17 $ 1.99 Diluted $ 1.12 $ 1.15 $ 1.97 Loss per share - discontinued operations: Basic $ — $ — $ (0.27 ) Diluted $ — $ — $ (0.27 ) Earnings per share - net income: Basic $ 1.13 $ 1.17 $ 1.72 Diluted $ 1.12 $ 1.15 $ 1.71 Share-based awards of 0.7 million, 0.6 million, and 2.4 million were outstanding during the years ended December 31, 2015, 2014 and 2013, respectively, but were not included in the computation of diluted earnings per share because the effect would have been anti-dilutive. For the years ended December 31, 2015, 2014 and 2013, the undistributed earnings allocable to participating securities were $0.2 million, $0.3 million, and $0.2 million, respectively. Accounting for Share-Based Payments —The Company records stock-based compensation expense related to stock options, non-vested shares and performance stock units based on fair value. The amount of non-cash share-based expense recorded in the years ended December 31, 2015, 2014 and 2013 was $5.2 million, $4.3 million, and $6.2 million, respectively. Refer to Note 12, “Stock Options, Non-Vested Shares and Performance Stock Units” in the Notes to Consolidated Financial Statements of this Annual Report on Form 10-K for further details regarding the Company’s non-cash share-based compensation. The fair value of stock options is determined using the Black-Scholes valuation model. This model takes into account the exercise price of the stock option, the fair value of the common stock underlying the stock option as measured on the date of grant and an estimation of the volatility of the common stock underlying the stock option. Such value is recognized as expense over the service period, net of estimated forfeitures, using the straight-line method. The fair value of non-vested shares is measured based upon the quoted closing market price for the stock on the date of grant. The compensation cost is recognized on a straight-line basis over the vesting period. The fair value of each performance stock unit granted is estimated using a Monte Carlo pricing model. The Monte Carlo simulation model is based on a discounted cash flow approach, with the simulation of a large number of possible stock price outcomes for the Company’s stock and the applicable index. termination of an individual’s service prior to fulfilling the requisite service period will result in forfeiture of units and compensation cost will be reversed. The estimation of stock awards that will ultimately vest requires judgment, and to the extent actual results or updated estimates differ from the Company’s current estimates, such amounts will be recorded as a cumulative adjustment in the period estimates are revised. The Company considers many factors when estimating expected forfeitures, including types of awards, employee class and historical experience. Actual results, and future changes in estimates, may differ from the Company’s current estimates. Income Taxes —Deferred income tax assets and liabilities are recognized for future income tax consequences attributable to temporary differences between the financial statement carrying amounts of existing assets and liabilities and their respective income tax bases and for net operating loss and tax credit carryforwards. Deferred income tax assets and liabilities are measured using enacted tax rates expected to apply to taxable income in the years in which those temporary differences are expected to be recovered or settled. The effect on deferred income tax assets and liabilities of a change in income tax rates is recorded in earnings in the period of enactment. A valuation allowance is provided for deferred income tax assets when it is more likely than not that future tax benefits will not be realized. Deferred income tax assets are reviewed on a quarterly basis to determine if a valuation allowance is necessary based on current and historical performance, along with other relevant factors. The income tax provision includes United States federal, state and local income taxes and is based on pre-tax income or loss. In determining the estimated annual effective income tax rate, we analyze various factors, including projections of our annual earnings and taxing jurisdictions in which earnings will be generated, the impact of state and local income taxes and our ability to use tax credits and net operating loss carryforwards. The Company recognizes the benefits of uncertain tax positions taken or expected to be taken in tax returns in the provision for income taxes only for those positions that are more likely than not to be realized. The Company follows a two-step approach to recognizing and measuring uncertain tax positions. The first step is to evaluate the tax position for recognition by determining if the weight of available evidence indicates it is more likely than not that the position will be sustained on audit, including resolution of related appeals or litigation processes, if any. The second step is to measure the tax benefit as the largest amount that is more than 50% likely of being realized upon ultimate settlement. The Company considers many factors when evaluating and estimating our tax positions and tax benefits, which may require periodic adjustments and which may not accurately forecast actual outcomes. The Company’s policy is to include interest and penalties associated with income tax obligations in income tax expense. Foreign Currency Translation —As a result of the sale of global data business in April 2013, the Company is paid and makes payments in U.S. Dollars and is no longer exposed to any significant foreign currency risk. Concentrations —For the years ended 2015, 2014 and 2013, the aggregate revenue of four customers accounted for 77%, 73% and 65% of total revenue from continuing operations, respectively. At December 31, 2015 and 2014, the aggregate accounts receivable of four customers accounted for 79% and 77% of the Company’s total trade accounts receivable balance, respectively. In 2015, the Company had three customers in excess of ten percent of revenue, which were 31% , 26% and 14% of the Company’s total revenue from continuing operations. At December 31, 2015, the Company had two customers that in aggregate accounted for 69% of the Company’s accounts receivable balance. In 2014, the Company had two customers in excess of ten percent of revenue, which were 35% and 25% of the Company’s total revenue from continuing operations. At December 31, 2014, the Company had two customers that in aggregate accounted for 62% of the Company’s accounts receivable balance. In 2013, the Company had two customers in excess of ten percent of revenue, which were 34% and 20% of the Company’s total revenue from continuing operations. At December 31, 2013, the Company had two customers that in aggregate accounted for 61% of the Company’s accounts receivable balance. Recent Accounting Pronouncements — In May 2014, the Financial Accounting Standards Board (“FASB”) issued Accounting Standards Update (“ASU”) No. 2014-09, Revenue from Contracts with Customers , which outlines a single comprehensive model for entities to use in accounting for revenue arising from contracts with customers and supersedes most current revenue recognition guidance, including industry-specific guidance. The ASU is based on the principle that an entity should recognize revenue to depict the transfer of 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. The ASU also requires additional disclosure about the nature, amount, timing and uncertainty of revenue and cash flows arising from customer contracts, including significant judgments and changes in judgments and assets recognized from costs incurred to fulfill a contract. Entities have the option of using either a full retrospective or a modified retrospective approach for the adoption of the new standard. The ASU is effective for annual reporting periods beginning after December 15, 2017 and early adoption as of December 15, 2016 is permitted. The Company is currently assessing the impact of this standard on the Company’s financial position, results of operations and cash flows. In June 2015, the FASB issued ASU No. 2015-10, Technical Corrections and Improvements, and interim periods within those fiscal years, early adoption is permitted. In November 2015, the FASB issued ASU No. 2015-17, Balance Sheet Classification of Deferred Taxes No other new accounting pronouncement issued or effective during the fiscal year had or is expected to have a material impact on the consolidated financial statements.

BUSINESS DISPOSITION

BUSINESS DISPOSITION	12 Months Ended
	Dec. 31, 2015
Discontinued Operations And Disposal Groups [Abstract]
BUSINESS DISPOSITION	3. BUSINESS DISPOSITION On April 30, 2013, the Company sold its global data business to GTT and, as a result, no longer provides data services. The transaction consisted of the sale of the Americas, EMEA and APAC reporting units’ data assets and liabilities. The data activity associated with the EMEA and APAC reporting units is reflected in the consolidated statements of operations and in the consolidated balance sheets as discontinued operations. Historical information related to these reporting units has been reclassified accordingly. The Americas reporting unit of the global data business did not qualify for discontinued operations because it did not constitute a separate component of the Company. The data activity associated with the Americas reporting unit is reported in continuing operations in the consolidated statements of operations and consolidated balance sheets. The Company sold its global data business for $54.5 million, which consisted of $52.5 million in cash, subject to net working capital adjustments, and $2.0 million of non-cash commercial services to be provided by GTT to the Company over a three-year period. After an initial net working capital reduction of $3.3 million based on the balance sheet information as of March 31, 2013, the Company received $51.2 million of cash and non-cash services from GTT. Transaction costs and the additional net working capital adjustment, resulting from balance sheet changes during the month of April following the initial calculation, amounted to approximately $2.4 million and $1.0 million, respectively, reducing net cash and non-cash consideration to approximately $47.8 million. Of this amount, $43.5 million was allocated to the sale of the Americas reporting unit of the global data business and the remaining amount of $4.3 million was allocated to the EMEA and APAC reporting units of the global data business. The Company based its allocation of $47.8 million upon the relative percentage of the fair value of the Americas reporting unit and the EMEA and APAC reporting units, to the total fair value of these three reporting units combined. Subsequent to the date of sale, the Company and GTT disagreed over the amount of certain post-closing purchase price adjustment provisions in the agreement governing the sale of the Company’s global data business to GTT. GTT claimed that the Company owed GTT $3.8 million. The Company, however, believed that GTT owed the Company $1.1 million. During the three months ended March 31, 2014, the parties tentatively agreed to resolve their differences with respect to the post-closing adjustments to the purchase price in a manner that would require neither party to make a payment to the other and would waive all other claims. As a result of the tentative agreement, the Company reduced other assets by $1.1 million and charged $1.1 million to continuing operations within Loss on sale of Americas Data assets. During the three months ended September 30, 2014, the agreement was finalized. There were no accounting impacts as a result of the final agreement. Disposition Not Qualifying for Discontinued Operations The Americas reporting unit assets, which were sold as part of the sale of the global data business, had an approximate net book value of $14.7 million at the time of the sale. The purchase price allocation of $43.5 million for this portion of the global data business, less its net book basis of assets and liabilities yielded a gain from sale of $28.8 million. Discontinued Operations The net book basis of the assets and liabilities for the EMEA and APAC reporting units of the global data business at the date of sale was approximately $10.1 million. In addition, the Company was entitled to approximately $1.0 million of cash that remained with the EMEA and APAC reporting units of the global data business at the time of the transaction. The purchase price allocation of $4.3 million for this portion of the global data business plus the additional $1.0 million of cash yielded a loss on the sale from discontinued operations of $4.8 million. The following table displays summarized activity in the Company’s consolidated statements of operations for discontinued operations during the years ended December 31, 2015, 2014 and 2013. Years Ended December 31, 2015 2014 2013 Revenue $ — $ — $ 15,205 Operating loss — — (3,130 ) Loss before provision for income taxes — — (3,581 ) Provision for income tax — — 227 Loss from discontinued operations — — (3,808 ) Loss on sale of discontinued operations $ — $ — $ (4,837 ) The Company did not have any assets or liabilities related to its discontinued operations on its consolidated balance sheets as of December 31, 2015 or December 31, 2014.

PROPERTY AND EQUIPMENT

PROPERTY AND EQUIPMENT	12 Months Ended
	Dec. 31, 2015
Property Plant And Equipment [Abstract]
PROPERTY AND EQUIPMENT	4. PROPERTY AND EQUIPMENT Property and equipment as of December 31, 2015 and 2014 consist of the following: December 31, 2015 2014 Network equipment $ 59,439 $ 37,207 Computer software 5,617 3,546 Computer equipment 3,999 2,699 Tools and test equipment 488 450 Furniture and fixtures 644 352 Leasehold improvements 1,842 1,533 Wireless equipment — 6 72,029 45,793 Less accumulated depreciation (36,779 ) (26,431 ) 35,250 19,362 Construction in process 2,086 4,316 Property and equipment-net $ 37,336 $ 23,678 The carrying value of long-lived assets are reviewed whenever events or changes in circumstances indicate that the related carrying amounts may not be recoverable.

RECEIVABLES

RECEIVABLES	12 Months Ended
	Dec. 31, 2015
Receivables [Abstract]
RECEIVABLES	5. RECEIVABLES Receivables as of December 31, 2015 and 2014 consist of the following: December 31, 2015 2014 Receivables $ 41,954 $ 35,102 Less allowance for doubtful accounts (2,365 ) (2,336 ) Receivables—net of allowance for doubtful accounts $ 39,589 $ 32,766 The increase in receivables as of December 31, 2015 is due to the growth of revenues in 2015. The allowance for doubtful accounts balance as of December 31, 2015 remains relatively unchanged from the prior year end and consists of reserves established from an ongoing dispute with certain long-distance carriers that have challenged the validity of certain switched access charges.

FAIR VALUE MEASUREMENT

FAIR VALUE MEASUREMENT	12 Months Ended
	Dec. 31, 2015
Fair Value Disclosures [Abstract]
FAIR VALUE MEASUREMENT	6. FAIR VALUE MEASUREMENT The Company’s investment in three money market funds is recognized and disclosed at fair value in the financial statements on a recurring basis. Fair value is defined as the price that would be received to sell an asset in an orderly transaction between market participants as of the measurement date. Fair value is measured using the fair value hierarchy and related valuation methodologies as defined in the authoritative literature. This guidance specifies a hierarchy of valuation techniques based on whether the inputs to each measurement are observable or unobservable. Observable inputs reflect market data obtained from independent sources, while unobservable inputs reflect the Company’s assumptions about current market conditions. The prescribed fair value hierarchy and related valuation methodologies are as follows: Level 1 —Quoted prices for identical instruments in active markets. Level 2 —Quoted prices for similar instruments in active markets, quoted prices for identical or similar instruments in markets that are not active and model-derived valuations, in which all significant inputs are observable in active markets. Level 3 —Valuations derived from valuation techniques, in which one or more significant inputs are unobservable. The fair value of the Company’s financial assets by level in the fair value hierarchy as of December 31, 2015 and 2014 was as follows: December 31, 2015 Level 1 Level 2 Level 3 Total Assets: Money Market Funds $ 86,871 $ — $ — $ 86,871 December 31, 2014 Level 1 Level 2 Level 3 Total Assets: Money Market Funds $ 71,836 $ — $ — $ 71,836 Valuation methodology Level 1—Quoted market prices in active markets are available for investments in money market funds. As such, these investments are classified within Level 1.

401(k) SAVINGS PLAN

401(k) SAVINGS PLAN	12 Months Ended
	Dec. 31, 2015
Compensation And Retirement Disclosure [Abstract]
401(k) SAVINGS PLAN	7. 401(k) SAVINGS PLAN The Company sponsors a 401(k) plan covering substantially all United States employees. The plan is a defined contribution savings plan in which employees may contribute up to 87% of their salary, subject to certain limitations. The Company may elect to make discretionary contributions into the Plan. The Company contributed $0.5 million to this plan during each of the years ended December 31, 2015, 2014 and 2013.

COMMON STOCK

COMMON STOCK	12 Months Ended
	Dec. 31, 2015
Equity [Abstract]
COMMON STOCK	8. COMMON STOCK The Company’s total authorized capital stock consists of 150,000,000 shares of common stock, par value $0.001 per share. Voting —Each holder of common stock has one vote in respect to each share of stock held on record for the election of directors and on all matters submitted to a vote of shareholders of the Company. Dividends —Subject to the preferential rights of any outstanding preferred stock, the holders of shares of common stock are entitled to receive, when and if declared by the Board of Directors, out of assets of the Company which are by law available therefore, dividends payable either in cash, in property or in shares of capital stock. On May 29, 2013, the Company declared a special cash dividend of $1.25 per outstanding share of common stock, or $40.5 million in the aggregate, which was paid on June 28, 2013 (the 2013 Special Dividend). In addition, beginning on May 29, 2013 the Company began the declaration of regular quarterly dividends. The table below summarizes the regular quarterly dividends declared and paid during the years ended December 31, 2015, 2014 and 2013: (quarter ended) Dividend Per Share Date Declared Date Paid June 30, 2013 $ 0.0625 05/29/13 06/24/13 September 30, 2013 $ 0.0625 08/27/13 09/27/13 December 31, 2013 $ 0.0625 12/04/13 12/30/13 March 31, 2014 $ 0.075 02/27/14 03/27/14 June 30, 2014 $ 0.075 05/21/14 06/26/14 September 30, 2014 $ 0.15 08/13/14 09/24/14 December 31, 2014 $ 0.15 11/10/14 12/08/14 March 31, 2015 $ 0.15 02/12/15 03/12/15 June 30, 2015 $ 0.15 05/11/15 06/08/15 September 30, 2015 $ 0.15 08/10/15 09/07/15 December 31, 2015 $ 0.15 11/11/15 12/09/15 In 2013 the Company paid $6.0 million as a result of regular quarterly dividends. Total 2013 aggregate dividend payments, inclusive of a special cash dividend and regular quarterly dividends, of $46.5 million includes $0.6 million related to the expected forfeitures of non-vested shares that the Company has recognized as compensation expense. In 2014, the Company paid $14.9 million as a result of regular quarterly dividends. There was no special cash dividend declared in 2014 and the expected forfeitures of non-vested shares that the Company has recognized as compensation expense was less than $0.1 million. In 2015, the Company paid $20.2 million as a result of regular quarterly dividends. There was no special cash dividend declared in 2015 and the expected forfeitures of non-vested shares that the Company has recognized as compensation expense was zero. Liquidation —In the event of any liquidation, dissolution or winding up of the Company, after distribution in full of the preferential amounts, if any, to be distributed to the holders of shares of any outstanding preferred stock, holders of all common stock shares, including converted preferred stock, are entitled to receive all of the remaining assets of the Company of whatever kind available for distribution to shareholders ratably in proportion to the number of shares of common stock held by them respectively.

COMMITMENTS AND CONTINGENCIES

COMMITMENTS AND CONTINGENCIES	12 Months Ended
	Dec. 31, 2015
Commitments And Contingencies Disclosure [Abstract]
COMMITMENTS AND CONTINGENCIES	9. COMMITMENTS AND CONTINGENCIES Operating Lease Obligations —The Company leases its facilities and certain equipment under operating leases which expire through March 2026. Rental expense was $4.3 million, $4.3 million and $5.2 million for each of the years ended December 2015, 2014 and 2013, respectively. The following table represents future lease payments under the operating leases: December 31, 2015 2016 $ 4,712 2017 4,684 2018 4,061 2019 3,975 2020 3,502 Thereafter 8,057 Total $ 28,991 Purchase Obligations – The Company has service agreements with certain major telecommunications service providers, where it has committed to purchase a minimum amount of services through September 2018. Additionally, the Company has contractual commitments with third parties to purchase network circuits through August 2020. In the event the Company was to terminate these circuit agreements before their expiration, early termination penalties would apply, for which the Company would be required to pay. The following table below represents the minimum future purchase obligations. These amounts do not represent the Company’s entire anticipated purchases in the future, but represent only its estimate of those items for which the Company is committed . December 31, 2015 2016 $ 12,844 2017 3,781 2018 643 2019 74 2020 64 Total $ 17,406 Legal Proceedings —From time to time, the Company is a party to legal proceedings arising in the normal course of its business. Aside from the matters discussed below, the Company does not believe that it is a party to any pending legal action that could reasonably be expected to have a material adverse effect on its business or operating results, financial position or cash flows. OTT Access Charge Dispute On November 18, 2011, the FCC issued an order establishing, among other things, an intercarrier compensation framework for the exchange of switched access traffic. In its order, the FCC attempted to clarify the circumstances under which local exchange carriers are eligible to receive access charges when they deliver access traffic in partnership with entities that utilize VoIP technology. The FCC determined that, under certain circumstances, local exchange carriers are eligible to receive access charges when delivering access traffic in partnership with VoIP providers. The FCC has referred to its determination on this issue as the “VoIP Symmetry Rule.” Subsequent to the FCC’s November 2011 order, further disputes developed within the industry concerning the interpretation of the VoIP Symmetry Rule. A number of long distance carriers took the position that, notwithstanding the VoIP Symmetry Rule, local exchange carriers were still not eligible to receive access charges when delivering access traffic in partnership with VoIP providers that deliver service using OTT technology. On February 11, 2015, the FCC released an order clarifying that, pursuant to its VoIP Symmetry Rule, local exchange carriers are entitled to receive access charges when delivering access traffic in partnership with VoIP providers that utilize OTT technology under certain circumstances. This order has been appealed to a federal appellate court. The Company has disputes with several long distance carriers regarding the payment of access charges to the Company relating to the origination and termination of traffic to VoIP providers that utilize OTT technology. The Company has made judgments as to its ability to collect based on known facts and circumstances and has only recorded revenue when collection has been deemed reasonably assured.

CREDIT FACILITY

CREDIT FACILITY	12 Months Ended
	Dec. 31, 2015
Debt Disclosure [Abstract]
CREDIT FACILITY	1 0 . CREDIT FACILITY On March 5, 2013, the Company entered into a $15.0 million revolving credit facility. The credit facility has a term of three years and an interest rate of LIBOR + 3.25%. The Company may borrow under the revolving credit facility and use the funds for general corporate purposes. There were no obligations outstanding under the revolving credit facility at any time during the year ended December 31, 2015. As of December 31, 2015, the Company is in compliance with all of the covenants of the credit facility agreement.

INCOME TAXES

INCOME TAXES	12 Months Ended
	Dec. 31, 2015
Income Tax Disclosure [Abstract]
INCOME TAXES	1 1 . INCOME TAXES Income before provision for income taxes, and the related provision for income taxes, for the years ended December 31 2015, 2014 and 2013, were as follows: Years Ended December 31, 2015 2014 2013 Income before provision for income taxes $ 60,701 $ 63,226 $ 77,822 Provision for income taxes Current: Federal $ 17,241 $ 21,728 $ 15,391 State 2,270 2,967 428 Total current 19,511 24,695 15,819 Deferred (prepaid): Federal 3,027 (200 ) (1,713 ) State 34 208 (582 ) Total deferred (prepaid) 3,061 8 (2,295 ) Total provision for income taxes $ 22,572 $ 24,703 $ 13,524 The Company’s effective income tax rate was 37.2% for the year ended December 31, 2015, compared to 39.1% for the year ended December 31, 2014. This difference in rates results primarily due to a true up to the impact of the sale of the global data business during the year ended December 31, 2014 and a reassessment of the recoverability of the deferred tax assets for Illinois EDGE and R&D credits. The change in the effective tax rate of 39.1% for the year ended December 31, 2014 compared to 17.4% for the year ended December 31, 2013 was due to the sale of the global data business during the year ended December 31, 2013. A reconciliation of the federal statutory rate to our effective tax rate is as follows: December 31, 2015 2014 2013 Statutory federal rate 35.0 % 35.0 % 35.0 % State income tax, net of federal benefit 2.8 % 3.4 % 3.2 % Illinois state EDGE credit net of valuation allowance (0.4 )% (0.2 )% (1.0 )% Impact of sale of global data business — 0.7 % (15.5 )% Americas Data assets allocation — — (4.7 )% Other (0.2 )% 0.2 % 0.4 % Effective income tax rate 37.2 % 39.1 % 17.4 % Deferred income taxes reflect the net tax effects of temporary differences between the carrying amount of assets and liabilities for financial reporting purposes and the amounts used for income tax purposes. Effective December 31, 2015, the Company reclassified net current deferred tax assets to net non-current deferred tax assets as described in Note 2 “Summary of Significant Accounting Policies-Recent Accounting Pronouncements.” Significant components of the Company’s deferred income taxes are as follows: December 31, 2015 2014 Deferred tax assets and liabilities Deferred tax assets: Stock option compensation $ 5,313 $ 5,232 State credit carry forward 1,725 2,380 Capital loss on sale of Tinet stock 21,531 21,580 Accrued other 3,320 3,075 Total deferred tax assets 31,889 32,267 Deferred tax liabilities: Depreciation (7,102 ) (3,898 ) Prepaids (1,008 ) (732 ) Total deferred tax liabilities (8,110 ) (4,630 ) Valuation allowance (22,720 ) (23,517 ) Net deferred income tax asset $ 1,059 $ 4,120 The Company evaluates its deferred income taxes quarterly to determine if a valuation allowance is required or should be adjusted. The Company assesses whether a valuation allowance should be established against deferred tax assets based upon consideration of all available evidence, both positive and negative, using a more likely than not standard. This assessment considers, among other matters, forecasts of future profitability, the duration of statutory carry-forward periods, the Company’s experience with tax attributes expiring unused and tax planning strategies. In making such judgments, significant weight is given to evidence that can be objectively verified. A valuation allowance has been established against the deferred tax asset resulting from the sale of Tinet stock and a partial valuation allowance has been established against the deferred income tax asset related to the Illinois EDGE and R&D credits. The valuation allowance of $21.5 million was established for the deferred tax asset related to the capital loss from the sale of Tinet stock after weighing all available evidence, both positive and negative, including the potential for the Company to have sufficient capital gains to be offset by the capital losses during the five year carryforward period. The Company’s Illinois EDGE and R&D credits can also be carried forward five years. During the year ended December 31, 2015, the Company released $0.7 million of the valuation allowance related to the Illinois EDGE and R&D credits. The Company now has a partial valuation allowance of $1.2 million for the Illinois EDGE and R&D credits deferred income tax asset as the Company believes it is more likely than not that future taxable income will be insufficient to realize the full benefit of the credit. The Company files income tax returns in the U.S. federal jurisdiction, and various state and local jurisdictions. With few exceptions, the Company is no longer subject to U.S. federal, state and local income tax examinations by tax authorities for years before 2012. The Internal Revenue Service (“IRS”) has commenced an examination of the Company’s 2013 federal income tax return. As of December 31, 2015, the IRS has not proposed any material adjustments to such income tax return. Audit outcomes and timing of audit settlements are subject to significant uncertainty. It is reasonably possible that within the next twelve months, the Company will resolve any matters that may arise during the audit of the Company’s 2013 federal income tax return. The Company’s liabilities for uncertain tax positions were $0.1 million at December 31, 2015 and December 31, 2014, respectively. Differences result from uncertain tax positions related to the R&D credits earned for 2013, 2014 and 2015. A reconciliation of the beginning and ending amount of uncertain tax positions is as follows: 2015 2014 Balance at January 1 $ 75 $ 40 Increases related to prior periods 42 8 Increases related to current year 27 27 Lapse of statute of limitations (25 ) — Balance on December 31 $ 119 $ 75 The Company recognizes accrued interest and penalties related to its unrecognized tax benefits as income tax expense.

STOCK OPTIONS, NON-VESTED SHARE

STOCK OPTIONS, NON-VESTED SHARES AND PERFORMANCE STOCK UNITS	12 Months Ended
	Dec. 31, 2015
Disclosure Of Compensation Related Costs Sharebased Payments [Abstract]
STOCK OPTIONS AND NON-VESTED SHARES	1 2 . STOCK OPTIONS, NON-VESTED SHARES AND PERFORMANCE STOCK UNITS The Company established the 2003 Stock Option and Stock Incentive Plan (2003 Plan), which provided for issuance of up to 4.7 million options, non-vested shares and performance stock units to directors, employees, and other individuals (whether or not employees) who render services to the Company. In 2007 the Company adopted the Neutral Tandem, Inc. 2007 Long-Term Equity Incentive Plan (2007 Plan) and ceased awarding equity grants under the 2003 plan. As of December 31, 2015, the Company had granted a total of 1.4 million options, 0.3 million non-vested shares and 0.1 million performance stock units that remained outstanding under the 2007 Plan. Awards for 2.1 million shares, representing approximately 6.2% of the Company’s outstanding common stock as of December 31, 2015, remained available for additional grants under the 2007 Plan. In connection with the 2013 Special Dividend, to compensate holders of outstanding options for the reduction in the Company’s stock price that resulted from the payment of the 2013 Special Dividend, the Company’s Compensation Committee approved (i) an adjustment to the exercise price of outstanding options, subject to the limitations of Section 409A of the Internal Revenue Code, and (ii) the issuance of non-vested shares (available for issuance under the 2007 Plan) to holders of outstanding options with exercise prices that could not be fully adjusted because of the limitations of Section 409A of the Internal Revenue Code. The effect of the exercise price adjustment and the issuance of non-vested shares, taken together, was to provide each optionholder with the same economic value after the time that the Company’s common stock began trading ex-dividend as such optionholder had immediately prior to such time. As a result of these adjustments, the exercise price of the 3.5 million outstanding options under the Plans was reduced by an average of $1.08 per option, and the Company issued 0.1 million non-vested shares under the 2007 Plan to make optionholders whole. In 2012, the 2003 Plan was amended in connection with the 2012 Special Dividend to provide that, in order to prevent an extraordinary cash dividend like the 2012 Special Dividend from diluting the rights of optionholders, the Company’s Compensation Committee shall have the discretion to reduce the exercise price of outstanding options so long as any such adjustment does not increase the intrinsic value of any such option, as measured prior to the ex-dividend date of such extraordinary cash dividend. As a result of the amendment, the Company recognized $0.3 million of non-cash share-based compensation expense in 2013 in connection with 2013 Special Dividend. The options under the 2007 Plan were modified by the mandated antidilutive provisions contained in the 2007 Plan, and as a result, no additional non-cash share-based compensation expense was required to be recognized. The Company records share-based compensation expense in connection with any grant of options, non-vested shares and performance stock units. The Company calculates the expense associated with each award by determining the fair value of the options, non-vested shares and performance stock unit as described in Note 2 “Summary of Significant Accounting Policies- Accounting for Share-Based Payments.” Options All options granted under the 2003 Plan and the 2007 Plan have an exercise price equal to the market value of the underlying common stock on the date of the grant. During the years ended December 31, 2015 and 2014, the Company granted 0.1 million and less than 0.1 million options at a weighted-average exercise price of $17.02 and $13.86, respectively. The fair value of each option granted is estimated on the date of grant using the Black-Scholes option pricing model. For the years ended December 31, 2015, 2014 and 2013, fair value of stock options was measured using the following assumptions: Years Ended December 31, 2015 2014 2013 Expected life 7.0 years 7.2 years 7.3 years Risk-free interest rate 1.9% 2.1% 1.3% Expected dividends 3.7% 2.1% 0.0% Volatility 49.6% 60.0% 45.0% The weighted-average fair value of options granted, as determined by using the Black-Scholes valuation model, during the period was $6.03, $6.90 and $1.64 for the years ended December 31, 2015, 2014 and 2013, respectively. The total grant date fair value of options that vested during years ended December 31, 2015, 2014 and 2013 was approximately $0.6 million, $1.1 million and $2.4 million, respectively. The total intrinsic value (market value of stock less option exercise price) of stock options exercised was $4.3 million, $4.5 million and $0.9 million during the years ended December 31, 2015, 2014 and 2013, respectively. The following summarizes activity under the Company’s stock option plan: Weighted Aggregate Weighted Average Intrinsic Average Shares Exercise Value Remaining (000) Price ($000) Term (yrs) Options outstanding — December 31, 2013 2,991 $ 12.91 Granted 41 13.86 Exercised (1,096 ) 11.43 Cancelled (221 ) 20.08 Options outstanding — December 31, 2014 1,715 $ 12.97 Granted 124 17.02 Exercised (320 ) 6.90 Cancelled (89 ) 5.48 Options outstanding — December 31, 2015 1,430 $ 15.10 $ 5,953 4.04 Vested or expected to vest — December 31, 2015 1,425 $ 15.10 $ 5,935 4.02 Exercisable — December 31, 2015 1,148 $ 16.44 $ 3,628 3.12 The unrecognized compensation cost associated with options outstanding at December 31, 2015 is $0.8 million. The weighted average remaining term that the compensation will be recorded is 2.7 years as of December 31, 2015. Non-vested Shares During both the years ended December 31, 2015 and 2014, the Company’s Board of Directors granted approximately 0.2 million non-vested shares. The non-vested shares were issued as part of the 2007 Plan. The shares typically vest over a four-year period. The fair value of the non-vested shares is determined using the Company’s closing stock price on the grant date. Compensation cost, measured using the grant date fair value, is recognized over the requisite service period on a straight-line basis. A summary of the Company’s non-vested share activity and related information for the years ended December 31, 2015 and 2014 is as follows: Weighted Aggregate Average Intrinsic Shares Grant Date Value (000) Fair Value ($000) Non-vested shares outstanding — December 31, 2013 477 $ 9.66 Granted 226 13.04 Vested (307 ) 10.59 Cancelled — — Non-vested shares outstanding — December 31, 2014 396 $ 10.87 Granted 188 17.19 Vested (241 ) 12.02 Cancelled (9 ) 4.30 Non-vested shares outstanding — December 31, 2015 334 $ 13.77 $ 5,935 Non-vested shares vested or expected to vest —December 31, 2015 325 $ 13.74 $ 5,775 The aggregate intrinsic value represents the total pre-tax intrinsic value based on the Company’s closing stock price of $17.77 on December 31, 2015. The amount changes based upon the fair market value of the Company’s common stock. The unrecognized compensation cost associated with non-vested shares at December 31, 2015 was $3.0 million. The weighted average remaining term that the compensation will be recorded is 2.3 years as of December 31, 2015. Performance Stock Units During the year ended December 31, 2015, the Company awarded 0.1 million performance stock units. These performance stock units represent a target number of shares (“Target Award”) of the Company’s common stock that the recipient would receive upon the Company’s attainment of the applicable performance goal. These performance stock units were issued in three tranches under the 2007 Plan. Performance is determined based on total shareholder return (“TSR”) during an 18-month, two- and three-year performance period for each of the three tranches, respectively. At the end of the performance period, the performance stock units will be distributed (to the extent earned and vested) in shares of the Company’s common stock based upon the level of achievement of the Company’s TSR performance targets set for the performance periods. Awards are payable on a graduated basis based on thresholds that measure the Company's performance relative to peers that comprise the applicable index on which each years' awards are measured. Awards can be paid up to 200% of the Target Award or forfeited with no payout if performance is below a minimum established performance threshold. In the event the participant’s employment is terminated without cause and more than half of the performance period has passed, the number of performance stock units issued shall be adjusted proportionately to the number of days of service rendered in the performance period over the total performance period. A summary of the Company’s performance stock unit activity and related information for the year ended December 31, 2015 is as follows: Performance Weighted Stock Average Units Grant Date (000) Fair Value Performance stock units outstanding — December 31, 2014 — $ — Granted 119 22.94 Vested (20 ) 21.73 Cancelled — — Performance stock units outstanding — December 31, 2015 99 $ 23.19 Each vested performance stock unit will be settled by delivery of common stock no later than March 15 of the calendar year following the calendar year in which the performance stock unit becomes vested. On December 31, 2015 the first tranche of performance stock units became vested and on February 8, 2016 these shares were settled as 30 thousand shares of common stock, based on the Company’s actual TSR achievement. The unrecognized compensation cost associated with performance stock units outstanding at December 31, 2015 was $1.6 million. The weighted average remaining term that the compensation will be recorded is 1.7 years as of December 31, 2015. Non-cash compensation expense of $5.2 million recorded during the year ended December 31, 2015 included $3.4 million related to non-vested restricted shares, $0.7 million related to options and $1.1 million related to performance stock units. Non-cash compensation expense of $4.3 million recorded during the year ended December 31, 2014 included $3.3 million related non-vested restricted shares and $1.0 million related to options. Non-cash compensation expense of $6.2 million recorded during the year ended December 31, 2013 included $2.4 million related to non-vested restricted shares and $3.8 million related to options.

SEGMENT AND GEOGRAPHIC INFORMAT

SEGMENT AND GEOGRAPHIC INFORMATION	12 Months Ended
	Dec. 31, 2015
Segment Reporting [Abstract]
SEGMENT AND GEOGRAPHIC INFORMATION	1 3 . SEGMENT AND GEOGRAPHIC INFORMATION Segment reporting establishes standards for reporting information about operating segments. Operating segments are defined as components of an enterprise about which separate financial information is available that is evaluated regularly by the chief operating decision maker, or decision making group, in deciding how to allocate resources and in assessing performance. The Company’s chief operating decision maker is the Chief Executive Officer. The Chief Executive Officer reviews financial information presented on a consolidated basis. The Company operates in one industry segment, which is to provide voice interconnection services via the Company’s telecommunications network to fulfill customer agreements. Therefore, the Company has concluded that it has one operating segment. The following is a summary of geographical information as of and for the year ended December 31, 2015, 2014 and 2013: Years Ended December 31, 2015 2014 2013 Revenue from external customers: United States of America $ 248,619 $ 220,508 $ 209,310 Other countries within Americas reporting unit — — 2,351 $ 248,619 $ 220,508 $ 211,661 Long-lived assets: United States of America $ 37,336 $ 23,678 $ 25,660 Other countries — — 155 $ 37,336 $ 23,678 $ 25,815 The Company includes property and equipment in its long-lived assets.

QUARTERLY FINANCIAL DATA (UNAUD

QUARTERLY FINANCIAL DATA (UNAUDITED)	12 Months Ended
	Dec. 31, 2015
Quarterly Financial Information Disclosure [Abstract]
QUARTERLY FINANCIAL DATA (UNAUDITED)	1 4 . QUARTERLY FINANCIAL DATA (UNAUDITED) 2015 1st 2nd 3rd 4th Operating Results: Revenue $ 55,054 $ 52,886 $ 63,716 $ 76,963 Operating expense: Network and facilities expense (excluding depreciation and amortization) 22,765 21,295 34,858 46,427 Operations 7,620 7,391 7,955 8,204 Sales and marketing 643 765 690 776 General and administrative 4,555 4,942 4,648 4,363 Depreciation and amortization 2,643 2,600 2,894 3,255 Loss (gain) on sale of property and equipment 33 (149 ) (4 ) 10 Total operating expense 38,259 36,844 51,041 63,035 Income from operations 16,795 16,042 12,675 13,928 Other (income) expense: Interest expense (income) 16 11 9 (7 ) Other income (1,290 ) — — — Total (income) other expense (1,274 ) 11 9 (7 ) Income before provision for income taxes 18,069 16,031 12,666 13,935 Provision for income taxes 6,887 6,031 4,399 5,255 Net income $ 11,182 $ 10,000 $ 8,267 $ 8,680 Per Share Data: Earnings per common share-net income-basic $ 0.33 $ 0.30 $ 0.25 $ 0.26 Earnings per common share-net income-diluted $ 0.33 $ 0.29 $ 0.24 $ 0.25 Weighted average number of shares outstanding-basic 33,496 33,568 33,620 33,843 Weighted average number of shares outstanding-diluted 33,970 34,033 34,138 34,213 2014 1st 2nd 3rd 4th Operating Results: Revenue $ 56,217 $ 54,881 $ 54,045 $ 55,365 Operating expense: Network and facilities expense (excluding depreciation and amortization) 24,890 23,129 23,016 23,960 Operations 7,307 7,202 7,432 7,355 Sales and marketing 676 818 1,048 722 General and administrative 3,800 5,254 3,645 4,141 Depreciation and amortization 3,141 3,010 2,985 2,681 (Gain) loss on sale of property and equipment — (31 ) 2 (31 ) Loss on sale of Americas Data assets 1,081 — — — Total operating expense 40,895 39,382 38,128 38,828 Income from operations 15,322 15,499 15,917 16,537 Other expense (income): Interest expense 2 17 18 14 Other (income) — (2 ) — — Total other expense 2 15 18 14 Income before provision for income taxes 15,320 15,484 15,899 16,523 Provision for income taxes 6,127 6,036 6,123 6,417 Net income $ 9,193 $ 9,448 $ 9,776 $ 10,106 Per Share Data: Earnings per common share-net income-basic $ 0.28 $ 0.29 $ 0.30 $ 0.30 Earnings per common share-net income-diluted $ 0.28 $ 0.28 $ 0.29 $ 0.30 Weighted average number of shares outstanding-basic 32,273 32,832 33,115 33,316 Weighted average number of shares outstanding-diluted 32,616 33,369 33,343 33,785

Schedule II_ Valuation and Qual

Schedule II: Valuation and Qualifying Accounts	12 Months Ended
	Dec. 31, 2015
Valuation And Qualifying Accounts [Abstract]
Schedule II: Valuation and Qualifying Accounts	Schedule II: Valuation and Qualifying Accounts The following table presents the valuation and qualifying account activity for the years ended December 31, 2015, 2014 and 2013: Balance at Charged to Balance at (In thousands) January 1, Earnings Used December 31, 2015 Allowance for doubtful accounts $ 2,336 $ 197 $ (168 ) $ 2,365 2014 Allowance for doubtful accounts $ 900 $ 1,925 $ (489 ) $ 2,336 2013 Allowance for doubtful accounts $ 423 $ 900 $ (423 ) $ 900 Schedules not listed above have been omitted because the information required to be set forth therein is not applicable or is shown in the consolidated financial statements or notes thereto. (a)(3) Exhibits. See Index to Exhibits. The Exhibits listed in the accompanying Index to Exhibits are filed or incorporated by reference as part of this Annual Report on Form 10-K. The agreements and other documents filed as exhibits to this report are not intended to provide factual information or other disclosure other than with respect to the terms of the agreements or other documents themselves and you should not rely on them for that purpose. In particular, any representations and warranties made by us in these agreements or other documents were made solely within the specific context of the relevant agreement or document and may not describe the actual state of affairs as of the date they were made or at any other time.

SUMMARY OF SIGNIFICANT ACCOUN23

SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES (Policies)	12 Months Ended
	Dec. 31, 2015
Accounting Policies [Abstract]
Principles of Consolidation	Principles of Consolidation — The consolidated financial statements include the accounts of the Company and its wholly owned subsidiaries. All intercompany balances and transactions have been eliminated in consolidation.
Changes in Presentation	Changes in Presentation —On April 30, 2013, the Company sold its global data business to GTT for $ 54.5 million, subject to certain adjustments. The Company determined that the appropriate level in which to assess discontinued operations was at its reporting unit level. As such, the Company’s Europe, Middle East and Africa (EMEA) and Asia Pacific (APAC) reporting units of the global data business consist of results of operations and cash flows that can be clearly distinguished from the rest of the entity and are therefore reflected in the consolidated statements of operations and in the consolidated balance sheets as discontinued operations. Historical information related to these reporting units have been reclassified accordingly. The Americas reporting unit of the global data business does not consist of results of operations and cash flows that can be clearly distinguished, operationally and for financial reporting purposes, from the rest of the entity. This reporting unit does not qualify for discontinued operations accounting treatment. Therefore, the Americas reporting unit of the global data business is reported in continuing operations in the consolidated statements of operations and in the consolidated balance sheets. Refer to Note 3 “Business Disposition” in the Notes to Consolidated Financial Statements of this Annual Report on Form 10-K for more information regarding the sale of the global data business.
Use of Estimates	Use of Estimates — The Company’s consolidated financial statements are prepared in accordance with accounting principles generally accepted in the United States of America. These accounting principles require management to make certain estimates and assumptions that can affect the reported amounts of assets and liabilities and disclosure of contingent liabilities at the date of the consolidated financial statements, as well as the reported amounts of revenues and expenses during the periods presented. The Company believes that the estimates and assumptions upon which it relies are reasonable based upon information available to it at the time that these estimates and assumptions are made. To the extent there are material differences between these estimates and actual results, the Company’s consolidated financial statements will be affected.
Cash and Cash Equivalents	Cash and Cash Equivalents —The Company considers all highly liquid investments with an original maturity of 90 days or less to be cash equivalents. The carrying values of our cash and cash equivalents approximate fair value. At December 31, 2015, the Company had $22.2 million of cash in banks and $86.9 million in three money market funds. At December 31, 2014, the Company had $32.9 million of cash in banks and $71.8 million in three money market funds.
Fair Value Measurements	Fair Value Measurements — Certain assets and liabilities are required to be recorded at fair value on a recurring basis. Fair value is determined based on the exchange price that would be received for an asset or paid to transfer a liability (an exit price) in the principal or most advantageous market for the asset or liability in an orderly transaction between market participants. Assets measured at fair value on a nonrecurring basis include long-lived assets held and used. The fair value of cash and cash equivalents, accounts receivable, accounts payable and accrued liabilities approximate their carrying values. The three-tier value hierarchy, which prioritizes valuation methodologies based on the reliability of the inputs, is: Level 1—Valuations based on quoted prices for identical assets and liabilities in active markets. Level 2—Valuations based on observable inputs other than quoted prices included in Level 1, such as quoted prices for similar assets and liabilities in active markets, quoted prices for identical or similar assets and liabilities in markets that are not active, or other inputs that are observable or can be corroborated by observable market data. Level 3—Valuations based on unobservable inputs reflecting the Company’s own assumptions, consistent with reasonably available assumptions made by other market participants.
Accounts Receivable and Allowance for Doubtful Accounts	Accounts Receivable and Allowance for Doubtful Accounts — Accounts receivable consist of trade receivables recorded upon recognition of revenue from sales of voice services, reduced by reserves for estimated bad debts. Trade accounts receivable are generally recorded at the invoiced amount and do not bear interest. Credit is extended based on evaluation of the customer’s financial condition. We make judgments as to our ability to collect outstanding receivables and provide allowances for a portion of receivables when collection becomes doubtful. The specific identification method is applied to all significant outstanding invoices to determine this provision. At December 31, 2015 and December 31, 2014, our allowance for doubtful accounts was $2.4 million and $2.3 million, respectively.
Property and Equipment	Property and Equipment — Property and equipment is recorded at cost. These values are depreciated over the estimated useful lives of the individual assets using the straight-line method. Any gains and losses from the disposition of property and equipment are included in operations as incurred. The estimated useful life for network equipment , wireless equipment and tools and test equipment is five years. The estimated useful life for computer equipment, computer software and furniture and fixtures is three years. Leasehold improvements are amortized on a straight-line basis over an estimated useful life of five years or the life of the lease, whichever is less. As discussed in further detail below, the impairment of long-lived assets is evaluated when events or changes in circumstances indicate that a potential impairment has occurred.
Long-lived Assets	Long-lived Assets — The carrying value of long-lived assets, including property and equipment, are reviewed whenever events or changes in circumstances indicate that the related carrying amounts may not be recoverable. Impairment of assets with definite lives is generally determined by comparing projected undiscounted cash flows to be generated by the asset, or appropriate grouping of assets, to its carrying value. If an impairment is identified, a loss is recorded equal to the excess of the asset’s net book value over its fair value. The fair value becomes the new cost basis of the asset. Determining the extent of an impairment, if any, typically requires various estimates and assumptions including using management’s judgment, cash flows directly attributable to the asset, the useful life of the asset and residual value, if any. In addition, the remaining useful life of the impaired asset is revised, if necessary. There were no property and equipment impairment charges in 2015, 2014 or 2013.
Revenue Recognition	Revenue Recognition — The Company generates revenue from sales of its voice services. The Company maintains tariffs and executed service agreements with each of its customers in which specific fees and rates are determined. One customer agreement contains multiple voice service elements and is accounted for as a multiple-element arrangement under ASC topic 605-25, Revenue Recognition-Multiple Element Arrangements. Following the requirements of ASC 605-25, the Company evaluated the multiple-element arrangement to determine which deliverables represented separate units of accounting and then allocated consideration to each unit of accounting based on their selling prices using relative fair values. Some of these deliverables are treated as non-monetary transactions which are also recorded at fair value. Voice revenue is recorded each month on an accrual basis, when collection is probable, based upon minutes of traffic switched by the Company’s network by each customer, which is referred to as minutes of use. Prior to the sale of the Company’s global data business in April 2013, IP Transit and Ethernet services revenues that related to the Company’s Americas reporting were recorded each month on an accrual basis based upon bandwidth used by each customer. The rates charged were the total of a monthly fee for bandwidth (the Committed Traffic Rate) plus additional charges for the sustained peak bandwidth used monthly in excess of the Committed Traffic Rate.
Earnings (Loss) Per Share	Earnings (Loss) Per Share —Basic earnings (loss) per share is computed based on the weighted average number of common shares and participating securities outstanding. Diluted earnings (loss) per share is computed based on the weighted average number of common shares and participating securities outstanding adjusted by the number of additional shares that would have been outstanding during the period had the potentially dilutive securities been issued. The following table presents a reconciliation of the numerators and denominators of basic and diluted earnings (loss) per share of common stock: Years Ended December 31, (In thousands, except per share amounts) 2015 2014 2013 Numerator: Income from continuing operations $ 38,129 $ 38,523 $ 64,298 Loss from discontinued operations, net of provision for income taxes — — (3,808 ) Loss on sale of discontinued operations, net of provision for income taxes — — (4,837 ) Net income $ 38,129 $ 38,523 $ 55,653 Denominator: Weighted average common shares outstanding 33,633 32,887 32,306 Effect of dilutive securities: Stock options and performance stock units 437 497 251 Denominator for diluted earnings per share 34,070 33,384 32,557 Earnings per share - continuing operations: Basic $ 1.13 $ 1.17 $ 1.99 Diluted $ 1.12 $ 1.15 $ 1.97 Loss per share - discontinued operations: Basic $ — $ — $ (0.27 ) Diluted $ — $ — $ (0.27 ) Earnings per share - net income: Basic $ 1.13 $ 1.17 $ 1.72 Diluted $ 1.12 $ 1.15 $ 1.71 Share-based awards of 0.7 million, 0.6 million, and 2.4 million were outstanding during the years ended December 31, 2015, 2014 and 2013, respectively, but were not included in the computation of diluted earnings per share because the effect would have been anti-dilutive. For the years ended December 31, 2015, 2014 and 2013, the undistributed earnings allocable to participating securities were $0.2 million, $0.3 million, and $0.2 million, respectively.
Accounting for Share-Based Payments	Accounting for Share-Based Payments — The Company records stock-based compensation expense related to stock options, non-vested shares and performance stock units based on fair value. The amount of non-cash share-based expense recorded in the years ended December 31, 2015, 2014 and 2013 was $5.2 million, $4.3 million, and $6.2 million, respectively. Refer to Note 12, “Stock Options, Non-Vested Shares and Performance Stock Units” in the Notes to Consolidated Financial Statements of this Annual Report on Form 10-K for further details regarding the Company’s non-cash share-based compensation. The fair value of stock options is determined using the Black-Scholes valuation model. This model takes into account the exercise price of the stock option, the fair value of the common stock underlying the stock option as measured on the date of grant and an estimation of the volatility of the common stock underlying the stock option. Such value is recognized as expense over the service period, net of estimated forfeitures, using the straight-line method. The fair value of non-vested shares is measured based upon the quoted closing market price for the stock on the date of grant. The compensation cost is recognized on a straight-line basis over the vesting period. The fair value of each performance stock unit granted is estimated using a Monte Carlo pricing model. The Monte Carlo simulation model is based on a discounted cash flow approach, with the simulation of a large number of possible stock price outcomes for the Company’s stock and the applicable index. termination of an individual’s service prior to fulfilling the requisite service period will result in forfeiture of units and compensation cost will be reversed. The estimation of stock awards that will ultimately vest requires judgment, and to the extent actual results or updated estimates differ from the Company’s current estimates, such amounts will be recorded as a cumulative adjustment in the period estimates are revised. The Company considers many factors when estimating expected forfeitures, including types of awards, employee class and historical experience. Actual results, and future changes in estimates, may differ from the Company’s current estimates.
Income Taxes	Income Taxes —Deferred income tax assets and liabilities are recognized for future income tax consequences attributable to temporary differences between the financial statement carrying amounts of existing assets and liabilities and their respective income tax bases and for net operating loss and tax credit carryforwards. Deferred income tax assets and liabilities are measured using enacted tax rates expected to apply to taxable income in the years in which those temporary differences are expected to be recovered or settled. The effect on deferred income tax assets and liabilities of a change in income tax rates is recorded in earnings in the period of enactment. A valuation allowance is provided for deferred income tax assets when it is more likely than not that future tax benefits will not be realized. Deferred income tax assets are reviewed on a quarterly basis to determine if a valuation allowance is necessary based on current and historical performance, along with other relevant factors. The income tax provision includes United States federal, state and local income taxes and is based on pre-tax income or loss. In determining the estimated annual effective income tax rate, we analyze various factors, including projections of our annual earnings and taxing jurisdictions in which earnings will be generated, the impact of state and local income taxes and our ability to use tax credits and net operating loss carryforwards. The Company recognizes the benefits of uncertain tax positions taken or expected to be taken in tax returns in the provision for income taxes only for those positions that are more likely than not to be realized. The Company follows a two-step approach to recognizing and measuring uncertain tax positions. The first step is to evaluate the tax position for recognition by determining if the weight of available evidence indicates it is more likely than not that the position will be sustained on audit, including resolution of related appeals or litigation processes, if any. The second step is to measure the tax benefit as the largest amount that is more than 50% likely of being realized upon ultimate settlement. The Company considers many factors when evaluating and estimating our tax positions and tax benefits, which may require periodic adjustments and which may not accurately forecast actual outcomes. The Company’s policy is to include interest and penalties associated with income tax obligations in income tax expense.
Foreign Currency Translation	Foreign Currency Translation —As a result of the sale of global data business in April 2013, the Company is paid and makes payments in U.S. Dollars and is no longer exposed to any significant foreign currency risk.
Concentration	Concentrations — For the years ended 2015, 2014 and 2013, the aggregate revenue of four customers accounted for 77%, 73% and 65% of total revenue from continuing operations, respectively. At December 31, 2015 and 2014, the aggregate accounts receivable of four customers accounted for 79% and 77% of the Company’s total trade accounts receivable balance, respectively. In 2015, the Company had three customers in excess of ten percent of revenue, which were 31% , 26% and 14% of the Company’s total revenue from continuing operations. At December 31, 2015, the Company had two customers that in aggregate accounted for 69% of the Company’s accounts receivable balance. In 2014, the Company had two customers in excess of ten percent of revenue, which were 35% and 25% of the Company’s total revenue from continuing operations. At December 31, 2014, the Company had two customers that in aggregate accounted for 62% of the Company’s accounts receivable balance. In 2013, the Company had two customers in excess of ten percent of revenue, which were 34% and 20% of the Company’s total revenue from continuing operations. At December 31, 2013, the Company had two customers that in aggregate accounted for 61% of the Company’s accounts receivable balance.
Recent Accounting Pronouncements	Recent Accounting Pronouncements — In May 2014, the Financial Accounting Standards Board (“FASB”) issued Accounting Standards Update (“ASU”) No. 2014-09, Revenue from Contracts with Customers , which outlines a single comprehensive model for entities to use in accounting for revenue arising from contracts with customers and supersedes most current revenue recognition guidance, including industry-specific guidance. The ASU is based on the principle that an entity should recognize revenue to depict the transfer of 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. The ASU also requires additional disclosure about the nature, amount, timing and uncertainty of revenue and cash flows arising from customer contracts, including significant judgments and changes in judgments and assets recognized from costs incurred to fulfill a contract. Entities have the option of using either a full retrospective or a modified retrospective approach for the adoption of the new standard. The ASU is effective for annual reporting periods beginning after December 15, 2017 and early adoption as of December 15, 2016 is permitted. The Company is currently assessing the impact of this standard on the Company’s financial position, results of operations and cash flows. In June 2015, the FASB issued ASU No. 2015-10, Technical Corrections and Improvements, and interim periods within those fiscal years, early adoption is permitted. In November 2015, the FASB issued ASU No. 2015-17, Balance Sheet Classification of Deferred Taxes No other new accounting pronouncement issued or effective during the fiscal year had or is expected to have a material impact on the consolidated financial statements.

SUMMARY OF SIGNIFICANT ACCOUN24

SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES (Tables)	12 Months Ended
	Dec. 31, 2015
Accounting Policies [Abstract]
Earnings (Loss) Per Share	The following table presents a reconciliation of the numerators and denominators of basic and diluted earnings (loss) per share of common stock: Years Ended December 31, (In thousands, except per share amounts) 2015 2014 2013 Numerator: Income from continuing operations $ 38,129 $ 38,523 $ 64,298 Loss from discontinued operations, net of provision for income taxes — — (3,808 ) Loss on sale of discontinued operations, net of provision for income taxes — — (4,837 ) Net income $ 38,129 $ 38,523 $ 55,653 Denominator: Weighted average common shares outstanding 33,633 32,887 32,306 Effect of dilutive securities: Stock options and performance stock units 437 497 251 Denominator for diluted earnings per share 34,070 33,384 32,557 Earnings per share - continuing operations: Basic $ 1.13 $ 1.17 $ 1.99 Diluted $ 1.12 $ 1.15 $ 1.97 Loss per share - discontinued operations: Basic $ — $ — $ (0.27 ) Diluted $ — $ — $ (0.27 ) Earnings per share - net income: Basic $ 1.13 $ 1.17 $ 1.72 Diluted $ 1.12 $ 1.15 $ 1.71

BUSINESS DISPOSITION (Tables)

BUSINESS DISPOSITION (Tables)	12 Months Ended
	Dec. 31, 2015
Discontinued Operations And Disposal Groups [Abstract]
Summarized Activity in Company's Consolidated Statements of Income and Summary of Assets and Liabilities for Discontinued Operations	The following table displays summarized activity in the Company’s consolidated statements of operations for discontinued operations during the years ended December 31, 2015, 2014 and 2013. Years Ended December 31, 2015 2014 2013 Revenue $ — $ — $ 15,205 Operating loss — — (3,130 ) Loss before provision for income taxes — — (3,581 ) Provision for income tax — — 227 Loss from discontinued operations — — (3,808 ) Loss on sale of discontinued operations $ — $ — $ (4,837 )

PROPERTY AND EQUIPMENT (Tables)

PROPERTY AND EQUIPMENT (Tables)	12 Months Ended
	Dec. 31, 2015
Property Plant And Equipment [Abstract]
Property and Equipment	Property and equipment as of December 31, 2015 and 2014 consist of the following: December 31, 2015 2014 Network equipment $ 59,439 $ 37,207 Computer software 5,617 3,546 Computer equipment 3,999 2,699 Tools and test equipment 488 450 Furniture and fixtures 644 352 Leasehold improvements 1,842 1,533 Wireless equipment — 6 72,029 45,793 Less accumulated depreciation (36,779 ) (26,431 ) 35,250 19,362 Construction in process 2,086 4,316 Property and equipment-net $ 37,336 $ 23,678

RECEIVABLES (Tables)

RECEIVABLES (Tables)	12 Months Ended
	Dec. 31, 2015
Receivables [Abstract]
Receivables	Receivables as of December 31, 2015 and 2014 consist of the following: December 31, 2015 2014 Receivables $ 41,954 $ 35,102 Less allowance for doubtful accounts (2,365 ) (2,336 ) Receivables—net of allowance for doubtful accounts $ 39,589 $ 32,766

FAIR VALUE MEASUREMENT (Tables)

FAIR VALUE MEASUREMENT (Tables)	12 Months Ended
	Dec. 31, 2015
Fair Value Disclosures [Abstract]
Fair Value of Company's Financial Assets by Level in Fair Value Hierarchy	The fair value of the Company’s financial assets by level in the fair value hierarchy as of December 31, 2015 and 2014 was as follows: December 31, 2015 Level 1 Level 2 Level 3 Total Assets: Money Market Funds $ 86,871 $ — $ — $ 86,871 December 31, 2014 Level 1 Level 2 Level 3 Total Assets: Money Market Funds $ 71,836 $ — $ — $ 71,836

COMMON STOCK (Tables)

COMMON STOCK (Tables)	12 Months Ended
	Dec. 31, 2015
Equity [Abstract]
SCHEDULE OF QUARTERLY DIVIDENDS DECLARED AND PAID	The table below summarizes the regular quarterly dividends declared and paid during the years ended December 31, 2015, 2014 and 2013: (quarter ended) Dividend Per Share Date Declared Date Paid June 30, 2013 $ 0.0625 05/29/13 06/24/13 September 30, 2013 $ 0.0625 08/27/13 09/27/13 December 31, 2013 $ 0.0625 12/04/13 12/30/13 March 31, 2014 $ 0.075 02/27/14 03/27/14 June 30, 2014 $ 0.075 05/21/14 06/26/14 September 30, 2014 $ 0.15 08/13/14 09/24/14 December 31, 2014 $ 0.15 11/10/14 12/08/14 March 31, 2015 $ 0.15 02/12/15 03/12/15 June 30, 2015 $ 0.15 05/11/15 06/08/15 September 30, 2015 $ 0.15 08/10/15 09/07/15 December 31, 2015 $ 0.15 11/11/15 12/09/15

COMMITMENTS AND CONTINGENCIES (

COMMITMENTS AND CONTINGENCIES (Tables)	12 Months Ended
	Dec. 31, 2015
Commitments And Contingencies Disclosure [Abstract]
Future Lease Payments of Operating Leases	The following table represents future lease payments under the operating leases: December 31, 2015 2016 $ 4,712 2017 4,684 2018 4,061 2019 3,975 2020 3,502 Thereafter 8,057 Total $ 28,991
Minimum Future Purchase Obligations	The following table below represents the minimum future purchase obligations. These amounts do not represent the Company’s entire anticipated purchases in the future, but represent only its estimate of those items for which the Company is committed . December 31, 2015 2016 $ 12,844 2017 3,781 2018 643 2019 74 2020 64 Total $ 17,406

INCOME TAXES (Tables)

INCOME TAXES (Tables)	12 Months Ended
	Dec. 31, 2015
Income Tax Disclosure [Abstract]
Income Before Income Tax, Domestic and Foreign	Income before provision for income taxes, and the related provision for income taxes, for the years ended December 31 2015, 2014 and 2013, were as follows: Years Ended December 31, 2015 2014 2013 Income before provision for income taxes $ 60,701 $ 63,226 $ 77,822 Provision for income taxes Current: Federal $ 17,241 $ 21,728 $ 15,391 State 2,270 2,967 428 Total current 19,511 24,695 15,819 Deferred (prepaid): Federal 3,027 (200 ) (1,713 ) State 34 208 (582 ) Total deferred (prepaid) 3,061 8 (2,295 ) Total provision for income taxes $ 22,572 $ 24,703 $ 13,524
Effective Income Tax Rate Reconciliation	A reconciliation of the federal statutory rate to our effective tax rate is as follows: December 31, 2015 2014 2013 Statutory federal rate 35.0 % 35.0 % 35.0 % State income tax, net of federal benefit 2.8 % 3.4 % 3.2 % Illinois state EDGE credit net of valuation allowance (0.4 )% (0.2 )% (1.0 )% Impact of sale of global data business — 0.7 % (15.5 )% Americas Data assets allocation — — (4.7 )% Other (0.2 )% 0.2 % 0.4 % Effective income tax rate 37.2 % 39.1 % 17.4 %
Deferred Tax Assets and Liabilities	Significant components of the Company’s deferred income taxes are as follows: December 31, 2015 2014 Deferred tax assets and liabilities Deferred tax assets: Stock option compensation $ 5,313 $ 5,232 State credit carry forward 1,725 2,380 Capital loss on sale of Tinet stock 21,531 21,580 Accrued other 3,320 3,075 Total deferred tax assets 31,889 32,267 Deferred tax liabilities: Depreciation (7,102 ) (3,898 ) Prepaids (1,008 ) (732 ) Total deferred tax liabilities (8,110 ) (4,630 ) Valuation allowance (22,720 ) (23,517 ) Net deferred income tax asset $ 1,059 $ 4,120
Reconciliation of Beginning and Ending Amount of Uncertain Tax Positions	A reconciliation of the beginning and ending amount of uncertain tax positions is as follows: 2015 2014 Balance at January 1 $ 75 $ 40 Increases related to prior periods 42 8 Increases related to current year 27 27 Lapse of statute of limitations (25 ) — Balance on December 31 $ 119 $ 75

STOCK OPTIONS, NON-VESTED SHA32

STOCK OPTIONS, NON-VESTED SHARES AND PERFORMANCE STOCK UNITS (Tables)	12 Months Ended
	Dec. 31, 2015
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Assumptions Used to Estimate Fair Value of Stock Options	The fair value of each option granted is estimated on the date of grant using the Black-Scholes option pricing model. For the years ended December 31, 2015, 2014 and 2013, fair value of stock options was measured using the following assumptions: Years Ended December 31, 2015 2014 2013 Expected life 7.0 years 7.2 years 7.3 years Risk-free interest rate 1.9% 2.1% 1.3% Expected dividends 3.7% 2.1% 0.0% Volatility 49.6% 60.0% 45.0%
Stock Option Plan Activity	The following summarizes activity under the Company’s stock option plan: Weighted Aggregate Weighted Average Intrinsic Average Shares Exercise Value Remaining (000) Price ($000) Term (yrs) Options outstanding — December 31, 2013 2,991 $ 12.91 Granted 41 13.86 Exercised (1,096 ) 11.43 Cancelled (221 ) 20.08 Options outstanding — December 31, 2014 1,715 $ 12.97 Granted 124 17.02 Exercised (320 ) 6.90 Cancelled (89 ) 5.48 Options outstanding — December 31, 2015 1,430 $ 15.10 $ 5,953 4.04 Vested or expected to vest — December 31, 2015 1,425 $ 15.10 $ 5,935 4.02 Exercisable — December 31, 2015 1,148 $ 16.44 $ 3,628 3.12
Non-Vested Share Activity	A summary of the Company’s non-vested share activity and related information for the years ended December 31, 2015 and 2014 is as follows: Weighted Aggregate Average Intrinsic Shares Grant Date Value (000) Fair Value ($000) Non-vested shares outstanding — December 31, 2013 477 $ 9.66 Granted 226 13.04 Vested (307 ) 10.59 Cancelled — — Non-vested shares outstanding — December 31, 2014 396 $ 10.87 Granted 188 17.19 Vested (241 ) 12.02 Cancelled (9 ) 4.30 Non-vested shares outstanding — December 31, 2015 334 $ 13.77 $ 5,935 Non-vested shares vested or expected to vest —December 31, 2015 325 $ 13.74 $ 5,775
Performance Stock Units
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Non-Vested Share Activity	A summary of the Company’s performance stock unit activity and related information for the year ended December 31, 2015 is as follows: Performance Weighted Stock Average Units Grant Date (000) Fair Value Performance stock units outstanding — December 31, 2014 — $ — Granted 119 22.94 Vested (20 ) 21.73 Cancelled — — Performance stock units outstanding — December 31, 2015 99 $ 23.19

SEGMENT AND GEOGRAPHIC INFORM33

SEGMENT AND GEOGRAPHIC INFORMATION (Tables)	12 Months Ended
	Dec. 31, 2015
Segment Reporting [Abstract]
Summary of Geographical Information	The following is a summary of geographical information as of and for the year ended December 31, 2015, 2014 and 2013: Years Ended December 31, 2015 2014 2013 Revenue from external customers: United States of America $ 248,619 $ 220,508 $ 209,310 Other countries within Americas reporting unit — — 2,351 $ 248,619 $ 220,508 $ 211,661 Long-lived assets: United States of America $ 37,336 $ 23,678 $ 25,660 Other countries — — 155 $ 37,336 $ 23,678 $ 25,815

QUARTERLY FINANCIAL DATA (UNA34

QUARTERLY FINANCIAL DATA (UNAUDITED) (Tables)	12 Months Ended
	Dec. 31, 2015
Quarterly Financial Information Disclosure [Abstract]
Quarterly Financial Data	2015 1st 2nd 3rd 4th Operating Results: Revenue $ 55,054 $ 52,886 $ 63,716 $ 76,963 Operating expense: Network and facilities expense (excluding depreciation and amortization) 22,765 21,295 34,858 46,427 Operations 7,620 7,391 7,955 8,204 Sales and marketing 643 765 690 776 General and administrative 4,555 4,942 4,648 4,363 Depreciation and amortization 2,643 2,600 2,894 3,255 Loss (gain) on sale of property and equipment 33 (149 ) (4 ) 10 Total operating expense 38,259 36,844 51,041 63,035 Income from operations 16,795 16,042 12,675 13,928 Other (income) expense: Interest expense (income) 16 11 9 (7 ) Other income (1,290 ) — — — Total (income) other expense (1,274 ) 11 9 (7 ) Income before provision for income taxes 18,069 16,031 12,666 13,935 Provision for income taxes 6,887 6,031 4,399 5,255 Net income $ 11,182 $ 10,000 $ 8,267 $ 8,680 Per Share Data: Earnings per common share-net income-basic $ 0.33 $ 0.30 $ 0.25 $ 0.26 Earnings per common share-net income-diluted $ 0.33 $ 0.29 $ 0.24 $ 0.25 Weighted average number of shares outstanding-basic 33,496 33,568 33,620 33,843 Weighted average number of shares outstanding-diluted 33,970 34,033 34,138 34,213 2014 1st 2nd 3rd 4th Operating Results: Revenue $ 56,217 $ 54,881 $ 54,045 $ 55,365 Operating expense: Network and facilities expense (excluding depreciation and amortization) 24,890 23,129 23,016 23,960 Operations 7,307 7,202 7,432 7,355 Sales and marketing 676 818 1,048 722 General and administrative 3,800 5,254 3,645 4,141 Depreciation and amortization 3,141 3,010 2,985 2,681 (Gain) loss on sale of property and equipment — (31 ) 2 (31 ) Loss on sale of Americas Data assets 1,081 — — — Total operating expense 40,895 39,382 38,128 38,828 Income from operations 15,322 15,499 15,917 16,537 Other expense (income): Interest expense 2 17 18 14 Other (income) — (2 ) — — Total other expense 2 15 18 14 Income before provision for income taxes 15,320 15,484 15,899 16,523 Provision for income taxes 6,127 6,036 6,123 6,417 Net income $ 9,193 $ 9,448 $ 9,776 $ 10,106 Per Share Data: Earnings per common share-net income-basic $ 0.28 $ 0.29 $ 0.30 $ 0.30 Earnings per common share-net income-diluted $ 0.28 $ 0.28 $ 0.29 $ 0.30 Weighted average number of shares outstanding-basic 32,273 32,832 33,115 33,316 Weighted average number of shares outstanding-diluted 32,616 33,369 33,343 33,785

Description of the Business - A

Description of the Business - Additional Information (Detail) - USD ($) $ in Thousands	Apr. 30, 2013	Mar. 31, 2015	Dec. 31, 2015	Dec. 31, 2013
Business Acquisition [Line Items]
Proceeds from sale of business	$ 54,500
Proceed from sale of business, cash	52,500			$ 42,587
Sale of business non-cash consideration	$ 2,000
Period of free service provided	3 years
Divestiture related costs included in gain on sale of business	$ 2,400
Payment from escrow fund			$ 1,290
Tinet global data business
Business Acquisition [Line Items]
Payment from escrow fund		$ 1,300

Summary of Significant Accoun36

Summary of Significant Accounting Policies - Additional Information (Detail) $ in Thousands, shares in Millions	Apr. 30, 2013USD ($)	Dec. 31, 2015USD ($)InvestmentCustomershares	Dec. 31, 2014USD ($)InvestmentCustomershares	Dec. 31, 2013USD ($)Customershares
Summary Of Significant Accounting Policies [Line Items]
Proceeds from sale of business	$ 54,500
Cash in banks		$ 22,200	$ 32,900
Money market mutual funds		$ 86,900	$ 71,800
Number of money market mutual fund invested | Investment		3	3
Receivables, allowance		$ 2,365	$ 2,336
Impairment of property and equipment		0	0	$ 0
Undistributed earnings (loss) allocable to participating securities		200	300	200
Share-based expense		$ 5,200	$ 4,300	$ 6,200
Percentage of tax benefit realized upon settlement		50.00%
Number of customers | Customer		3	3	3
Sales | Customer Concentration Risk
Summary Of Significant Accounting Policies [Line Items]
Number of customers | Customer		4	4	4
Concentration risks percentage		77.00%	73.00%	65.00%
Sales | Customer Concentration Risk | Customer 1
Summary Of Significant Accounting Policies [Line Items]
Concentration risks percentage		31.00%	35.00%	34.00%
Sales | Customer Concentration Risk | Customer 2
Summary Of Significant Accounting Policies [Line Items]
Concentration risks percentage		26.00%	25.00%	20.00%
Sales | Customer Concentration Risk | Customer 3
Summary Of Significant Accounting Policies [Line Items]
Concentration risks percentage		14.00%
Accounts Receivable | Credit Concentration Risk
Summary Of Significant Accounting Policies [Line Items]
Number of customers | Customer		4	4
Concentration risks percentage		79.00%	77.00%
Accounts Receivable | Credit Concentration Risk | Two Major Customers
Summary Of Significant Accounting Policies [Line Items]
Concentration risks percentage		69.00%	62.00%	61.00%
Number of major customers | Customer		2	2	2
Share-based awards
Summary Of Significant Accounting Policies [Line Items]
Anti-dilutive securities not included in the computation of diluted earnings per share | shares		0.7	0.6	2.4
Network Equipment And Tools And Test Equipment
Summary Of Significant Accounting Policies [Line Items]
Estimated useful lives, years		5 years
Computer equipment
Summary Of Significant Accounting Policies [Line Items]
Estimated useful lives, years		3 years
Computer software
Summary Of Significant Accounting Policies [Line Items]
Estimated useful lives, years		3 years
Furniture and fixtures
Summary Of Significant Accounting Policies [Line Items]
Estimated useful lives, years		3 years
Leasehold Improvements
Summary Of Significant Accounting Policies [Line Items]
Estimated useful lives, description		Five years or the life of the lease, whichever is less

Earnings Per Share (Detail)

Earnings Per Share (Detail) - USD ($) $ / shares in Units, $ in Thousands	Apr. 30, 2013	Dec. 31, 2015	Sep. 30, 2015	Jun. 30, 2015	Mar. 31, 2015	Dec. 31, 2014	Sep. 30, 2014	Jun. 30, 2014	Mar. 31, 2014	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Accounting Policies [Abstract]
Income from continuing operations										$ 38,129	$ 38,523	$ 64,298
Loss from discontinued operations, net of provision for income taxes												(3,808)
Loss on sale of discontinued operations, net of provision for income taxes	$ 4,800											(4,837)
Net income		$ 8,680	$ 8,267	$ 10,000	$ 11,182	$ 10,106	$ 9,776	$ 9,448	$ 9,193	$ 38,129	$ 38,523	$ 55,653
Weighted average common shares outstanding		33,843	33,620	33,568	33,496	33,316	33,115	32,832	32,273	33,633,000	32,887,000	32,306,000
Stock options and performance stock units										437,000	497,000	251,000
Denominator for diluted earnings per share		34,213	34,138	34,033	33,970	33,785	33,343	33,369	32,616	34,070,000	33,384,000	32,557,000
Earnings per share- continuing operations:
Basic										$ 1.13	$ 1.17	$ 1.99
Diluted										1.12	1.15	1.97
Loss per share - discontinued operations:
Basic												(0.27)
Diluted												(0.27)
Earnings per share - net income:
Basic		$ 0.26	$ 0.25	$ 0.30	$ 0.33	$ 0.30	$ 0.30	$ 0.29	$ 0.28	1.13	1.17	1.72
Diluted		$ 0.25	$ 0.24	$ 0.29	$ 0.33	$ 0.30	$ 0.29	$ 0.28	$ 0.28	$ 1.12	$ 1.15	$ 1.71

Business Disposition - Addition

Business Disposition - Additional Information (Detail) $ in Thousands	Apr. 30, 2013USD ($)Unit	Mar. 31, 2014USD ($)	Dec. 31, 2014USD ($)	Dec. 31, 2013USD ($)
Income Statement Balance Sheet And Additional Disclosures By Disposal Groups Including Discontinued Operations [Line Items]
Proceeds from sale of business	$ 54,500
Proceed from sale of business, cash	52,500			$ 42,587
Sale of business non-cash consideration	$ 2,000
Period of free service provided	3 years
Proceeds from business after working capital adjustment	$ 3,300
Proceeds from sale of discontinued operations	51,200
Transaction costs from sale of business	2,400
Working capital adjustment	1,000
Proceeds from sale of business net of working capital adjustment and transaction cost	$ 47,800
Number of reporting units | Unit	3
Claims pursuant to post closing purchase price adjustment by GTT	$ 3,800
Due from GTT related to post closing purchase price adjustment	1,100
Gain (Loss) on sale of asset held for sale	28,800	$ (1,081)	$ (1,081)	28,791
Book value of asset held for sale	14,700
Purchase Price Allocation	4,300
Disposal group of business plus additional cash	1,000
Gain (Loss) on sale of the global data business	4,800			$ (4,837)
Americas
Income Statement Balance Sheet And Additional Disclosures By Disposal Groups Including Discontinued Operations [Line Items]
Proceeds from sale of asset held for sale	43,500
Reduction in other assets	1,100
Gain (Loss) on sale of asset held for sale	1,100
EMEA and APAC
Income Statement Balance Sheet And Additional Disclosures By Disposal Groups Including Discontinued Operations [Line Items]
Proceeds from sale of discontinued operations	4,300
Book value of asset held for sale	10,100
Disposal group including discontinued operation cash and cash equivalents	$ 1,000

Summarized Activity in Consolid

Summarized Activity in Consolidated Statements of Income for Discontinued Operations (Detail) - USD ($) $ in Thousands	Apr. 30, 2013	Dec. 31, 2013
Discontinued Operations And Disposal Groups [Abstract]
Revenue		$ 15,205
Operating loss		(3,130)
Loss before provision for income taxes		(3,581)
Provision for income tax		227
Loss from discontinued operations, net of provision for income taxes		(3,808)
Loss on sale of discontinued operations, net of provision for income taxes	$ 4,800	$ (4,837)

Property and Equipment (Detail)

Property and Equipment (Detail) - USD ($) $ in Thousands	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Property, Plant and Equipment [Line Items]
Property, plant and equipment, gross	$ 72,029	$ 45,793
Less accumulated depreciation	(36,779)	(26,431)
Property and equipment, net excluding construction in process	35,250	19,362
Construction in process	2,086	4,316
Property and equipment-net	37,336	23,678	$ 25,815
Network equipment
Property, Plant and Equipment [Line Items]
Property, plant and equipment, gross	59,439	37,207
Computer software
Property, Plant and Equipment [Line Items]
Property, plant and equipment, gross	5,617	3,546
Computer equipment
Property, Plant and Equipment [Line Items]
Property, plant and equipment, gross	3,999	2,699
Tools and test equipment
Property, Plant and Equipment [Line Items]
Property, plant and equipment, gross	488	450
Furniture and fixtures
Property, Plant and Equipment [Line Items]
Property, plant and equipment, gross	644	352
Leasehold Improvements
Property, Plant and Equipment [Line Items]
Property, plant and equipment, gross	$ 1,842	1,533
Wireless
Property, Plant and Equipment [Line Items]
Property, plant and equipment, gross		$ 6

Receivables (Detail)

Receivables (Detail) - USD ($) $ in Thousands	Dec. 31, 2015	Dec. 31, 2014
Receivables [Abstract]
Receivables	$ 41,954	$ 35,102
Less allowance for doubtful accounts	(2,365)	(2,336)
Receivables—net of allowance for doubtful accounts	$ 39,589	$ 32,766

Fair Value of Company's Financi

Fair Value of Company's Financial Assets by Level in Fair Value Hierarchy (Detail) - Fair Value, Measurements, Recurring - Money Market Funds - USD ($) $ in Thousands	Dec. 31, 2015	Dec. 31, 2014
Assets:
Assets, fair Value	$ 86,871	$ 71,836
Level 1
Assets:
Assets, fair Value	$ 86,871	$ 71,836

401(k) Savings Plan - Additiona

401(k) Savings Plan - Additional Information (Detail) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Compensation And Retirement Disclosure [Abstract]
Defined benefit plan, employees' contribution in percentage, maximum	87.00%
Employer's contribution to 401 (k) defined contribution saving plan	$ 0.5	$ 0.5	$ 0.5

Common Stock - Additional Infor

Common Stock - Additional Information (Detail) - USD ($)

May. 29, 2013

Dec. 31, 2015

Sep. 30, 2015

Jun. 30, 2015

Mar. 31, 2015

Dec. 31, 2014

Sep. 30, 2014

Jun. 30, 2014

Mar. 31, 2014

Dec. 31, 2013

Sep. 30, 2013

Jun. 30, 2013

Dec. 31, 2015

Dec. 31, 2014

Dec. 31, 2013

Class Of Stock [Line Items]

Common stock, authorized shares

150,000,000

150,000,000

150,000,000

150,000,000

Common stock, par value

$ 0.001

$ 0.001

$ 0.001

$ 0.001

Common stock voting rights

Each holder of common stock has one vote in respect to each share of stock held on record for the election of directors and on all matters submitted to a vote of shareholders of the Company.

Special cash dividend declared per share of common stock

$ 1.25

Special cash dividend declared for common stock

$ 40,500,000

Dividend declaration date

Nov. 11, 2015

Aug. 10, 2015

May 11, 2015

Feb. 12, 2015

Nov. 10, 2014

Aug. 13, 2014

May 21, 2014

Feb. 27, 2014

Dec. 4, 2013

Aug. 27, 2013

May 29, 2013

Dividend payable date

Dec. 9, 2015

Sep. 7, 2015

Jun. 8, 2015

Mar. 12, 2015

Dec. 8, 2014

Sep. 24, 2014

Jun. 26, 2014

Mar. 27, 2014

Dec. 30, 2013

Sep. 27, 2013

Jun. 24, 2013

Special cash dividend and regular quarterly dividend payment for common stock

$ 6,000,000

$ 0

$ 0

Dividends paid

$ 20,200,000

$ 14,900,000

20,187,000

14,940,000

$ 45,922,000

Special cash dividends related to expected forfeitures of non-vested Shares

$ 0

$ 100,000

$ 600,000

2013 Special Dividend

Class Of Stock [Line Items]

Dividend declaration date

May 29, 2013

Dividend payable date

Jun. 28, 2013

Common Stock - Schedule of Quar

Common Stock - Schedule of Quarterly Dividends Declared and Paid (Detail) - $ / shares	3 Months Ended
	Dec. 31, 2015	Sep. 30, 2015	Jun. 30, 2015	Mar. 31, 2015	Dec. 31, 2014	Sep. 30, 2014	Jun. 30, 2014	Mar. 31, 2014	Dec. 31, 2013	Sep. 30, 2013	Jun. 30, 2013
Equity [Abstract]
Dividend per share	$ 0.15	$ 0.15	$ 0.15	$ 0.15	$ 0.15	$ 0.15	$ 0.075	$ 0.075	$ 0.0625	$ 0.0625	$ 0.0625
Dividend declaration date	Nov. 11, 2015	Aug. 10, 2015	May 11, 2015	Feb. 12, 2015	Nov. 10, 2014	Aug. 13, 2014	May 21, 2014	Feb. 27, 2014	Dec. 4, 2013	Aug. 27, 2013	May 29, 2013
Dividend payable date	Dec. 9, 2015	Sep. 7, 2015	Jun. 8, 2015	Mar. 12, 2015	Dec. 8, 2014	Sep. 24, 2014	Jun. 26, 2014	Mar. 27, 2014	Dec. 30, 2013	Sep. 27, 2013	Jun. 24, 2013

Commitments and Contingencies -

Commitments and Contingencies - Additional Information (Detail) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Commitments And Contingencies Disclosure [Abstract]
Operating lease expiration	Mar. 31, 2026
Rental expense	$ 4.3	$ 4.3	$ 5.2
Service purchase commitment, description	The Company has service agreements with certain major telecommunications service providers, where it has committed to purchase a minimum amount of services through September 2018. Additionally, the Company has contractual commitments with third parties to purchase network circuits through August 2020.

Future Lease Payments of Operat

Future Lease Payments of Operating Leases (Detail) $ in Thousands	Dec. 31, 2015USD ($)
Operating Leases Future Minimum Payments Due [Abstract]
2,016	$ 4,712
2,017	4,684
2,018	4,061
2,019	3,975
2,020	3,502
Thereafter	8,057
Total	$ 28,991

Minimum Future Purchase Obligat

Minimum Future Purchase Obligation (Detail) $ in Thousands	Dec. 31, 2015USD ($)
Purchase Obligation Fiscal Year Maturity [Abstract]
2,016	$ 12,844
2,017	3,781
2,018	643
2,019	74
2,020	64
Total	$ 17,406

Credit Facility - Additional In

Credit Facility - Additional Information (Detail) - Revolving Credit Facility - USD ($)	Mar. 05, 2013	Dec. 31, 2015
Line Of Credit Facility [Line Items]
Credit facility, initiation date		Mar. 5, 2013
Credit facility, maximum borrowing capacity	$ 15,000,000
Credit facility, maturity term	3 years
Revolving credit facility outstanding		$ 0
LIBOR
Line Of Credit Facility [Line Items]
Credit facility, interest rate	3.25%

Income Before Provision for Inc

Income Before Provision for Income Taxes and Related Provision for Income Taxes (Detail) - USD ($) $ in Thousands	3 Months Ended								12 Months Ended
	Dec. 31, 2015	Sep. 30, 2015	Jun. 30, 2015	Mar. 31, 2015	Dec. 31, 2014	Sep. 30, 2014	Jun. 30, 2014	Mar. 31, 2014	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Income Tax Disclosure [Abstract]
Income before provision for income taxes	$ 13,935	$ 12,666	$ 16,031	$ 18,069	$ 16,523	$ 15,899	$ 15,484	$ 15,320	$ 60,701	$ 63,226	$ 77,822
Current:
Federal, provision for income taxes, current									17,241	21,728	15,391
State, provision for income taxes, current									2,270	2,967	428
Total current									19,511	24,695	15,819
Deferred (prepaid):
Federal, provision for income taxes, deferred									3,027	(200)	(1,713)
State, provision for income taxes, deferred									34	208	(582)
Total deferred (prepaid)									3,061	8	(2,295)
Total provision for income taxes	$ 5,255	$ 4,399	$ 6,031	$ 6,887	$ 6,417	$ 6,123	$ 6,036	$ 6,127	$ 22,572	$ 24,703	$ 13,524

Income Taxes - Additional Infor

Income Taxes - Additional Information (Detail) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Income Tax [Line Items]
Estimated effective income tax rate	37.20%	39.10%	17.40%
Valuation allowance	$ 22,720	$ 23,517
Income tax examination, year under examination	2,013
Liabilities for uncertain tax positions	$ 100	$ 100
ILLINOIS
Income Tax [Line Items]
Valuation allowance	1,200
Released valuation allowance related to Illinois EDGE R&D credits	700
Italy | Foreign Tax Authority
Income Tax [Line Items]
Valuation allowance	$ 21,500

Effective Income Tax Rate Recon

Effective Income Tax Rate Reconciliation (Detail)	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Income Tax Disclosure [Abstract]
Statutory federal rate	35.00%	35.00%	35.00%
State income tax, net of federal benefit	2.80%	3.40%	3.20%
Illinois state EDGE credit net of valuation allowance	(0.40%)	(0.20%)	(1.00%)
Impact of sale of global data business		0.70%	(15.50%)
Americas Data assets allocation			(4.70%)
Other	(0.20%)	0.20%	0.40%
Effective income tax rate	37.20%	39.10%	17.40%

Deferred Tax Assets and Liabili

Deferred Tax Assets and Liabilities (Detail) - USD ($) $ in Thousands	Dec. 31, 2015	Dec. 31, 2014
Deferred tax assets:
Stock option compensation	$ 5,313	$ 5,232
State credit carry forward	1,725	2,380
Capital loss on sale of Tinet stock	21,531	21,580
Accrued other	3,320	3,075
Total deferred tax assets	31,889	32,267
Deferred tax liabilities:
Depreciation	(7,102)	(3,898)
Prepaids	(1,008)	(732)
Total deferred tax liabilities	(8,110)	(4,630)
Valuation allowance	(22,720)	(23,517)
Net deferred income tax asset	$ 1,059	$ 4,120

Reconciliation of Beginning and

Reconciliation of Beginning and Ending Amount of Uncertain Tax Positions (Detail) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014
Income Tax Disclosure [Abstract]
Balance at January 1	$ 75	$ 40
Increases related to prior periods	42	8
Increases related to current year	27	27
Lapse of statute of limitations	(25)
Balance on December 31	$ 119	$ 75

Stock Options, Non-Vested Sha55

Stock Options, Non-Vested Shares and Performance Stock Units - Additional Information (Detail)	12 Months Ended
	Dec. 31, 2015USD ($)Tranche$ / sharesshares	Dec. 31, 2014USD ($)$ / sharesshares	Dec. 31, 2013USD ($)$ / sharesshares
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Granted options outstanding	1,430,000	1,715,000	2,991,000
Granted Performance stock units outstanding	188,000	226,000
Non-vested granted shares remaining outstanding	334,000	396,000	477,000
Non-cash compensation expense | $	$ 5,200,000	$ 4,300,000	$ 6,200,000
Weighted Average Exercise Price, Granted | $ / shares	$ 17.02	$ 13.86
Options granted	100,000	100,000
Weighted-average fair value of options granted | $ / shares	$ 6.03	$ 6.90	$ 1.64
Total grant date fair value of options vested | $	$ 600,000	$ 1,100,000	$ 2,400,000
Total intrinsic value of stock options exercised | $	$ 4,300,000	$ 4,500,000	900,000
Closing stock price | $ / shares	$ 17.77
2003 Plan
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Issuance of stock options, non-vested shares and performance stock units	4,700,000
Non-cash compensation expense | $	$ 300,000
2007 Plan
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Granted options outstanding	3,500,000
Additional outstanding shares available for grant	2,100,000
Shares available for grant as a percentage of the Company's outstanding common stock	6.20%
Options exercise price decreased | $ / shares	$ 1.08
Unrecognized compensation cost | $	$ 0
Performance Stock Units
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Granted Performance stock units outstanding	119,000
Non-vested granted shares remaining outstanding	99,000
Non-cash compensation expense | $	$ 1,100,000
Unrecognized compensation cost | $	$ 1,600,000
Weighted average remaining term recorded for options, in years	1 year 8 months 12 days
Percentage of Target Award to be paid	200.00%
Minimum performance threshold forfeited | $	$ 0
Performance stock unit vesting date.	Dec. 31, 2015
Performance stock unit settlement date	Feb. 8, 2016
Issuance of common stock upon settlement of performance units shares	30,000
Performance Stock Units | First Tranche
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Stock-based compensation, recognition period	18 months
Performance Stock Units | Second Tranche
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Stock-based compensation, recognition period	2 years
Performance Stock Units | Third Tranche
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Stock-based compensation, recognition period	3 years
Performance Stock Units | 2007 Plan
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Granted Performance stock units outstanding	100,000
Number of tranches | Tranche	3
Non-Vested Shares
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Granted Performance stock units outstanding	200,000	200,000
Shares issued	100,000
Weighted average remaining term recorded for options, in years	2 years 3 months 18 days
Non-vested shares, vesting period, years	4 years
Unrecognized compensation cost | $	$ 3,000,000
Stock Options
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Non-cash compensation expense | $	700,000	$ 1,000,000	3,800,000
Unrecognized compensation cost | $	$ 800,000
Weighted average remaining term recorded for options, in years	2 years 8 months 12 days
Nonvested Restricted Shares
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Non-cash compensation expense | $	$ 3,400,000	$ 3,300,000	$ 2,400,000

Estimated Fair Value of Options

Estimated Fair Value of Options (Detail)	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Disclosure Of Compensation Related Costs Sharebased Payments [Abstract]
Expected life	7 years	7 years 2 months 12 days	7 years 3 months 18 days
Risk-free interest rate	1.90%	2.10%	1.30%
Expected dividends	3.70%	2.10%	0.00%
Volatility	49.60%	60.00%	45.00%

Stock Option Activity (Detail)

Stock Option Activity (Detail) - USD ($) $ / shares in Units, shares in Thousands, $ in Thousands	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014
Disclosure Of Compensation Related Costs Sharebased Payments [Abstract]
Shares, Options outstanding beginning	1,715	2,991
Shares, Granted	124	41
Shares, Exercised	(320)	(1,096)
Shares, Cancelled	(89)	(221)
Shares, Options outstanding ending	1,430	1,715
Shares, Vested or expected to vest	1,425
Shares, Exercisable	1,148
Weighted Average Exercise Price, Options outstanding beginning	$ 12.97	$ 12.91
Weighted Average Exercise Price, Granted	17.02	13.86
Weighted Average Exercise Price, Exercised	6.90	11.43
Weighted Average Exercise Price, Cancelled	5.48	20.08
Weighted Average Exercise Price, Options outstanding ending	15.10	$ 12.97
Weighted Average Exercise Price, Vested or expected to vest	15.10
Weighted Average Exercise Price, Exercisable	$ 16.44
Aggregate Intrinsic Value, Options outstanding ending	$ 5,953
Aggregate Intrinsic Value, Vested or expected to vest	5,935
Aggregate Intrinsic Value, Exercisable	$ 3,628
Weighted Average Remaining Term, Options outstanding ending, years	4 years 15 days
Weighted Average Remaining Term, Vested or expected to vest, years	4 years 7 days
Weighted Average Remaining Term, Exercisable, years	3 years 1 month 13 days

Non-Vested Share Activity (Deta

Non-Vested Share Activity (Detail) - USD ($) $ / shares in Units, shares in Thousands, $ in Thousands	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Shares, Non-vested shares outstanding beginning	396	477
Shares, Granted	188	226
Shares, Vested	(241)	(307)
Shares, Cancelled	(9)
Shares, Non-vested shares outstanding ending	334	396
Shares, Non-vested shares vested or expected to vest	325
Weighted Average Grant Date Fair Value, Non-vested shares outstanding beginning	$ 10.87	$ 9.66
Weighted Average Grant Date Fair Value, Granted	17.19	13.04
Weighted Average Grant Date Fair Value, Vested	12.02	10.59
Weighted Average Grant Date Fair Value, Cancelled	4.30
Weighted Average Grant Date Fair Value, Non-vested shares outstanding ending	13.77	$ 10.87
Weighted Average Grant Date Fair Value, Non-vested shares vested or expected to vest	$ 13.74
Aggregate Intrinsic Value, Non-vested shares outstanding ending	$ 5,935
Aggregate Intrinsic Value, Non-vested shares vested or expected to vest	$ 5,775
Performance Stock Units
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Shares, Granted	119
Shares, Vested	(20)
Shares, Non-vested shares outstanding ending	99
Weighted Average Grant Date Fair Value, Granted	$ 22.94
Weighted Average Grant Date Fair Value, Vested	21.73
Weighted Average Grant Date Fair Value, Non-vested shares outstanding ending	$ 23.19

Segment and Geographic Inform59

Segment and Geographic Information - Additional Information (Detail)	12 Months Ended
	Dec. 31, 2015Segment
Segment Reporting [Abstract]
Number of operating segments	1

Revenues and Assets from Extern

Revenues and Assets from External Customers (Detail) - USD ($) $ in Thousands	3 Months Ended								12 Months Ended
	Dec. 31, 2015	Sep. 30, 2015	Jun. 30, 2015	Mar. 31, 2015	Dec. 31, 2014	Sep. 30, 2014	Jun. 30, 2014	Mar. 31, 2014	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Revenues From External Customers And Long Lived Assets [Line Items]
Revenue from external customers	$ 76,963	$ 63,716	$ 52,886	$ 55,054	$ 55,365	$ 54,045	$ 54,881	$ 56,217	$ 248,619	$ 220,508	$ 211,661
Long-lived assets	37,336				23,678				37,336	23,678	25,815
UNITED STATES
Revenues From External Customers And Long Lived Assets [Line Items]
Revenue from external customers									248,619	220,508	209,310
Long-lived assets	$ 37,336				$ 23,678				$ 37,336	$ 23,678	25,660
Other countries within Americas reporting unit
Revenues From External Customers And Long Lived Assets [Line Items]
Revenue from external customers											2,351
Other Countries
Revenues From External Customers And Long Lived Assets [Line Items]
Long-lived assets											$ 155

Quarterly Financial Data (Detai

Quarterly Financial Data (Detail) - USD ($) $ / shares in Units, $ in Thousands	Apr. 30, 2013	Dec. 31, 2015	Sep. 30, 2015	Jun. 30, 2015	Mar. 31, 2015	Dec. 31, 2014	Sep. 30, 2014	Jun. 30, 2014	Mar. 31, 2014	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Quarterly Financial Information Disclosure [Abstract]
Revenue		$ 76,963	$ 63,716	$ 52,886	$ 55,054	$ 55,365	$ 54,045	$ 54,881	$ 56,217	$ 248,619	$ 220,508	$ 211,661
Operating expense:
Network and facilities expense (excluding depreciation and amortization)		46,427	34,858	21,295	22,765	23,960	23,016	23,129	24,890	125,345	94,995	94,867
Operations		8,204	7,955	7,391	7,620	7,355	7,432	7,202	7,307	31,170	29,296	28,595
Sales and marketing		776	690	765	643	722	1,048	818	676	2,874	3,264	5,554
General and administrative		4,363	4,648	4,942	4,555	4,141	3,645	5,254	3,800	18,508	16,840	18,772
Depreciation and amortization		3,255	2,894	2,600	2,643	2,681	2,985	3,010	3,141	11,392	11,817	14,652
(Gain) loss on sale of property and equipment		10	(4)	(149)	33	(31)	2	(31)		(110)	(60)	192
Loss (gain) on sale of Americas data assets	$ (28,800)								1,081		1,081	(28,791)
Total operating expense		63,035	51,041	36,844	38,259	38,828	38,128	39,382	40,895	189,179	157,233	133,841
Income from operations		13,928	12,675	16,042	16,795	16,537	15,917	15,499	15,322	59,440	63,275	77,820
Other (income) expense:
Interest expense (income)		(7)	9	11	16	14	18	17	2	29	51	(6)
Other (income) expense					(1,290)			(2)		(1,290)	(2)	4
Total other (income) expense		(7)	9	11	(1,274)	14	18	15	2	(1,261)	49	(2)
Income before provision for income taxes		13,935	12,666	16,031	18,069	16,523	15,899	15,484	15,320	60,701	63,226	77,822
Provision for income taxes		5,255	4,399	6,031	6,887	6,417	6,123	6,036	6,127	22,572	24,703	13,524
Net income		$ 8,680	$ 8,267	$ 10,000	$ 11,182	$ 10,106	$ 9,776	$ 9,448	$ 9,193	$ 38,129	$ 38,523	$ 55,653
Earnings per share - net income:
Earnings per common share-net income-basic		$ 0.26	$ 0.25	$ 0.30	$ 0.33	$ 0.30	$ 0.30	$ 0.29	$ 0.28	$ 1.13	$ 1.17	$ 1.72
Earnings per common share-net income-diluted		$ 0.25	$ 0.24	$ 0.29	$ 0.33	$ 0.30	$ 0.29	$ 0.28	$ 0.28	$ 1.12	$ 1.15	$ 1.71
Weighted average common shares outstanding		33,843	33,620	33,568	33,496	33,316	33,115	32,832	32,273	33,633,000	32,887,000	32,306,000
Weighted average number of shares outstanding-diluted		34,213	34,138	34,033	33,970	33,785	33,343	33,369	32,616	34,070,000	33,384,000	32,557,000

Valuation and Qualifying Accoun

Valuation and Qualifying Account (Detail) - Allowance for Doubtful Accounts - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Valuation and Qualifying Accounts Disclosure [Line Items]
Beginning balance	$ 2,336	$ 900	$ 423
Charged to Earnings	197	1,925	900
Used	(168)	(489)	(423)
Ending balance	$ 2,365	$ 2,336	$ 900