Endurance International 10-Q 2 Nov 18 2018 Q3 Quarterly report Financial data

Document and Entity Information

Document and Entity Information - shares	9 Months Ended
	Sep. 30, 2018	Oct. 29, 2018
Document And Entity Information [Abstract]
Document Type	10-Q
Amendment Flag	false
Document Period End Date	Sep. 30, 2018
Document Fiscal Year Focus	2,018
Document Fiscal Period Focus	Q3
Trading Symbol	EIGI
Entity Registrant Name	Endurance International Group Holdings, Inc.
Entity Central Index Key	1,237,746
Current Fiscal Year End Date	--12-31
Entity Filer Category	Accelerated Filer
Entity Emerging Growth Company	false
Entity Small Business	false
Entity Common Stock, Shares Outstanding		143,855,398

Consolidated Balance Sheets

Consolidated Balance Sheets - USD ($) $ in Thousands	Sep. 30, 2018	Dec. 31, 2017
Current assets:
Cash and cash equivalents	$ 89,674	$ 66,493
Restricted cash	1,832	2,625
Accounts receivable	14,105	15,945
Prepaid domain name registry fees	57,114	53,805
Prepaid commissions	41,744	0
Prepaid expenses and other current assets	27,101	29,327
Total current assets	231,570	168,195
Property and equipment—net	79,315	95,452
Goodwill	1,849,264	1,850,582
Other intangible assets—net	377,670	455,440
Deferred financing costs—net	2,879	3,189
Investments	15,266	15,267
Prepaid domain name registry fees, net of current portion	11,337	10,806
Prepaid commissions, net of current portion	42,081	0
Other assets	9,021	2,155
Total assets	2,618,403	2,601,086
Current liabilities:
Accounts payable	10,812	11,058
Accrued expenses	70,204	79,991
Accrued interest	15,109	24,457
Deferred revenue	380,564	361,940
Current portion of notes payable	31,606	33,945
Current portion of capital lease obligations	7,595	7,630
Deferred consideration—short term	2,386	4,365
Other current liabilities	3,753	4,031
Total current liabilities	522,029	527,417
Long-term deferred revenue	96,419	90,972
Notes payable—long term, net of original issue discounts of $25,811 and $22,445 and deferred financing costs of $37,736 and $33,515, respectively	1,792,436	1,858,300
Capital lease obligations—long term	2,067	7,719
Deferred tax liability	36,498	19,696
Deferred consideration—long term	1,342	3,551
Other liabilities	11,014	10,426
Total liabilities	2,461,805	2,518,081
Stockholders’ equity:
Preferred Stock—par value $0.0001; 5,000,000 shares authorized; no shares issued or outstanding	0	0
Common Stock—par value $0.0001; 500,000,000 shares authorized; 140,190,695 and 143,306,748 shares issued at December 31, 2017 and September 30, 2018, respectively; 140,190,695 and 143,306,411 outstanding at December 31, 2017 and September 30, 2018, respectively	14	14
Additional paid-in capital	953,971	931,033
Accumulated other comprehensive loss	(1,034)	(541)
Accumulated deficit	(796,353)	(847,501)
Total stockholders’ equity	156,598	83,005
Total liabilities and stockholders’ equity	$ 2,618,403	$ 2,601,086

Consolidated Balance Sheets (Pa

Consolidated Balance Sheets (Parenthetical) - USD ($) $ in Thousands	Sep. 30, 2018	Dec. 31, 2017
Statement of Financial Position [Abstract]
Notes payable-long term original issue discounts, net	$ 22,445	$ 25,811
Deferred financing costs	$ 33,515	$ 37,736
Preferred stock, par value (in usd per share)	$ 0.0001	$ 0.0001
Preferred stock, shares authorized (in shares)	5,000,000	5,000,000
Preferred stock, shares issued (in shares)	0	0
Preferred stock, shares outstanding (in shares)	0	0
Common stock, par value (in usd per share)	$ 0.0001	$ 0.0001
Common stock, shares authorized (in shares)	500,000,000	500,000,000
Common stock, shares issued (in shares)	143,306,748	140,190,695
Common stock, shares outstanding (in shares)	143,306,411	140,190,695

Consolidated Statements of Oper

Consolidated Statements of Operations and Comprehensive Loss - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2018	Sep. 30, 2017	Sep. 30, 2018	Sep. 30, 2017
Income Statement [Abstract]
Revenue	$ 283,770	$ 295,222	$ 862,896	$ 882,617
Cost of revenue	128,945	158,865	393,597	454,197
Gross profit	154,825	136,357	469,299	428,420
Operating expense:
Sales and marketing	63,831	66,276	197,733	211,154
Engineering and development	22,683	19,882	64,559	60,393
General and administrative	25,693	51,269	95,212	130,929
Transaction expenses and charges	0	0	0	773
Total operating expense	112,207	137,427	357,504	403,249
(Loss) income from operations	42,618	(1,070)	111,795	25,171
Other income (expense):
Other income (expense), net	0	(600)	0	(600)
Interest income	289	203	720	506
Interest expense	(37,527)	(35,848)	(111,923)	(121,022)
Total other expense—net	(37,238)	(36,245)	(111,203)	(121,116)
(Loss) income before income taxes and equity earnings of unconsolidated entities	5,380	(37,315)	592	(95,945)
Income tax expense	11,715	2,982	8,826	11,384
Loss before equity earnings of unconsolidated entities	(6,335)	(40,297)	(8,234)	(107,329)
Equity (income) loss of unconsolidated entities, net of tax	0	(33)	2	(72)
Net loss	(6,335)	(40,264)	(8,236)	(107,257)
Net loss attributable to non-controlling interest	0	0	0	277
Excess accretion of non-controlling interest	0	0	0	7,247
Total net loss attributable to non-controlling interest	0	0		7,524
Net loss attributable to Endurance International Group Holdings, Inc.	(6,335)	(40,264)	(8,236)	(114,781)
Comprehensive income (loss):
Foreign currency translation adjustments	(644)	1,070	(2,489)	2,984
Unrealized gain (loss) on cash flow hedge, net of taxes of $48 and $256, and $(182) and $626 for the three and nine months ended September 30, 2017 and 2018, respectively	812	83	1,996	(309)
Total comprehensive (loss) income	$ (6,167)	$ (39,111)	$ (8,729)	$ (112,106)
Earnings Per Share, Basic and Diluted
Basic net income (loss) per share (in usd per share)	$ (0.04)	$ (0.29)	$ (0.06)	$ (0.84)
Diluted net income (loss) per share (in usd per share)	$ (0.04)	$ (0.29)	$ (0.06)	$ (0.84)
Weighted-average common shares used in computing net loss per share attributable to Endurance International Group Holdings, Inc.:
Weighted average number of basic shares outstanding (in shares)	143,107,122	137,793,609	141,946,574	136,688,115
Weighted average number of diluted shares outstanding (in shares)	143,107,122	137,793,609	141,946,574	136,688,115

Consolidated Statements of Op_2

Consolidated Statements of Operations and Comprehensive Loss (Parenthetical) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2018	Sep. 30, 2017	Sep. 30, 2018	Sep. 30, 2017
Income Statement [Abstract]
Unrealized gain (loss) arising during period, tax	$ 256	$ 48	$ 626	$ (182)

Consolidated Statements of Cash

Consolidated Statements of Cash Flows - USD ($)	9 Months Ended
	Sep. 30, 2018	Sep. 30, 2017
Cash flows from operating activities:
Net loss	$ (8,236,000)	$ (107,257,000)
Adjustments to reconcile net loss to net cash provided by operating activities:
Depreciation of property and equipment	36,753,000	40,733,000
Amortization of other intangible assets	77,890,000	104,554,000
Impairment of long lived assets	0	13,848,000
Impairment of investments	0	600,000
Amortization of deferred financing costs	4,708,000	5,403,000
Amortization of net present value of deferred consideration	311,000	504,000
Dividend from minority interest	0	100,000
Amortization of original issue discounts	3,209,000	2,791,000
Stock-based compensation	21,932,000	48,749,000
Deferred tax expense (benefit)	8,839,000	6,442,000
(Gain) loss on sale of assets	191,000	(317,000)
(Gain) loss of unconsolidated entities	2,000	(72,000)
Financing costs expensed	1,228,000	5,487,000
Loss on early extinguishment of debt	331,000	992,000
Changes in operating assets and liabilities, net of acquisitions:
Accounts receivable	1,687,000	(872,000)
Prepaid expenses and other current assets	(3,033,000)	(510,000)
Accounts payable and accrued expenses	(15,721,000)	(7,309,000)
Deferred revenue	3,502,000	15,000,000
Net cash provided by operating activities	133,593,000	128,866,000
Cash flows from investing activities:
Purchases of property and equipment	(22,343,000)	(32,095,000)
Proceeds from sale of assets	6,000	292,000
Purchases of intangible assets	0	(1,966,000)
Net cash used in investing activities	(22,337,000)	(33,769,000)
Cash flows from financing activities:
Proceeds from issuance of term loan and notes, net of original issue discounts	1,580,305,000	1,693,007,000
Repayments of term loans	(1,656,094,000)	(1,733,147,000)
Payment of financing costs	(1,580,000)	(6,304,000)
Payment of deferred consideration	(4,500,000)	(5,408,000)
Payment of redeemable non-controlling interest liability	0	(25,000,000)
Principal payments on capital lease obligations	(5,609,000)	(5,679,000)
Proceeds from exercise of stock options	756,000	1,548,000
Net cash used in financing activities	(86,722,000)	(80,983,000)
Net effect of exchange rate on cash and cash equivalents and restricted cash	(2,146,000)	2,156,000
Net increase in cash and cash equivalents and restricted cash	22,388,000	16,270,000
Cash and cash equivalents and restricted cash:
Beginning of period	69,118,000	56,898,000
End of period	91,506,000	73,168,000
Supplemental cash flow information:
Interest paid	110,139,000	118,276,000
Income taxes paid	$ 3,725,000	$ 3,958,000

Nature of Business

Nature of Business	9 Months Ended
	Sep. 30, 2018
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Nature of Business	Nature of Business Formation and Nature of Business Endurance International Group Holdings, Inc. (“Holdings”) is a Delaware corporation, which, together with its wholly owned subsidiary company, EIG Investors Corp. (“EIG Investors”), its primary operating subsidiary company, The Endurance International Group, Inc. (“EIG”), and other subsidiaries of EIG, collectively form the “Company.” The Company is a leading provider of cloud-based platform solutions designed to help small- and medium-sized businesses succeed online. EIG and EIG Investors were incorporated in April 1997 and May 2007, respectively, and Holdings was originally formed as a limited liability company in October 2011 in connection with the acquisition of a controlling interest in EIG Investors, EIG and EIG's subsidiaries by investment funds and entities affiliated with Warburg Pincus and Goldman, Sachs & Co. on December 22, 2011. On November 7, 2012, Holdings reorganized as a Delaware limited partnership and on June 25, 2013, Holdings converted into a Delaware C-corporation and changed its name to Endurance International Group Holdings, Inc.

Summary of Significant Accounti

Summary of Significant Accounting Policies	9 Months Ended
	Sep. 30, 2018
Accounting Policies [Abstract]
Summary of Significant Accounting Policies	Summary of Significant Accounting Policies Basis of Preparation The accompanying consolidated financial statements, which include the accounts of the Company and its subsidiaries, have been prepared using accounting principles generally accepted in the United States of America (“U.S. GAAP”). All intercompany transactions were eliminated on consolidation. Segment Information From the fourth quarter of fiscal year 2016, through the third quarter of fiscal year 2017, the Company had two reportable segments, web presence and email marketing. The Company experienced significant changes in its management structure during fiscal year 2017, including a change in its chief executive officer, who is the Company's chief operating decision maker ("CODM"). The Company's leadership structure has been revised to centralize management of certain domain-focused brands in order to improve overall performance. As a result of these management changes, management has revised internal financial reporting structures, and broken the former web presence segment into two reportable segments, web presence and domains. The Company's third reportable segment, email marketing, remains unchanged. The products and services included in each of the three reportable segments are as follows: Web Presence. The web presence segment consists primarily of the Company's web hosting brands, such as Bluehost and HostGator, and related products such as domain names, website security, website design tools and services, and e-commerce products. Domain. The domain segment consists of domain-focused brands such as Domain.com, ResellerClub and LogicBoxes as well as certain web hosting brands that are under common management with domain-focused brands. This segment sells domain names and domain management services to resellers and end users, as well as premium domain names, and also generates advertising revenue from domain name parking. It also resells domain names and domain management services to the web presence segment. Email Marketing. The email marketing segment consists of Constant Contact email marketing tools and related products and the SinglePlatform digital storefront solution. The Company's segments share certain resources, primarily related to sales and marketing, engineering and general and administrative functions. Management allocates these costs to each respective segment based on a consistently applied methodology, primarily based on a percentage of revenue. The Company has revised amounts reported for gross profit, net loss and adjusted EBITDA for the web presence and the domain segments in the segment disclosures, which impacted fiscal years 2016 and 2017. The amounts reported for the email marketing segment were not impacted. The revisions arose because of an error in the classification of certain domain registration expenses. Domain segment gross profit, net income (loss) and adjusted EBITDA were overstated by $3.0 million for fiscal year 2016, and by $6.9 million for fiscal year 2017, and web presence segment gross profit, net income (loss) and adjusted EBITDA were understated by equal amounts. Consolidated results were not impacted by this misstatement. See Note 21, Segment Information , for further details. Use of Estimates U.S. GAAP requires management to make certain estimates, judgments and assumptions that affect the reported amounts of assets, liabilities and disclosure of contingent assets and liabilities at the date of the consolidated financial statements and the reported amounts of revenue and expenses during the reporting period. These estimates, judgments and assumptions used in preparing the accompanying consolidated financial statements are based on the relevant facts and circumstances as of the date of the consolidated financial statements. Although the Company regularly assesses these estimates, judgments and assumptions used in preparing the consolidated financial statements, actual results could differ from those estimates. Changes in estimates are recorded in the period in which they become known. The more significant estimates reflected in these consolidated financial statements include estimates of fair value of assets acquired and liabilities assumed under purchase accounting related to the Company’s acquisitions and when evaluating goodwill and long-lived assets for potential impairment, the estimated useful lives of intangible and depreciable assets, revenue recognition for multiple-element arrangements, stock-based compensation, contingent consideration, derivative instruments, certain accruals, reserves and deferred taxes. Unaudited Interim Financial Information The accompanying interim consolidated balance sheet as of September 30, 2018 , and the related consolidated statements of operations and comprehensive loss for the three and nine months ended September 30, 2017 and 2018 , cash flows for the nine months ended September 30, 2017 and 2018 , and the notes to consolidated financial statements are unaudited. These unaudited consolidated financial statements have been prepared on the same basis as the audited consolidated financial statements. The unaudited consolidated financial statements include, in the opinion of management, all adjustments, consisting only of normal recurring adjustments that are necessary for a fair presentation of the Company’s financial position at September 30, 2018 , results of operations for the three and nine months ended September 30, 2017 and 2018 and cash flows for the nine months ended September 30, 2017 and 2018 . The consolidated results in the consolidated statements of operations and comprehensive loss are not necessarily indicative of the results of operations to be expected for the full fiscal year ending December 31, 2018 . Cash Equivalents Cash and cash equivalents include all highly liquid investments with remaining maturities of three months or less at the date of purchase. Restricted Cash Restricted cash is composed of certificates of deposit and cash held by merchant banks and payment processors, which provide collateral against any chargebacks, fees, or other items that may be charged back to the Company by credit card companies and other merchants, and collateral for certain facility leases. Accounts Receivable Accounts receivable is primarily composed of cash due from credit card companies for unsettled transactions charged to subscribers’ credit cards. As these amounts reflect authenticated transactions that are fully collectible, the Company does not maintain an allowance for doubtful accounts. The Company also accrues for earned referral fees and commissions, which are governed by reseller or affiliate agreements, when the amount is reasonably estimable. Prepaid Domain Name Registry Fees Prepaid domain name registry fees represent amounts that are paid in full at the time a domain is registered by one of the Company’s registrars on behalf of a customer. The registry fees are recognized on a straight-line basis over the term of the domain registration period. Fair Value of Financial Instruments The carrying amounts of the Company's financial instruments, which include cash equivalents, accounts receivable, accounts payable and certain accrued expenses, approximate their fair values due to their short maturities. The fair value of the Company's notes payable is based on the borrowing rates currently available to the Company for debt with similar terms and average maturities and approximates their carrying value. Derivative Instruments and Hedging Activities FASB Accounting Standards Codification ("ASC") 815, Derivatives and Hedging, or ASC 815, provides the disclosure requirements for derivatives and hedging activities with the intent to provide users of financial statements with an enhanced understanding of: (a) how and why an entity uses derivative instruments, (b) how the entity accounts for derivative instruments and related hedged items, and (c) how derivative instruments and related hedged items affect an entity’s financial position, financial performance, and cash flows. Further, qualitative disclosures are required that explain the Company’s objectives and strategies for using derivatives, as well as quantitative disclosures about the fair value of and gains and losses on derivative instruments, and disclosures about credit-risk-related contingent features in derivative instruments. As required by ASC 815, the Company records all derivatives on the balance sheet at fair value. The accounting for changes in the fair value of derivatives depends on the intended use of the derivative, whether the Company has elected to designate a derivative in a hedging relationship and apply hedge accounting and whether the hedging relationship has satisfied the criteria necessary to apply hedge accounting. Derivatives designated and qualifying as a hedge of the exposure to changes in the fair value of an asset, liability, or firm commitment attributable to a particular risk, such as interest rate risk, are considered fair value hedges. Derivatives designated and qualifying as a hedge of the exposure to variability in expected future cash flows, or other types of forecasted transactions, are considered cash flow hedges. Derivatives may also be designated as hedges of the foreign currency exposure of a net investment in a foreign operation. Hedge accounting generally provides for the matching of the timing of gain or loss recognition on the hedging instrument with the recognition of the changes in the fair value of the hedged asset or liability that are attributable to the hedged risk in a fair value hedge or the earnings effect of the hedged forecasted transactions in a cash flow hedge. The Company may enter into derivative contracts that are intended to economically hedge certain of its risks, even though hedge accounting does not apply or the Company elects not to apply hedge accounting. In accordance with the FASB’s fair value measurement guidance in FASB Accounting Standards Update ("ASU") 2011-4, Fair Value Measurement (Topic 820): Amendments to Achieve Common Fair Value Measurement and Disclosure Requirements, the Company made an accounting policy election to measure the credit risk of its derivative financial instruments that are subject to master netting agreements on a net basis by counterparty portfolio. Property and Equipment Property and equipment is recorded at cost or fair value if acquired in an acquisition. The Company also capitalizes the direct costs of constructing additional computer equipment for internal use, as well as upgrades to existing computer equipment which extend the useful life, capacity or operating efficiency of the equipment. Capitalized costs include the cost of materials, shipping and taxes. Materials used for repairs and maintenance of computer equipment are expensed and recorded as a cost of revenue. Materials on hand and construction-in-process are recorded as property and equipment. Assets recorded under capital lease are depreciated over the lease term. Depreciation is computed using the straight-line method over the estimated useful lives of the related assets as follows: Building Thirty-five years Software Two to three years Computers and office equipment Three years Furniture and fixtures Five years Leasehold improvements Shorter of useful life or remaining term of the lease Software Development Costs The Company accounts for software development costs for internal-use software under the provisions of ASC 350-40, Internal-Use Software. Accordingly, certain costs to develop internal-use computer software are capitalized, provided these costs are expected to be recoverable. During the three and nine months ended September 30, 2017 , the Company capitalized internal-use software development costs of $2.2 million and $8.4 million , respectively. During the three and nine months ended September 30, 2018 , the Company capitalized internal-use software costs of $2.8 million and $7.1 million , respectively. Goodwill Goodwill relates to amounts that arose in connection with the Company’s various business combinations and represents the difference between the purchase price and the fair value of the identifiable intangible and tangible net assets when accounted for using the purchase method of accounting. Goodwill is not amortized, but is subject to periodic review for impairment. Events that would indicate impairment and trigger an interim impairment assessment include, but are not limited to, current economic and market conditions, including a decline in the equity value of the Company's business, a significant adverse change in agreements that would materially affect reported operating results, business climate or operational performance of the business and an adverse action or assessment by a regulator. Additionally, a reorganization or change in the number of reporting units could result in the reassignment of goodwill between reporting units and may trigger an impairment assessment. In accordance with ASC 350, Intangibles—Goodwill and Other , or ASC 350, the Company is required to review goodwill by reporting unit for impairment at least annually or more often if there are indicators of impairment present. Under U.S. GAAP, a reporting unit is either the equivalent of, or one level below, an operating segment. The Company has historically performed its annual goodwill test as of December 31 of each fiscal year. As a result of changes in the Company’s management structure during fiscal year 2017, including the change in its chief executive officer / CODM, the Company has revised its internal financial reporting structure, which has resulted in a change to its reporting units. The Company has identified a total of ten reporting units under the new structure. With the increase in reporting units, the Company determined that more time would be required to perform future goodwill impairment tests, and as a result, decided to accelerate its annual goodwill impairment test date to October 31 of each fiscal year, starting with the fiscal year 2017 test. Before testing goodwill at October 31, 2017, the Company allocated assets and liabilities to their respective reporting units. Goodwill was allocated to each reporting unit in accordance with ASC 350-20-40, which requires that goodwill be allocated based on the relative fair values of each reporting unit. After completing this valuation process, the Company allocated goodwill to seven reporting units. The Company did not allocate any goodwill to three smaller reporting units that were determined to have no material fair value. The carrying value of each reporting unit is based on the assignment of the appropriate assets and liabilities to each reporting unit. Assets and liabilities were assigned to each reporting unit if the assets or liabilities are employed in the operations of the reporting unit and the asset and liability is considered in the determination of the reporting unit fair value. Certain assets and liabilities are shared by multiple reporting units, and were allocated to each reporting unit based on the relative size of a reporting unit, primarily based on revenue. The fair value of each reporting unit is determined by the income approach. The Company also compared the fair value from the income approach to a market based approach to validate that the value derived from the income approach was reasonable. For the income approach, fair value is determined based on the present value of estimated future after-tax cash flows, discounted at an appropriate risk adjusted rate. The Company uses internal forecasts to estimate future after-tax cash flows, which includes an estimate of long-term future growth rates based on the long-term outlook for each reporting unit. Actual results may differ from those assumed in each forecast. The Company derives discount rates using a capital asset pricing model and analyzing published rates for industries relevant to the reporting units to estimate the weighted average cost of capital. The Company uses discount rates that are commensurate with the risks and uncertainty inherent in the business and in internally developed forecasts. For fiscal year 2017, the Company used a discount rate of 10.0% , and also performed sensitivity analysis on the discount rates. For the market approach validation, values were derived based on valuation multiples from sales of comparable companies. The Company has also early adopted the provisions of ASU 2017-4, which eliminates the second step of the goodwill impairment test. As a result, the goodwill impairment test as of October 31, 2017 includes only one step, which is a comparison of the carrying value of each reporting unit to its fair value, and any excess carrying value, up to the amount of goodwill allocated to that reporting unit, is impaired. The goodwill impairment test as of October 31, 2017 resulted in a $12.1 million impairment of goodwill to the Company's domain monetization reporting unit within the domain segment. The impairment is a direct result of a more rapid decline in domain parking revenue than originally expected, and to a lesser extent, reduced sales of premium domain names. Goodwill for this reporting unit has been completely impaired. Goodwill allocated to the other six reporting units was not impaired. Goodwill as of December 31, 2017 was $1,850.6 million . Approximately $1,820.7 million of this goodwill relates to reporting units where fair value exceeds the carrying value of the respective reporting unit by at least 20% . One reporting unit, the domain.com reporting unit within the domain segment, has a goodwill balance of $29.9 million , and a fair value that exceeds its carrying value by 6% . The Company has one reporting unit, the cloud backup reporting unit within the web presence segment, that has a negative carrying value and has been allocated $2.3 million of goodwill. During the quarter ended March 31, 2018, the Company further adjusted management responsibilities regarding certain reporting units, which resulted in additional adjustments to internal financial reporting structures. The total number of reporting units remains at ten , however, goodwill was reallocated between reporting units as a result of this change. The Company estimated the amount of goodwill to be reallocated at $48.0 million . The Company tested goodwill for impairment based on the goodwill reallocation. No impairment charge was identified as a result of this test. Goodwill as of September 30, 2018 is $1,849.3 million . The carrying value of goodwill that was allocated to the domain, email marketing and web presence reporting segments was $ 29.9 million , $604.3 million and $1,215.1 million , respectively. For the three and nine months ended September 30, 2018 , no impairment triggering events were identified and no impairment has been recorded. Long-Lived Assets The Company’s long-lived assets consist primarily of intangible assets, including acquired subscriber relationships, trade names, intellectual property, developed technology, domain names available for sale and in-process research and development (“IPR&D”). The Company also has long-lived tangible assets, primarily consisting of property and equipment. The majority of the Company’s intangible assets are recorded in connection with its various acquisitions. The Company’s intangible assets are recorded at fair value at the time of their acquisition. The Company amortizes intangible assets over their estimated useful lives. Determination of the estimated useful lives of the individual categories of intangible assets is based on the nature of the applicable intangible asset and the expected future cash flows to be derived from the intangible asset. Amortization of intangible assets with finite lives other than developed technology is recognized in accordance with their estimated projected cash flows. The Company evaluates long-lived intangible and tangible assets whenever events or changes in circumstances indicate that the carrying amount of an asset may not be recoverable. If indicators of impairment are present and undiscounted future cash flows are less than the carrying amount, the fair value of the assets is determined and compared to the carrying value. If the fair value is less than the carrying value, then the carrying value of the asset is reduced to the estimated fair value and an impairment loss is charged to expense in the period the impairment is identified. During the three and nine months ended September 30, 2017, the Company recognized an impairment charge of $13.8 million relating to certain domain name intangible assets acquired in 2014, which was recorded in cost of revenue in the consolidated statements of operations and comprehensive loss. The impairment resulted from diminished cash flows associated with this intangible asset. No such impairment losses have been identified in the three and nine months ended September 30, 2018. Indefinite life intangible assets include domain names that are available for sale which are recorded at cost to acquire. These assets are not being amortized and are being tested for impairment annually and whenever events or changes in circumstance indicate that their carrying value may not be recoverable. When a domain name is sold, the Company records the cost of the domain in cost of revenue. Acquired In-Process Research and Development (IPR&D) Acquired IPR&D represents the fair value assigned to research and development assets that the Company acquires in connection with business combinations that have not been completed at the date of acquisition. The acquired IPR&D is capitalized as an intangible asset and reviewed on a quarterly basis to determine future use. Any impairment loss of the acquired IPR&D is charged to expense in the period the impairment is identified. No impairment loss was identified during the nine months ended September 30, 2017 and 2018. Revenue Recognition In May 2014, the FASB issued ASU No. 2014-09, Revenue from Contracts with Customers (Topic 606) , or ASU 2014-09 or ASC 606, which supersedes nearly all existing revenue recognition guidance under U.S. GAAP. Since then, the FASB has also issued ASU 2016-08, Revenue from Contracts with Customers (Topic 606), Principals versus Agent Considerations, ASU 2016-10, Revenue from Contracts with Customers (Topic 606), Identifying Performance Obligations and Licensing, and ASU 2017-13, Revenue Recognition (Topic 605), Revenue from Contracts with Customers (Topic 606) , Amendments to SEC Paragraphs Pursuant to the Staff Announcement at the July 20, 2017 EITF Meeting and Rescission of Prior SEC Staff Announcements and Observer Comments, which further elaborate on the original ASU No. 2014-09. The Company adopted the guidance in ASC 606 on January 1, 2018. Revenue is recognized when control of the promised products or services is transferred to the Company’s customers, in an amount that reflects the consideration the Company expects to be entitled to for those products and services. In general, the Company determines revenue recognition through the following steps: • Identification of the contract, or contracts, with the customer • Identification of the performance obligations in the contract • Determination of the transaction price • Allocation of the transaction price to the performance obligations in the contract • Recognition of revenue when, or as, the Company satisfies a performance obligation. The Company provides cloud-based subscription services, which include website hosting and related add-ons, search engine optimization (SEO) services, domain registration services and email marketing. Website hosting gives subscribers access to an environment where the Company hosts a customer’s website. The related contract terms are generally for one year , but can range from 30 days to 3 years . Website hosting services are typically sold in bundled offerings that include website hosting, domain registration services and various add-ons. The Company recognizes revenue for website hosting and domain registration services over the term of the contract. The main add-on services related to website hosting are domain privacy, secure sockets layer (SSL) security, site backup and restoration, and website builder tools. These services may be included in website hosting bundles, or they may be purchased on a standalone basis. Certain add-on services are provided by third parties. In cases where the Company is acting as an agent for the sale of third party add-on services, the Company recognizes revenue on a net basis at the time of sale. In cases where the Company is acting as a principal for the sale of third party add-on services (i.e., the Company has the primary responsibility to provide specific goods or services, it has discretion to establish prices and it may assume inventory risk), the Company recognizes revenue on a gross basis over the term of the contract. The revenue for Company-provided add-on services is primarily recognized over the term of the contract. SEO services are monthly subscriptions that provide a customer with increased traffic to their website over the term of the subscription. Revenue from SEO services is recognized over the monthly term of the contract. In the case of domain registration services, the Company is an accredited registrar and can provide registration services to the customer, or it can select an accredited third party registrar to perform these duties. Domain registration services are generally annual subscriptions, but can cover multiple years. Revenue for these services is recognized over time. Email marketing services provide subscribers with a cloud based platform that can send broadcast emails to a customer list managed by the subscriber. Pricing is based on contract list volume from the prior monthly period, which determines the contractual billing price for the upcoming month. Revenue for this service is recognized over the monthly term of the contract. Non-subscription based services include certain professional services, primarily website design or re-design services, marketing development fund revenue ("MDF"), premium domain names and domain parking services. Website design and re-design services are recognized when the service is complete. Marketing development funds consist of commissions earned by the Company when a third party sells its products or services directly to the Company’s subscribers, and advertising revenue for third party ads placed on Company websites. The Company records revenue when the service is provided and calculates it based on the contractual revenue share arrangement or over the term of the advertisement. Domain parking allows the Company to monetize certain of its premium domain names by loaning them to specialized third parties that generate advertising revenue from these parked domains on a pay per click ("PPC") basis. Revenue is recognized when earned and calculated based on the revenue share arrangement with the third party. Revenue from the sale of premium domains is recognized when persuasive evidence of an arrangement to sell such domains exists and delivery of an authorization key to access the domain name has occurred. Premium domain names are paid for in advance prior to the delivery of the domain name. For most of the Company’s performance obligations, the customer simultaneously receives and consumes the service over a period of time as the Company performs the service, resulting in the recognition of revenue over the subscription period. This method provides an appropriate depiction of the timing of the transfer of services to the customer. In limited instances, the customer obtains control of the promised service at a point in time, with no future obligations on the part of the Company. In these instances, the Company recognizes revenue at the point in time control is transferred. The contracts that the Company enters into typically do not contain any variable or non-cash considerations. The Company maintains a reserve for refunds and chargebacks related to revenue that has been recognized and is expected to be refunded, as calculated based on observed historical trends. The Company had a refund and chargeback reserve of $0.5 million and $0.3 million as of December 31, 2017 and September 30, 2018 , respectively. The portion of deferred revenue that is expected to be refunded at December 31, 2017 and September 30, 2018 was $1.8 million and $1.8 million , respectively. Based on refund history, approximately 83% of all refunds happen in the same fiscal month that the contract starts or renews, and approximately 96% of all refunds happen within 45 days of the contract start or renewal date. The Company did not apply any practical expedients during its adoption of ASC 606. The Company elected to use the portfolio method in the calculation of the deferred contract assets. Contracts with Multiple Performance Obligations A considerable amount of the Company’s revenue is generated from transactions that are contracts with customers that may include hosting plans, domain name registrations, and other cloud-based products and services. In these cases, the Company determines whether the products and services are distinct performance obligations that should be accounted for separately versus together. The Company allocates revenue to each performance obligation based on its relative standalone selling price, generally based on the price charged to customers. Hosting services, domain name registrations, and other cloud-based products and services have distinct performance obligations and are often sold separately. If the promise is not distinct and therefore not a performance obligation, then the total transaction amount is allocated to the identified performance obligation based on a relative selling price hierarchy. When multiple performance obligations are included in a contract, the total transaction amount for the contract is allocated to the performance obligations based on a relative selling price hierarchy. The Company determines the relative selling price for a performance obligation based on standalone selling price (“SSP”). The Company determines SSP by considering its observed standalone selling prices, competitive prices in the marketplace and management judgment; these standalone selling prices may vary depending upon the particular facts and circumstances related to each deliverable. The Company analyzes the standalone selling prices used in its allocation of transaction amount, at a minimum, on a quarterly basis. Deferred Revenue The Company records deferred revenue when cash payments are received or are due in advance of the Company’s performance, including amounts that are refundable. The change in the deferred revenue balance for the nine months ended September 30, 2018 is primarily driven by cash payments received or due in advance of the Company satisfying its performance obligations, offset by $331.9 million of revenue recognized that were included in the deferred revenue balance at the beginning of the period. The following table provides a reconciliation of the Company's deferred revenue as of September 30, 2018 : Short-term Long-term (in thousands) Balance at December 31, 2017 $ 361,940 $ 90,972 Effect of adoption of ASC 606 to balances at December 31, 2017 20,275 2,882 Recognition of the beginning deferred revenue into revenue, as a result of performance obligations satisfied (331,939 ) — Cash received in advance during the period 657,821 193,119 Recognition of cash received in the period into revenue, as a result of performance obligations satisfied (518,087 ) — Reclassification between short-term and long-term 190,554 (190,554 ) Balance at September 30, 2018 $ 380,564 $ 96,419 The difference between the opening and closing balances of the Company’s deferred liabilities primarily results from the timing difference between the Company’s performance and the customer’s payment. During the nine months ended September 30, 2018 , the Company recognized $331.9 million and $0.0 million , respectively, from beginning deferred revenue current and long-term balances existing at December 31, 2017 . The Company did not recognize any revenue from performance obligations satisfied in prior periods. The following table provides the remaining performance obligation amounts as of September 30, 2018 . These amounts are equivalent to the ending deferred revenue balance of $477.0 million , which includes both short and long-term amounts: Web presence Email marketing Domain Total (in thousands) Remaining performance obligation, short-term $ 265,984 $ 55,055 $ 59,525 $ 380,564 Remainin

Correction of Income Tax Expens

Correction of Income Tax Expense - Fiscal Year 2018	9 Months Ended
	Sep. 30, 2018
Accounting Changes and Error Corrections [Abstract]
Correction of Income Tax Expense - Fiscal Year 2018	Correction of Income Tax Expense - Fiscal Year 2018 The Company has revised its deferred income tax provision for the first and second quarter of 2018 to reflect a revision that favorably impacted net income (loss) for these periods. During fiscal year 2017, the Company began a process to reorganize, and in some instances, eliminate legal entities associated with certain products introduced in 2015 and 2016. This reorganization is expected to provide tax benefits, as the Company can deduct losses on the investments in these entities in its U.S. income tax filings. After further review of these losses, the Company has determined that a significant portion of these losses should have been reflected in its 2017 income tax provision calculations. The Company has increased its net operating loss ("NOL") carry-forwards available to offset future U.S. federal taxable income from $157.6 million as of December 31, 2017, to $236.3 million . Additionally, NOL carry-forwards available to offset future state taxable income were increased from $128.6 million as of December 31, 2017, to $168.3 million . These changes in NOL carry-forwards did not impact the actual income tax provision recorded in 2017; however, due to the changes enacted in the 2017 Tax Cuts and Jobs Act, the manner in which net operating loss carry-forwards are handled does impact the Company's 2018 provision for non-cash deferred income taxes. The impact of this revision on the Company’s financial statements as originally filed for the first and second quarter of fiscal year 2018 is detailed below. The following table represents the impact of the income statement revision to the first and second quarters of 2018 due to the revised deferred income tax provision (in thousands, except per share data): Three Months Ended March 31, 2018 Three Months Ended June 30, 2018 Originally Filed Adjustment Revised Originally Filed Adjustment Revised Loss before income taxes and equity earnings of unconsolidated subsidiaries $ (4,444 ) $ — $ (4,444 ) $ (344 ) $ — $ (344 ) Income tax expense (benefit) 2,617 (4,560 ) (1,943 ) 1,650 (2,596 ) (946 ) Loss before equity earnings of unconsolidated subsidiaries (7,061 ) $ 4,560 $ (2,501 ) (1,994 ) $ 2,596 $ 602 Equity (income) loss of unconsolidated subsidiaries 27 — 27 $ (25 ) (25 ) Net income (loss) $ (7,088 ) $ 4,560 $ (2,528 ) $ (1,969 ) $ 2,596 $ 627 Comprehensive income (loss) Foreign currency translation 580 — 580 (2,425 ) — (2,425 ) Unrealized (gain) loss on cash flow hedge, net of tax 1,041 — 1,041 144 — 144 Total comprehensive loss $ (5,467 ) $ 4,560 $ (907 ) $ (4,250 ) $ 2,596 $ (1,654 ) Basic net income (loss) per share $ (0.05 ) $ 0.03 $ (0.02 ) $ (0.01 ) $ 0.01 $0.00 Diluted net income (loss) per share $ (0.05 ) $ 0.03 $ (0.02 ) $ (0.01 ) $ 0.01 $0.00 Weighted-average common shares used in computing net income (loss) per share Basic 140,361,982 — 140,361,982 142,340,561 — 142,340,561 Diluted 140,361,982 — 140,361,982 142,340,561 2,361,441 144,702,002 Six Months Ended June 30, 2018 Originally Filed Adjustment Revised Loss before income taxes and equity earnings of unconsolidated subsidiaries $ (4,788 ) $ — $ (4,788 ) Income tax expense (benefit) 4,267 (7,156 ) (2,889 ) Loss before equity earnings of unconsolidated subsidiaries (9,055 ) 7,156 (1,899 ) Equity (income) loss of unconsolidated subsidiaries 2 — 2 Net income (loss) (9,057 ) 7,156 $ (1,901 ) Comprehensive income (loss) Foreign currency translation (1,845 ) — (1,845 ) Unrealized gain on cash flow hedge, net of tax 1,184 — 1,184 Total comprehensive loss (9,718 ) 7,156 $ (2,562 ) Basic net income (loss) per share $ (0.06 ) $ 0.05 $ (0.01 ) Diluted net income (loss) per share $ (0.06 ) $ 0.05 $ (0.01 ) Weighted-average common shares used in computing net income (loss) per share Basic 141,356,567 — 141,356,567 Diluted 141,356,567 — 141,356,567 The following table represents the impact of the revised deferred income tax provision on the impacted balance sheet accounts as of the dates shown (in thousands): March 31, 2018 June 30, 2018 Originally Filed Adjustment Revised Originally Filed Adjustment Revised Deferred tax liability $ 27,679 $ (4,560 ) $ 23,119 $ 29,897 $ (7,156 ) $ 22,741 Total liabilities 2,533,619 (4,560 ) 2,529,059 2,490,106 (7,156 ) 2,482,950 Accumulated deficit (795,206 ) 4,560 (790,646 ) (797,175 ) 7,156 (790,019 ) Total stockholders' equity 144,189 4,560 148,749 147,759 7,156 154,915 Total liabilities and stockholders' equity 2,677,808 — 2,677,808 2,637,865 — 2,637,865 The following table represents the impact of the revised deferred income tax provision on the impacted lines of the statement of cash flows for the periods shown (in thousands): Three Months Ended March 31, 2018 Six Months Ended June 30, 2018 Originally Filed Adjustment Revised Originally Filed Adjustment Revised Net income (loss) $ (7,088 ) $ 4,560 $ (2,528 ) $ (9,057 ) $ 7,156 $ (1,901 ) Deferred tax expense 492 (4,560 ) (4,068 ) 2,672 (7,156 ) (4,484 ) Net cash provided by operating activities 52,360 — 52,360 82,252 — 82,252

Acquisitions

Acquisitions	9 Months Ended
	Sep. 30, 2018
Business Combinations [Abstract]
Acquisitions	Acquisitions The Company did not make any acquisitions during the three and nine months ended September 30, 2017 and 2018. The Company has a remaining deferred consideration liability related to its acquisition of AppMachine B.V., which had taken place in 2016. Deferred consideration at December 31, 2017 related to AppMachine was $7.9 million , of which, $4.4 million was classified as short-term. Deferred consideration at September 30, 2018 related to AppMachine was $3.7 million , of which $2.4 million was classified as short-term.

Property and Equipment and Capi

Property and Equipment and Capital Lease Obligations	9 Months Ended
	Sep. 30, 2018
Property, Plant and Equipment [Abstract]
Property and Equipment and Capital Lease Obligations	Property and Equipment and Capital Lease Obligations Components of property and equipment consisted of the following: December 31, 2017 September 30, 2018 (in thousands) Land $ 790 $ 790 Building 5,037 7,294 Software 82,618 88,376 Computers and office equipment 153,273 158,188 Furniture and fixtures 18,825 19,259 Leasehold improvements 22,260 19,672 Construction in process 3,800 2,215 Property and equipment—at cost 286,603 295,794 Less accumulated depreciation (191,151 ) (216,479 ) Property and equipment—net $ 95,452 $ 79,315 Depreciation expense related to property and equipment for the three months ended September 30, 2017 and 2018 was $13.6 million and $11.9 million , respectively. Depreciation expense related to property and equipment for the nine months ended September 30, 2017 and 2018 was $40.7 million and $36.8 million , respectively. Property under capital lease with a cost basis of $ 15.5 million was included in software as of September 30, 2018 . The net carrying value of property under capital lease as of September 30, 2018 was $10.6 million .

Fair Value Measurements

Fair Value Measurements	9 Months Ended
	Sep. 30, 2018
Fair Value Disclosures [Abstract]
Fair Value Measurements	Fair Value Measurements The following valuation hierarchy is used for disclosure of the valuation inputs used to measure fair value. This hierarchy prioritizes the inputs into three broad levels as follows: • Level 1 inputs are quoted prices (unadjusted) in active markets for identical assets or liabilities. • Level 2 inputs are quoted prices for similar assets or liabilities in active markets or inputs that are observable for the asset or liability, either directly or indirectly through market corroboration, for substantially the full term of the financial instrument. • Level 3 inputs are unobservable inputs based on the Company’s own assumptions used to measure assets and liabilities at fair value. A financial asset or liability’s classification within the hierarchy is determined based on the lowest level input that is significant to the fair value measurement. As of December 31, 2017 and September 30, 2018 , the Company’s financial assets required to be measured on a recurring basis consist of the 2015 interest rate cap and the 2018 interest rate cap. The Company has classified these interest rate caps, which are discussed in Note 7 below, within Level 2 of the fair value hierarchy. Basis of Fair Value Measurements Balance Quoted Prices in Active Markets for Identical Items (Level 1) Significant Other Observable Inputs (Level 2) Significant Unobservable Inputs (Level 3) (in thousands) Balance at December 31, 2017 Financial assets: Interest rate cap (included in other assets) $ 452 — $ 452 $ — Total financial assets $ 452 $ — $ 452 $ — Balance at September 30, 2018 Financial assets: Interest rate caps (included in other assets) $ 6,863 — $ 6,863 $ — Total financial assets $ 6,863 $ — $ 6,863 $ — The carrying amounts of the Company's other financial assets and liabilities including cash, accounts receivable, accounts payable and accrued liabilities approximate their respective fair values because of the relatively short period of time between their origination and their expected realization or settlement.

Derivatives and Hedging Activit

Derivatives and Hedging Activities	9 Months Ended
	Sep. 30, 2018
Derivative Instruments and Hedging Activities Disclosure [Abstract]
Derivatives and Hedging Activities	Derivatives and Hedging Activities Risk Management Objective of Using Derivatives The Company is exposed to certain risk arising from both its business operations and economic conditions. The Company principally manages its exposures to a wide variety of business and operational risks through management of its core business activities. The Company manages economic risks, including interest rate, liquidity, and credit risk primarily by managing the amount, sources, and duration of its debt funding and the use of derivative financial instruments. Specifically, the Company may enter into derivative financial instruments to manage exposures that arise from business activities that result in the receipt or payment of future known and uncertain cash amounts, the value of which are determined by interest rates. The Company’s derivative financial instruments are used to manage differences in the amount, timing, and duration of the Company’s known or expected cash receipts and its known or expected cash payments principally related to the Company’s investments and borrowings. Cash Flow Hedges of Interest Rate Risk The Company has entered into two three -year interest rate caps as part of its risk management strategy. The interest rate caps, designated as cash flow hedges of interest rate risk, provide for the payment to the Company of variable amounts if interest rates rise above the strike rate on the contract in exchange for an upfront premium. Therefore, these derivatives limit the Company’s exposure if the interest rate rises, but also allow the Company to benefit when the interest rate falls. The changes in the fair value of derivatives that qualify as cash flow hedges is recorded in Accumulated Other Comprehensive Income ("AOCI"), and is subsequently reclassified into earnings in the period that the hedged forecasted transaction affects earnings. Amounts reported in AOCI related to derivatives will be reclassified to interest expense as interest payments are made on the Company’s variable-rate debt. In December 2015, the Company entered into a three-year interest rate cap with $500.0 million notional value outstanding. This interest rate cap was effective beginning on February 29, 2016. The fair value of this interest rate contract included in other assets on the consolidated balance sheet as of September 30, 2018 was $1.0 million , and the Company recognized $0.6 million and $1.2 million of interest expense, respectively, in the Company’s consolidated statement of operations for the three and nine months ended September 30, 2018 . The Company recognized a $1.9 million gain, net of a tax expense of $0.1 million , in AOCI for the nine months ended September 30, 2018 . The Company estimates that a cumulative amount of $0.1 million will be reclassified from AOCI to interest expense (as an increase to interest expense) in the next twelve months. In June 2018, the Company entered into a three -year interest rate cap with $800.0 million notional value outstanding. This interest rate cap was effective beginning on August 28, 2018. The fair value of this interest rate contract included in other assets on the consolidated balance sheet as of September 30, 2018 was $5.9 million , and the Company recognized $0.4 million and $0.5 million , respectively, of interest expense in the Company’s consolidated statement of operations for the three and nine months ended September 30, 2018 . The Company recognized a $0.7 million gain, net of a tax expense of $0.2 million , in AOCI for the nine months ended September 30, 2018 . The Company estimates that $1.7 million will be reclassified from AOCI to interest expense (as an increase to interest expense) in the next twelve months.

Goodwill and Other Intangible A

Goodwill and Other Intangible Assets	9 Months Ended
	Sep. 30, 2018
Goodwill and Intangible Assets Disclosure [Abstract]
Goodwill and Other Intangible Assets	Goodwill and Other Intangible Assets The following table summarizes the changes in the Company’s goodwill balances from December 31, 2017 to September 30, 2018 : Web Presence Email Marketing Domain Total (in thousands) Goodwill balance at December 31, 2017 $ 1,216,419 $ 604,305 $ 29,858 $ 1,850,582 Foreign translation impact (1,318 ) — — (1,318 ) Goodwill balance at September 30, 2018 $ 1,215,101 $ 604,305 $ 29,858 $ 1,849,264 In accordance with ASC 350, the Company reviews goodwill and other indefinite-lived intangible assets for indicators of impairment on an annual basis and between tests if an event occurs or circumstances change that would more likely than not reduce the fair value of goodwill below its carrying amount. At December 31, 2017 , other intangible assets consisted of the following: Gross Carrying Amount Accumulated Amortization Net Carrying Amount Weighted Average Useful Life (dollars in thousands) Developed technology $ 285,911 $ 149,514 $ 136,397 7 years Subscriber relationships 659,732 431,938 227,794 7 years Trade-names 134,054 73,019 61,035 8 years Intellectual property 34,313 27,336 6,977 5 years Domain names available for sale 30,458 7,221 23,237 Indefinite Total December 31, 2017 $ 1,144,468 $ 689,028 $ 455,440 During the nine months ended September 30, 2017 and 2018 , there were no impairment charges of intangible assets. At September 30, 2018 , other intangible assets consisted of the following: Gross Carrying Amount Accumulated Amortization Net Carrying Amount Weighted Average Useful Life (dollars in thousands) Developed technology $ 284,312 $ 173,203 $ 111,109 7 years Subscriber relationships 659,376 472,625 186,751 7 years Trade-names 134,046 81,740 52,306 8 years Intellectual property 34,306 28,566 5,740 5 years Domain names available for sale 30,855 9,091 21,764 Indefinite Total September 30, 2018 $ 1,142,895 $ 765,225 $ 377,670 The estimated useful lives of the individual categories of other intangible assets are based on the nature of the applicable intangible asset and the expected future cash flows to be derived from the intangible asset. Amortization of intangible assets with finite lives is recognized over the period of time the assets are expected to contribute to future cash flows. The Company amortizes finite-lived intangible assets over the period in which the economic benefits are expected to be realized based upon their estimated projected cash flows. The Company’s amortization expense is included in cost of revenue in the consolidated statement of operations and comprehensive loss in the aggregate amounts of $35.3 million and $26.2 million for the three months ended September 30, 2017 and 2018 , respectively. The Company's amortization expense is included in cost of revenue in the aggregate amounts of $104.6 million and $77.9 million for the nine months ended September 30, 2017 and 2018 , respectively.

Investments

Investments	9 Months Ended
	Sep. 30, 2018
Investments, Debt and Equity Securities [Abstract]
Investments	Investments As of December 31, 2017 and September 30, 2018 , the Company’s carrying value of investments in privately-held companies was $15.3 million and $15.3 million , respectively. In January 2012, the Company made an initial investment of $ 0.3 million to acquire a 25% interest in BlueZone Labs, LLC (“BlueZone”), a provider of “do-it-yourself” tools and managed search engine optimization services. The Company also has an agreement with BlueZone to purchase products and services. During the three months ended September 30, 2017 and 2018 , the Company purchased $ 0.4 million and $ 0.2 million , respectively, of products and services from BlueZone, which is included in cost of revenue in the Company’s consolidated statements of operations and comprehensive loss. During the nine months ended September 30, 2017 and 2018, the Company purchased $1.3 million and $0.9 million , respectively, of products and services from BlueZone, which is included in cost of revenue in the Company's consolidated statements of operations and comprehensive loss. As of December 31, 2017 and September 30, 2018 , $ 0.1 million and $ 0.0 million , respectively, relating to the Company’s investment in BlueZone was included in accounts payable and accrued expense in the Company’s consolidated balance sheet. As of December 31, 2017 and September 30, 2018 , $ 0.7 million and $ 0.1 million , respectively, relating to the Company’s investment in BlueZone was included in prepaid expenses and other current assets in the Company’s consolidated balance sheet. The investment is accounted for using the measurement alternative under ASU 2016-01 , Financial Instruments - Overall , as fair value is not readily available. In May 2014, the Company made a strategic investment of $ 15.0 million in Automattic, Inc. (“Automattic”), which provides content management systems associated with WordPress. The investment represents less than 5% of the outstanding shares of Automattic and better aligns the Company with an important partner. The investment is accounted for using the measurement alternative under ASU 2016-01 as fair value is not readily available. Investments in which the Company’s interest is less than 20% and which are not classified as available-for-sale securities are carried at the lower of cost or net realizable value unless it is determined that the Company exercises significant influence over the investee company, in which case the equity method of accounting is used. For those investments in which the Company’s voting interest is between 20% and 50% , the equity method of accounting is used. Under this method, the investment balance, originally recorded at cost, is adjusted to recognize the Company’s share of net earnings or losses of the investee company, as they occur, limited to the extent of the Company’s investment in, advances to and commitments for the investee. These adjustments are reflected in equity (income) loss of unconsolidated entities, net of tax in the Company’s consolidated statements of operations and comprehensive loss. The amount of (income) loss recognized from these investments in all periods presented in the Company's consolidated statement of operations has not been material for any of those periods.From time to time, the Company may make new and follow-on investments and may receive distributions from investee companies. As of September 30, 2018 , the Company was not obligated to fund any follow-on investments in these investee companies. As of September 30, 2018 , the Company did not have an equity method investment in which the Company’s proportionate share of the investee’s net income or loss exceeded 10% of the Company’s consolidated assets or income from continuing operations.

Notes Payable

Notes Payable	9 Months Ended
	Sep. 30, 2018
Debt Disclosure [Abstract]
Notes Payable	Notes Payable At December 31, 2017 and September 30, 2018 , notes payable, net of original issuance discounts (sometimes referred to as "OID") and deferred financing costs, consisted of the following: At December 31, 2017 At September 30, 2018 (in thousands) 2018 First Lien Term Loan $ — $ 1,493,131 2017 First Lien Term Loan 1,563,197 — Notes 329,048 330,911 Revolving credit facilities — — Total notes payable 1,892,245 1,824,042 Current portion of notes payable 33,945 31,606 Notes payable - long term $ 1,858,300 $ 1,792,436 2018 First Lien Term Loan Facility In connection with the Company's June 20, 2018 refinancing of its then-outstanding term loan (the "2018 Refinancing"), the Company entered into its current first lien term loan facility (the "2018 Term Loan") with an original balance of $1,580.3 million and a maturity date of February 9, 2023. As of September 30, 2018 , the 2018 Term Loan had an outstanding balance of: At September 30, 2018 (in thousands) 2018 First Lien Term Loan $ 1,530,002 Unamortized deferred financing costs (19,594 ) Unamortized original issue discount (17,277 ) Net 2018 First Lien Term Loan 1,493,131 Current portion of 2018 First Lien Term Loan 31,606 2018 First Lien Term Loan - long term $ 1,461,525 The 2018 Term Loan was issued at par and automatically bears interest at an alternate base rate unless the Company gives notice to opt for the LIBOR-based interest rate. The LIBOR-based interest rate for the 2018 Term Loan is 3.75% per annum plus the greater of an adjusted LIBOR and 1.00% . The alternate base rate for the 2018 Term Loan is 2.75% per annum plus the greatest of the prime rate, the federal funds effective rate plus 0.50% , an adjusted LIBOR for a one-month interest period plus 1.00% , and 2.00% . The 2018 Term Loan requires quarterly mandatory repayments of principal. During the nine months ended September 30, 2018 , following the 2018 Refinancing, the Company made two mandatory repayments of $7.9 million each, one voluntary prepayment of $17.0 million and one voluntary prepayment of $17.5 million . Interest is payable on maturity of the elected interest period for a term loan with a LIBOR-based interest rate, which interest period can be one, two, three or six months. Interest is payable at the end of each fiscal quarter for a term loan with an alternate base rate. 2017 First Lien Term Loan Facility The Company's prior first lien term loan facility (the "2017 Term Loan") was entered into in connection with the Company's June 14, 2017 refinancing of its then-outstanding term loans (the "2017 Refinancing"). The 2017 Term Loan had an original balance of $1,697.3 million and a maturity date of February 9, 2023. As of December 31, 2017 and September 30, 2018 , the 2017 Term Loan had an outstanding balance of: At December 31, 2017 At September 30, 2018 (in thousands) 2017 First Lien Term Loan $ 1,605,792 $ — Unamortized deferred financing costs (22,456 ) — Unamortized original issue discount (20,139 ) — Net 2017 First Lien Term Loan 1,563,197 — Current portion of 2017 First Lien Term Loan 33,945 — 2017 First Lien Term Loan - long term $ 1,529,252 $ — The 2017 Term Loan was issued at a price of 99.75% of par and automatically bore interest at an alternate base rate unless the Company gave notice to opt for the LIBOR-based interest rate. The LIBOR-based interest rate for the 2017 Term Loan was 4.00% per annum plus the greater of an adjusted LIBOR and 1.00% . The alternate base rate for the 2017 Term Loan was 3.00% per annum plus the greatest of the prime rate, the federal funds effective rate plus 0.50% , an adjusted LIBOR for a one-month interest period plus 1.00% , and 2.00% . The 2017 Term Loan required quarterly mandatory repayments of principal. During the nine months ended September 30, 2018 , prior to the 2018 Refinancing, the Company made one mandatory repayment of $8.5 million and one voluntary repayment of $17.0 million . Interest was payable on maturity of the elected interest period for a term loan with a LIBOR-based interest rate, which interest period could be one, two, three or six months. Interest was payable at the end of each fiscal quarter for a term loan with an alternate base rate. As part of the 2018 Refinancing, the Company refinanced the then-outstanding 2017 Term Loan balance of $1,580.3 million . Revolving Credit Facility In connection with the Company's February 9, 2016 acquisition of Constant Contact and the related financing of that transaction (the "Constant Contact Financing"), the Company entered into a revolving credit facility (the “2016 Revolver”) that replaced the Company's prior revolving credit facility. The 2016 Revolver has an aggregate available amount of $165.0 million . As of December 31, 2017 and September 30, 2018, the Company did not have any balances outstanding under the 2016 Revolver and the full amount of the facility was unused and available. In June 2018, the Company extended the maturity of a portion of the 2016 Revolver. The 2016 Revolver consists of a non-extended tranche of approximately $58.8 million and an extended tranche of approximately $106.2 million . The non-extended tranche has a maturity date of February 9, 2021. The extended tranche has a maturity date of June 20, 2023, with a "springing" maturity date of November 10, 2022 if the 2018 Term Loan has not been repaid in full or otherwise extended to September 19, 2023 or later prior to November 10, 2022. The Company has the ability to draw down against the 2016 Revolver using a LIBOR-based interest rate or an alternate base rate. The LIBOR-based interest rate for a non-extended revolving loan is 4.0% per annum (subject to a leverage-based step-down) and for an extended revolving loan is 3.25% per annum (subject to a leverage-based step-down), in each case plus an adjusted LIBOR for a selected interest period. The alternate base rate for a non-extended revolving loan is 3.0% per annum (subject to a leverage-based step-down) and for an extended revolving loan is 2.25% per annum (subject to a leverage-based step-down), in each case plus the greatest of the prime rate, the federal funds rate plus 0.50% and an adjusted LIBOR or a one-month interest period plus 1.00% . There is also a non-refundable commitment fee, equal to 0.50% per annum (subject to a leverage-based step-down) of the daily unused principal amount of the 2016 Revolver, which is payable in arrears on the last day of each fiscal quarter. Interest is payable on maturity of the elected interest period for a revolver loan with a LIBOR-based interest rate, which interest period can be one, two, three or six months. Interest is payable at the end of each fiscal quarter for a revolver loan with an alternate base rate. Senior Notes In connection with the Constant Contact Financing, EIG Investors issued $350.0 million aggregate principal amount of senior notes (the "Senior Notes") with a maturity date of February 1, 2024. The Senior Notes were issued at a price of 98.065% of par and bear interest at the rate of 10.875% per annum. The Senior Notes have been fully and unconditionally guaranteed, on a senior unsecured basis, by the Company and its subsidiaries that guarantee the 2018 Term Loan and the 2016 Revolver (including Constant Contact and certain of its subsidiaries). The Company has the right to redeem all or a part of the Senior Notes at any time for a premium which is based on the applicable redemption date. As of December 31, 2017 and September 30, 2018 , the Senior Notes had an outstanding balance of: At December 31, 2017 At September 30, 2018 (in thousands) Senior Notes $ 350,000 $ 350,000 Unamortized deferred financing costs (15,280 ) (13,921 ) Unamortized original issuance discount (5,672 ) (5,168 ) Net Senior Notes 329,048 330,911 Current portion of Senior Notes — — Senior Notes - long term $ 329,048 $ 330,911 Interest on the Senior Notes is payable twice a year, on August 1 and February 1. On January 30, 2017, the Company completed a registered exchange offer for the Senior Notes, as required under the registration rights agreement it entered into with the initial purchasers of the Senior Notes. All of the $350.0 million aggregate principal amount of the Senior Notes was validly tendered for exchange as part of this exchange offer. Maturity of Notes Payable The maturity of the notes payable at September 30, 2018 is as follows: Amounts maturing in: (in thousands) (Remainder of) 2018 $ 7,902 2019 31,606 2020 31,606 2021 31,606 2022 31,606 Thereafter 1,745,676 Total $ 1,880,002 Interest The Company recorded $35.8 million and $37.5 million in interest expense for the three months ended September 30, 2017 and 2018 , respectively, and $121.0 million and $111.9 million for the nine months ended September 30, 2017 and 2018 , respectively. The following table provides a summary of interest rates and interest expense for the three and nine months ended September 30, 2017 and 2018 : Three Months Ended September 30, 2017 Three Months Ended September 30, 2018 Nine Months Ended September 30, 2017 Nine Months Ended September 30, 2018 (percentage per annum) Interest rate—LIBOR 5.14%-5.32% 5.81%-6.07% 5.14%-6.68% 5.46%-6.32% Interest rate—reference * * * * Interest rate—Senior Notes 10.875 % 10.875 % 10.875 % 10.875 % Non-refundable fee—unused facility 0.50 % 0.50 % 0.50 % 0.50 % (dollars in thousands) Interest expense and service fees $ 32,551 $ 34,469 $ 105,371 $ 101,575 Loss on extinguishment of debt — — 992 331 Deferred financing fees immediately expensed — — 5,487 1,228 Amortization of deferred financing fees 1,873 1,722 5,403 4,708 Amortization of original issue discounts 1,059 1,083 2,791 3,209 Amortization of net present value of deferred consideration 127 60 504 311 Other interest expense 238 193 474 561 Total interest expense $ 35,848 $ 37,527 $ 121,022 $ 111,923 * The Company did not have debt bearing interest based on the alternate base rate for the three and nine months ended September 30, 2017 and 2018. The Company concluded that the 2017 Refinancing was primarily a debt modification of the existing term loans in accordance with ASC 470-50, Debt: Modifications and Extinguishments, with extinguishment relating only to a few existing lenders that did not participate in the 2017 Refinancing. As a result, during the second quarter of 2017, the Company capitalized $4.2 million of additional OID and $0.9 million of deferred financing costs related to new lenders participating in the 2017 Term Loan. These capitalized costs were being amortized over the remaining life of the loan using the effective interest method. Additionally in the second quarter of 2017, the Company recorded a charge of $1.0 million , included in interest expense, to write off OID and deferred financing costs related to the refinanced debt for lenders not participating in the 2017 Term Loan. Lastly, the Company recorded a charge of $5.5 million during the second quarter of 2017, included in interest expense, for deferred financing costs incurred for the 2017 Term Loan that related to existing lenders that carried over from the refinanced debt. The Company concluded that the 2018 Refinancing was primarily a debt modification of the existing term loan in accordance with ASC 470-50, Debt: Modifications and Extinguishments, with extinguishment relating only to one existing lender that did not participate in the 2018 Refinancing. As a result, during the second quarter of 2018, the Company capitalized $0.4 million of deferred financing costs related to new lenders participating in the 2018 Term Loan. These capitalized costs will be amortized over the remaining life of the loan using the effective interest method. Additionally, in the second quarter of 2018, the Company recorded a charge of $0.3 million , included in interest expense, to write off OID and deferred financing costs related to the refinanced debt for the lender not participating in the 2018 Term Loan. Lastly, the Company recorded a charge of $1.2 million during the second quarter of 2018, included in interest expense, for deferred financing costs incurred for the 2018 Term Loan that related to existing lenders that carried over from the refinanced debt. Debt Covenants The 2018 Term Loan and 2016 Revolver (together, the "Senior Credit Facilities") require that the Company complies with a financial covenant to maintain a maximum ratio of consolidated senior secured net indebtedness to an adjusted consolidated EBITDA measure. The Senior Credit Facilities also contain covenants that limit the Company's ability to, among other things, incur additional debt or issue certain preferred shares; pay dividends on or make other distributions in respect of capital stock; make other restricted payments; make certain investments; sell or transfer certain assets; create liens on certain assets to secure debt; consolidate, merge, sell or otherwise dispose of all or substantially all of its assets; and enter into certain transactions with affiliates. These covenants are subject to a number of important limitations and exceptions. Additionally, the Senior Credit Facilities require the Company to comply with certain negative covenants and specify certain events of default that could result in amounts becoming payable, in whole or in part, prior to their maturity dates. With the exception of certain equity interests and other excluded assets under the terms of the Senior Credit Facilities, substantially all of the Company's assets are pledged as collateral for the obligations under the Senior Credit Facilities. The indenture with respect to the Senior Notes contains covenants that limit the Company's ability to, among other things, incur additional debt or issue certain preferred shares; pay dividends on or make other distributions in respect of capital stock; make other restricted payments; make certain investments; sell or transfer certain assets; create liens on certain assets to secure debt; consolidate, merge sell or otherwise dispose of all or substantially all of its assets; and enter into certain transactions with affiliates. Upon a change of control as defined in the indenture, the Company must offer to repurchase the Senior Notes at 101% of the aggregate principal amount thereof, plus accrued and unpaid interest, if any, up to, but not including, the repurchase date. These covenants are subject to a number of important limitations and exceptions. The indenture also provides for events of default, which, if any of them occurs, may permit or, in certain circumstances, require the principal, premium, if any, interest and any other monetary obligations on all the then outstanding Senior Notes to be due and payable immediately. The Company was in compliance with all covenants at September 30, 2018 .

Stockholders' Equity

Stockholders' Equity	9 Months Ended
	Sep. 30, 2018
Equity [Abstract]
Stockholders' Equity	Stockholders’ Equity Voting Rights All holders of common stock are entitled to one vote per share. Changes in Total Stockholders' Equity The following table presents the changes in total stockholders’ equity during the nine months ended September 30, 2018 : Total Stockholders’ Equity (in thousands) Balance at December 31, 2017 $ 83,005 Stock-based compensation 21,932 Reclassification of stock-compensation liability award 250 Stock option exercises 756 Foreign currency translation adjustment (2,489 ) Unrealized gain on derivative 1,996 Adjustment to beginning retained earnings resulting from adoption of ASC 606, net of tax impact of $7.0 million 59,384 Net loss attributable to Endurance International Group Holdings, Inc. (8,236 ) Balance at September 30, 2018 $ 156,598

Stock-Based Compensation

Stock-Based Compensation	9 Months Ended
	Sep. 30, 2018
Disclosure of Compensation Related Costs, Share-based Payments [Abstract]
Stock-Based Compensation	Stock-Based Compensation 2013 Stock Incentive Plan The Amended and Restated 2013 Stock Incentive Plan (the “2013 Plan”) of the Company became effective upon the closing of its initial public offering ("IPO"). The 2013 Plan provides for the grant of options, stock appreciation rights, restricted stock, restricted stock units and other stock-based awards to employees, officers, directors, consultants and advisers of the Company. Under the 2013 Plan, the Company may issue up to 38,000,000 shares of the Company’s common stock. At September 30, 2018 , there were 16,722,969 shares available for grant under the 2013 Plan. 2011 Stock Incentive Plan As of February 9, 2016, the effective date of the acquisition of Constant Contact, the Company assumed and converted certain outstanding equity awards granted by Constant Contact under the Constant Contact 2011 Stock Incentive Plan (the “2011 Plan”) prior to the effective date of the acquisition (the “Assumed Awards”) into corresponding equity awards with respect to shares of the Company’s common stock. In addition, the Company assumed certain shares of Constant Contact common stock, par value $0.01 per share, available for issuance under the 2011 Plan (the “Available Shares”), which will be available for future issuance under the 2011 Plan in satisfaction of the vesting, exercise or other settlement of options and other equity awards that may be granted by the Company following the effective date of the acquisition of Constant Contact in reliance on the prior approval of the 2011 Plan by the stockholders of Constant Contact. The Assumed Awards were converted into 2,143,987 stock options and 2,202,846 restricted stock units with respect to the Company’s common stock and the Available Shares were converted into 10,000,000 shares of the Company’s common stock reserved for future awards under the 2011 Plan. At September 30, 2018 , there were 8,390,174 shares available for grant under the 2011 Plan. All Plans The following table presents total stock-based compensation expense recorded in the consolidated statement of operations and comprehensive loss for all awards granted under the Company’s 2013 Plan and 2011 Plan: Three Months Ended Nine Months Ended 2017 2018 2017 2018 (in thousands) Cost of revenue $ 1,553 $ 828 $ 4,720 $ 3,223 Sales and marketing 2,263 1,478 7,027 4,009 Engineering and development 1,807 1,237 4,707 3,519 General and administrative 13,956 4,007 32,295 11,181 Total stock-based compensation expense $ 19,579 $ 7,550 $ 48,749 $ 21,932 2013 Stock Incentive Plan The following table provides a summary of the Company’s stock options as of September 30, 2018 and the stock option activity for all stock options granted under the 2013 Plan during the nine months ended September 30, 2018 : Stock Options Weighted- Average Exercise Price Weighted- Average Remaining Contractual Term (in years) Aggregate Intrinsic Value(3) (in thousands) Outstanding at December 31, 2017 8,575,150 $ 12.30 Granted 611,010 $ 7.50 Exercised (19,049 ) $ 8.09 Forfeited (304,382 ) $ 12.79 Expired (1,516,912 ) $ 13.56 Outstanding at September 30, 2018 7,345,817 $ 11.63 5.1 $ 1,600 Exercisable at September 30, 2018 5,475,357 $ 12.39 3.9 $ 283 Expected to vest after September 30, 2018 (1) 1,870,460 $ 9.39 8.4 $ 1,317 Exercisable as of September 30, 2018 and expected to vest (2) 7,345,817 $ 11.63 5.1 $ 1,600 (1) This represents the number of unvested options outstanding as of September 30, 2018 that are expected to vest in the future. (2) This represents the number of vested options as of September 30, 2018 plus the number of unvested options outstanding as of September 30, 2018 that are expected to vest in the future. (3) The aggregate intrinsic value was calculated based on the positive difference, if any, between the estimated fair value of the Company’s common stock on September 30, 2018 of $8.80 per share, or the date of exercise, as appropriate, and the exercise price of the underlying options. Restricted stock units granted under the 2013 Plan generally vest annually over a three -year period, unless otherwise determined by the Company’s board of directors. The following table provides a summary of the Company’s restricted stock unit activity for the 2013 Plan during the nine months ended September 30, 2018 : Restricted Stock Units Weighted Average Grant Date Fair Value Non-vested at December 31, 2017 3,004,137 $ 7.93 Granted 3,846,567 $ 7.55 Vested (1,185,704 ) $ 9.08 Canceled (394,763 ) $ 7.78 Non-vested at September 30, 2018 5,270,237 $ 7.67 Restricted stock awards granted under the 2013 Plan generally vest annually over a four -year period, unless otherwise determined by the Company’s board of directors. Performance-based restricted stock awards are earned based on the achievement of performance criteria established by the Company’s compensation committee and board of directors. The following table provides a summary of the Company’s restricted stock award activity for the 2013 Plan during the nine months ended September 30, 2018 : Restricted Stock Weighted Non-vested at December 31, 2017 3,432,946 $ 13.79 Granted — $ — Vested (819,886 ) $ 12.29 Canceled (2,134,075 ) $ 14.85 Non-vested at September 30, 2018 478,985 $ 11.62 2015 Performance Based Award During fiscal year 2015, the Company granted a performance-based restricted stock award to the Company’s chief executive officer ("CEO") at that time, Hari Ravichandran, which provided for the opportunity to earn up to 3,693,754 shares of the Company’s common stock (the “Award Shares”) over a three -year period beginning July 1, 2015 and ending on June 30, 2018 (the “Performance Period”). Award Shares could be earned based on the Company achieving pre-established threshold, target and maximum performance metrics. In April 2017, the Company announced that its board of directors and Mr. Ravichandran adopted a CEO transition plan. As a result of this transition, Mr. Ravichandran's employment with the Company ended during the fourth quarter of fiscal year 2017. Upon the end of his employment, in accordance with the terms of the award, Mr. Ravichandran received the Award Shares earned in the quarters completed prior to the separation, plus the number of Award Shares that would have been earned in the quarter in which the separation occurred, which amounted to an aggregate of 1,661,439 shares. The unearned 2,032,315 shares were forfeited. All charges relating to this award were recognized prior to January 1, 2018. 2016 Performance Based Awards On February 16, 2016, the compensation committee of the board of directors of the Company approved the grant of performance-based restricted stock awards to the Company’s chief financial officer (“CFO”), chief operating officer (“COO”) at that time and chief administrative officer (“CAO”) at that time. Based on the Company's achievement of Constant Contact revenue, adjusted EBITDA and cash flow metrics, each executive earned the maximum number of shares subject to his or her award. The CFO earned 223,214 shares of the Company’s stock, the COO earned 260,416 shares of the Company’s stock, and the CAO earned 148,810 shares of the Company’s stock. These earned shares vested on March 31, 2017. During the three months ended March 31, 2017, the Company recognized $1.2 million of stock-based compensation expense related to these performance-based awards, which was the last quarter stock-based compensation was recorded relating to these awards. New CEO Award On August 11, 2017, the Company and Jeffrey H. Fox entered into an employment agreement (the “Employment Agreement”) appointing Mr. Fox as the Company’s president and chief executive officer effective upon his employment start date (the “Effective Date”) of August 22, 2017. The Employment Agreement provided for Mr. Fox to receive, on the Effective Date, an equity award under the 2013 Plan with a total value of $10,375,000 as of August 11, 2017, split between an award of 1,032,500 restricted stock units (the “RSU Award”) and an option to purchase 612,419 shares of the Company’s common stock (the “Stock Option Grant”). Two Hundred Eighty-Two Thousand Five Hundred ( 282,500 ) of the restricted stock units subject to the RSU Award vested immediately on the Effective Date, but are subject to a requirement that Mr. Fox hold the shares underlying such restricted stock units until the earlier of the third anniversary of the Effective Date, his death or disability (as defined in the Employment Agreement) or a change in control of the Company (as defined in the Employment Agreement). The Company recorded a charge of $2.2 million for these immediately vested shares during the three months ended September 30, 2017. The remaining 750,000 restricted stock units subject to the RSU Award will vest over a three -year period, with 250,000 of such restricted stock units vesting annually on the anniversary of the Effective Date. The Stock Option Grant will vest over a three -year period, with one-third of the total number of shares subject to the Stock Option Grant vesting on the first anniversary of the Effective Date and the remainder vesting in equal monthly installments thereafter. 2011 Stock Incentive Plan The following table provides a summary of the Company’s stock options as of September 30, 2018 and the stock option activity for all stock options granted under the 2011 Plan during the nine months ended September 30, 2018 : Stock Options Weighted- Average Exercise Price Weighted- Average Remaining Contractual Term (In Years) Aggregate Intrinsic Value(3) (in thousands) Outstanding at December 31, 2017 888,260 $ 8.75 Granted — $ — Exercised (92,229 ) $ 6.53 Forfeited (10,256 ) $ 10.47 Expired (38,652 ) $ 9.21 Outstanding at September 30, 2018 747,123 $ 8.98 3.7 $ 546 Exercisable at September 30, 2018 563,823 $ 8.76 3.5 $ 499 Expected to vest after September 30, 2018 (1) 183,300 $ 9.65 4.2 $ 47 Exercisable as of September 30, 2018 and expected to vest (2) 747,123 $ 8.98 3.7 $ 546 (1) This represents the number of unvested options outstanding as of September 30, 2018 that are expected to vest in the future. (2) This represents the number of vested options as of September 30, 2018 plus the number of unvested options outstanding as of September 30, 2018 that are expected to vest in the future. (3) The aggregate intrinsic value was calculated based on the positive difference, if any, between the estimated fair value of the Company’s common stock on September 30, 2018 of $8.80 per share, or the date of exercise, as appropriate, and the exercise price of the underlying options. Unless otherwise determined by the Company’s board of directors, restricted stock units granted under the 2011 Plan generally vest annually over a three - or a four -year period. The following table provides a summary of the Company’s restricted stock unit activity for the 2011 Plan during the nine months ended September 30, 2018 : Restricted Stock Units Weighted Average Grant Date Fair Value Non-vested at December 31, 2017 1,541,141 $ 8.30 Granted 41,379 $ 7.25 Vested (516,600 ) $ 8.38 Canceled (92,030 ) $ 8.53 Non-vested at September 30, 2018 973,890 $ 8.20 Under both the 2011 and 2013 Plans combined, as of September 30, 2018 the Company had approximately $8.9 million of unrecognized stock-based compensation expense related to option awards that will be recognized over 1.6 years and approximately $43.7 million of unrecognized stock-based compensation expense related to restricted stock awards and restricted stock units that will be recognized over 2.1 years.

Accumulated Other Comprehensive

Accumulated Other Comprehensive Income	9 Months Ended
	Sep. 30, 2018
Equity [Abstract]
Accumulated Other Comprehensive Income	Accumulated Other Comprehensive Income The following table presents the components of accumulated other comprehensive income (loss): Foreign Currency Translation Adjustments Unrealized Gains (Losses) on Cash Flow Hedges Total (in thousands) Balance at December 31, 2017 $ 696 $ (1,237 ) $ (541 ) Other comprehensive income (loss) (2,489 ) 1,996 (493 ) Balance at September 30, 2018 $ (1,793 ) $ 759 $ (1,034 )

Variable Interest Entity

Variable Interest Entity	9 Months Ended
	Sep. 30, 2018
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Variable Interest Entity	Variable Interest Entity The Company, through a subsidiary formed in China, entered into various agreements with Shanghai Xiao Lan Network Technology Co., Ltd (“Shanghai Xiao”) and its shareholders that allowed the Company to effectively control Shanghai Xiao, making it a variable interest entity (“VIE”). Shanghai Xiao has a technology license that allows it to provide local hosting services to customers located in China. During fiscal year 2018, the Company ceased operations of the VIE, and has begun the process to liquidate the entity. From inception and through the period ended September 30, 2018 , the financial position and results of operations of Shanghai Xiao are consolidated within, but are not material to, the Company’s consolidated financial position or results of operations.

Revenue

Revenue	9 Months Ended
	Sep. 30, 2018
Revenue from Contract with Customer [Abstract]
Revenue	Revenue Adoption of ASC Topic 606, “Revenue from Contracts with Customers” The Company recorded a net increase to opening retained earnings of $59.4 million as of January 1, 2018 due to the cumulative impact of adopting Topic 606, with the impact primarily related to customer acquisition costs. The impact to revenue and customer acquisition costs during the three months ended September 30, 2018 as a result of applying Topic 606 was a decrease of $0.6 million and an increase of $0.0 million , respectively. The impact to revenue and customer acquisition costs during the nine months ended September 30, 2018 was a decrease of $1.2 million and an increase of $0.5 million , respectively. During the three and nine months ended September 30, 2018 , the Company recognized $283.8 million and $862.9 million of revenue, respectively, the majority of which was derived from contracts with customers. During the three and nine months ended September 30, 2018 , the Company did not incur any impairment losses on any receivables or contract assets arising from the Company’s contracts with customers. During the three and nine months ended September 30, 2018 , the Company did not incur any credit losses on any receivables or contract assets, arising from the Company’s contracts with customers. In accordance with ASC 606, the Company disaggregates revenue from contracts with customers based on the timing of revenue recognition. The Company determined that disaggregating revenue into these categories depicts how the nature, amount, timing and uncertainty of revenue and cash flows are affected by economic factors. As discussed in Note 21. Segment Information , the Company business consists of the web presence, domain and email marketing segments. The following table presents disaggregated revenues by category for the three and nine months ended September 30, 2018 : Three Months Ended September 30, 2018 Web presence Email marketing Domain Total (in thousands) Subscriber revenue Direct revenue from subscribers $ 138,869 $ 100,816 $ 12,911 $ 252,596 Professional services 3,387 299 103 3,789 Reseller revenue 5,241 855 12,585 18,681 Total subscriber revenue $ 147,497 $ 101,970 $ 25,599 $ 275,066 Non-subscriber revenue MDF $ 2,199 $ 141 $ 252 $ 2,592 Premium domains 3 — 5,067 5,070 Domain parking 172 — 870 1,042 Total non-subscriber revenue $ 2,374 $ 141 $ 6,189 $ 8,704 Total revenue: $ 149,871 $ 102,111 $ 31,788 $ 283,770 Nine Months Ended September 30, 2018 Web presence Email marketing Domain Total (in thousands) Subscriber revenue Direct revenue from subscribers $ 424,321 $ 302,583 $ 39,185 $ 766,089 Professional services 10,091 1,045 300 11,436 Reseller revenue 16,487 2,620 39,136 58,243 Total subscriber revenue $ 450,899 $ 306,248 $ 78,621 $ 835,768 Non-subscriber revenue MDF $ 6,012 $ 464 $ 473 $ 6,949 Premium domains 70 — 15,823 15,893 Domain parking 622 — 3,664 4,286 Total non-subscriber revenue $ 6,704 $ 464 $ 19,960 $ 27,128 Total revenue: $ 457,603 $ 306,712 $ 98,581 $ 862,896 Subscriber revenue is primarily recognized over time, when the services are performed, except for third party products for which the Company acts as an agent. Revenue from third party products for which the Company acts as an agent is recognized at a point in time, when the revenue is earned. Revenue, classified by the major geographic areas in which the Company’s customers are located, was as follows for the three and nine months ended September 30, 2018 : Three Months Ended September 30, 2018 Web presence Email marketing Domain Total (in thousands) Domestic $ 100,065 $ 93,992 $ 12,509 $ 206,566 International 49,806 8,119 19,279 77,204 Total $ 149,871 $ 102,111 $ 31,788 $ 283,770 Nine Months Ended September 30, 2018 Web presence Email marketing Domain Total (in thousands) Domestic $ 306,724 $ 281,717 $ 38,525 $ 626,966 International 150,879 24,995 60,056 235,930 Total $ 457,603 $ 306,712 $ 98,581 $ 862,896

Redeemable Non-controlling Inte

Redeemable Non-controlling Interest	9 Months Ended
	Sep. 30, 2018
Noncontrolling Interest [Abstract]
Redeemable Non-controlling Interest	Redeemable Non-controlling Interest On January 6, 2016, the Company increased its stake from a 49.0% to a 57.5% controlling interest in WZ (UK) Ltd. ("WZ UK"), an entity specialized in marketing certain of the Company's products. The minority shareholders could put their non-controlling interest, or NCI, to the Company within pre-specified put periods. As the NCI was subject to a put option that was outside the control of the Company, it was deemed a redeemable non-controlling interest and was not recorded in permanent equity, and was presented in mezzanine redeemable non-controlling interest on the consolidated balance sheet. The Company increased its ownership interest in WZ UK to 77.5% in May of 2016. On July 13, 2016, the Company completed a restructuring with the minority shareholders that resulted in Pseudio Limited and Resume Labs Limited becoming wholly-owned subsidiaries of WZ UK, and acquired an increased ownership interest in the consolidated entity which brought the Company's ownership of WZ UK to 86.4% . The restructuring significantly reduced the amount of the potential redemption amount payable to the minority shareholders, and gave the Company the flexibility to reduce investments in this business. Based on these reduced investments, the estimated value of the non-controlling interest was below the expected redemption amount of $25.0 million , which resulted in $14.2 million of excess accretion that reduced income available to common shareholders for the period starting on the date of the restructuring through the redemption date of July 1, 2017. The Company recognized excess accretion of $0.0 million and $7.2 million for the three and nine months ended September 30, 2017 , respectively, which is reflected in net loss attributable to accretion of non-controlling interest in the Company’s consolidated statements of operations and comprehensive loss. Prior to the third quarter of 2016, the Company did not have any accretion amounts in excess of fair value. On July 7, 2017, the Company redeemed the remaining redeemable non-controlling interest for $25.0 million .

Income Taxes

Income Taxes	9 Months Ended
	Sep. 30, 2018
Income Tax Disclosure [Abstract]
Income Taxes	Income Taxes On December 22, 2017, the United States enacted tax reform legislation by passage of the commonly named Tax Cuts and Jobs Act, which significantly changes the existing U.S. tax laws, including a reduction in the corporate tax rate from 35% to 21% and a move from a worldwide tax system to a territorial system, as well as other changes. As a result of enactment of the legislation, the Company incurred an additional one-time income tax benefit on the re-measurement of certain deferred tax assets and liabilities in the amount of $16.9 million for the year ended December 31, 2017. The legislation also introduced substantial international tax reform that moves the U.S. toward a territorial system, in which income earned in other countries will generally not be subject to U.S. taxation. The accumulated foreign earnings of U.S. shareholders of certain foreign corporations will be subject to a one-time transition tax. Amounts held in cash or cash equivalents will be subject to a 15.5% tax, while amounts held in illiquid assets will be subject to an eight percent tax. Due to an accumulated deficit in the undistributed earnings of the Company's foreign subsidiaries, the one-time transition tax will not apply to the Company. Additionally, the legislation also contains provisions which would generally limit the Company's deduction for interest expense to 30% of adjusted taxable earnings before interest, taxes, depreciation and amortization ("Tax EBITDA"). The legislation includes provisions which provide a deduction related to intangible income that is owned in the U.S., an additional tax charge related to income from intangibles owned outside the U.S., and a new base-erosion and anti-abuse tax. Although the Company has substantially completed its work on the effects of the Tax Cuts and Jobs Act, it continues to evaluate certain sections of the new law that may be pertinent to the Company's tax situation. The Company has also adopted an accounting policy, as provided by the FASB in their January 10, 2018 Board Meeting, to account for the tax effects of the Global Intangible Low Tax Income ("GILTI") in the periods that the Company is subject to such tax. As a result of this accounting policy, the Company will not be recording the tax effect of the deferred tax assets and liabilities associated with the GILTI tax. During fiscal year 2017, the Company recorded a deferred tax expense and maintained a deferred tax liability to account primarily for the different book and tax treatment of tax deductible goodwill. Prior to 2018, the Company could not utilize deferred tax assets against the portion of the deferred tax liability related to tax deductible goodwill, as that liability was considered to have an indefinite life. With the passage of the Tax Cuts and Jobs Act, NOL carry-forwards generated after 2017 and the carry-forward of disallowed interest expense are indefinite in life, and therefore are eligible to offset indefinite life deferred tax liabilities. The Company's deferred tax expense (benefit) during 2018 has been impacted by this change. As described in Note 3, the Company has revised its deferred income tax provision for the first and second quarter of 2018 to reflect an increase in NOL carry-forwards resulting from the reorganization and liquidation of certain affiliated entities which resulted in the recognition of a worthless stock loss of approximately $78.0 million during fiscal year 2017. This revision did not impact the previously reported income tax provision for fiscal year 2017; however, due to the changes enacted in the Tax Cuts and Jobs Act, the manner in which net operating loss carry-forwards are handled did impact the Company's 2018 provision for deferred income taxes previously recorded for the three months ended March 31, 2018 and for the three and six months ended June 30, 2018. The Company revised its provision (benefit) for income taxes for the three months ended March 31, 2018 from an expense of $2.6 million to a benefit of $(1.9) million . The Company also revised its provision (benefit) for income taxes for the three and six months ended June 30, 2018 from an expense of $1.7 million to a benefit of $(0.9) million , and an expense of $4.3 million to a benefit of $(2.9) million , respectively. All of these changes are attributable to changes in deferred tax expense (benefit). The Company regularly assesses its ability to realize its deferred tax assets. Assessing the realization of deferred tax assets requires significant management judgment. In determining whether its deferred tax assets are more likely than not realizable, the Company evaluated all available positive and negative evidence, and weighted the evidence based on its objectivity. Evidence the Company considered included: • NOLs incurred from the Company’s inception to September 30, 2018 ; • Expiration of various federal, state and foreign tax attributes; • Reversals of existing temporary differences; • Composition and cumulative amounts of existing temporary differences; and • Forecasted profit before tax. The Company updates the scheduling of the reversal of the consolidated U.S. deferred tax assets and liabilities each quarter, as the deferred tax liabilities have continued to decrease and the Company generated pre-tax losses. Based on the analysis of the above evidence, the Company recorded a reduction of $7.9 million to its valuation allowance during the three months ended September 30, 2018 . The Company recognizes, in its consolidated financial statements, the effect of a tax position when it is more likely than not, based on the technical merits, that the position will be sustained upon examination. During the quarter ended September 30, 2017, management concluded that the Company’s material tax positions require the recording of an ASC 740-10 reserve, with interest and penalties, for uncertain income tax positions as of September 30, 2017. The Company has unrecognized tax positions at December 31, 2017 and September 30, 2018 of $1.1 million and $2.9 million , respectively, that would affect its effective tax rate. The Company does not expect a significant change in the liability for unrecognized tax benefits in the next 12 months. For the three months ended September 30, 2017 and 2018 , the Company recognized a tax expense of $3.0 million and $11.7 million , respectively, in the consolidated statements of operations and comprehensive loss. The income tax expense for the three months ended September 30, 2018 was primarily attributable to a federal and state deferred tax expense of $12.9 million due primarily to the different book and tax treatment of goodwill, a federal and state current income tax expense of $0.1 million and a foreign deferred tax expense of $0.3 million , partially offset by a foreign current tax benefit of $1.6 million . The income tax expense for the three months ended September 30, 2017 was primarily attributable to a federal and state deferred tax expense of $1.9 million , federal and state current income taxes of $0.2 million , foreign current tax expense of $0.7 million , and a foreign deferred tax expense of $0.2 million . For the nine months ended September 30, 2017 and 2018 , the Company recognized a tax expense of $11.4 million and $8.8 million , respectively, in the consolidated statements of operations and comprehensive loss. The income tax expense for the nine months ended September 30, 2018 was primarily attributable to a federal and state deferred tax expense of $8.9 million , a federal and state current income tax expense of $0.5 million , a foreign deferred tax expense of $0.2 million , partially offset by a foreign current tax benefit of $0.8 million . The income tax expense for the nine months ended September 30, 2017 was primarily attributable to a federal and state deferred tax expense of $7.3 million , federal and state current income taxes of $2.6 million , a foreign current tax expense of $2.3 million , partially offset by a foreign deferred tax benefit of $0.8 million . As of December 31, 2017 , the Company had NOL carry-forwards available to offset future U.S. federal taxable income of approximately $236.3 million and future state taxable income of approximately $168.3 million . These NOL carry-forwards expire on various dates through 2037 . As of December 31, 2017, the Company had NOL carry-forwards in foreign jurisdictions available to offset future foreign taxable income by approximately $26.7 million . The Company has loss carry-forwards that begin to expire in 2021 in in China totaling $0.7 million . The Company has loss carry-forwards that begin to expire in 2020 in the Netherlands totaling $12.6 million . The Company also has loss carry-forwards in the United Kingdom and Singapore of $13.2 million and $0.2 million , respectively, which have an indefinite carry-forward period. A recent U.K. tax law change provides that U.K. losses can only offset 50% of trading profits incurred after April 1, 2017. In addition, the Company has $3.4 million of U.S. federal capital loss carry-forwards and $1.4 million in state capital loss carry-forwards, generally expiring through 2021. As of December 31, 2017, the Company had U.S. tax credit carry-forwards available to offset future U.S. federal and state taxes of approximately $17.6 million and $12.3 million , respectively. These credit carry-forwards expire on various dates through 2037. Utilization of the NOL carry-forwards may be subject to an annual limitation due to the ownership change rules under Section 382 of the Internal Revenue Code (“Section 382 limitation”). Ownership changes can limit the amount of net operating loss and other tax attributes that a company can use each year to offset future taxable income and taxes payable. Although the Company has experienced a number of ownership changes over time, it currently does not have any Section 382 limitation on its ability to utilize NOL carry-forwards. The Company files income tax returns in the United States for federal income taxes and in various state jurisdictions. The Company also files in several foreign jurisdictions. In the normal course of business, the Company is subject to examination by tax authorities throughout the world. Since the Company is in a loss carry-forward position, it is generally subject to U.S. federal and state income tax examinations by tax authorities for all years for which a loss carry-forward is utilized. One of the Company’s subsidiaries, Constant Contact, Inc., is under audit by the U.S. Internal Revenue Service and the New York City Department of Finance for periods ended December 31, 2015 and February 9, 2016. The Company is also currently under audit in India for fiscal years ended March 31, 2014, 2015 and 2016 and Israel for the fiscal years ended December 31, 2012, 2013, 2014 and 2015.

Severance and Other Exit Costs

Severance and Other Exit Costs	9 Months Ended
	Sep. 30, 2018
Restructuring and Related Activities [Abstract]
Severance and Other Exit Costs	Severance and Other Exit Costs The Company continues to evaluate its data center, sales and marketing, support and engineering operations and the general and administrative function in an effort to optimize its cost structure. As a result, the Company may incur charges for employee severance, exiting facilities and restructuring data center commitments and other related costs. 2018 Restructuring Plan In January 2018, the Company announced plans to eliminate approximately 71 positions, later increased to approximately 95 positions, primarily in the Asia Pacific region and to a lesser extent in the U.S., in order to streamline operations and create operational efficiencies (the "2018 Restructuring Plan"). During the three and nine months ended September 30, 2018 , the Company incurred severance costs of $0.1 million and $3.0 million , and paid $0.6 million and $2.4 million , respectively, and had a remaining accrued severance liability of $0.6 million as of September 30, 2018 in connection with the 2018 Restructuring Plan. The Company expects to complete severance charges related to the 2018 Restructuring Plan during the year ending December 31, 2018. 2017 Restructuring Plan In January 2017, the Company announced plans to close certain offices as part of a plan to consolidate certain web presence customer support operations, resulting in severance costs. These severance charges were associated with the elimination of approximately 660 positions, primarily in customer support. Additionally, the Company implemented additional restructuring plans to create operational efficiencies and synergies related to the Constant Contact acquisition, which resulted in additional severance charges for the elimination of approximately 50 positions. During the three and nine months ended September 30, 2018 , in connection with these plans (together, the “2017 Restructuring Plan”), the Company recorded severance charges of $0.0 million and $0.0 million , respectively, and paid $0.5 million and $3.3 million , respectively. The Company had a remaining accrued severance liability of $0.4 million as of September 30, 2018 . In connection with the 2017 Restructuring Plan, the Company closed offices in Orem, Utah and relocated certain employees to its Tempe, Arizona office. During the three and nine months ended September 30, 2018 , the Company recorded an expense of $0.0 million and reductions of $0.2 million , respectively, and paid $0.0 million and $0.1 million , respectively. The Company had a remaining accrued facility liability of $0.0 million as of September 30, 2018 . The Company expects to complete severance charges related to the 2017 Restructuring Plan during the year ending December 31, 2018. 2016 Restructuring Plan In connection with the Company’s acquisition of Constant Contact on February 9, 2016, the Company implemented a plan to create operational efficiencies and synergies resulting in severance costs and facility exit costs (the “2016 Restructuring Plan”). The severance charges were associated with the elimination of approximately 265 positions across the business. The Company incurred all employee-related charges associated with the 2016 Restructuring Plan during the year ended December 31, 2016 and all severance payments were complete at December 31, 2017. There is no severance accrual remaining as of September 30, 2018 . The 2016 Restructuring Plan included the closure of offices in San Francisco, California, Delray Beach, Florida, New York, New York, Miami, Florida, the United Kingdom and Brazil, and the relocation of certain employees to the Company's Austin, Texas office. The Company also closed a portion of the Constant Contact offices in Waltham, Massachusetts. During the three and nine months ended September 30, 2018 , the Company recorded charges of $0.1 million and $0.2 million , respectively. The Company paid $0.5 million and $1.5 million , respectively, of facility costs related to the 2016 Restructuring Plan during the three and nine months ended September 30, 2018 . The Company had a remaining accrued facility liability of $4.3 million as of September 30, 2018 . The Company completed facility-related charges associated with the 2016 Restructuring Plan during the year ended December 31, 2016, and expects to complete facility exit cost payments related to this plan during the year ending December 31, 2022. Activity of Combined Restructuring Plans The following table provides a summary of the aggregate activity for the nine months ended September 30, 2018 related to the Company’s combined restructuring plans' severance accrual: Employee Severance (in thousands) Total Balance at December 31, 2017 $ 3,668 Severance charges 2,978 Cash paid (5,646 ) Balance at September 30, 2018 $ 1,000 The following table provides a summary of the aggregate activity for the nine months ended September 30, 2018 related to the Company’s combined restructuring plans' facilities exit accrual: Facilities (in thousands) Total Balance at December 31, 2017 $ 6,005 Facility adjustments 43 Sublease income received 322 Cash paid (2,080 ) Balance at September 30, 2018 $ 4,290 The following table presents restructuring charges recorded in the consolidated statements of operations and comprehensive loss for the periods presented: For the Three Months Ended September 30, For the Nine Months Ended September 30, 2017 2018 2017 2018 (in thousands) Cost of revenue $ 449 $ 37 $ 3,892 $ 1,443 Sales and marketing 1,011 17 3,260 133 Engineering and development 271 33 1,349 389 General and administrative 2,758 110 6,083 1,056 Total restructuring charges $ 4,489 $ 197 $ 14,584 $ 3,021

Commitments and Contingencies

Commitments and Contingencies	9 Months Ended
	Sep. 30, 2018
Commitments and Contingencies Disclosure [Abstract]
Commitments and Contingencies	Commitments and Contingencies From time to time, the Company is involved in legal proceedings or subject to claims arising in the ordinary course of its business. The Company is not presently involved in any such legal proceeding or subject to any such claim that, in the opinion of its management, would have a material adverse effect on its business, operating results or financial condition. However, the results of such legal proceedings or claims cannot be predicted with certainty, and regardless of the outcome, can have an adverse impact on the Company because of defense and settlement costs, diversion of management resources and other factors. Neither the ultimate outcome of the Machado and McGee shareholder litigation matters listed below nor an estimate of any probable losses or any reasonably possible losses (other than the reserves specifically discussed below) can be assessed at this time. The Company received a subpoena dated December 10, 2015 from the Boston Regional Office of the SEC, requiring the production of certain documents, including, among other things, documents related to its financial reporting, including operating and non-GAAP metrics, refund, sales and marketing practices and transactions with related parties. On June 5, 2018, the Company announced that it had settled both this investigation and the Constant Contact investigation discussed below by consenting to the SEC's entry of a cease and desist order (the "Order"), without admitting or denying the SEC's findings set forth in the Order, and by paying a civil monetary penalty. The Company accrued the penalty in the fiscal quarter ended September 30, 2017 and paid the penalty in the fiscal quarter ended June 30, 2018. On May 4, 2015, Christopher Machado, a purported holder of the Company’s common stock, filed a civil action in the United States District Court for the District of Massachusetts against the Company and its former chief executive officer and former chief financial officer, captioned Machado v. Endurance International Group Holdings, Inc., et al., Civil Action No. 1:15-cv-11775-GAO. The plaintiff filed an amended complaint on December 8, 2015, and a second amended complaint on March 18, 2016. The Company moved to dismiss the second amended complaint, but before the court ruled on the Company's motion, with the Company's assent, the plaintiff filed a third amended complaint on June 30, 2017. In the third amended complaint, plaintiffs Christopher Machado and Michael Rubin allege claims for violations of Section 10(b) and 20(a) of the Exchange Act, and Sections 11, 12(a)(2), and 15 of the Securities Act, on behalf of a purported class of purchasers of the Company’s securities between October 25, 2013 and December 16, 2015, including persons or entities who purchased or acquired the Company's shares pursuant or traceable to the registration statement and prospectus issued in connection with the Company's October 25, 2013 initial public offering. The plaintiffs challenge as false or misleading certain of the Company’s disclosures about the total number of subscribers, average revenue per subscriber, the number of customers paying over $500 per year for the Company’s products and services, and the average number of products sold per subscriber. The plaintiffs seek, on behalf of themselves and the purported class, compensatory damages, rescissory damages as to class members who purchased shares pursuant to the offering and the plaintiffs' costs and expenses of litigation. The Company moved to dismiss the third amended complaint on August 29, 2017. The plaintiffs' memorandum in opposition to the Company's motion to dismiss was filed on October 30, 2017, and the Company's reply memorandum was filed on December 14, 2017. On January 12, 2018, the parties filed a joint motion to stay all proceedings pending the outcome of a mediation between the parties scheduled for February 23, 2018. The court granted the stay on February 21, 2018. The parties did not resolve the matter at the mediation on February 23, 2018, but continued thereafter to productively discuss a potential resolution of this matter. The court extended the stay to allow the parties to continue their discussions. On May 17, 2018, the parties executed a term sheet memorializing their agreement in principal to settle the action. The parties then negotiated the terms and conditions of a stipulation and agreement of settlement and related papers, which provide for the release of all claims asserted against the Company and its former chief executive officer and former chief financial officer. On July 6, 2018, the plaintiffs filed an unopposed motion seeking preliminary approval of the proposed settlement, certification of the proposed settlement class for settlement purposes only, and approval of notice to the settlement class. The court has not yet ruled on this motion. The Company's contribution to the settlement pool under the proposed settlement would be approximately equal to the amount it reserved in connection with a possible settlement of this action. The aggregate amount of this reserve and the reserve for the Constant Contact McGee litigation discussed below was originally $8.5 million recorded during the three months ended March 31, 2018, and subsequently adjusted to $8.3 million during the three months ended June 30, 2018 and to $7.3 million during the three months ended September 30, 2018. The Company cannot make any assurances as to whether or when the settlement will be approved by the court. Constant Contact On February 9, 2016, the Company acquired all of the outstanding shares of common stock of Constant Contact. On December 10, 2015, Constant Contact received a subpoena from the Boston Regional Office of the SEC, requiring the production of documents pertaining to Constant Contact’s sales, marketing, and customer retention practices, as well as periodic public disclosure of financial and operating metrics. As discussed above, on June 5, 2018, the Company announced that it had settled both this investigation and the Endurance investigation discussed above by consenting to the SEC's entry of the Order, without admitting or denying the SEC's findings set forth in the Order, and by paying a civil monetary penalty. The Company accrued the penalty in its fiscal quarter ended September 30, 2017 and paid the penalty in the fiscal quarter ended June 30, 2018. On August 7, 2015, a purported class action lawsuit, William McGee v. Constant Contact, Inc., et al, was filed in the United States District Court for the District of Massachusetts against Constant Contact and two of its former officers. An amended complaint, which named an additional former officer as a defendant, was filed December 19, 2016. The lawsuit asserts claims under Sections 10(b) and 20(a) of the Exchange Act, and is premised on allegedly false and/or misleading statements, and non-disclosure of material facts, regarding Constant Contact’s business, operations, prospects and performance during the proposed class period of October 23, 2014 to July 23, 2015. The parties mediated the claims on March 27, 2018, and as a result of that mediation reached an agreement in principle with the lead plaintiff to settle the action. The parties then negotiated the terms and conditions of a stipulation and agreement of settlement and related papers, which provide for the release of all claims asserted against Constant Contact and its former officers. On May 18, 2018, the plaintiffs filed an unopposed motion seeking preliminary approval of the proposed settlement, certification of the proposed settlement class for settlement purposes only, and approval of notice to the settlement class. The court has not yet ruled on this motion. The Company's contribution to the settlement pool under the proposed settlement would be approximately equal to the amount it reserved in connection with a possible settlement of this action. The aggregate amount of this reserve and the reserve for the Endurance Machado litigation discussed above was originally $8.5 million recorded during the three months ended March 31, 2018, and subsequently adjusted to $8.3 million during the three months ended June 30, 2018 and to $7.3 million during the three months ended September 30, 2018. The Company cannot make any assurances as to whether or when the settlement will be approved by the court.

Related Party Transactions

Related Party Transactions	9 Months Ended
	Sep. 30, 2018
Related Party Transactions [Abstract]
Related Party Transactions	Related Party Transactions The Company has various agreements in place with related parties. Below are details of significant related party transactions that occurred during the three and nine months ended September 30, 2017 and 2018 . Tregaron: The Company has contracts with Tregaron India Holdings, LLC and its affiliates, including Diya Systems (Mangalore) Private Limited, Glowtouch Technologies Pvt. Ltd. and Touchweb Designs, LLC (collectively, “Tregaron”), for outsourced services, including email- and chat-based customer and technical support, network monitoring, engineering and development support and web design and web building services, and an office space lease. These entities are owned directly or indirectly by family members of the Company’s former chief executive officer, who is also a holder of more than 5.0% of the Company's capital stock. The following table presents the amounts of related party transactions recorded in the consolidated statements of operations and comprehensive loss for the periods presented relating to services provided by Tregaron and its affiliates under these agreements: Three Months Ended Nine Months Ended 2017 2018 2017 2018 (in thousands) Cost of revenue $ 3,100 $ 3,330 $ 9,100 $ 10,555 Sales and marketing 500 160 1,000 605 Engineering and development 200 290 850 960 General and administrative 50 20 150 65 Total related party transaction expense, net $ 3,850 $ 3,800 $ 11,100 $ 12,185 As of December 31, 2017 , approximately $1.5 million was included in accounts payable and accrued expense relating to services provided by Tregaron. As of September 30, 2018 , approximately $2.2 million was included in accounts payable and accrued expense relating to services provided by Tregaron. Innovative Business Services, LLC: The Company also has agreements with Innovative Business Services, LLC (“IBS”), which provides multi-layered third-party security and website performance applications that are sold by the Company. During the three months ended September 30, 2018 , a director of the Company and the Company’s former chief executive officer, who is a holder of more than 5.0% of the Company's capital stock, continued to hold a material financial interest in IBS. During the quarter ended March 31, 2017, the Company’s principal agreement with this entity was amended to permit the Company to purchase a specific IBS website performance product at no charge, and in exchange, to increase the revenue share to IBS on certain website performance products. The Company records revenue on the sale of IBS products on a net basis, since the Company views IBS as the primary obligor to deliver these services. As a result, the revenue share paid by the Company to IBS is recorded as contra-revenue. Further, IBS pays the Company a fee on sales made by IBS directly to customers of the Company. The Company records these fees as revenue. The following table presents the amounts of related party transactions recorded in the consolidated statements of operations and comprehensive loss for the periods presented relating to services provided by IBS and its affiliates under these agreements: Three Months Ended Nine Months Ended 2017 2018 2017 2018 (in thousands) Revenue $ (1,050 ) $ (1,430 ) $ (2,150 ) $ (4,075 ) Revenue (contra) 1,850 1,800 4,050 6,140 Total related party transaction impact to revenue $ 800 $ 370 $ 1,900 $ 2,065 Cost of revenue 150 170 350 490 Total related party transaction expense, net $ 950 $ 540 $ 2,250 $ 2,555 As of December 31, 2017 and September 30, 2018 , approximately $0.2 million and $0.1 million , respectively, was included in prepaid expenses and other current assets relating to the Company’s agreements with IBS. As of December 31, 2017 and September 30, 2018 , approximately $1.3 million and $1.2 million , respectively was included in accounts payable and accrued expense relating to the Company’s agreements with IBS. As of December 31, 2017 and September 30, 2018 , approximately $0.7 million and $1.0 million , respectively, was included in accounts receivable relating to the Company’s agreements with IBS. Goldman, Sachs & Co.: The Company entered into a three -year interest rate cap on December 9, 2015 with a subsidiary of Goldman, Sachs & Co. ("Goldman"). The Company paid $3.0 million to the Goldman subsidiary as a premium for the interest rate cap during the year ended December 31, 2016. No further premiums are payable under this interest rate cap. Goldman is a significant stockholder of the Company. Refer to Note 6 : Fair Value Measurements , for further details. Goldman Sachs Lending Partners LLC, a subsidiary of Goldman, was one of the joint bookrunners and joint lead arrangers for the 2017 Refinancing and the 2018 Refinancing. In that capacity, Goldman Sachs Lending Partners LLC received an arrangement fee of $0.5 million and $0.3 million , respectively, and was reimbursed for an immaterial amount of expenses.

Segment Information

Segment Information	9 Months Ended
	Sep. 30, 2018
Segment Reporting [Abstract]
Segment Information	Segment Information Operating segments are defined as components of an enterprise that engage in business activities for which discrete financial information is available and regularly reviewed by the CODM. The Company experienced significant changes in its management structure during fiscal year 2017, including a change in its chief executive officer, who is the Company's CODM. The Company's leadership structure has been revised to centralize management of certain domain-focused brands in order to improve overall performance. As a result of these management changes, management has revised internal financial reporting structures, and broken the former web presence segment into two reportable segments, web presence and domains. The Company's third reportable segment, email marketing, remains unchanged. The products and services included in each of the three reportable segments are as follows: Web Presence. The web presence segment consists primarily of the Company's web hosting brands, such as Bluehost and HostGator, and related products such as domain names, website security, website design tools and services, and e-commerce products. Domain. The domain segment consists of domain-focused brands such as Domain.com, ResellerClub and LogicBoxes as well as certain web hosting brands that are under common management with domain-focused brands. This segment sells domain names and domain management services to resellers and end users, as well as premium domain names, and also generates advertising revenue from domain name parking. It also resells domain names and domain management services to the web presence segment. Email marketing. The email marketing segment consists of Constant Contact email marketing tools and related products and the Company's SinglePlatform digital storefront solution. The Company measures profitability of these segments based on revenue, gross profit, and adjusted EBITDA. The accounting policies of each segment are the same as those described in the summary of significant accounting policies; please refer to Note 2 : Summary of Significant Accounting Policies , for further details. The following tables contain financial information for each reportable segment for the three and nine months ended September 30, 2017 and 2018 : Three Months Ended September 30, 2017 Web presence Email marketing Domain Total (in thousands) (as revised) Revenue (1) $ 159,530 $ 101,526 $ 34,166 $ 295,222 Gross profit $ 77,032 $ 65,286 $ (5,961 ) $ 136,357 Net (loss) income $ (20,403 ) $ 2,202 $ (22,063 ) $ (40,264 ) Interest expense, net (2) 14,686 20,514 445 35,645 Income tax expense (benefit) 798 1,323 861 2,982 Depreciation 9,399 3,233 939 13,571 Amortization of other intangible assets 14,884 18,770 1,693 35,347 Stock-based compensation 15,510 1,668 2,402 19,580 Restructuring expenses 3,468 682 339 4,489 (Gain) loss of unconsolidated entities (33 ) — — (33 ) Impairment of other long-lived assets 600 — 13,848 14,448 SEC investigations reserve 4,323 2,751 926 8,000 Adjusted EBITDA $ 43,232 $ 51,143 $ (610 ) $ 93,765 Three Months Ended September 30, 2018 Web presence Email marketing Domain Total (in thousands) Revenue (1) $ 149,871 $ 102,111 $ 31,788 $ 283,770 Gross profit $ 75,074 $ 71,356 $ 8,395 $ 154,825 Net (loss) income $ (7,565 ) $ 6,596 $ (5,366 ) $ (6,335 ) Interest expense, net (2) 18,132 17,128 1,978 37,238 Income tax expense (benefit) 6,136 4,179 1,400 11,715 Depreciation 8,401 2,538 950 11,889 Amortization of other intangible assets 11,941 13,384 852 26,177 Stock-based compensation 1,569 4,472 1,509 7,550 Restructuring expenses 54 141 2 197 Shareholder litigation reserve (768 ) — (167 ) (935 ) Adjusted EBITDA $ 37,900 $ 48,438 $ 1,158 $ 87,496 Nine Months Ended September 30, 2017 Web presence Email marketing Domain Total (in thousands) (as revised) Revenue (1) $ 483,661 $ 298,401 $ 100,555 $ 882,617 Gross profit $ 229,186 $ 188,181 $ 11,053 $ 428,420 Net (loss) income $ (67,226 ) $ (8,026 ) $ (32,005 ) $ (107,257 ) Interest expense, net (2) 50,877 68,212 1,427 120,516 Income tax expense (benefit) 12,645 (4,821 ) 3,560 11,384 Depreciation 27,401 10,632 2,700 40,733 Amortization of other intangible assets 44,431 55,697 4,426 104,554 Stock-based compensation 38,023 5,392 5,334 48,749 Restructuring expenses 8,944 4,743 897 14,584 Transaction expenses and charges — 773 — 773 (Gain) loss of unconsolidated entities (72 ) — — (72 ) Impairment of other long-lived assets 600 — 13,848 14,448 SEC investigations reserve 4,323 2,751 926 8,000 Shareholder litigation reserve — — — — Adjusted EBITDA $ 119,946 $ 135,353 $ 1,113 $ 256,412 Nine Months Ended September 30, 2018 Web presence Email marketing Domain Total (in thousands) Revenue (1) $ 457,603 $ 306,712 $ 98,581 $ 862,896 Gross profit $ 225,149 $ 214,909 $ 29,241 $ 469,299 Net (loss) income $ (20,549 ) $ 22,350 $ (10,037 ) $ (8,236 ) Interest expense, net (2) 53,503 50,866 6,834 111,203 Income tax expense (benefit) 960 8,009 (143 ) 8,826 Depreciation 24,769 9,090 2,894 36,753 Amortization of other intangible assets 35,812 39,716 2,362 77,890 Stock-based compensation 12,066 7,168 2,698 21,932 Restructuring expenses 1,654 723 644 3,021 (Gain) loss of unconsolidated entities 2 — — 2 Shareholder litigation reserve 4,780 1,500 1,045 7,325 Adjusted EBITDA $ 112,997 $ 139,422 $ 6,297 $ 258,716 (1) Revenue excludes intercompany transactions relating to domain sales and domain services from the domain segment to the web presence segment of $2.5 million and $8.1 million , respectively, for the three and nine months ended September 30, 2017 , and $2.5 million and $7.6 million , respectively, for the three and nine months ended September 30, 2018 . (2) Interest expense includes impact of amortization of deferred financing costs, original issuance discounts and interest income. The CODM does not use asset information to allocate resources or make operating decisions. The Company has revised amounts reported for gross profit, net loss and adjusted EBITDA for the web presence and the domain segments in the segment disclosures, which impacted fiscal years 2016 and 2017. The amounts reported for the email marketing segment were not impacted. The revisions arose because of an error in the classification of certain domain registration expenses. Domain segment gross profit, net income (loss) and adjusted EBITDA were overstated by $3.0 million for fiscal year 2016, and by $6.9 million for fiscal year 2017, and web presence segment gross profit, net income (loss) and adjusted EBITDA were understated by equal amounts. Consolidated results were not impacted by this misstatement. The following table reflects the differences between the amounts as reported and the amounts as revised for gross profit, net loss and adjusted EBITDA for the web presence and domain segments for the three and nine months ended September 30, 2017 : Three Months Ended September 30, 2017 Web presence Domain (in thousands) (as reported) (as revised) (as reported) (as revised) Gross profit $ 75,097 $ 77,032 $ (4,026 ) $ (5,961 ) Net loss $ (22,416 ) $ (20,403 ) $ (20,050 ) $ (22,063 ) Adjusted EBITDA $ 41,297 $ 43,232 $ 1,325 $ (610 ) Nine Months Ended September 30, 2017 Web presence Domain (in thousands) (as reported) (as revised) (as reported) (as revised) Gross profit $ 224,300 $ 229,186 $ 15,939 $ 11,053 Net loss $ (73,346 ) $ (67,226 ) $ (25,885 ) $ (32,005 ) Adjusted EBITDA $ 115,060 $ 119,946 $ 5,999 $ 1,113

Subsequent Events

Subsequent Events	9 Months Ended
	Sep. 30, 2018
Subsequent Events [Abstract]
Subsequent Events	Subsequent Events The Company evaluated all subsequent events occurring through November 2, 2018 to determine if any such events should be reflected in these financial statements. There were no material recognized subsequent events recorded in the September 30, 2018 financial statements.

Supplemental Guarantor Financia

Supplemental Guarantor Financial Information	9 Months Ended
	Sep. 30, 2018
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Supplemental Guarantor Financial Information	Supplemental Guarantor Financial Information In February 2016, EIG Investors Corp., a wholly-owned subsidiary of the Company (the “Issuer”), issued $350.0 million aggregate principal amount of its 10.875% Senior Notes due 2024 (refer to Note 10 : Notes Payable in the consolidated financial statements), which it exchanged for new 10.875% Senior Notes due 2024 pursuant to a registration statement on Form S-4. The registered exchange offer for the Senior Notes was completed on January 30, 2017. The Senior Notes are fully and unconditionally guaranteed, jointly and severally, on a senior unsecured basis by the Company, and the following wholly-owned subsidiaries: The Endurance International Group, Inc., Bluehost Inc., FastDomain Inc., Domain Name Holding Company, Inc., Endurance International Group – West, Inc., HostGator.com LLC, A Small Orange, LLC, Constant Contact, Inc., and SinglePlatform, LLC, (collectively, the “Subsidiary Guarantors”), subject to certain customary guarantor release conditions. The Company’s other domestic subsidiaries and its foreign subsidiaries (collectively, the “Non-Guarantor Subsidiaries”) have not guaranteed the Senior Notes. The Company sold two immaterial guarantors, CardStar, Inc. and CardStar Publishing, LLC (collectively, "CardStar"), during the quarter ended December 31, 2016. CardStar was released and discharged from the guarantee as a result of the sale and no longer guarantees the debt of the Company as of December 1, 2016. Proceeds from the sale of CardStar were approximately $0.1 million . The following tables present supplemental condensed consolidating balance sheet information of the Company (“Parent”), the Issuer, the Subsidiary Guarantors and the Non-Guarantor Subsidiaries as of December 31, 2017 and September 30, 2018 , supplemental condensed consolidating results of operations for the three and nine months ended September 30, 2017 and 2018 , and cash flow information for the nine months ended September 30, 2017 and 2018 : Condensed Consolidating Balance Sheets December 31, 2017 (in thousands) Parent Issuer Guarantor Subsidiaries Non-Guarantor Subsidiaries Eliminations Consolidated Assets: Current assets: Cash and cash equivalents $ 92 $ 2 $ 54,473 $ 11,926 $ — $ 66,493 Restricted cash — — 2,472 153 — 2,625 Accounts receivable — — 12,386 3,559 — 15,945 Prepaid domain name registry fees — — 28,291 25,514 — 53,805 Prepaid expenses & other current assets (12 ) 86 20,062 9,191 — 29,327 Total current assets 80 88 117,684 50,343 — 168,195 Intercompany receivables, net 33,637 606,834 (498,213 ) (142,258 ) — — Property and equipment, net — — 81,693 13,759 — 95,452 Goodwill — — 1,673,851 176,731 — 1,850,582 Other intangible assets, net — — 450,778 4,662 — 455,440 Investment in subsidiaries 49,288 1,355,013 37,200 — (1,441,501 ) — Other assets — 3,639 21,373 6,405 — 31,417 Total assets $ 83,005 $ 1,965,574 $ 1,884,366 $ 109,642 $ (1,441,501 ) $ 2,601,086 Liabilities and stockholders' equity: Current liabilities: Accounts payable $ — $ — $ 9,532 $ 1,526 $ — $ 11,058 Accrued expenses and other current liabilities — 24,509 75,819 8,151 — 108,479 Deferred revenue — — 309,395 52,545 — 361,940 Current portion of notes payable — 33,945 — — — 33,945 Current portion of capital lease obligations — — 7,630 — — 7,630 Deferred consideration, short-term — — 4,365 — — 4,365 Total current liabilities — 58,454 406,741 62,222 — 527,417 Deferred revenue, long-term — — 81,199 9,773 — 90,972 Notes payable — 1,858,300 — — — 1,858,300 Capital lease obligations — — 7,719 — — 7,719 Deferred consideration — — 3,551 — — 3,551 Other long-term liabilities — (468 ) 30,143 447 — 30,122 Total liabilities — 1,916,286 529,353 72,442 — 2,518,081 Equity 83,005 49,288 1,355,013 37,200 (1,441,501 ) 83,005 Total liabilities and stockholders' equity $ 83,005 $ 1,965,574 $ 1,884,366 $ 109,642 $ (1,441,501 ) $ 2,601,086 Condensed Consolidating Balance Sheets September 30, 2018 (in thousands) Parent Issuer Guarantor Subsidiaries Non-Guarantor Subsidiaries Eliminations Consolidated Assets: Current assets: Cash and cash equivalents $ 207 $ 2 $ 59,890 $ 29,575 $ — $ 89,674 Restricted cash — — 1,731 101 — 1,832 Accounts receivable — — 11,906 2,199 — 14,105 Prepaid domain name registry fees — — 32,729 24,385 — 57,114 Prepaid commissions — — 41,085 659 — 41,744 Prepaid expenses & other current assets — 174 18,361 8,566 — 27,101 Total current assets 207 176 165,702 65,485 — 231,570 Intercompany receivables, net 34,278 441,001 (354,298 ) (120,981 ) — — Property and equipment, net — — 66,772 12,543 — 79,315 Goodwill — — 1,673,851 175,413 — 1,849,264 Other intangible assets, net — — 376,441 1,229 — 377,670 Investment in subsidiaries 122,114 1,510,592 74,478 — (1,707,184 ) — Prepaid commissions, net of current portion — — 41,346 735 — 42,081 Other assets — 9,742 22,351 6,410 — 38,503 Total assets $ 156,599 $ 1,961,511 $ 2,066,643 $ 140,834 $ (1,707,184 ) $ 2,618,403 Liabilities and stockholders' equity: Current liabilities: Accounts payable $ — $ — $ 10,239 $ 573 $ — $ 10,812 Accrued expenses and other current liabilities — 15,197 69,493 4,376 — 89,066 Deferred revenue — — 330,178 50,386 — 380,564 Current portion of notes payable — 31,606 — — — 31,606 Current portion of capital lease obligations — — 7,595 — — 7,595 Deferred consideration, short-term — — 2,386 — — 2,386 Total current liabilities — 46,803 419,891 55,335 — 522,029 Deferred revenue, long-term — — 86,133 10,286 — 96,419 Notes payable — 1,792,436 — — — 1,792,436 Capital lease obligations — — 2,067 — — 2,067 Deferred consideration — — 1,342 — — 1,342 Other long-term liabilities — 158 46,618 736 — 47,512 Total liabilities — 1,839,397 556,051 66,357 — 2,461,805 Equity 156,599 122,114 1,510,592 74,477 (1,707,184 ) 156,598 Total liabilities and stockholders' equity $ 156,599 $ 1,961,511 $ 2,066,643 $ 140,834 $ (1,707,184 ) $ 2,618,403 Condensed Consolidating Statements of Operations and Comprehensive Income (Loss) Three Months Ended September 30, 2017 (in thousands) Parent Issuer Guarantor Subsidiaries Non-Guarantor Subsidiaries Eliminations Consolidated Revenue $ — $ — $ 266,985 $ 30,019 $ (1,782 ) $ 295,222 Cost of revenue — — 139,044 21,155 (1,334 ) 158,865 Gross profit — — 127,941 8,864 (448 ) 136,357 Operating expense: Sales and marketing — — 61,376 4,900 — 66,276 Engineering and development — — 17,412 2,470 — 19,882 General and administrative — 56 50,353 1,465 (605 ) 51,269 Total operating expense — 56 129,141 8,835 (605 ) 137,427 (Loss) income from operations — (56 ) (1,200 ) 29 157 (1,070 ) Interest expense and other income, net — 35,661 756 (172 ) — 36,245 (Loss) income before income taxes and equity earnings of unconsolidated entities — (35,717 ) (1,956 ) 201 157 (37,315 ) Income tax (benefit) expense — (13,201 ) 15,494 689 — 2,982 (Loss) income before equity earnings of unconsolidated entities — (22,516 ) (17,450 ) (488 ) 157 (40,297 ) Equity loss (income) of unconsolidated entities, net of tax 40,422 17,906 456 — (58,817 ) (33 ) Net (loss) income $ (40,422 ) $ (40,422 ) $ (17,906 ) $ (488 ) $ 58,974 $ (40,264 ) Net (loss) income attributable to Endurance International Group Holdings, Inc. $ (40,422 ) $ (40,422 ) $ (17,906 ) $ (488 ) $ 58,974 $ (40,264 ) Comprehensive income (loss): Foreign currency translation adjustments — — — 1,070 — 1,070 Unrealized gain on cash flow hedge, net of taxes — 83 — — — 83 Total comprehensive (loss) income $ (40,422 ) $ (40,339 ) $ (17,906 ) $ 582 $ 58,974 $ (39,111 ) Condensed Consolidating Statements of Operations and Comprehensive Income (Loss) Nine Months Ended September 30, 2017 (in thousands) Parent Issuer Guarantor Subsidiaries Non-Guarantor Subsidiaries Eliminations Consolidated Revenue $ — $ — $ 788,806 $ 98,321 $ (4,510 ) $ 882,617 Cost of revenue — — 392,447 65,392 (3,642 ) 454,197 Gross profit — — 396,359 32,929 (868 ) 428,420 Operating expense: Sales and marketing — — 195,392 15,765 (3 ) 211,154 Engineering and development — — 51,053 9,340 — 60,393 General and administrative — 166 123,736 7,632 (605 ) 130,929 Transaction costs — — 773 — — 773 Total operating expense — 166 370,954 32,737 (608 ) 403,249 (Loss) income from operations — (166 ) 25,405 192 (260 ) 25,171 Interest expense and other income, net — 120,313 1,150 (347 ) — 121,116 (Loss) income before income taxes and equity earnings of unconsolidated entities — (120,479 ) 24,255 539 (260 ) (95,945 ) Income tax (benefit) expense — (44,512 ) 54,744 1,152 — 11,384 (Loss) income before equity earnings of unconsolidated entities — (75,967 ) (30,489 ) (613 ) (260 ) (107,329 ) Equity loss (income) of unconsolidated entities, net of tax 106,999 31,033 543 — (138,647 ) (72 ) Net (loss) income $ (106,999 ) $ (107,000 ) $ (31,032 ) $ (613 ) $ 138,387 $ (107,257 ) Net loss attributable to non-controlling interest — — 7,524 — — 7,524 Net (loss) income attributable to Endurance International Group Holdings, Inc. $ (106,999 ) $ (107,000 ) $ (38,556 ) $ (613 ) $ 138,387 $ (114,781 ) Comprehensive income (loss): Foreign currency translation adjustments — — — 2,984 — 2,984 Unrealized gain on cash flow hedge, net of taxes — (309 ) — — — (309 ) Total comprehensive (loss) income $ (106,999 ) $ (107,309 ) $ (38,556 ) $ 2,371 $ 138,387 $ (112,106 ) Condensed Consolidating Statements of Operations and Comprehensive Income (Loss) Three Months Ended September 30, 2018 (in thousands) Parent Issuer Guarantor Subsidiaries Non-Guarantor Subsidiaries Eliminations Consolidated Revenue $ — $ — $ 258,388 $ 26,730 $ (1,348 ) $ 283,770 Cost of revenue — — 110,808 19,485 (1,348 ) 128,945 Gross profit — — 147,580 7,245 — 154,825 Operating expense: Sales and marketing — — 60,341 3,490 — 63,831 Engineering and development — — 20,524 2,159 — 22,683 General and administrative (11 ) 52 24,187 1,465 — 25,693 Total operating expense (11 ) 52 105,052 7,114 — 112,207 (Loss) income from operations 11 (52 ) 42,528 131 — 42,618 Interest expense and other income, net — 37,305 74 (141 ) — 37,238 (Loss) income before income taxes and equity earnings of unconsolidated entities 11 (37,357 ) 42,454 272 — 5,380 Income tax (benefit) expense — (8,891 ) 22,020 (1,414 ) — 11,715 (Loss) income before equity earnings of unconsolidated entities 11 (28,466 ) 20,434 1,686 — (6,335 ) Equity loss (income) of unconsolidated entities, net of tax 6,346 (22,120 ) (1,686 ) — 17,460 — Net (loss) income $ (6,335 ) $ (6,346 ) $ 22,120 $ 1,686 $ (17,460 ) $ (6,335 ) Net (loss) income attributable to Endurance International Group Holdings, Inc. $ (6,335 ) $ (6,346 ) $ 22,120 $ 1,686 $ (17,460 ) $ (6,335 ) Comprehensive income (loss): Foreign currency translation adjustments — — — (644 ) — (644 ) Unrealized gain on cash flow hedge, net of taxes — 812 — — — 812 Total comprehensive (loss) income $ (6,335 ) $ (5,534 ) $ 22,120 $ 1,042 $ (17,460 ) $ (6,167 ) Condensed Consolidating Statements of Operations and Comprehensive Income (Loss) Nine Months Ended September 30, 2018 (in thousands) Parent Issuer Guarantor Subsidiaries Non-Guarantor Subsidiaries Eliminations Consolidated Revenue $ — $ — $ 783,611 $ 83,995 $ (4,710 ) $ 862,896 Cost of revenue — — 338,885 59,422 (4,710 ) 393,597 Gross profit — — 444,726 24,573 — 469,299 Operating expense: Sales and marketing — — 187,175 10,558 — 197,733 Engineering and development — — 58,850 5,709 — 64,559 General and administrative (11 ) 169 124,317 (29,263 ) — 95,212 Total operating expense (11 ) 169 370,342 (12,996 ) — 357,504 (Loss) income from operations 11 (169 ) 74,384 37,569 — 111,795 Interest expense and other income, net — 111,051 539 (387 ) — 111,203 (Loss) income before income taxes and equity earnings of unconsolidated entities 11 (111,220 ) 73,845 37,956 — 592 Income tax (benefit) expense — (26,470 ) 35,897 (601 ) — 8,826 (Loss) income before equity earnings of unconsolidated entities 11 (84,750 ) 37,948 38,557 — (8,234 ) Equity loss (income) of unconsolidated entities, net of tax 8,247 (76,503 ) (38,554 ) 18 106,794 2 Net (loss) income $ (8,236 ) $ (8,247 ) $ 76,502 $ 38,539 $ (106,794 ) $ (8,236 ) Net (loss) income attributable to Endurance International Group Holdings, Inc. $ (8,236 ) $ (8,247 ) $ 76,502 $ 38,539 $ (106,794 ) $ (8,236 ) Comprehensive income (loss): Foreign currency translation adjustments — — — (2,489 ) — (2,489 ) Unrealized gain on cash flow hedge, net of taxes — 1,996 — — — 1,996 Total comprehensive (loss) income $ (8,236 ) $ (6,251 ) $ 76,502 $ 36,050 $ (106,794 ) $ (8,729 ) Condensed Consolidating Statement of Cash Flows Nine Months Ended September 30, 2017 (in thousands) Parent Issuer Guarantor Subsidiaries Non-Guarantor Subsidiaries Eliminations Consolidated Net cash (used in) provided by operating activities $ (32 ) $ (72,687 ) $ 204,768 $ (3,183 ) $ — $ 128,866 Cash flows from investing activities: Purchases of property and equipment — — (28,140 ) (3,955 ) — (32,095 ) Proceeds from sale of property and equipment — — 292 — — 292 Proceeds from note receivable — — — — — — Purchases of intangible assets — — (1,932 ) (34 ) — (1,966 ) Net cash used in investing activities — — (29,780 ) (3,989 ) — (33,769 ) Cash flows from financing activities: Proceeds from issuance of notes payable and draws on revolver — 1,693,007 — — — 1,693,007 Repayment of notes payable and revolver — (1,733,147 ) — — — (1,733,147 ) Payment of financing costs — (6,304 ) — — — (6,304 ) Payment of deferred consideration — — (4,550 ) (858 ) — (5,408 ) Payment of redeemable non-controlling interest liability — — (25,000 ) — — (25,000 ) Principal payments on capital lease obligations — — (5,679 ) — — (5,679 ) Proceeds from exercise of stock options 1,548 — — — — 1,548 Intercompany loans and investments (1,058 ) 119,128 (124,060 ) 5,990 — — Net cash (used in) provided by financing activities 490 72,684 (159,289 ) 5,132 — (80,983 ) Net effect of exchange rate on cash and cash equivalents and restricted cash — — — 2,156 — 2,156 Net (decrease) increase in cash and cash equivalents and restricted cash 458 (3 ) 15,699 116 — 16,270 Cash and cash equivalents and restricted cash: Beginning of period 3 4 41,654 15,237 — 56,898 End of period $ 461 $ 1 $ 57,353 $ 15,353 $ — $ 73,168 Condensed Consolidating Statement of Cash Flows Nine Months Ended September 30, 2018 (in thousands) Parent Issuer Guarantor Subsidiaries Non-Guarantor Subsidiaries Eliminations Consolidated Net cash (used in) provided by operating activities $ — $ (88,464 ) $ 180,852 $ 41,205 $ — $ 133,593 Cash flows from investing activities: Purchases of property and equipment — — (22,159 ) (184 ) — (22,343 ) Proceeds from sale of property and equipment — — 6 — — 6 Net cash used in investing activities — — (22,153 ) (184 ) — (22,337 ) Cash flows from financing activities: Proceeds from issuance of term loan and notes, net of original issue discounts — 1,580,305 — — — 1,580,305 Repayment of term loans — (1,656,094 ) — — — (1,656,094 ) Payment of financing costs — (1,580 ) — — — (1,580 ) Payment of deferred consideration — — (4,500 ) — — (4,500 ) Principal payments on capital lease obligations — — (5,609 ) — — (5,609 ) Proceeds from exercise of stock options 756 — — — — 756 Intercompany loans and investments (641 ) 165,833 (143,914 ) (21,278 ) — — Net cash provided by (used in) financing activities 115 88,464 (154,023 ) (21,278 ) — (86,722 ) Net effect of exchange rate on cash and cash equivalents and restricted cash — — — (2,146 ) — (2,146 ) Net increase (decrease) in cash and cash equivalents and restricted cash 115 — 4,676 17,597 — 22,388 Cash and cash equivalents and restricted cash: Beginning of period 92 2 56,945 12,079 — 69,118 End of period $ 207 $ 2 $ 61,621 $ 29,676 $ — $ 91,506

Summary of Significant Accoun_2

Summary of Significant Accounting Policies (Policies)	9 Months Ended
	Sep. 30, 2018
Accounting Policies [Abstract]
Basis of Preparation	Basis of Preparation The accompanying consolidated financial statements, which include the accounts of the Company and its subsidiaries, have been prepared using accounting principles generally accepted in the United States of America (“U.S. GAAP”). All intercompany transactions were eliminated on consolidation.
Segment Information	Segment Information From the fourth quarter of fiscal year 2016, through the third quarter of fiscal year 2017, the Company had two reportable segments, web presence and email marketing. The Company experienced significant changes in its management structure during fiscal year 2017, including a change in its chief executive officer, who is the Company's chief operating decision maker ("CODM"). The Company's leadership structure has been revised to centralize management of certain domain-focused brands in order to improve overall performance. As a result of these management changes, management has revised internal financial reporting structures, and broken the former web presence segment into two reportable segments, web presence and domains. The Company's third reportable segment, email marketing, remains unchanged. The products and services included in each of the three reportable segments are as follows: Web Presence. The web presence segment consists primarily of the Company's web hosting brands, such as Bluehost and HostGator, and related products such as domain names, website security, website design tools and services, and e-commerce products. Domain. The domain segment consists of domain-focused brands such as Domain.com, ResellerClub and LogicBoxes as well as certain web hosting brands that are under common management with domain-focused brands. This segment sells domain names and domain management services to resellers and end users, as well as premium domain names, and also generates advertising revenue from domain name parking. It also resells domain names and domain management services to the web presence segment. Email Marketing. The email marketing segment consists of Constant Contact email marketing tools and related products and the SinglePlatform digital storefront solution. The Company's segments share certain resources, primarily related to sales and marketing, engineering and general and administrative functions. Management allocates these costs to each respective segment based on a consistently applied methodology, primarily based on a percentage of revenue.
Use of Estimates	Use of Estimates U.S. GAAP requires management to make certain estimates, judgments and assumptions that affect the reported amounts of assets, liabilities and disclosure of contingent assets and liabilities at the date of the consolidated financial statements and the reported amounts of revenue and expenses during the reporting period. These estimates, judgments and assumptions used in preparing the accompanying consolidated financial statements are based on the relevant facts and circumstances as of the date of the consolidated financial statements. Although the Company regularly assesses these estimates, judgments and assumptions used in preparing the consolidated financial statements, actual results could differ from those estimates. Changes in estimates are recorded in the period in which they become known. The more significant estimates reflected in these consolidated financial statements include estimates of fair value of assets acquired and liabilities assumed under purchase accounting related to the Company’s acquisitions and when evaluating goodwill and long-lived assets for potential impairment, the estimated useful lives of intangible and depreciable assets, revenue recognition for multiple-element arrangements, stock-based compensation, contingent consideration, derivative instruments, certain accruals, reserves and deferred taxes.
Unaudited Interim Financial Information	Unaudited Interim Financial Information The accompanying interim consolidated balance sheet as of September 30, 2018 , and the related consolidated statements of operations and comprehensive loss for the three and nine months ended September 30, 2017 and 2018 , cash flows for the nine months ended September 30, 2017 and 2018 , and the notes to consolidated financial statements are unaudited. These unaudited consolidated financial statements have been prepared on the same basis as the audited consolidated financial statements. The unaudited consolidated financial statements include, in the opinion of management, all adjustments, consisting only of normal recurring adjustments that are necessary for a fair presentation of the Company’s financial position at September 30, 2018 , results of operations for the three and nine months ended September 30, 2017 and 2018 and cash flows for the nine months ended September 30, 2017 and 2018 . The consolidated results in the consolidated statements of operations and comprehensive loss are not necessarily indicative of the results of operations to be expected for the full fiscal year ending December 31, 2018 .
Cash Equivalents	Cash Equivalents Cash and cash equivalents include all highly liquid investments with remaining maturities of three months or less at the date of purchase.
Restricted Cash	Restricted Cash Restricted cash is composed of certificates of deposit and cash held by merchant banks and payment processors, which provide collateral against any chargebacks, fees, or other items that may be charged back to the Company by credit card companies and other merchants, and collateral for certain facility leases.
Accounts Receivable	Accounts Receivable Accounts receivable is primarily composed of cash due from credit card companies for unsettled transactions charged to subscribers’ credit cards. As these amounts reflect authenticated transactions that are fully collectible, the Company does not maintain an allowance for doubtful accounts. The Company also accrues for earned referral fees and commissions, which are governed by reseller or affiliate agreements, when the amount is reasonably estimable.
Prepaid Domain Name Registry Fees	Prepaid Domain Name Registry Fees Prepaid domain name registry fees represent amounts that are paid in full at the time a domain is registered by one of the Company’s registrars on behalf of a customer. The registry fees are recognized on a straight-line basis over the term of the domain registration period.
Fair Value of Financial Instruments	Fair Value of Financial Instruments The carrying amounts of the Company's financial instruments, which include cash equivalents, accounts receivable, accounts payable and certain accrued expenses, approximate their fair values due to their short maturities. The fair value of the Company's notes payable is based on the borrowing rates currently available to the Company for debt with similar terms and average maturities and approximates their carrying value.
Derivative Instruments and Hedging Activities	Derivative Instruments and Hedging Activities FASB Accounting Standards Codification ("ASC") 815, Derivatives and Hedging, or ASC 815, provides the disclosure requirements for derivatives and hedging activities with the intent to provide users of financial statements with an enhanced understanding of: (a) how and why an entity uses derivative instruments, (b) how the entity accounts for derivative instruments and related hedged items, and (c) how derivative instruments and related hedged items affect an entity’s financial position, financial performance, and cash flows. Further, qualitative disclosures are required that explain the Company’s objectives and strategies for using derivatives, as well as quantitative disclosures about the fair value of and gains and losses on derivative instruments, and disclosures about credit-risk-related contingent features in derivative instruments. As required by ASC 815, the Company records all derivatives on the balance sheet at fair value. The accounting for changes in the fair value of derivatives depends on the intended use of the derivative, whether the Company has elected to designate a derivative in a hedging relationship and apply hedge accounting and whether the hedging relationship has satisfied the criteria necessary to apply hedge accounting. Derivatives designated and qualifying as a hedge of the exposure to changes in the fair value of an asset, liability, or firm commitment attributable to a particular risk, such as interest rate risk, are considered fair value hedges. Derivatives designated and qualifying as a hedge of the exposure to variability in expected future cash flows, or other types of forecasted transactions, are considered cash flow hedges. Derivatives may also be designated as hedges of the foreign currency exposure of a net investment in a foreign operation. Hedge accounting generally provides for the matching of the timing of gain or loss recognition on the hedging instrument with the recognition of the changes in the fair value of the hedged asset or liability that are attributable to the hedged risk in a fair value hedge or the earnings effect of the hedged forecasted transactions in a cash flow hedge. The Company may enter into derivative contracts that are intended to economically hedge certain of its risks, even though hedge accounting does not apply or the Company elects not to apply hedge accounting. In accordance with the FASB’s fair value measurement guidance in FASB Accounting Standards Update ("ASU") 2011-4, Fair Value Measurement (Topic 820): Amendments to Achieve Common Fair Value Measurement and Disclosure Requirements, the Company made an accounting policy election to measure the credit risk of its derivative financial instruments that are subject to master netting agreements on a net basis by counterparty portfolio.
Property and Equipment	Property and Equipment Property and equipment is recorded at cost or fair value if acquired in an acquisition. The Company also capitalizes the direct costs of constructing additional computer equipment for internal use, as well as upgrades to existing computer equipment which extend the useful life, capacity or operating efficiency of the equipment. Capitalized costs include the cost of materials, shipping and taxes. Materials used for repairs and maintenance of computer equipment are expensed and recorded as a cost of revenue. Materials on hand and construction-in-process are recorded as property and equipment. Assets recorded under capital lease are depreciated over the lease term. Depreciation is computed using the straight-line method over the estimated useful lives of the related assets as follows: Building Thirty-five years Software Two to three years Computers and office equipment Three years Furniture and fixtures Five years Leasehold improvements Shorter of useful life or remaining term of the lease
Software Development Costs	Software Development Costs The Company accounts for software development costs for internal-use software under the provisions of ASC 350-40, Internal-Use Software. Accordingly, certain costs to develop internal-use computer software are capitalized, provided these costs are expected to be recoverable.
Goodwill	Goodwill Goodwill relates to amounts that arose in connection with the Company’s various business combinations and represents the difference between the purchase price and the fair value of the identifiable intangible and tangible net assets when accounted for using the purchase method of accounting. Goodwill is not amortized, but is subject to periodic review for impairment. Events that would indicate impairment and trigger an interim impairment assessment include, but are not limited to, current economic and market conditions, including a decline in the equity value of the Company's business, a significant adverse change in agreements that would materially affect reported operating results, business climate or operational performance of the business and an adverse action or assessment by a regulator. Additionally, a reorganization or change in the number of reporting units could result in the reassignment of goodwill between reporting units and may trigger an impairment assessment. In accordance with ASC 350, Intangibles—Goodwill and Other , or ASC 350, the Company is required to review goodwill by reporting unit for impairment at least annually or more often if there are indicators of impairment present. Under U.S. GAAP, a reporting unit is either the equivalent of, or one level below, an operating segment. The Company has historically performed its annual goodwill test as of December 31 of each fiscal year. As a result of changes in the Company’s management structure during fiscal year 2017, including the change in its chief executive officer / CODM, the Company has revised its internal financial reporting structure, which has resulted in a change to its reporting units. The Company has identified a total of ten reporting units under the new structure. With the increase in reporting units, the Company determined that more time would be required to perform future goodwill impairment tests, and as a result, decided to accelerate its annual goodwill impairment test date to October 31 of each fiscal year, starting with the fiscal year 2017 test. Before testing goodwill at October 31, 2017, the Company allocated assets and liabilities to their respective reporting units. Goodwill was allocated to each reporting unit in accordance with ASC 350-20-40, which requires that goodwill be allocated based on the relative fair values of each reporting unit. After completing this valuation process, the Company allocated goodwill to seven reporting units. The Company did not allocate any goodwill to three smaller reporting units that were determined to have no material fair value. The carrying value of each reporting unit is based on the assignment of the appropriate assets and liabilities to each reporting unit. Assets and liabilities were assigned to each reporting unit if the assets or liabilities are employed in the operations of the reporting unit and the asset and liability is considered in the determination of the reporting unit fair value. Certain assets and liabilities are shared by multiple reporting units, and were allocated to each reporting unit based on the relative size of a reporting unit, primarily based on revenue. The fair value of each reporting unit is determined by the income approach. The Company also compared the fair value from the income approach to a market based approach to validate that the value derived from the income approach was reasonable. For the income approach, fair value is determined based on the present value of estimated future after-tax cash flows, discounted at an appropriate risk adjusted rate. The Company uses internal forecasts to estimate future after-tax cash flows, which includes an estimate of long-term future growth rates based on the long-term outlook for each reporting unit. Actual results may differ from those assumed in each forecast. The Company derives discount rates using a capital asset pricing model and analyzing published rates for industries relevant to the reporting units to estimate the weighted average cost of capital. The Company uses discount rates that are commensurate with the risks and uncertainty inherent in the business and in internally developed forecasts. For fiscal year 2017, the Company used a discount rate of 10.0% , and also performed sensitivity analysis on the discount rates. For the market approach validation, values were derived based on valuation multiples from sales of comparable companies. The Company has also early adopted the provisions of ASU 2017-4, which eliminates the second step of the goodwill impairment test. As a result, the goodwill impairment test as of October 31, 2017 includes only one step, which is a comparison of the carrying value of each reporting unit to its fair value, and any excess carrying value, up to the amount of goodwill allocated to that reporting unit, is impaired. The goodwill impairment test as of October 31, 2017 resulted in a $12.1 million impairment of goodwill to the Company's domain monetization reporting unit within the domain segment. The impairment is a direct result of a more rapid decline in domain parking revenue than originally expected, and to a lesser extent, reduced sales of premium domain names. Goodwill for this reporting unit has been completely impaired. Goodwill allocated to the other six reporting units was not impaired.
Long-Lived Assets	Long-Lived Assets The Company’s long-lived assets consist primarily of intangible assets, including acquired subscriber relationships, trade names, intellectual property, developed technology, domain names available for sale and in-process research and development (“IPR&D”). The Company also has long-lived tangible assets, primarily consisting of property and equipment. The majority of the Company’s intangible assets are recorded in connection with its various acquisitions. The Company’s intangible assets are recorded at fair value at the time of their acquisition. The Company amortizes intangible assets over their estimated useful lives. Determination of the estimated useful lives of the individual categories of intangible assets is based on the nature of the applicable intangible asset and the expected future cash flows to be derived from the intangible asset. Amortization of intangible assets with finite lives other than developed technology is recognized in accordance with their estimated projected cash flows. The Company evaluates long-lived intangible and tangible assets whenever events or changes in circumstances indicate that the carrying amount of an asset may not be recoverable. If indicators of impairment are present and undiscounted future cash flows are less than the carrying amount, the fair value of the assets is determined and compared to the carrying value. If the fair value is less than the carrying value, then the carrying value of the asset is reduced to the estimated fair value and an impairment loss is charged to expense in the period the impairment is identified. During the three and nine months ended September 30, 2017, the Company recognized an impairment charge of $13.8 million relating to certain domain name intangible assets acquired in 2014, which was recorded in cost of revenue in the consolidated statements of operations and comprehensive loss. The impairment resulted from diminished cash flows associated with this intangible asset. No such impairment losses have been identified in the three and nine months ended September 30, 2018. Indefinite life intangible assets include domain names that are available for sale which are recorded at cost to acquire. These assets are not being amortized and are being tested for impairment annually and whenever events or changes in circumstance indicate that their carrying value may not be recoverable. When a domain name is sold, the Company records the cost of the domain in cost of revenue.
Acquired In-Process Research and Development (IPR&D)	Acquired In-Process Research and Development (IPR&D) Acquired IPR&D represents the fair value assigned to research and development assets that the Company acquires in connection with business combinations that have not been completed at the date of acquisition. The acquired IPR&D is capitalized as an intangible asset and reviewed on a quarterly basis to determine future use. Any impairment loss of the acquired IPR&D is charged to expense in the period the impairment is identified.
Revenue Recognition	Revenue Recognition In May 2014, the FASB issued ASU No. 2014-09, Revenue from Contracts with Customers (Topic 606) , or ASU 2014-09 or ASC 606, which supersedes nearly all existing revenue recognition guidance under U.S. GAAP. Since then, the FASB has also issued ASU 2016-08, Revenue from Contracts with Customers (Topic 606), Principals versus Agent Considerations, ASU 2016-10, Revenue from Contracts with Customers (Topic 606), Identifying Performance Obligations and Licensing, and ASU 2017-13, Revenue Recognition (Topic 605), Revenue from Contracts with Customers (Topic 606) , Amendments to SEC Paragraphs Pursuant to the Staff Announcement at the July 20, 2017 EITF Meeting and Rescission of Prior SEC Staff Announcements and Observer Comments, which further elaborate on the original ASU No. 2014-09. The Company adopted the guidance in ASC 606 on January 1, 2018. Revenue is recognized when control of the promised products or services is transferred to the Company’s customers, in an amount that reflects the consideration the Company expects to be entitled to for those products and services. In general, the Company determines revenue recognition through the following steps: • Identification of the contract, or contracts, with the customer • Identification of the performance obligations in the contract • Determination of the transaction price • Allocation of the transaction price to the performance obligations in the contract • Recognition of revenue when, or as, the Company satisfies a performance obligation. The Company provides cloud-based subscription services, which include website hosting and related add-ons, search engine optimization (SEO) services, domain registration services and email marketing. Website hosting gives subscribers access to an environment where the Company hosts a customer’s website. The related contract terms are generally for one year , but can range from 30 days to 3 years . Website hosting services are typically sold in bundled offerings that include website hosting, domain registration services and various add-ons. The Company recognizes revenue for website hosting and domain registration services over the term of the contract. The main add-on services related to website hosting are domain privacy, secure sockets layer (SSL) security, site backup and restoration, and website builder tools. These services may be included in website hosting bundles, or they may be purchased on a standalone basis. Certain add-on services are provided by third parties. In cases where the Company is acting as an agent for the sale of third party add-on services, the Company recognizes revenue on a net basis at the time of sale. In cases where the Company is acting as a principal for the sale of third party add-on services (i.e., the Company has the primary responsibility to provide specific goods or services, it has discretion to establish prices and it may assume inventory risk), the Company recognizes revenue on a gross basis over the term of the contract. The revenue for Company-provided add-on services is primarily recognized over the term of the contract. SEO services are monthly subscriptions that provide a customer with increased traffic to their website over the term of the subscription. Revenue from SEO services is recognized over the monthly term of the contract. In the case of domain registration services, the Company is an accredited registrar and can provide registration services to the customer, or it can select an accredited third party registrar to perform these duties. Domain registration services are generally annual subscriptions, but can cover multiple years. Revenue for these services is recognized over time. Email marketing services provide subscribers with a cloud based platform that can send broadcast emails to a customer list managed by the subscriber. Pricing is based on contract list volume from the prior monthly period, which determines the contractual billing price for the upcoming month. Revenue for this service is recognized over the monthly term of the contract. Non-subscription based services include certain professional services, primarily website design or re-design services, marketing development fund revenue ("MDF"), premium domain names and domain parking services. Website design and re-design services are recognized when the service is complete. Marketing development funds consist of commissions earned by the Company when a third party sells its products or services directly to the Company’s subscribers, and advertising revenue for third party ads placed on Company websites. The Company records revenue when the service is provided and calculates it based on the contractual revenue share arrangement or over the term of the advertisement. Domain parking allows the Company to monetize certain of its premium domain names by loaning them to specialized third parties that generate advertising revenue from these parked domains on a pay per click ("PPC") basis. Revenue is recognized when earned and calculated based on the revenue share arrangement with the third party. Revenue from the sale of premium domains is recognized when persuasive evidence of an arrangement to sell such domains exists and delivery of an authorization key to access the domain name has occurred. Premium domain names are paid for in advance prior to the delivery of the domain name. For most of the Company’s performance obligations, the customer simultaneously receives and consumes the service over a period of time as the Company performs the service, resulting in the recognition of revenue over the subscription period. This method provides an appropriate depiction of the timing of the transfer of services to the customer. In limited instances, the customer obtains control of the promised service at a point in time, with no future obligations on the part of the Company. In these instances, the Company recognizes revenue at the point in time control is transferred. The contracts that the Company enters into typically do not contain any variable or non-cash considerations. The Company maintains a reserve for refunds and chargebacks related to revenue that has been recognized and is expected to be refunded, as calculated based on observed historical trends. The Company had a refund and chargeback reserve of $0.5 million and $0.3 million as of December 31, 2017 and September 30, 2018 , respectively. The portion of deferred revenue that is expected to be refunded at December 31, 2017 and September 30, 2018 was $1.8 million and $1.8 million , respectively. Based on refund history, approximately 83% of all refunds happen in the same fiscal month that the contract starts or renews, and approximately 96% of all refunds happen within 45 days of the contract start or renewal date. The Company did not apply any practical expedients during its adoption of ASC 606. The Company elected to use the portfolio method in the calculation of the deferred contract assets. Contracts with Multiple Performance Obligations A considerable amount of the Company’s revenue is generated from transactions that are contracts with customers that may include hosting plans, domain name registrations, and other cloud-based products and services. In these cases, the Company determines whether the products and services are distinct performance obligations that should be accounted for separately versus together. The Company allocates revenue to each performance obligation based on its relative standalone selling price, generally based on the price charged to customers. Hosting services, domain name registrations, and other cloud-based products and services have distinct performance obligations and are often sold separately. If the promise is not distinct and therefore not a performance obligation, then the total transaction amount is allocated to the identified performance obligation based on a relative selling price hierarchy. When multiple performance obligations are included in a contract, the total transaction amount for the contract is allocated to the performance obligations based on a relative selling price hierarchy. The Company determines the relative selling price for a performance obligation based on standalone selling price (“SSP”). The Company determines SSP by considering its observed standalone selling prices, competitive prices in the marketplace and management judgment; these standalone selling prices may vary depending upon the particular facts and circumstances related to each deliverable. The Company analyzes the standalone selling prices used in its allocation of transaction amount, at a minimum, on a quarterly basis. Deferred Revenue The Company records deferred revenue when cash payments are received or are due in advance of the Company’s performance, including amounts that are refundable. The change in the deferred revenue balance for the nine months ended September 30, 2018 is primarily driven by cash payments received or due in advance of the Company satisfying its performance obligations, offset by $331.9 million of revenue recognized that were included in the deferred revenue balance at the beginning of the period. The following table provides a reconciliation of the Company's deferred revenue as of September 30, 2018 : Short-term Long-term (in thousands) Balance at December 31, 2017 $ 361,940 $ 90,972 Effect of adoption of ASC 606 to balances at December 31, 2017 20,275 2,882 Recognition of the beginning deferred revenue into revenue, as a result of performance obligations satisfied (331,939 ) — Cash received in advance during the period 657,821 193,119 Recognition of cash received in the period into revenue, as a result of performance obligations satisfied (518,087 ) — Reclassification between short-term and long-term 190,554 (190,554 ) Balance at September 30, 2018 $ 380,564 $ 96,419 The difference between the opening and closing balances of the Company’s deferred liabilities primarily results from the timing difference between the Company’s performance and the customer’s payment. During the nine months ended September 30, 2018 , the Company recognized $331.9 million and $0.0 million , respectively, from beginning deferred revenue current and long-term balances existing at December 31, 2017 . The Company did not recognize any revenue from performance obligations satisfied in prior periods. The following table provides the remaining performance obligation amounts as of September 30, 2018 . These amounts are equivalent to the ending deferred revenue balance of $477.0 million , which includes both short and long-term amounts: Web presence Email marketing Domain Total (in thousands) Remaining performance obligation, short-term $ 265,984 $ 55,055 $ 59,525 $ 380,564 Remaining performance obligation, long-term 81,805 — 14,614 96,419 Total $ 347,789 $ 55,055 $ 74,139 $ 476,983 This backlog of revenue related to future performance obligations is prepaid by customers and supported by executed contracts with customers. The Company has established a reserve of $0.3 million for refunds and chargebacks, 96% of which is expected to materialize in the first 45 days. The remainder of the deferred revenue is expected to be recognized in future periods. Deferred Customer Acquisition Costs As a result of the implementation of ASC 606, the Company now capitalizes the incremental costs directly related to obtaining and fulfilling a contract (such as sales commissions and certain direct sales and marketing success based costs), if these costs are expected to be recovered. These costs are amortized over the period the services are transferred to the customer, which is estimated based on customer churn rates for various segments of the business. The Company includes only those incremental costs that would not have been incurred if the contracts had not been entered into: Short-term Long-term (in thousands) Balance at December 31, 2017 $ — $ — Adjustments resulting from adoption of ASC 606 43,408 40,040 Deferred customer acquisition costs incurred in the period 13,391 25,307 Amounts recognized as expense in the period (38,192 ) — Impact of foreign exchange rates (142 ) 13 Reclassification between short-term and long-term 23,279 (23,279 ) Balance at September 30, 2018 $ 41,744 $ 42,081 As of September 30, 2018 , the Company has a total of $71.0 million in deferred assets relating to costs incurred to obtain or fulfill contracts in its web presence segment, consisting of $0.0 million of incremental, recoverable sales and marketing costs, and $71.0 million of recoverable, specific, success-based sales commissions. As of September 30, 2018 , the Company has a total of $11.4 million deferred assets relating to costs incurred to obtain or fulfill contracts in its email marketing segment, consisting of $0.0 million of incremental, recoverable sales and marketing costs, and $11.4 million of recoverable, specific, success-based sales commissions. As of September 30, 2018 , the Company has a total of $1.4 million deferred assets relating to costs incurred to obtain or fulfill contracts in its domain segment, consisting of $0.0 million of incremental, recoverable sales and marketing costs, and $1.4 million of recoverable, specific, success-based sales commissions. During the nine months ended September 30, 2018 , the Company recognized total amortization costs related to the above items of $34.5 million , $3.4 million , and $0.3 million in its web presence, email marketing and domain segments, respectively. Significant Judgments The Company sells a number of third party cloud based services to enhance a subscriber’s overall website hosting experience. The Company exercises considerable judgment to determine if it is the principal or agent in each of these arrangements, and in some instances, has concluded that it is an agent of the third party and recognizes revenue at time of subscriber purchase in an amount that is net of the revenue share payable to the third party. The Company exercises judgment to determine the standalone selling price for each distinct performance obligation. In instances where the standalone selling price is not directly observable, such as when the Company does not sell the product or service separately, the Company determines the standalone selling price using information that may include a competitive market assessment approach and other observable inputs. The Company typically has more than one standalone selling price for individual products and services. Judgment is required to determine whether particular types of sales and marketing costs incurred, including commissions, are incremental and recoverable costs incurred to obtain and fulfill the customer contract. In addition, judgment is required to determine the life of the customer over which deferred customer acquisition costs are amortized.
Income Taxes	Income Taxes Income taxes are accounted for in accordance with ASC 740, Accounting for Income Taxes , or ASC 740. Deferred tax assets and liabilities are recognized for the estimated future tax consequences attributable to differences between the financial statement carrying amounts of existing assets and liabilities and their respective tax bases and operating loss and tax credit carry-forwards. Deferred 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 tax assets and liabilities of a change in tax rates is recognized in income in the period that includes the enactment date. ASC 740 clarifies the accounting for income taxes by prescribing a minimum recognition threshold that a tax position is required to meet before being recognized in the financial statements. The Company recognizes the effect of income tax positions only if those positions are more likely than not to be sustained. Recognized income tax positions are measured at the largest amount that is more likely than not to be realized. Changes in recognition or measurement are reflected in the period in which the change in judgment occurs. The Company had unrecognized tax benefits at December 31, 2017 and September 30, 2018 of $1.1 million and $2.9 million , respectively. The Company records interest related to unrecognized tax benefits in interest expense and penalties in operating expenses.
Stock-Based Compensation	Stock-Based Compensation The Company may issue restricted stock units, restricted stock awards and stock options which vest upon the satisfaction of a performance condition and/or a service condition. The Company follows the provisions of ASC 718, Compensation—Stock Compensation , or ASC 718, which requires employee stock-based payments to be accounted for under the fair value method. Under this method, the Company is required to record compensation cost based on the estimated fair value for stock-based awards granted over the requisite service periods for the individual awards, which generally equals the vesting periods, net of estimated forfeitures. The Company uses the straight-line amortization method for recognizing stock-based compensation expense. In addition, for stock-based awards where vesting is dependent upon achieving certain performance goals, the Company estimates the likelihood of achieving the performance goals against established performance targets. The Company estimates the fair value of employee stock options on the date of grant using the Black-Scholes option-pricing model, which requires the use of highly subjective estimates and assumptions. For restricted stock awards and restricted stock units granted, the Company estimates the fair value of each restricted stock award or restricted stock unit based on the closing trading price of its common stock on the date of grant.
Net Loss per Share	Net Loss per Share The Company considered ASC 260-10, Earnings per Share , or ASC 260-10, which requires the presentation of both basic and diluted earnings per share in the consolidated statements of operations and comprehensive loss. The Company’s basic net loss per share is computed by dividing net loss by the weighted average number of shares of common stock outstanding for the period, and, if there are dilutive securities, diluted income per share is computed by including common stock equivalents which includes shares issuable upon the exercise of stock options, net of shares assumed to have been purchased with the proceeds, using the treasury stock method.
Recent Accounting Pronouncements	Recent Accounting Pronouncements - Recently Adopted In May 2014, the FASB issued ASU No. 2014-09, Revenue from Contracts with Customers (Topic 606), or ASU 2014-09, which supersedes nearly all existing revenue recognition guidance under U.S. GAAP. Since then, the FASB has also issued ASU 2016-08, Revenue from Contracts with Customers (Topic 606), Principals versus Agent Considerations, ASU 2016-10, Revenue from Contracts with Customers (Topic 606), Identifying Performance Obligations and Licensing, and ASU 2017-13, Revenue Recognition (Topic 605), Revenue from Contracts with Customers (Topic 606) , Amendments to SEC Paragraphs Pursuant to the Staff Announcement at the July 20, 2017 EITF Meeting and Rescission of Prior SEC Staff Announcements and Observer Comments, which further elaborate on the original ASU No. 2014-09. The core principle of these updates is to recognize revenue when promised goods or services are transferred to customers in an amount that reflects the consideration to which the entity expects to be entitled for those goods or services. ASU 2014-09 defines a five step process to achieve this core principle and, in doing so, more judgments and estimates may be required within the revenue recognition process than are required under previous U.S. GAAP. In July 2015, the FASB approved a one-year deferral of the effective date to January 1, 2018, with early adoption to be permitted as of the original effective date of January 1, 2017. Once this standard became effective, companies may use either of the following transition methods: (i) a full retrospective approach reflecting the application of the standard in each reporting period with the option to elect certain practical expedients, or (ii) a retrospective approach with the cumulative effect of initially adopting ASU 2014-09 recognized at the date of adoption (which includes additional footnote disclosures) (the "modified retrospective approach"). The Company adopted this guidance on January 1, 2018 using the modified retrospective approach. The new standard impacted the timing of when certain sales incentive payments, primarily to external parties, are charged to expense as these costs must now be deferred over the life of the related customer relationship, whereas previously these amounts were expensed as incurred. In addition, a small portion of the Company's revenue recognition was impacted by this new guidance. The impact to opening retained earnings as a result of the adoption of the new guidance was $59.4 million , which consists of an $83.4 million deferred asset relating to customer acquisition costs and a $6.1 million deferred asset for domain registration costs, partially offset by a $23.1 million liability for deferred revenue, net of a deferred tax liability of $7.0 million . The Company applied the new guidance to all revenue contracts and did not use any practical expedients. The adoption of Topic 606 impacted the results of operations and certain balance sheet accounts. The impact of applying Topic 606 on the results for reporting periods and balance sheet beginning after January 1, 2018 is presented under Topic 606, while prior amounts are not adjusted and continue to be reported in accordance with the Company’s historic accounting under Topic 605. The impact of applying Topic 606 as of September 30, 2018 is as follows: For the three months ended September 30, 2018 under topic 606 For the three months ended September 30, 2018 under topic 605 Increase (decrease) Consolidated statement of operations and comprehensive loss data (in thousands) Revenue $ 283,770 $ 284,343 $ (573 ) Cost of revenue 128,945 128,583 362 Sales and marketing 63,831 63,816 15 As of September, 2018 under topic 606 As of September 30, 2018 under topic 605 Increase (decrease) Consolidated balance sheet data (in thousands) Prepaid commissions, current portion $ 41,744 $ — $ 41,744 Prepaid commissions, long-term 42,081 — 42,081 Deferred revenue, current 380,564 379,343 1,221 Deferred revenue, long-term 96,419 96,419 — For the three months ended September 30, 2018 under topic 606 For the three months ended September 30, 2018 under topic 605 Increase (decrease) Consolidated statement of cash flow data (in thousands) Net (loss) income $ (6,335 ) $ (6,139 ) $ (196 ) Change in prepaid expenses and other assets 5,527 5,904 (377 ) Change in deferred revenue (4,691 ) (4,118 ) 573 Cash flows from operations 51,341 51,341 — For the nine months ended September 30, 2018 under topic 606 For the nine months ended September 30, 2018 under topic 605 Increase (decrease) Consolidated statement of operations and comprehensive loss data (in thousands) Revenue $ 862,896 $ 864,117 $ (1,221 ) Cost of revenue 393,597 393,345 252 Sales and marketing 197,733 198,240 (507 ) As of September, 2018 under topic 606 As of September 30, 2018 under topic 605 Increase (decrease) Consolidated balance sheet data (in thousands) Prepaid commissions, current portion $ 41,744 $ — $ 41,744 Prepaid commissions, long-term 42,081 — 42,081 Deferred revenue, current 380,564 379,343 1,221 Deferred revenue, long-term 96,419 96,419 — For the nine months ended September 30, 2018 under topic 606 For the nine months ended September 30, 2018 under topic 605 Increase (decrease) Consolidated statement of cash flow data (in thousands) Net (loss) income $ (8,236 ) $ (7,270 ) $ (966 ) Change in prepaid expenses and other assets (3,033 ) (2,778 ) (255 ) Change in deferred revenue 3,502 4,723 1,221 Cash flows from operations 133,593 133,593 — In January 2016, the FASB issued ASU No. 2016-01, Financial Instruments-Overall: Recognition and Measurement of Financial Assets and Financial Liabilities . This new standard enhances the reporting model for financial instruments to provide users of financial statements with more decision-useful information. This amendment is effective for annual periods beginning after December 15, 2017, and early adoption is permitted. The adoption of this standard did not have a material impact on the Company's consolidated financial statements. In November 2016, the FASB issued ASU No. 2016-18, Statement of Cash Flows: Restricted Cash . This new standard requires that a statement of cash flows explain the change during the period in the total of cash, cash equivalents, and restricted cash. This amendment is effective for annual periods beginning after December 15, 2017, and early adoption is permitted. The adoption of this standard did not have a material impact on the Company's statement of cash flows. In August 2016, the FASB issued ASU No. 2016-15, Statement of Cash Flows: Classification of Certain Cash Receipts and Cash Payments . This new standard clarifies certain statement of cash flow presentation issues. This amendment is effective for annual periods beginning after December 15, 2017, and early adoption is permitted. The adoption of this standard did not have a material impact on the Company's statement of cash flows. In January 2017, the FASB issued ASU No. 2017-04, Intangibles - Goodwill and Other: Simplifying the Test for Goodwill Impairment. This new standard eliminates step two of the prior goodwill test, and instead requires that an entity perform its annual, or interim, goodwill impairment test by comparing the fair value of a reporting unit with its carrying amount. This amendment is effective for annual or interim goodwill impairment tests in fiscal years beginning after December 31, 2019, and should be applied on a prospective basis. The Company elected to early adopt the provisions of ASU 2017-04 effective in the fourth quarter of fiscal year 2017, which simplified the process of calculating the $12.1 million impairment to goodwill during the fourth quarter of fiscal year 2017. In May 2017, the FASB issued ASU No. 2017-09, Compensation - Stock Compensation (Topic 718) . This new standard provides guidance about which changes to the terms or conditions of a share-based payment award require an entity to apply modification accounting in Topic 718. This amendment is effective for annual or interim periods in fiscal years beginning after December 15, 2017, and should be applied prospectively to an award modified on or after the adoption date. The Company adopted this guidance as of January 1, 2018 and will apply this guidance to any modifications, based on the new definition of a modification, for all periods beginning on or after January 1, 2018. During the three and nine months ended September 30, 2018, there were no modifications that would impact the Company's consolidated financial statements. In August 2017, the FASB issued ASU No. 2017-12, Derivatives and Hedging (Topic 815): Targeted Improvements to Accounting for Hedging Activities. This new guidance better aligns an entity's risk management activities and financial reporting for hedging relationships through changes to the designation and measurement guidance for qualifying hedging relationships and to the method of presenting hedge results. The amendments in this guidance require an entity to present the earnings effect of the hedging instrument in the same income statement line item in which the earnings effect of the hedged item is reported, to allow users to better understand the results and costs of an entity's hedging program. This new guidance is effective for fiscal years beginning after December 15, 2019 and early adoption is allowed. The amended presentation and disclosure guidance is required only prospectively, while the measurement guidance should be applied to hedges existing at the time of adoption through a one-time cumulative-effect adjustment to accumulated other comprehensive income with respect to the elimination of the separate measurement of ineffectiveness with a corresponding adjustment to the opening balance of the retained earnings. The Company adopted this guidance on June 1, 2018 using the modified retrospective approach. The adoption of the new guidance did not have a material impact on the Company's consolidated financial statements. Recent Accounting Pronouncements - Recently Issued In February 2016, the FASB issued ASU No. 2016-02, Leases . Since then, the FASB has also issued ASU No. 2018-10, Codification Improvements to Topic 842, Leases , which further clarifies ASU No. 2016-02 and corrects unintended application of guidance. The new standard establishes a right-of-use ("ROU") model that requires a lessee to record a ROU asset and a lease liability on the balance sheet for all leases with terms longer than 12 months. Leases will be classified as either finance or operating, with classification affecting the pattern of expense recognition in the income statement. The new standard is effective for fiscal years beginning after December 15, 2018, including interim periods within those fiscal years. A modified retrospective transition approach is required for capital and operating leases existing at, or entered into after, the beginning of the earliest comparative period presented in the financial statements, with certain practical expedients available. The Company is currently evaluating the impact of its pending adoption of the new standard on its consolidated financial statements, but expects that the adoption will materially increase its assets and liabilities. In October 2016, the FASB issued ASU No. 2016-16, Income Taxes: Intra-Entity Transfers of Assets Other Than Inventory . This new standard improves the accounting for the income tax consequences of intra-entity transfers of assets other than inventory. This amendment is effective for annual periods beginning after December 15, 2018, and early adoption is permitted. The Company does not believe the adoption of this ASU will have a material impact on its consolidated financial statements. In July 2018, the FASB issued ASU No. 2018-07, Compensation - Stock Compensation (Topic 718) . The new guidance expands the scope of Topic 718 to include share-based payment transactions for acquiring goods and services from nonemployees. The amendments in ASU No. 2018-07 specify that Topic 718 applies to all share-based payment transactions in which a grantor acquires goods or services to be used or consumed in a grantor's own operations by issuing share-based payment awards to a non-employee. The amendments also clarify that Topic 718 does not apply to share-based payments used to effectively provide (1) financing to the issuer or (2) awards granted in conjunction with selling goods or services to customers as part of a contract accounted for under Topic 606, Revenue from Contract with Customers . The new guidance is effective for public companies for fiscal years beginning after December 15, 2018, including interim periods within those fiscal years and early adoption is permitted, provided the company has already adopted the guidance in Topic 606. A company should only remeasure liability-classified awards that have not been settled by the date of adoption and equity-classified awards for which a measurement date has not been established through a cumulative-effect adjustment to retained earnings as of the beginning of the fiscal year of adoption. Upon transition, the company is required to measure these nonemployee awards at fair value as of the adoption date. The Company does not believe the adoption of this ASU will have a material impact on its consolidated financial statements.

Summary of Significant Accoun_3

Summary of Significant Accounting Policies (Tables)	9 Months Ended
	Sep. 30, 2018
Accounting Policies [Abstract]
Summary of Estimated Useful Lives	Depreciation is computed using the straight-line method over the estimated useful lives of the related assets as follows: Building Thirty-five years Software Two to three years Computers and office equipment Three years Furniture and fixtures Five years Leasehold improvements Shorter of useful life or remaining term of the lease
Contract with Customer, Asset and Liability	The Company includes only those incremental costs that would not have been incurred if the contracts had not been entered into: Short-term Long-term (in thousands) Balance at December 31, 2017 $ — $ — Adjustments resulting from adoption of ASC 606 43,408 40,040 Deferred customer acquisition costs incurred in the period 13,391 25,307 Amounts recognized as expense in the period (38,192 ) — Impact of foreign exchange rates (142 ) 13 Reclassification between short-term and long-term 23,279 (23,279 ) Balance at September 30, 2018 $ 41,744 $ 42,081 The following table provides a reconciliation of the Company's deferred revenue as of September 30, 2018 : Short-term Long-term (in thousands) Balance at December 31, 2017 $ 361,940 $ 90,972 Effect of adoption of ASC 606 to balances at December 31, 2017 20,275 2,882 Recognition of the beginning deferred revenue into revenue, as a result of performance obligations satisfied (331,939 ) — Cash received in advance during the period 657,821 193,119 Recognition of cash received in the period into revenue, as a result of performance obligations satisfied (518,087 ) — Reclassification between short-term and long-term 190,554 (190,554 ) Balance at September 30, 2018 $ 380,564 $ 96,419
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction	These amounts are equivalent to the ending deferred revenue balance of $477.0 million , which includes both short and long-term amounts: Web presence Email marketing Domain Total (in thousands) Remaining performance obligation, short-term $ 265,984 $ 55,055 $ 59,525 $ 380,564 Remaining performance obligation, long-term 81,805 — 14,614 96,419 Total $ 347,789 $ 55,055 $ 74,139 $ 476,983
Schedule of New Accounting Pronouncements and Changes in Accounting Principles	The impact of applying Topic 606 as of September 30, 2018 is as follows: For the three months ended September 30, 2018 under topic 606 For the three months ended September 30, 2018 under topic 605 Increase (decrease) Consolidated statement of operations and comprehensive loss data (in thousands) Revenue $ 283,770 $ 284,343 $ (573 ) Cost of revenue 128,945 128,583 362 Sales and marketing 63,831 63,816 15 As of September, 2018 under topic 606 As of September 30, 2018 under topic 605 Increase (decrease) Consolidated balance sheet data (in thousands) Prepaid commissions, current portion $ 41,744 $ — $ 41,744 Prepaid commissions, long-term 42,081 — 42,081 Deferred revenue, current 380,564 379,343 1,221 Deferred revenue, long-term 96,419 96,419 — For the three months ended September 30, 2018 under topic 606 For the three months ended September 30, 2018 under topic 605 Increase (decrease) Consolidated statement of cash flow data (in thousands) Net (loss) income $ (6,335 ) $ (6,139 ) $ (196 ) Change in prepaid expenses and other assets 5,527 5,904 (377 ) Change in deferred revenue (4,691 ) (4,118 ) 573 Cash flows from operations 51,341 51,341 — For the nine months ended September 30, 2018 under topic 606 For the nine months ended September 30, 2018 under topic 605 Increase (decrease) Consolidated statement of operations and comprehensive loss data (in thousands) Revenue $ 862,896 $ 864,117 $ (1,221 ) Cost of revenue 393,597 393,345 252 Sales and marketing 197,733 198,240 (507 ) As of September, 2018 under topic 606 As of September 30, 2018 under topic 605 Increase (decrease) Consolidated balance sheet data (in thousands) Prepaid commissions, current portion $ 41,744 $ — $ 41,744 Prepaid commissions, long-term 42,081 — 42,081 Deferred revenue, current 380,564 379,343 1,221 Deferred revenue, long-term 96,419 96,419 — For the nine months ended September 30, 2018 under topic 606 For the nine months ended September 30, 2018 under topic 605 Increase (decrease) Consolidated statement of cash flow data (in thousands) Net (loss) income $ (8,236 ) $ (7,270 ) $ (966 ) Change in prepaid expenses and other assets (3,033 ) (2,778 ) (255 ) Change in deferred revenue 3,502 4,723 1,221 Cash flows from operations 133,593 133,593 —
Summary of Calculation of Basic and Diluted Net Loss Per Share	Three Months Ended Nine Months Ended 2017 2018 2017 2018 (unaudited) (in thousands, except share amounts and per share data) Net loss attributable to Endurance International Group Holdings, Inc. $ (40,264 ) $ (6,335 ) $ (114,781 ) $ (8,236 ) Net loss per share attributable to Endurance International Group Holdings, Inc.: Basic net loss per share attributable to Endurance International Group Holdings, Inc. $ (0.29 ) $ (0.04 ) $ (0.84 ) $ (0.06 ) Diluted net loss per share attributable to Endurance International Group Holdings, Inc. $ (0.29 ) $ (0.04 ) $ (0.84 ) $ (0.06 ) Weighted-average common shares used in computing net loss per share attributable to Endurance International Group Holdings, Inc.: Basic 137,793,609 143,107,122 136,688,115 141,946,574 Diluted 137,793,609 143,107,122 136,688,115 141,946,574
Summary of Weighted Average Potentially Dilutive Shares Excluded From Calculation of Diluted Loss Per Share	The following number of weighted average potentially dilutive shares were excluded from the calculation of diluted loss per share because the effect of including such potentially dilutive shares would have been anti-dilutive: Three Months Ended Nine Months Ended 2017 2018 2017 2018 (unaudited) Restricted stock awards and units 7,782,806 6,915,158 6,974,708 6,470,097 Options 10,593,596 8,362,719 10,947,661 8,644,464 Total 18,376,402 15,277,877 17,922,369 15,114,561

Correction of Income Tax Expe_2

Correction of Income Tax Expense - Fiscal Year 2018 (Tables)	9 Months Ended
	Sep. 30, 2018
Accounting Changes and Error Corrections [Abstract]
Schedule of Error Corrections	The following table represents the impact of the revised deferred income tax provision on the impacted lines of the statement of cash flows for the periods shown (in thousands): Three Months Ended March 31, 2018 Six Months Ended June 30, 2018 Originally Filed Adjustment Revised Originally Filed Adjustment Revised Net income (loss) $ (7,088 ) $ 4,560 $ (2,528 ) $ (9,057 ) $ 7,156 $ (1,901 ) Deferred tax expense 492 (4,560 ) (4,068 ) 2,672 (7,156 ) (4,484 ) Net cash provided by operating activities 52,360 — 52,360 82,252 — 82,252 The following table represents the impact of the income statement revision to the first and second quarters of 2018 due to the revised deferred income tax provision (in thousands, except per share data): Three Months Ended March 31, 2018 Three Months Ended June 30, 2018 Originally Filed Adjustment Revised Originally Filed Adjustment Revised Loss before income taxes and equity earnings of unconsolidated subsidiaries $ (4,444 ) $ — $ (4,444 ) $ (344 ) $ — $ (344 ) Income tax expense (benefit) 2,617 (4,560 ) (1,943 ) 1,650 (2,596 ) (946 ) Loss before equity earnings of unconsolidated subsidiaries (7,061 ) $ 4,560 $ (2,501 ) (1,994 ) $ 2,596 $ 602 Equity (income) loss of unconsolidated subsidiaries 27 — 27 $ (25 ) (25 ) Net income (loss) $ (7,088 ) $ 4,560 $ (2,528 ) $ (1,969 ) $ 2,596 $ 627 Comprehensive income (loss) Foreign currency translation 580 — 580 (2,425 ) — (2,425 ) Unrealized (gain) loss on cash flow hedge, net of tax 1,041 — 1,041 144 — 144 Total comprehensive loss $ (5,467 ) $ 4,560 $ (907 ) $ (4,250 ) $ 2,596 $ (1,654 ) Basic net income (loss) per share $ (0.05 ) $ 0.03 $ (0.02 ) $ (0.01 ) $ 0.01 $0.00 Diluted net income (loss) per share $ (0.05 ) $ 0.03 $ (0.02 ) $ (0.01 ) $ 0.01 $0.00 Weighted-average common shares used in computing net income (loss) per share Basic 140,361,982 — 140,361,982 142,340,561 — 142,340,561 Diluted 140,361,982 — 140,361,982 142,340,561 2,361,441 144,702,002 Six Months Ended June 30, 2018 Originally Filed Adjustment Revised Loss before income taxes and equity earnings of unconsolidated subsidiaries $ (4,788 ) $ — $ (4,788 ) Income tax expense (benefit) 4,267 (7,156 ) (2,889 ) Loss before equity earnings of unconsolidated subsidiaries (9,055 ) 7,156 (1,899 ) Equity (income) loss of unconsolidated subsidiaries 2 — 2 Net income (loss) (9,057 ) 7,156 $ (1,901 ) Comprehensive income (loss) Foreign currency translation (1,845 ) — (1,845 ) Unrealized gain on cash flow hedge, net of tax 1,184 — 1,184 Total comprehensive loss (9,718 ) 7,156 $ (2,562 ) Basic net income (loss) per share $ (0.06 ) $ 0.05 $ (0.01 ) Diluted net income (loss) per share $ (0.06 ) $ 0.05 $ (0.01 ) Weighted-average common shares used in computing net income (loss) per share Basic 141,356,567 — 141,356,567 Diluted 141,356,567 — 141,356,567 The following table represents the impact of the revised deferred income tax provision on the impacted balance sheet accounts as of the dates shown (in thousands): March 31, 2018 June 30, 2018 Originally Filed Adjustment Revised Originally Filed Adjustment Revised Deferred tax liability $ 27,679 $ (4,560 ) $ 23,119 $ 29,897 $ (7,156 ) $ 22,741 Total liabilities 2,533,619 (4,560 ) 2,529,059 2,490,106 (7,156 ) 2,482,950 Accumulated deficit (795,206 ) 4,560 (790,646 ) (797,175 ) 7,156 (790,019 ) Total stockholders' equity 144,189 4,560 148,749 147,759 7,156 154,915 Total liabilities and stockholders' equity 2,677,808 — 2,677,808 2,637,865 — 2,637,865 The following table reflects the differences between the amounts as reported and the amounts as revised for gross profit, net loss and adjusted EBITDA for the web presence and domain segments for the three and nine months ended September 30, 2017 : Three Months Ended September 30, 2017 Web presence Domain (in thousands) (as reported) (as revised) (as reported) (as revised) Gross profit $ 75,097 $ 77,032 $ (4,026 ) $ (5,961 ) Net loss $ (22,416 ) $ (20,403 ) $ (20,050 ) $ (22,063 ) Adjusted EBITDA $ 41,297 $ 43,232 $ 1,325 $ (610 ) Nine Months Ended September 30, 2017 Web presence Domain (in thousands) (as reported) (as revised) (as reported) (as revised) Gross profit $ 224,300 $ 229,186 $ 15,939 $ 11,053 Net loss $ (73,346 ) $ (67,226 ) $ (25,885 ) $ (32,005 ) Adjusted EBITDA $ 115,060 $ 119,946 $ 5,999 $ 1,113

Property and Equipment and Ca_2

Property and Equipment and Capital Lease Obligations (Tables)	9 Months Ended
	Sep. 30, 2018
Property, Plant and Equipment [Abstract]
Components of Property and Equipment	Components of property and equipment consisted of the following: December 31, 2017 September 30, 2018 (in thousands) Land $ 790 $ 790 Building 5,037 7,294 Software 82,618 88,376 Computers and office equipment 153,273 158,188 Furniture and fixtures 18,825 19,259 Leasehold improvements 22,260 19,672 Construction in process 3,800 2,215 Property and equipment—at cost 286,603 295,794 Less accumulated depreciation (191,151 ) (216,479 ) Property and equipment—net $ 95,452 $ 79,315

Fair Value Measurements (Tables

Fair Value Measurements (Tables)	9 Months Ended
	Sep. 30, 2018
Fair Value Disclosures [Abstract]
Basis of Fair Value Measurements	Basis of Fair Value Measurements Balance Quoted Prices in Active Markets for Identical Items (Level 1) Significant Other Observable Inputs (Level 2) Significant Unobservable Inputs (Level 3) (in thousands) Balance at December 31, 2017 Financial assets: Interest rate cap (included in other assets) $ 452 — $ 452 $ — Total financial assets $ 452 $ — $ 452 $ — Balance at September 30, 2018 Financial assets: Interest rate caps (included in other assets) $ 6,863 — $ 6,863 $ — Total financial assets $ 6,863 $ — $ 6,863 $ —

Goodwill and Other Intangible_2

Goodwill and Other Intangible Assets (Tables)	9 Months Ended
	Sep. 30, 2018
Goodwill and Intangible Assets Disclosure [Abstract]
Changes in Goodwill Balances	The following table summarizes the changes in the Company’s goodwill balances from December 31, 2017 to September 30, 2018 : Web Presence Email Marketing Domain Total (in thousands) Goodwill balance at December 31, 2017 $ 1,216,419 $ 604,305 $ 29,858 $ 1,850,582 Foreign translation impact (1,318 ) — — (1,318 ) Goodwill balance at September 30, 2018 $ 1,215,101 $ 604,305 $ 29,858 $ 1,849,264
Summary of Other Intangible Assets	At December 31, 2017 , other intangible assets consisted of the following: Gross Carrying Amount Accumulated Amortization Net Carrying Amount Weighted Average Useful Life (dollars in thousands) Developed technology $ 285,911 $ 149,514 $ 136,397 7 years Subscriber relationships 659,732 431,938 227,794 7 years Trade-names 134,054 73,019 61,035 8 years Intellectual property 34,313 27,336 6,977 5 years Domain names available for sale 30,458 7,221 23,237 Indefinite Total December 31, 2017 $ 1,144,468 $ 689,028 $ 455,440 At September 30, 2018 , other intangible assets consisted of the following: Gross Carrying Amount Accumulated Amortization Net Carrying Amount Weighted Average Useful Life (dollars in thousands) Developed technology $ 284,312 $ 173,203 $ 111,109 7 years Subscriber relationships 659,376 472,625 186,751 7 years Trade-names 134,046 81,740 52,306 8 years Intellectual property 34,306 28,566 5,740 5 years Domain names available for sale 30,855 9,091 21,764 Indefinite Total September 30, 2018 $ 1,142,895 $ 765,225 $ 377,670

Notes Payable (Tables)

Notes Payable (Tables)	9 Months Ended
	Sep. 30, 2018
Debt Disclosure [Abstract]
Schedule of Long-term Debt Instruments	At December 31, 2017 and September 30, 2018 , notes payable, net of original issuance discounts (sometimes referred to as "OID") and deferred financing costs, consisted of the following: At December 31, 2017 At September 30, 2018 (in thousands) 2018 First Lien Term Loan $ — $ 1,493,131 2017 First Lien Term Loan 1,563,197 — Notes 329,048 330,911 Revolving credit facilities — — Total notes payable 1,892,245 1,824,042 Current portion of notes payable 33,945 31,606 Notes payable - long term $ 1,858,300 $ 1,792,436 As of December 31, 2017 and September 30, 2018 , the Senior Notes had an outstanding balance of: At December 31, 2017 At September 30, 2018 (in thousands) Senior Notes $ 350,000 $ 350,000 Unamortized deferred financing costs (15,280 ) (13,921 ) Unamortized original issuance discount (5,672 ) (5,168 ) Net Senior Notes 329,048 330,911 Current portion of Senior Notes — — Senior Notes - long term $ 329,048 $ 330,911 As of September 30, 2018 , the 2018 Term Loan had an outstanding balance of: At September 30, 2018 (in thousands) 2018 First Lien Term Loan $ 1,530,002 Unamortized deferred financing costs (19,594 ) Unamortized original issue discount (17,277 ) Net 2018 First Lien Term Loan 1,493,131 Current portion of 2018 First Lien Term Loan 31,606 2018 First Lien Term Loan - long term $ 1,461,525 As of December 31, 2017 and September 30, 2018 , the 2017 Term Loan had an outstanding balance of: At December 31, 2017 At September 30, 2018 (in thousands) 2017 First Lien Term Loan $ 1,605,792 $ — Unamortized deferred financing costs (22,456 ) — Unamortized original issue discount (20,139 ) — Net 2017 First Lien Term Loan 1,563,197 — Current portion of 2017 First Lien Term Loan 33,945 — 2017 First Lien Term Loan - long term $ 1,529,252 $ —
Summary of Future Debt Maturities	The maturity of the notes payable at September 30, 2018 is as follows: Amounts maturing in: (in thousands) (Remainder of) 2018 $ 7,902 2019 31,606 2020 31,606 2021 31,606 2022 31,606 Thereafter 1,745,676 Total $ 1,880,002
Summary of Interest Rates and Interest Expense	The following table provides a summary of interest rates and interest expense for the three and nine months ended September 30, 2017 and 2018 : Three Months Ended September 30, 2017 Three Months Ended September 30, 2018 Nine Months Ended September 30, 2017 Nine Months Ended September 30, 2018 (percentage per annum) Interest rate—LIBOR 5.14%-5.32% 5.81%-6.07% 5.14%-6.68% 5.46%-6.32% Interest rate—reference * * * * Interest rate—Senior Notes 10.875 % 10.875 % 10.875 % 10.875 % Non-refundable fee—unused facility 0.50 % 0.50 % 0.50 % 0.50 % (dollars in thousands) Interest expense and service fees $ 32,551 $ 34,469 $ 105,371 $ 101,575 Loss on extinguishment of debt — — 992 331 Deferred financing fees immediately expensed — — 5,487 1,228 Amortization of deferred financing fees 1,873 1,722 5,403 4,708 Amortization of original issue discounts 1,059 1,083 2,791 3,209 Amortization of net present value of deferred consideration 127 60 504 311 Other interest expense 238 193 474 561 Total interest expense $ 35,848 $ 37,527 $ 121,022 $ 111,923 * The Company did not have debt bearing interest based on the alternate base rate for the three and nine months ended September 30, 2017 and 2018.

Stockholders' Equity (Tables)

Stockholders' Equity (Tables)	9 Months Ended
	Sep. 30, 2018
Equity [Abstract]
Summary of Changes in Stockholders' Equity	The following table presents the changes in total stockholders’ equity during the nine months ended September 30, 2018 : Total Stockholders’ Equity (in thousands) Balance at December 31, 2017 $ 83,005 Stock-based compensation 21,932 Reclassification of stock-compensation liability award 250 Stock option exercises 756 Foreign currency translation adjustment (2,489 ) Unrealized gain on derivative 1,996 Adjustment to beginning retained earnings resulting from adoption of ASC 606, net of tax impact of $7.0 million 59,384 Net loss attributable to Endurance International Group Holdings, Inc. (8,236 ) Balance at September 30, 2018 $ 156,598

Stock-Based Compensation (Table

Stock-Based Compensation (Tables)	9 Months Ended
	Sep. 30, 2018
Disclosure of Compensation Related Costs, Share-based Payments [Abstract]
Summary of Total Stock-Based Compensation Expense	The following table presents total stock-based compensation expense recorded in the consolidated statement of operations and comprehensive loss for all awards granted under the Company’s 2013 Plan and 2011 Plan: Three Months Ended Nine Months Ended 2017 2018 2017 2018 (in thousands) Cost of revenue $ 1,553 $ 828 $ 4,720 $ 3,223 Sales and marketing 2,263 1,478 7,027 4,009 Engineering and development 1,807 1,237 4,707 3,519 General and administrative 13,956 4,007 32,295 11,181 Total stock-based compensation expense $ 19,579 $ 7,550 $ 48,749 $ 21,932
Summary of Stock Options	The following table provides a summary of the Company’s stock options as of September 30, 2018 and the stock option activity for all stock options granted under the 2013 Plan during the nine months ended September 30, 2018 : Stock Options Weighted- Average Exercise Price Weighted- Average Remaining Contractual Term (in years) Aggregate Intrinsic Value(3) (in thousands) Outstanding at December 31, 2017 8,575,150 $ 12.30 Granted 611,010 $ 7.50 Exercised (19,049 ) $ 8.09 Forfeited (304,382 ) $ 12.79 Expired (1,516,912 ) $ 13.56 Outstanding at September 30, 2018 7,345,817 $ 11.63 5.1 $ 1,600 Exercisable at September 30, 2018 5,475,357 $ 12.39 3.9 $ 283 Expected to vest after September 30, 2018 (1) 1,870,460 $ 9.39 8.4 $ 1,317 Exercisable as of September 30, 2018 and expected to vest (2) 7,345,817 $ 11.63 5.1 $ 1,600 (1) This represents the number of unvested options outstanding as of September 30, 2018 that are expected to vest in the future. (2) This represents the number of vested options as of September 30, 2018 plus the number of unvested options outstanding as of September 30, 2018 that are expected to vest in the future. (3) The aggregate intrinsic value was calculated based on the positive difference, if any, between the estimated fair value of the Company’s common stock on September 30, 2018 of $8.80 per share, or the date of exercise, as appropriate, and the exercise price of the underlying options. The following table provides a summary of the Company’s stock options as of September 30, 2018 and the stock option activity for all stock options granted under the 2011 Plan during the nine months ended September 30, 2018 : Stock Options Weighted- Average Exercise Price Weighted- Average Remaining Contractual Term (In Years) Aggregate Intrinsic Value(3) (in thousands) Outstanding at December 31, 2017 888,260 $ 8.75 Granted — $ — Exercised (92,229 ) $ 6.53 Forfeited (10,256 ) $ 10.47 Expired (38,652 ) $ 9.21 Outstanding at September 30, 2018 747,123 $ 8.98 3.7 $ 546 Exercisable at September 30, 2018 563,823 $ 8.76 3.5 $ 499 Expected to vest after September 30, 2018 (1) 183,300 $ 9.65 4.2 $ 47 Exercisable as of September 30, 2018 and expected to vest (2) 747,123 $ 8.98 3.7 $ 546 (1) This represents the number of unvested options outstanding as of September 30, 2018 that are expected to vest in the future. (2) This represents the number of vested options as of September 30, 2018 plus the number of unvested options outstanding as of September 30, 2018 that are expected to vest in the future. (3) The aggregate intrinsic value was calculated based on the positive difference, if any, between the estimated fair value of the Company’s common stock on September 30, 2018 of $8.80 per share, or the date of exercise, as appropriate, and the exercise price of the underlying options.
Summary of Restricted Stock Awards and Restricted Stock Units	The following table provides a summary of the Company’s restricted stock unit activity for the 2011 Plan during the nine months ended September 30, 2018 : Restricted Stock Units Weighted Average Grant Date Fair Value Non-vested at December 31, 2017 1,541,141 $ 8.30 Granted 41,379 $ 7.25 Vested (516,600 ) $ 8.38 Canceled (92,030 ) $ 8.53 Non-vested at September 30, 2018 973,890 $ 8.20 The following table provides a summary of the Company’s restricted stock unit activity for the 2013 Plan during the nine months ended September 30, 2018 : Restricted Stock Units Weighted Average Grant Date Fair Value Non-vested at December 31, 2017 3,004,137 $ 7.93 Granted 3,846,567 $ 7.55 Vested (1,185,704 ) $ 9.08 Canceled (394,763 ) $ 7.78 Non-vested at September 30, 2018 5,270,237 $ 7.67 The following table provides a summary of the Company’s restricted stock award activity for the 2013 Plan during the nine months ended September 30, 2018 : Restricted Stock Weighted Non-vested at December 31, 2017 3,432,946 $ 13.79 Granted — $ — Vested (819,886 ) $ 12.29 Canceled (2,134,075 ) $ 14.85 Non-vested at September 30, 2018 478,985 $ 11.62

Accumulated Other Comprehensi_2

Accumulated Other Comprehensive Income (Tables)	9 Months Ended
	Sep. 30, 2018
Equity [Abstract]
Schedule of Accumulated Other Comprehensive Income	The following table presents the components of accumulated other comprehensive income (loss): Foreign Currency Translation Adjustments Unrealized Gains (Losses) on Cash Flow Hedges Total (in thousands) Balance at December 31, 2017 $ 696 $ (1,237 ) $ (541 ) Other comprehensive income (loss) (2,489 ) 1,996 (493 ) Balance at September 30, 2018 $ (1,793 ) $ 759 $ (1,034 )

Revenue (Tables)

Revenue (Tables)	9 Months Ended
	Sep. 30, 2018
Revenue from Contract with Customer [Abstract]
Disaggregation of Revenue	The following table presents disaggregated revenues by category for the three and nine months ended September 30, 2018 : Three Months Ended September 30, 2018 Web presence Email marketing Domain Total (in thousands) Subscriber revenue Direct revenue from subscribers $ 138,869 $ 100,816 $ 12,911 $ 252,596 Professional services 3,387 299 103 3,789 Reseller revenue 5,241 855 12,585 18,681 Total subscriber revenue $ 147,497 $ 101,970 $ 25,599 $ 275,066 Non-subscriber revenue MDF $ 2,199 $ 141 $ 252 $ 2,592 Premium domains 3 — 5,067 5,070 Domain parking 172 — 870 1,042 Total non-subscriber revenue $ 2,374 $ 141 $ 6,189 $ 8,704 Total revenue: $ 149,871 $ 102,111 $ 31,788 $ 283,770 Nine Months Ended September 30, 2018 Web presence Email marketing Domain Total (in thousands) Subscriber revenue Direct revenue from subscribers $ 424,321 $ 302,583 $ 39,185 $ 766,089 Professional services 10,091 1,045 300 11,436 Reseller revenue 16,487 2,620 39,136 58,243 Total subscriber revenue $ 450,899 $ 306,248 $ 78,621 $ 835,768 Non-subscriber revenue MDF $ 6,012 $ 464 $ 473 $ 6,949 Premium domains 70 — 15,823 15,893 Domain parking 622 — 3,664 4,286 Total non-subscriber revenue $ 6,704 $ 464 $ 19,960 $ 27,128 Total revenue: $ 457,603 $ 306,712 $ 98,581 $ 862,896 Revenue, classified by the major geographic areas in which the Company’s customers are located, was as follows for the three and nine months ended September 30, 2018 : Three Months Ended September 30, 2018 Web presence Email marketing Domain Total (in thousands) Domestic $ 100,065 $ 93,992 $ 12,509 $ 206,566 International 49,806 8,119 19,279 77,204 Total $ 149,871 $ 102,111 $ 31,788 $ 283,770 Nine Months Ended September 30, 2018 Web presence Email marketing Domain Total (in thousands) Domestic $ 306,724 $ 281,717 $ 38,525 $ 626,966 International 150,879 24,995 60,056 235,930 Total $ 457,603 $ 306,712 $ 98,581 $ 862,896

Severance and Other Exit Costs

Severance and Other Exit Costs (Tables)	9 Months Ended
	Sep. 30, 2018
Restructuring and Related Activities [Abstract]
Summary of Aggregate Activity Related to Company's Facilities Exit Costs Accrual and Severance Accrual	The following table provides a summary of the aggregate activity for the nine months ended September 30, 2018 related to the Company’s combined restructuring plans' facilities exit accrual: Facilities (in thousands) Total Balance at December 31, 2017 $ 6,005 Facility adjustments 43 Sublease income received 322 Cash paid (2,080 ) Balance at September 30, 2018 $ 4,290 The following table provides a summary of the aggregate activity for the nine months ended September 30, 2018 related to the Company’s combined restructuring plans' severance accrual: Employee Severance (in thousands) Total Balance at December 31, 2017 $ 3,668 Severance charges 2,978 Cash paid (5,646 ) Balance at September 30, 2018 $ 1,000
Summary of Total Restructuring Charges Recorded in the Consolidated Statements of Operations and Comprehensive Loss	The following table presents restructuring charges recorded in the consolidated statements of operations and comprehensive loss for the periods presented: For the Three Months Ended September 30, For the Nine Months Ended September 30, 2017 2018 2017 2018 (in thousands) Cost of revenue $ 449 $ 37 $ 3,892 $ 1,443 Sales and marketing 1,011 17 3,260 133 Engineering and development 271 33 1,349 389 General and administrative 2,758 110 6,083 1,056 Total restructuring charges $ 4,489 $ 197 $ 14,584 $ 3,021

Related Party Transactions (Tab

Related Party Transactions (Tables)	9 Months Ended
	Sep. 30, 2018
Related Party Transactions [Abstract]
Summary of Related Party Transactions	The following table presents the amounts of related party transactions recorded in the consolidated statements of operations and comprehensive loss for the periods presented relating to services provided by Tregaron and its affiliates under these agreements: Three Months Ended Nine Months Ended 2017 2018 2017 2018 (in thousands) Cost of revenue $ 3,100 $ 3,330 $ 9,100 $ 10,555 Sales and marketing 500 160 1,000 605 Engineering and development 200 290 850 960 General and administrative 50 20 150 65 Total related party transaction expense, net $ 3,850 $ 3,800 $ 11,100 $ 12,185 The following table presents the amounts of related party transactions recorded in the consolidated statements of operations and comprehensive loss for the periods presented relating to services provided by IBS and its affiliates under these agreements: Three Months Ended Nine Months Ended 2017 2018 2017 2018 (in thousands) Revenue $ (1,050 ) $ (1,430 ) $ (2,150 ) $ (4,075 ) Revenue (contra) 1,850 1,800 4,050 6,140 Total related party transaction impact to revenue $ 800 $ 370 $ 1,900 $ 2,065 Cost of revenue 150 170 350 490 Total related party transaction expense, net $ 950 $ 540 $ 2,250 $ 2,555

Segment Information (Tables)

Segment Information (Tables)	9 Months Ended
	Sep. 30, 2018
Segment Reporting [Abstract]
Schedule of Segment Reporting Information, by Segment	The following tables contain financial information for each reportable segment for the three and nine months ended September 30, 2017 and 2018 : Three Months Ended September 30, 2017 Web presence Email marketing Domain Total (in thousands) (as revised) Revenue (1) $ 159,530 $ 101,526 $ 34,166 $ 295,222 Gross profit $ 77,032 $ 65,286 $ (5,961 ) $ 136,357 Net (loss) income $ (20,403 ) $ 2,202 $ (22,063 ) $ (40,264 ) Interest expense, net (2) 14,686 20,514 445 35,645 Income tax expense (benefit) 798 1,323 861 2,982 Depreciation 9,399 3,233 939 13,571 Amortization of other intangible assets 14,884 18,770 1,693 35,347 Stock-based compensation 15,510 1,668 2,402 19,580 Restructuring expenses 3,468 682 339 4,489 (Gain) loss of unconsolidated entities (33 ) — — (33 ) Impairment of other long-lived assets 600 — 13,848 14,448 SEC investigations reserve 4,323 2,751 926 8,000 Adjusted EBITDA $ 43,232 $ 51,143 $ (610 ) $ 93,765 Three Months Ended September 30, 2018 Web presence Email marketing Domain Total (in thousands) Revenue (1) $ 149,871 $ 102,111 $ 31,788 $ 283,770 Gross profit $ 75,074 $ 71,356 $ 8,395 $ 154,825 Net (loss) income $ (7,565 ) $ 6,596 $ (5,366 ) $ (6,335 ) Interest expense, net (2) 18,132 17,128 1,978 37,238 Income tax expense (benefit) 6,136 4,179 1,400 11,715 Depreciation 8,401 2,538 950 11,889 Amortization of other intangible assets 11,941 13,384 852 26,177 Stock-based compensation 1,569 4,472 1,509 7,550 Restructuring expenses 54 141 2 197 Shareholder litigation reserve (768 ) — (167 ) (935 ) Adjusted EBITDA $ 37,900 $ 48,438 $ 1,158 $ 87,496 Nine Months Ended September 30, 2017 Web presence Email marketing Domain Total (in thousands) (as revised) Revenue (1) $ 483,661 $ 298,401 $ 100,555 $ 882,617 Gross profit $ 229,186 $ 188,181 $ 11,053 $ 428,420 Net (loss) income $ (67,226 ) $ (8,026 ) $ (32,005 ) $ (107,257 ) Interest expense, net (2) 50,877 68,212 1,427 120,516 Income tax expense (benefit) 12,645 (4,821 ) 3,560 11,384 Depreciation 27,401 10,632 2,700 40,733 Amortization of other intangible assets 44,431 55,697 4,426 104,554 Stock-based compensation 38,023 5,392 5,334 48,749 Restructuring expenses 8,944 4,743 897 14,584 Transaction expenses and charges — 773 — 773 (Gain) loss of unconsolidated entities (72 ) — — (72 ) Impairment of other long-lived assets 600 — 13,848 14,448 SEC investigations reserve 4,323 2,751 926 8,000 Shareholder litigation reserve — — — — Adjusted EBITDA $ 119,946 $ 135,353 $ 1,113 $ 256,412 Nine Months Ended September 30, 2018 Web presence Email marketing Domain Total (in thousands) Revenue (1) $ 457,603 $ 306,712 $ 98,581 $ 862,896 Gross profit $ 225,149 $ 214,909 $ 29,241 $ 469,299 Net (loss) income $ (20,549 ) $ 22,350 $ (10,037 ) $ (8,236 ) Interest expense, net (2) 53,503 50,866 6,834 111,203 Income tax expense (benefit) 960 8,009 (143 ) 8,826 Depreciation 24,769 9,090 2,894 36,753 Amortization of other intangible assets 35,812 39,716 2,362 77,890 Stock-based compensation 12,066 7,168 2,698 21,932 Restructuring expenses 1,654 723 644 3,021 (Gain) loss of unconsolidated entities 2 — — 2 Shareholder litigation reserve 4,780 1,500 1,045 7,325 Adjusted EBITDA $ 112,997 $ 139,422 $ 6,297 $ 258,716 (1) Revenue excludes intercompany transactions relating to domain sales and domain services from the domain segment to the web presence segment of $2.5 million and $8.1 million , respectively, for the three and nine months ended September 30, 2017 , and $2.5 million and $7.6 million , respectively, for the three and nine months ended September 30, 2018 . (2) Interest expense includes impact of amortization of deferred financing costs, original issuance discounts and interest income.
Schedule of Error Corrections	The following table represents the impact of the revised deferred income tax provision on the impacted lines of the statement of cash flows for the periods shown (in thousands): Three Months Ended March 31, 2018 Six Months Ended June 30, 2018 Originally Filed Adjustment Revised Originally Filed Adjustment Revised Net income (loss) $ (7,088 ) $ 4,560 $ (2,528 ) $ (9,057 ) $ 7,156 $ (1,901 ) Deferred tax expense 492 (4,560 ) (4,068 ) 2,672 (7,156 ) (4,484 ) Net cash provided by operating activities 52,360 — 52,360 82,252 — 82,252 The following table represents the impact of the income statement revision to the first and second quarters of 2018 due to the revised deferred income tax provision (in thousands, except per share data): Three Months Ended March 31, 2018 Three Months Ended June 30, 2018 Originally Filed Adjustment Revised Originally Filed Adjustment Revised Loss before income taxes and equity earnings of unconsolidated subsidiaries $ (4,444 ) $ — $ (4,444 ) $ (344 ) $ — $ (344 ) Income tax expense (benefit) 2,617 (4,560 ) (1,943 ) 1,650 (2,596 ) (946 ) Loss before equity earnings of unconsolidated subsidiaries (7,061 ) $ 4,560 $ (2,501 ) (1,994 ) $ 2,596 $ 602 Equity (income) loss of unconsolidated subsidiaries 27 — 27 $ (25 ) (25 ) Net income (loss) $ (7,088 ) $ 4,560 $ (2,528 ) $ (1,969 ) $ 2,596 $ 627 Comprehensive income (loss) Foreign currency translation 580 — 580 (2,425 ) — (2,425 ) Unrealized (gain) loss on cash flow hedge, net of tax 1,041 — 1,041 144 — 144 Total comprehensive loss $ (5,467 ) $ 4,560 $ (907 ) $ (4,250 ) $ 2,596 $ (1,654 ) Basic net income (loss) per share $ (0.05 ) $ 0.03 $ (0.02 ) $ (0.01 ) $ 0.01 $0.00 Diluted net income (loss) per share $ (0.05 ) $ 0.03 $ (0.02 ) $ (0.01 ) $ 0.01 $0.00 Weighted-average common shares used in computing net income (loss) per share Basic 140,361,982 — 140,361,982 142,340,561 — 142,340,561 Diluted 140,361,982 — 140,361,982 142,340,561 2,361,441 144,702,002 Six Months Ended June 30, 2018 Originally Filed Adjustment Revised Loss before income taxes and equity earnings of unconsolidated subsidiaries $ (4,788 ) $ — $ (4,788 ) Income tax expense (benefit) 4,267 (7,156 ) (2,889 ) Loss before equity earnings of unconsolidated subsidiaries (9,055 ) 7,156 (1,899 ) Equity (income) loss of unconsolidated subsidiaries 2 — 2 Net income (loss) (9,057 ) 7,156 $ (1,901 ) Comprehensive income (loss) Foreign currency translation (1,845 ) — (1,845 ) Unrealized gain on cash flow hedge, net of tax 1,184 — 1,184 Total comprehensive loss (9,718 ) 7,156 $ (2,562 ) Basic net income (loss) per share $ (0.06 ) $ 0.05 $ (0.01 ) Diluted net income (loss) per share $ (0.06 ) $ 0.05 $ (0.01 ) Weighted-average common shares used in computing net income (loss) per share Basic 141,356,567 — 141,356,567 Diluted 141,356,567 — 141,356,567 The following table represents the impact of the revised deferred income tax provision on the impacted balance sheet accounts as of the dates shown (in thousands): March 31, 2018 June 30, 2018 Originally Filed Adjustment Revised Originally Filed Adjustment Revised Deferred tax liability $ 27,679 $ (4,560 ) $ 23,119 $ 29,897 $ (7,156 ) $ 22,741 Total liabilities 2,533,619 (4,560 ) 2,529,059 2,490,106 (7,156 ) 2,482,950 Accumulated deficit (795,206 ) 4,560 (790,646 ) (797,175 ) 7,156 (790,019 ) Total stockholders' equity 144,189 4,560 148,749 147,759 7,156 154,915 Total liabilities and stockholders' equity 2,677,808 — 2,677,808 2,637,865 — 2,637,865 The following table reflects the differences between the amounts as reported and the amounts as revised for gross profit, net loss and adjusted EBITDA for the web presence and domain segments for the three and nine months ended September 30, 2017 : Three Months Ended September 30, 2017 Web presence Domain (in thousands) (as reported) (as revised) (as reported) (as revised) Gross profit $ 75,097 $ 77,032 $ (4,026 ) $ (5,961 ) Net loss $ (22,416 ) $ (20,403 ) $ (20,050 ) $ (22,063 ) Adjusted EBITDA $ 41,297 $ 43,232 $ 1,325 $ (610 ) Nine Months Ended September 30, 2017 Web presence Domain (in thousands) (as reported) (as revised) (as reported) (as revised) Gross profit $ 224,300 $ 229,186 $ 15,939 $ 11,053 Net loss $ (73,346 ) $ (67,226 ) $ (25,885 ) $ (32,005 ) Adjusted EBITDA $ 115,060 $ 119,946 $ 5,999 $ 1,113

Supplemental Guarantor Financ_2

Supplemental Guarantor Financial Information (Tables)	9 Months Ended
	Sep. 30, 2018
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Condensed Financial Statements	The following tables present supplemental condensed consolidating balance sheet information of the Company (“Parent”), the Issuer, the Subsidiary Guarantors and the Non-Guarantor Subsidiaries as of December 31, 2017 and September 30, 2018 , supplemental condensed consolidating results of operations for the three and nine months ended September 30, 2017 and 2018 , and cash flow information for the nine months ended September 30, 2017 and 2018 : Condensed Consolidating Balance Sheets December 31, 2017 (in thousands) Parent Issuer Guarantor Subsidiaries Non-Guarantor Subsidiaries Eliminations Consolidated Assets: Current assets: Cash and cash equivalents $ 92 $ 2 $ 54,473 $ 11,926 $ — $ 66,493 Restricted cash — — 2,472 153 — 2,625 Accounts receivable — — 12,386 3,559 — 15,945 Prepaid domain name registry fees — — 28,291 25,514 — 53,805 Prepaid expenses & other current assets (12 ) 86 20,062 9,191 — 29,327 Total current assets 80 88 117,684 50,343 — 168,195 Intercompany receivables, net 33,637 606,834 (498,213 ) (142,258 ) — — Property and equipment, net — — 81,693 13,759 — 95,452 Goodwill — — 1,673,851 176,731 — 1,850,582 Other intangible assets, net — — 450,778 4,662 — 455,440 Investment in subsidiaries 49,288 1,355,013 37,200 — (1,441,501 ) — Other assets — 3,639 21,373 6,405 — 31,417 Total assets $ 83,005 $ 1,965,574 $ 1,884,366 $ 109,642 $ (1,441,501 ) $ 2,601,086 Liabilities and stockholders' equity: Current liabilities: Accounts payable $ — $ — $ 9,532 $ 1,526 $ — $ 11,058 Accrued expenses and other current liabilities — 24,509 75,819 8,151 — 108,479 Deferred revenue — — 309,395 52,545 — 361,940 Current portion of notes payable — 33,945 — — — 33,945 Current portion of capital lease obligations — — 7,630 — — 7,630 Deferred consideration, short-term — — 4,365 — — 4,365 Total current liabilities — 58,454 406,741 62,222 — 527,417 Deferred revenue, long-term — — 81,199 9,773 — 90,972 Notes payable — 1,858,300 — — — 1,858,300 Capital lease obligations — — 7,719 — — 7,719 Deferred consideration — — 3,551 — — 3,551 Other long-term liabilities — (468 ) 30,143 447 — 30,122 Total liabilities — 1,916,286 529,353 72,442 — 2,518,081 Equity 83,005 49,288 1,355,013 37,200 (1,441,501 ) 83,005 Total liabilities and stockholders' equity $ 83,005 $ 1,965,574 $ 1,884,366 $ 109,642 $ (1,441,501 ) $ 2,601,086 Condensed Consolidating Balance Sheets September 30, 2018 (in thousands) Parent Issuer Guarantor Subsidiaries Non-Guarantor Subsidiaries Eliminations Consolidated Assets: Current assets: Cash and cash equivalents $ 207 $ 2 $ 59,890 $ 29,575 $ — $ 89,674 Restricted cash — — 1,731 101 — 1,832 Accounts receivable — — 11,906 2,199 — 14,105 Prepaid domain name registry fees — — 32,729 24,385 — 57,114 Prepaid commissions — — 41,085 659 — 41,744 Prepaid expenses & other current assets — 174 18,361 8,566 — 27,101 Total current assets 207 176 165,702 65,485 — 231,570 Intercompany receivables, net 34,278 441,001 (354,298 ) (120,981 ) — — Property and equipment, net — — 66,772 12,543 — 79,315 Goodwill — — 1,673,851 175,413 — 1,849,264 Other intangible assets, net — — 376,441 1,229 — 377,670 Investment in subsidiaries 122,114 1,510,592 74,478 — (1,707,184 ) — Prepaid commissions, net of current portion — — 41,346 735 — 42,081 Other assets — 9,742 22,351 6,410 — 38,503 Total assets $ 156,599 $ 1,961,511 $ 2,066,643 $ 140,834 $ (1,707,184 ) $ 2,618,403 Liabilities and stockholders' equity: Current liabilities: Accounts payable $ — $ — $ 10,239 $ 573 $ — $ 10,812 Accrued expenses and other current liabilities — 15,197 69,493 4,376 — 89,066 Deferred revenue — — 330,178 50,386 — 380,564 Current portion of notes payable — 31,606 — — — 31,606 Current portion of capital lease obligations — — 7,595 — — 7,595 Deferred consideration, short-term — — 2,386 — — 2,386 Total current liabilities — 46,803 419,891 55,335 — 522,029 Deferred revenue, long-term — — 86,133 10,286 — 96,419 Notes payable — 1,792,436 — — — 1,792,436 Capital lease obligations — — 2,067 — — 2,067 Deferred consideration — — 1,342 — — 1,342 Other long-term liabilities — 158 46,618 736 — 47,512 Total liabilities — 1,839,397 556,051 66,357 — 2,461,805 Equity 156,599 122,114 1,510,592 74,477 (1,707,184 ) 156,598 Total liabilities and stockholders' equity $ 156,599 $ 1,961,511 $ 2,066,643 $ 140,834 $ (1,707,184 ) $ 2,618,403 Condensed Consolidating Statements of Operations and Comprehensive Income (Loss) Three Months Ended September 30, 2017 (in thousands) Parent Issuer Guarantor Subsidiaries Non-Guarantor Subsidiaries Eliminations Consolidated Revenue $ — $ — $ 266,985 $ 30,019 $ (1,782 ) $ 295,222 Cost of revenue — — 139,044 21,155 (1,334 ) 158,865 Gross profit — — 127,941 8,864 (448 ) 136,357 Operating expense: Sales and marketing — — 61,376 4,900 — 66,276 Engineering and development — — 17,412 2,470 — 19,882 General and administrative — 56 50,353 1,465 (605 ) 51,269 Total operating expense — 56 129,141 8,835 (605 ) 137,427 (Loss) income from operations — (56 ) (1,200 ) 29 157 (1,070 ) Interest expense and other income, net — 35,661 756 (172 ) — 36,245 (Loss) income before income taxes and equity earnings of unconsolidated entities — (35,717 ) (1,956 ) 201 157 (37,315 ) Income tax (benefit) expense — (13,201 ) 15,494 689 — 2,982 (Loss) income before equity earnings of unconsolidated entities — (22,516 ) (17,450 ) (488 ) 157 (40,297 ) Equity loss (income) of unconsolidated entities, net of tax 40,422 17,906 456 — (58,817 ) (33 ) Net (loss) income $ (40,422 ) $ (40,422 ) $ (17,906 ) $ (488 ) $ 58,974 $ (40,264 ) Net (loss) income attributable to Endurance International Group Holdings, Inc. $ (40,422 ) $ (40,422 ) $ (17,906 ) $ (488 ) $ 58,974 $ (40,264 ) Comprehensive income (loss): Foreign currency translation adjustments — — — 1,070 — 1,070 Unrealized gain on cash flow hedge, net of taxes — 83 — — — 83 Total comprehensive (loss) income $ (40,422 ) $ (40,339 ) $ (17,906 ) $ 582 $ 58,974 $ (39,111 ) Condensed Consolidating Statements of Operations and Comprehensive Income (Loss) Nine Months Ended September 30, 2017 (in thousands) Parent Issuer Guarantor Subsidiaries Non-Guarantor Subsidiaries Eliminations Consolidated Revenue $ — $ — $ 788,806 $ 98,321 $ (4,510 ) $ 882,617 Cost of revenue — — 392,447 65,392 (3,642 ) 454,197 Gross profit — — 396,359 32,929 (868 ) 428,420 Operating expense: Sales and marketing — — 195,392 15,765 (3 ) 211,154 Engineering and development — — 51,053 9,340 — 60,393 General and administrative — 166 123,736 7,632 (605 ) 130,929 Transaction costs — — 773 — — 773 Total operating expense — 166 370,954 32,737 (608 ) 403,249 (Loss) income from operations — (166 ) 25,405 192 (260 ) 25,171 Interest expense and other income, net — 120,313 1,150 (347 ) — 121,116 (Loss) income before income taxes and equity earnings of unconsolidated entities — (120,479 ) 24,255 539 (260 ) (95,945 ) Income tax (benefit) expense — (44,512 ) 54,744 1,152 — 11,384 (Loss) income before equity earnings of unconsolidated entities — (75,967 ) (30,489 ) (613 ) (260 ) (107,329 ) Equity loss (income) of unconsolidated entities, net of tax 106,999 31,033 543 — (138,647 ) (72 ) Net (loss) income $ (106,999 ) $ (107,000 ) $ (31,032 ) $ (613 ) $ 138,387 $ (107,257 ) Net loss attributable to non-controlling interest — — 7,524 — — 7,524 Net (loss) income attributable to Endurance International Group Holdings, Inc. $ (106,999 ) $ (107,000 ) $ (38,556 ) $ (613 ) $ 138,387 $ (114,781 ) Comprehensive income (loss): Foreign currency translation adjustments — — — 2,984 — 2,984 Unrealized gain on cash flow hedge, net of taxes — (309 ) — — — (309 ) Total comprehensive (loss) income $ (106,999 ) $ (107,309 ) $ (38,556 ) $ 2,371 $ 138,387 $ (112,106 ) Condensed Consolidating Statements of Operations and Comprehensive Income (Loss) Three Months Ended September 30, 2018 (in thousands) Parent Issuer Guarantor Subsidiaries Non-Guarantor Subsidiaries Eliminations Consolidated Revenue $ — $ — $ 258,388 $ 26,730 $ (1,348 ) $ 283,770 Cost of revenue — — 110,808 19,485 (1,348 ) 128,945 Gross profit — — 147,580 7,245 — 154,825 Operating expense: Sales and marketing — — 60,341 3,490 — 63,831 Engineering and development — — 20,524 2,159 — 22,683 General and administrative (11 ) 52 24,187 1,465 — 25,693 Total operating expense (11 ) 52 105,052 7,114 — 112,207 (Loss) income from operations 11 (52 ) 42,528 131 — 42,618 Interest expense and other income, net — 37,305 74 (141 ) — 37,238 (Loss) income before income taxes and equity earnings of unconsolidated entities 11 (37,357 ) 42,454 272 — 5,380 Income tax (benefit) expense — (8,891 ) 22,020 (1,414 ) — 11,715 (Loss) income before equity earnings of unconsolidated entities 11 (28,466 ) 20,434 1,686 — (6,335 ) Equity loss (income) of unconsolidated entities, net of tax 6,346 (22,120 ) (1,686 ) — 17,460 — Net (loss) income $ (6,335 ) $ (6,346 ) $ 22,120 $ 1,686 $ (17,460 ) $ (6,335 ) Net (loss) income attributable to Endurance International Group Holdings, Inc. $ (6,335 ) $ (6,346 ) $ 22,120 $ 1,686 $ (17,460 ) $ (6,335 ) Comprehensive income (loss): Foreign currency translation adjustments — — — (644 ) — (644 ) Unrealized gain on cash flow hedge, net of taxes — 812 — — — 812 Total comprehensive (loss) income $ (6,335 ) $ (5,534 ) $ 22,120 $ 1,042 $ (17,460 ) $ (6,167 ) Condensed Consolidating Statements of Operations and Comprehensive Income (Loss) Nine Months Ended September 30, 2018 (in thousands) Parent Issuer Guarantor Subsidiaries Non-Guarantor Subsidiaries Eliminations Consolidated Revenue $ — $ — $ 783,611 $ 83,995 $ (4,710 ) $ 862,896 Cost of revenue — — 338,885 59,422 (4,710 ) 393,597 Gross profit — — 444,726 24,573 — 469,299 Operating expense: Sales and marketing — — 187,175 10,558 — 197,733 Engineering and development — — 58,850 5,709 — 64,559 General and administrative (11 ) 169 124,317 (29,263 ) — 95,212 Total operating expense (11 ) 169 370,342 (12,996 ) — 357,504 (Loss) income from operations 11 (169 ) 74,384 37,569 — 111,795 Interest expense and other income, net — 111,051 539 (387 ) — 111,203 (Loss) income before income taxes and equity earnings of unconsolidated entities 11 (111,220 ) 73,845 37,956 — 592 Income tax (benefit) expense — (26,470 ) 35,897 (601 ) — 8,826 (Loss) income before equity earnings of unconsolidated entities 11 (84,750 ) 37,948 38,557 — (8,234 ) Equity loss (income) of unconsolidated entities, net of tax 8,247 (76,503 ) (38,554 ) 18 106,794 2 Net (loss) income $ (8,236 ) $ (8,247 ) $ 76,502 $ 38,539 $ (106,794 ) $ (8,236 ) Net (loss) income attributable to Endurance International Group Holdings, Inc. $ (8,236 ) $ (8,247 ) $ 76,502 $ 38,539 $ (106,794 ) $ (8,236 ) Comprehensive income (loss): Foreign currency translation adjustments — — — (2,489 ) — (2,489 ) Unrealized gain on cash flow hedge, net of taxes — 1,996 — — — 1,996 Total comprehensive (loss) income $ (8,236 ) $ (6,251 ) $ 76,502 $ 36,050 $ (106,794 ) $ (8,729 ) Condensed Consolidating Statement of Cash Flows Nine Months Ended September 30, 2017 (in thousands) Parent Issuer Guarantor Subsidiaries Non-Guarantor Subsidiaries Eliminations Consolidated Net cash (used in) provided by operating activities $ (32 ) $ (72,687 ) $ 204,768 $ (3,183 ) $ — $ 128,866 Cash flows from investing activities: Purchases of property and equipment — — (28,140 ) (3,955 ) — (32,095 ) Proceeds from sale of property and equipment — — 292 — — 292 Proceeds from note receivable — — — — — — Purchases of intangible assets — — (1,932 ) (34 ) — (1,966 ) Net cash used in investing activities — — (29,780 ) (3,989 ) — (33,769 ) Cash flows from financing activities: Proceeds from issuance of notes payable and draws on revolver — 1,693,007 — — — 1,693,007 Repayment of notes payable and revolver — (1,733,147 ) — — — (1,733,147 ) Payment of financing costs — (6,304 ) — — — (6,304 ) Payment of deferred consideration — — (4,550 ) (858 ) — (5,408 ) Payment of redeemable non-controlling interest liability — — (25,000 ) — — (25,000 ) Principal payments on capital lease obligations — — (5,679 ) — — (5,679 ) Proceeds from exercise of stock options 1,548 — — — — 1,548 Intercompany loans and investments (1,058 ) 119,128 (124,060 ) 5,990 — — Net cash (used in) provided by financing activities 490 72,684 (159,289 ) 5,132 — (80,983 ) Net effect of exchange rate on cash and cash equivalents and restricted cash — — — 2,156 — 2,156 Net (decrease) increase in cash and cash equivalents and restricted cash 458 (3 ) 15,699 116 — 16,270 Cash and cash equivalents and restricted cash: Beginning of period 3 4 41,654 15,237 — 56,898 End of period $ 461 $ 1 $ 57,353 $ 15,353 $ — $ 73,168 Condensed Consolidating Statement of Cash Flows Nine Months Ended September 30, 2018 (in thousands) Parent Issuer Guarantor Subsidiaries Non-Guarantor Subsidiaries Eliminations Consolidated Net cash (used in) provided by operating activities $ — $ (88,464 ) $ 180,852 $ 41,205 $ — $ 133,593 Cash flows from investing activities: Purchases of property and equipment — — (22,159 ) (184 ) — (22,343 ) Proceeds from sale of property and equipment — — 6 — — 6 Net cash used in investing activities — — (22,153 ) (184 ) — (22,337 ) Cash flows from financing activities: Proceeds from issuance of term loan and notes, net of original issue discounts — 1,580,305 — — — 1,580,305 Repayment of term loans — (1,656,094 ) — — — (1,656,094 ) Payment of financing costs — (1,580 ) — — — (1,580 ) Payment of deferred consideration — — (4,500 ) — — (4,500 ) Principal payments on capital lease obligations — — (5,609 ) — — (5,609 ) Proceeds from exercise of stock options 756 — — — — 756 Intercompany loans and investments (641 ) 165,833 (143,914 ) (21,278 ) — — Net cash provided by (used in) financing activities 115 88,464 (154,023 ) (21,278 ) — (86,722 ) Net effect of exchange rate on cash and cash equivalents and restricted cash — — — (2,146 ) — (2,146 ) Net increase (decrease) in cash and cash equivalents and restricted cash 115 — 4,676 17,597 — 22,388 Cash and cash equivalents and restricted cash: Beginning of period 92 2 56,945 12,079 — 69,118 End of period $ 207 $ 2 $ 61,621 $ 29,676 $ — $ 91,506

Summary of Significant Accoun_4

Summary of Significant Accounting Policies - Additional Information (Detail)	Oct. 31, 2017USD ($)	Sep. 30, 2018USD ($)	Mar. 31, 2018USD ($)reporting_unit	Dec. 31, 2017USD ($)Segment	Sep. 30, 2017USD ($)	Sep. 30, 2018USD ($)Segment	Sep. 30, 2017USD ($)	Dec. 31, 2017USD ($)Segmentreporting_unit	Sep. 30, 2017Segment	Dec. 31, 2016USD ($)	Jun. 30, 2018USD ($)	Jan. 01, 2018USD ($)
Accounting Policies [Line Items]
Number of reportable segments | Segment						3			2
Number of reporting units | reporting_unit			10					10
Goodwill impairment		$ 0				$ 0
Goodwill		1,849,264,000		$ 1,850,582,000		1,849,264,000		$ 1,850,582,000
Goodwill to be reallocated between reporting units			$ 48,000,000
Impairment of long lived assets		0			$ 13,800,000	0	$ 13,848,000
Impairment of other intangible assets						0	0
Software development cost capitalized		2,800,000			2,200,000	7,100,000	8,400,000
Accumulated deficit		(796,353,000)	$ (790,646,000)	(847,501,000)		(796,353,000)		(847,501,000)			$ (790,019,000)
Deferred revenue		477,000,000				477,000,000
Reserves for refunds and chargebacks		300,000		500,000		300,000		500,000
Deferred revenue expected to be refunded		1,800,000		1,800,000		$ 1,800,000		1,800,000
Percentage of deferred revenue refunded within same fiscal month						83.00%
Percentage of deferred revenue refunded within 45 days						96.00%
Recognition of the beginning deferred revenue into revenue, as a result of performance obligations satisfied						$ 331,939,000
Recognition of the beginning deferred revenue into revenue, as a result of performance obligations satisfied						0
Unrecognized tax benefits		2,900,000		$ 1,100,000		2,900,000		$ 1,100,000
Unrecognized tax benefits, income tax penalties and interest expense		100,000			$ 0	300,000	0
Webzai Limited | Engineering and Development
Accounting Policies [Line Items]
Impairment of other intangible assets						0	$ 0
Web Presence
Accounting Policies [Line Items]
Number of reportable segments | Segment				2				2
Goodwill		1,215,101,000		$ 1,216,419,000		1,215,101,000		$ 1,216,419,000
Contract with customer, asset		71,000,000				71,000,000
Capitalized contract cost amortization		34,500,000
Domain
Accounting Policies [Line Items]
Goodwill		29,858,000		29,858,000		29,858,000		29,858,000
Contract with customer, asset		1,400,000				1,400,000
Capitalized contract cost amortization		300,000
Email Marketing
Accounting Policies [Line Items]
Goodwill		604,305,000		604,305,000		604,305,000		$ 604,305,000
Contract with customer, asset		11,400,000				$ 11,400,000
Capitalized contract cost amortization		3,400,000
Reporting Units With Goodwill Allocated
Accounting Policies [Line Items]
Number of reporting units | reporting_unit								7
Reporting Units With No Goodwill Allocated
Accounting Policies [Line Items]
Number of reporting units | reporting_unit								3
Domain monetization | Domain
Accounting Policies [Line Items]
Goodwill impairment	$ 12,100,000			12,100,000
Reporting Units With Goodwill And No Impairment
Accounting Policies [Line Items]
Number of reporting units | reporting_unit								6
Reporting Units Whose Fair Value Exceeds Carrying Value By 20%
Accounting Policies [Line Items]
Goodwill				1,820,700,000				$ 1,820,700,000
Fair value In excess of carrying value								20.00%
domain.com | Domain
Accounting Policies [Line Items]
Goodwill				29,900,000				$ 29,900,000
Fair value In excess of carrying value								6.00%
Backup Reporting Unit | Web Presence
Accounting Policies [Line Items]
Goodwill				$ 2,300,000				$ 2,300,000
Difference between Revenue Guidance in Effect before and after Topic 606 | Accounting Standards Update 2014-09
Accounting Policies [Line Items]
Accumulated deficit												$ 59,400,000
Deferred asset, customer acquisition costs												83,400,000
Deferred asset, domain registration costs												6,100,000
Deferred revenue												23,100,000
Deferred tax liabilities												$ 7,000,000
Web Hosting | Weighted Average
Accounting Policies [Line Items]
Contract term						1 year
Web Hosting | Minimum
Accounting Policies [Line Items]
Contract term						30 days
Web Hosting | Maximum
Accounting Policies [Line Items]
Contract term						3 years
EBITDA | Reclassification of Expenses Between Segments | Web Presence
Accounting Policies [Line Items]
Reclassification between segments								(6,900,000)		$ (3,000,000)
EBITDA | Reclassification of Expenses Between Segments | Domain
Accounting Policies [Line Items]
Reclassification between segments								6,900,000		3,000,000
Gross Profit | Reclassification of Expenses Between Segments | Web Presence
Accounting Policies [Line Items]
Reclassification between segments								(6,900,000)		(3,000,000)
Gross Profit | Reclassification of Expenses Between Segments | Domain
Accounting Policies [Line Items]
Reclassification between segments								$ 6,900,000		$ 3,000,000
Sales And Marketing Costs | Web Presence
Accounting Policies [Line Items]
Contract with customer, asset		0				$ 0
Sales And Marketing Costs | Domain
Accounting Policies [Line Items]
Contract with customer, asset		0				0
Sales And Marketing Costs | Email Marketing
Accounting Policies [Line Items]
Contract with customer, asset		0				0
Recoverable Sales Commissions | Web Presence
Accounting Policies [Line Items]
Contract with customer, asset		71,000,000				71,000,000
Recoverable Sales Commissions | Domain
Accounting Policies [Line Items]
Contract with customer, asset		1,400,000				1,400,000
Recoverable Sales Commissions | Email Marketing
Accounting Policies [Line Items]
Contract with customer, asset		$ 11,400,000				$ 11,400,000
Discount Rate
Accounting Policies [Line Items]
Discount rate				0.100				0.100

Summary of Significant Accoun_5

Summary of Significant Accounting Policies - Summary of Estimated Useful Lives (Detail) - USD ($)	3 Months Ended		9 Months Ended
	Sep. 30, 2018	Sep. 30, 2017	Sep. 30, 2018	Sep. 30, 2017
Property, Plant and Equipment [Line Items]
Goodwill impairment	$ 0		$ 0
Impairment of long lived assets	$ 0	$ 13,800,000	$ 0	$ 13,848,000
Building
Property, Plant and Equipment [Line Items]
Property, plant and equipment useful life			35 years
Software | Minimum
Property, Plant and Equipment [Line Items]
Property, plant and equipment useful life			2 years
Software | Maximum
Property, Plant and Equipment [Line Items]
Property, plant and equipment useful life			3 years
Computers and office equipment
Property, Plant and Equipment [Line Items]
Property, plant and equipment useful life			3 years
Furniture and fixtures
Property, Plant and Equipment [Line Items]
Property, plant and equipment useful life			5 years

Summary of Significant Accoun_6

Summary of Significant Accounting Policies - Summary of Changes in Deferred Income (Details) $ in Thousands	9 Months Ended
	Sep. 30, 2018USD ($)
Short-term
Balance at December 31, 2017	$ 361,940
Deferred revenue	361,940
Recognition of the beginning deferred revenue into revenue, as a result of performance obligations satisfied	(331,939)
Cash received in advance during the period	657,821
Recognition of cash received in the period into revenue, as a result of performance obligations satisfied	(518,087)
Reclassification between short-term and long-term	190,554
Balance at September 30, 2018	380,564
Long-term
Balance at December 31, 2017	90,972
Effect of adoption of ASC 606 to balances at December 31, 2017	90,972
Recognition of the beginning deferred revenue into revenue, as a result of performance obligations satisfied	0
Cash received in advance during the period	193,119
Recognition of cash received in the period into revenue, as a result of performance obligations satisfied	0
Reclassification between short-term and long-term	(190,554)
Balance at September 30, 2018	96,419
Effect of adoption of ASC 606 to balances at December 31, 2017 | Accounting Standards Update 2014-09
Short-term
Balance at December 31, 2017	20,275
Deferred revenue	20,275
Balance at September 30, 2018	1,221
Long-term
Balance at December 31, 2017	2,882
Effect of adoption of ASC 606 to balances at December 31, 2017	2,882
Balance at September 30, 2018	$ 0

Summary of Significant Accoun_7

Summary of Significant Accounting Policies - Remaining Performance Obligation (Details) $ in Thousands	Sep. 30, 2018USD ($)
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2018-10-01
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items]
Remaining performance obligation	$ 380,564
Expected timing of performance obligation satisfaction	1 year
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2019-10-01
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items]
Remaining performance obligation	$ 96,419
Expected timing of performance obligation satisfaction
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: (nil)
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items]
Remaining performance obligation	$ 476,983
Web Presence | Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2018-10-01
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items]
Remaining performance obligation	$ 265,984
Expected timing of performance obligation satisfaction	1 year
Web Presence | Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2019-10-01
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items]
Remaining performance obligation	$ 81,805
Expected timing of performance obligation satisfaction
Web Presence | Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: (nil)
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items]
Remaining performance obligation	$ 347,789
Email Marketing | Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2018-10-01
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items]
Remaining performance obligation	$ 55,055
Expected timing of performance obligation satisfaction	1 year
Email Marketing | Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2019-10-01
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items]
Remaining performance obligation	$ 0
Expected timing of performance obligation satisfaction
Email Marketing | Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: (nil)
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items]
Remaining performance obligation	$ 55,055
Domain | Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2018-10-01
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items]
Remaining performance obligation	$ 59,525
Expected timing of performance obligation satisfaction	1 year
Domain | Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2019-10-01
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items]
Remaining performance obligation	$ 14,614
Expected timing of performance obligation satisfaction
Domain | Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: (nil)
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items]
Remaining performance obligation	$ 74,139

Summary of Significant Accoun_8

Summary of Significant Accounting Policies - Deferred Customer Acquisition Costs (Details) $ in Thousands	9 Months Ended
	Sep. 30, 2018USD ($)
Short-term
Balance at December 31, 2017	$ 0
Prepaid commissions	0
Deferred customer acquisition costs incurred in the period	13,391
Amounts recognized as expense in the period	(38,192)
Impact of foreign exchange rates	(142)
Reclassification between short-term and long-term	23,279
Balance at September 30, 2018	41,744
Long-term
Balance at December 31, 2017	0
Prepaid commissions, net of current portion	0
Deferred customer acquisition costs incurred in the period	25,307
Amounts recognized as expense in the period	0
Impact of foreign exchange rates	13
Reclassification between short-term and long-term	(23,279)
Balance at September 30, 2018	42,081
Accounting Standards Update 2014-09 | Effect of adoption of ASC 606 to balances at December 31, 2017
Short-term
Balance at December 31, 2017	43,408
Prepaid commissions	43,408
Balance at September 30, 2018	41,744
Long-term
Balance at December 31, 2017	40,040
Prepaid commissions, net of current portion	40,040
Balance at September 30, 2018	$ 42,081

Summary of Significant Accoun_9

Summary of Significant Accounting Policies - Summary of Calculation of Basic and Diluted Net Loss Per Share (Detail) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended				6 Months Ended	9 Months Ended
	Sep. 30, 2018	Jun. 30, 2018	Mar. 31, 2018	Sep. 30, 2017	Jun. 30, 2018	Sep. 30, 2018	Sep. 30, 2017
Accounting Policies [Abstract]
Net loss attributable to Endurance International Group Holdings, Inc.	$ (6,335)			$ (40,264)		$ (8,236)	$ (114,781)
Net loss per share attributable to Endurance International Group Holdings, Inc.:
Basic net income (loss) per share (in usd per share)	$ (0.04)	$ 0	$ (0.02)	$ (0.29)	$ (0.01)	$ (0.06)	$ (0.84)
Diluted net income (loss) per share (in usd per share)	$ (0.04)	$ 0	$ (0.02)	$ (0.29)	$ (0.01)	$ (0.06)	$ (0.84)
Weighted-average common shares used in computing net loss per share attributable to Endurance International Group Holdings, Inc.:
Weighted average number of basic shares outstanding (in shares)	143,107,122	142,340,561	140,361,982	137,793,609	141,356,567	141,946,574	136,688,115
Weighted average number of diluted shares outstanding (in shares)	143,107,122	144,702,002	140,361,982	137,793,609	141,356,567	141,946,574	136,688,115

Summary of Significant Accou_10

Summary of Significant Accounting Policies - Summary Of Weighted Average Potentially Dilutive Shares Excluded From Calculation Of Diluted Loss Per Share (Detail) - shares	3 Months Ended		9 Months Ended
	Sep. 30, 2018	Sep. 30, 2017	Sep. 30, 2018	Sep. 30, 2017
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Total	15,277,877	18,376,402	15,114,561	17,922,369
Restricted Stock Awards and Units
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Total	6,915,158	7,782,806	6,470,097	6,974,708
Stock Option Awards
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Total	8,362,719	10,593,596	8,644,464	10,947,661

Summary of Significant Accou_11

Summary of Significant Accounting Policies - Schedule of Effects of Topic 606 (Details) - USD ($) $ in Thousands	3 Months Ended				6 Months Ended	9 Months Ended
	Sep. 30, 2018	Jun. 30, 2018	Mar. 31, 2018	Sep. 30, 2017	Jun. 30, 2018	Sep. 30, 2018	Sep. 30, 2017	Dec. 31, 2017
Revenue, Initial Application Period Cumulative Effect Transition [Line Items]
Revenue	$ 283,770			$ 295,222		$ 862,896	$ 882,617
Cost of revenue	128,945			158,865		393,597	454,197
Sales and marketing	63,831			66,276		197,733	211,154
Prepaid commissions	41,744					41,744		$ 0
Prepaid commissions, net of current portion	42,081					42,081		0
Deferred revenue	380,564					380,564		361,940
Long-term deferred revenue	96,419					96,419		90,972
Net loss	(6,335)	$ 627	$ (2,528)	$ (40,264)	$ (1,901)	(8,236)	(107,257)
Change in prepaid expenses and other assets	5,527					(3,033)	(510)
Deferred revenue	(4,691)					3,502	15,000
Net cash (used in) provided by operating activities	51,341		$ 52,360		$ 82,252	133,593	$ 128,866
Calculated under Revenue Guidance in Effect before Topic 606
Revenue, Initial Application Period Cumulative Effect Transition [Line Items]
Revenue	284,343					864,117
Cost of revenue	128,583					393,345
Sales and marketing	63,816					198,240
Prepaid commissions	0					0
Prepaid commissions, net of current portion	0					0
Deferred revenue	379,343					379,343
Long-term deferred revenue	96,419					96,419
Net loss	(6,139)					(7,270)
Change in prepaid expenses and other assets	5,904					(2,778)
Deferred revenue	(4,118)					4,723
Net cash (used in) provided by operating activities	51,341					133,593
Accounting Standards Update 2014-09 | Difference between Revenue Guidance in Effect before and after Topic 606
Revenue, Initial Application Period Cumulative Effect Transition [Line Items]
Revenue	(573)					(1,221)
Cost of revenue	362					252
Sales and marketing	15					(507)
Prepaid commissions	41,744					41,744		43,408
Prepaid commissions, net of current portion	42,081					42,081		40,040
Deferred revenue	1,221					1,221		20,275
Long-term deferred revenue	0					0		$ 2,882
Net loss	(196)					(966)
Change in prepaid expenses and other assets	(377)					(255)
Deferred revenue	573					1,221
Net cash (used in) provided by operating activities	$ 0					$ 0

Correction of Income Tax Expe_3

Correction of Income Tax Expense - Fiscal Year 2018 - Narrative (Details) $ in Millions	Dec. 31, 2017USD ($)
Domestic Tax Authority
Error Corrections and Prior Period Adjustments Restatement [Line Items]
Operating loss carryforwards	$ 236.3
Domestic Tax Authority | Originally Filed
Error Corrections and Prior Period Adjustments Restatement [Line Items]
Operating loss carryforwards	157.6
State and Local Jurisdiction
Error Corrections and Prior Period Adjustments Restatement [Line Items]
Operating loss carryforwards	168.3
State and Local Jurisdiction | Originally Filed
Error Corrections and Prior Period Adjustments Restatement [Line Items]
Operating loss carryforwards	$ 128.6

Correction of Income Tax Expe_4

Correction of Income Tax Expense - Fiscal Year 2018 - Effects on Income Statement (Details) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended				6 Months Ended	9 Months Ended
	Sep. 30, 2018	Jun. 30, 2018	Mar. 31, 2018	Sep. 30, 2017	Jun. 30, 2018	Sep. 30, 2018	Sep. 30, 2017
Error Corrections and Prior Period Adjustments Restatement [Line Items]
(Loss) income before income taxes and equity earnings of unconsolidated entities	$ 5,380	$ (344)	$ (4,444)	$ (37,315)	$ (4,788)	$ 592	$ (95,945)
Income tax expense	11,715	(946)	(1,943)	2,982	(2,889)	8,826	11,384
Loss before equity earnings of unconsolidated entities	(6,335)	602	(2,501)	(40,297)	(1,899)	(8,234)	(107,329)
Equity (income) loss of unconsolidated entities, net of tax	0	(25)	27	(33)	2	2	(72)
Net loss	(6,335)	627	(2,528)	(40,264)	(1,901)	(8,236)	(107,257)
Comprehensive income (loss):
Foreign currency translation adjustments	(644)	(2,425)	580	1,070	(1,845)	(2,489)	2,984
Unrealized gain on derivative	812	144	1,041	83	1,184	1,996	(309)
Total comprehensive (loss) income	$ (6,167)	$ (1,654)	$ (907)	$ (39,111)	$ (2,562)	$ (8,729)	$ (112,106)
Basic net income (loss) per share (in usd per share)	$ (0.04)	$ 0	$ (0.02)	$ (0.29)	$ (0.01)	$ (0.06)	$ (0.84)
Diluted net income (loss) per share (in usd per share)	$ (0.04)	$ 0	$ (0.02)	$ (0.29)	$ (0.01)	$ (0.06)	$ (0.84)
Weighted-average common shares used in computing net loss per share attributable to Endurance International Group Holdings, Inc.:
Weighted average number of basic shares outstanding (in shares)	143,107,122	142,340,561	140,361,982	137,793,609	141,356,567	141,946,574	136,688,115
Weighted average number of diluted shares outstanding (in shares)	143,107,122	144,702,002	140,361,982	137,793,609	141,356,567	141,946,574	136,688,115
Originally Filed
Error Corrections and Prior Period Adjustments Restatement [Line Items]
(Loss) income before income taxes and equity earnings of unconsolidated entities		$ (344)	$ (4,444)		$ (4,788)
Income tax expense		1,650	2,617		4,267
Loss before equity earnings of unconsolidated entities		(1,994)	(7,061)		(9,055)
Equity (income) loss of unconsolidated entities, net of tax		(25)	27		2
Net loss		(1,969)	(7,088)		(9,057)
Comprehensive income (loss):
Foreign currency translation adjustments		(2,425)	580		(1,845)
Unrealized gain on derivative		144	1,041		1,184
Total comprehensive (loss) income		$ (4,250)	$ (5,467)		$ (9,718)
Basic net income (loss) per share (in usd per share)		$ (0.01)	$ (0.05)		$ (0.06)
Diluted net income (loss) per share (in usd per share)		$ (0.01)	$ (0.05)		$ (0.06)
Weighted-average common shares used in computing net loss per share attributable to Endurance International Group Holdings, Inc.:
Weighted average number of basic shares outstanding (in shares)		142,340,561	140,361,982		141,356,567
Weighted average number of diluted shares outstanding (in shares)		142,340,561	140,361,982		141,356,567
Adjustment
Error Corrections and Prior Period Adjustments Restatement [Line Items]
(Loss) income before income taxes and equity earnings of unconsolidated entities		$ 0	$ 0		$ 0
Income tax expense		(2,596)	(4,560)		(7,156)
Loss before equity earnings of unconsolidated entities		2,596	4,560		7,156
Equity (income) loss of unconsolidated entities, net of tax			0		0
Net loss		2,596	4,560		7,156
Comprehensive income (loss):
Foreign currency translation adjustments		0	0		0
Unrealized gain on derivative		0	0		0
Total comprehensive (loss) income		$ 2,596	$ 4,560		$ 7,156
Basic net income (loss) per share (in usd per share)		$ 0.01	$ 0.03		$ 0.05
Diluted net income (loss) per share (in usd per share)		$ 0.01	$ 0.03		$ 0.05
Weighted-average common shares used in computing net loss per share attributable to Endurance International Group Holdings, Inc.:
Weighted average number of basic shares outstanding (in shares)		0	0		0
Weighted average number of diluted shares outstanding (in shares)		2,361,441	0		0

Correction of Income Tax Expe_5

Correction of Income Tax Expense - Fiscal Year 2018 - Effects on Balance Sheet (Details) - USD ($) $ in Thousands	Sep. 30, 2018	Jun. 30, 2018	Mar. 31, 2018	Dec. 31, 2017
Error Corrections and Prior Period Adjustments Restatement [Line Items]
Deferred tax liability	$ 36,498	$ 22,741	$ 23,119	$ 19,696
Total liabilities	2,461,805	2,482,950	2,529,059	2,518,081
Accumulated deficit	(796,353)	(790,019)	(790,646)	(847,501)
Total stockholders’ equity	156,598	154,915	148,749	83,005
Total liabilities and stockholders’ equity	$ 2,618,403	2,637,865	2,677,808	$ 2,601,086
Originally Filed
Error Corrections and Prior Period Adjustments Restatement [Line Items]
Deferred tax liability		29,897	27,679
Total liabilities		2,490,106	2,533,619
Accumulated deficit		(797,175)	(795,206)
Total stockholders’ equity		147,759	144,189
Total liabilities and stockholders’ equity		2,637,865	2,677,808
Adjustment
Error Corrections and Prior Period Adjustments Restatement [Line Items]
Deferred tax liability		(7,156)	(4,560)
Total liabilities		(7,156)	(4,560)
Accumulated deficit		7,156	4,560
Total stockholders’ equity		7,156	4,560
Total liabilities and stockholders’ equity		$ 0	$ 0

Correction of Income Tax Expe_6

Correction of Income Tax Expense - Fiscal Year 2018 - Effects on Cash Flow Statement (Details) - USD ($) $ in Thousands	3 Months Ended				6 Months Ended	9 Months Ended
	Sep. 30, 2018	Jun. 30, 2018	Mar. 31, 2018	Sep. 30, 2017	Jun. 30, 2018	Sep. 30, 2018	Sep. 30, 2017
Error Corrections and Prior Period Adjustments Restatement [Line Items]
Net loss	$ (6,335)	$ 627	$ (2,528)	$ (40,264)	$ (1,901)	$ (8,236)	$ (107,257)
Deferred tax expense (benefit)			(4,068)		(4,484)	8,839	6,442
Net cash (used in) provided by operating activities	$ 51,341		52,360		82,252	$ 133,593	$ 128,866
Originally Filed
Error Corrections and Prior Period Adjustments Restatement [Line Items]
Net loss		(1,969)	(7,088)		(9,057)
Deferred tax expense (benefit)			492		2,672
Net cash (used in) provided by operating activities			52,360		82,252
Adjustment
Error Corrections and Prior Period Adjustments Restatement [Line Items]
Net loss		$ 2,596	4,560		7,156
Deferred tax expense (benefit)			(4,560)		(7,156)
Net cash (used in) provided by operating activities			$ 0		$ 0

Acquisitions - Summary of Defer

Acquisitions - Summary of Deferred Consideration Related to Acquisition (Detail) - USD ($) $ in Thousands	Sep. 30, 2018	Dec. 31, 2017
Business Acquisition [Line Items]
Deferred consideration, short-term	$ 2,386	$ 4,365
AppMachine
Business Acquisition [Line Items]
Deferred consideration	3,700	7,900
Deferred consideration, short-term	$ 2,400	$ 4,400

Property and Equipment and Ca_3

Property and Equipment and Capital Lease Obligations - Components of Property and Equipment (Detail) - USD ($) $ in Thousands	Sep. 30, 2018	Dec. 31, 2017
Property, Plant and Equipment [Line Items]
Property and equipment—at cost	$ 295,794	$ 286,603
Less accumulated depreciation	(216,479)	(191,151)
Property and equipment—net	79,315	95,452
Land
Property, Plant and Equipment [Line Items]
Property and equipment—at cost	790	790
Building
Property, Plant and Equipment [Line Items]
Property and equipment—at cost	7,294	5,037
Software
Property, Plant and Equipment [Line Items]
Property and equipment—at cost	88,376	82,618
Computers and office equipment
Property, Plant and Equipment [Line Items]
Property and equipment—at cost	158,188	153,273
Furniture and fixtures
Property, Plant and Equipment [Line Items]
Property and equipment—at cost	19,259	18,825
Leasehold improvements
Property, Plant and Equipment [Line Items]
Property and equipment—at cost	19,672	22,260
Construction in process
Property, Plant and Equipment [Line Items]
Property and equipment—at cost	$ 2,215	$ 3,800

Property and Equipment and Ca_4

Property and Equipment and Capital Lease Obligations - Additional Information (Detail) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2018	Sep. 30, 2017	Sep. 30, 2018	Sep. 30, 2017
Property, Plant and Equipment [Abstract]
Depreciation	$ 11,889	$ 13,571	$ 36,753	$ 40,733
Capital lease included in software	15,500		15,500
Capital leases	$ 10,600		$ 10,600

Fair Value Measurements - Basis

Fair Value Measurements - Basis of Fair Value Measurements (Detail) - Fair Value, Measurements, Recurring - USD ($) $ in Thousands	Sep. 30, 2018	Dec. 31, 2017
Financial assets:
Interest rate cap (included in other assets)	$ 6,863	$ 452
Total financial assets	6,863	452
Significant Other Observable Inputs (Level 2)
Financial assets:
Interest rate cap (included in other assets)	6,863	452
Total financial assets	$ 6,863	$ 452

Derivatives And Hedging Activ_2

Derivatives And Hedging Activities - Additional Information (Detail)	1 Months Ended	3 Months Ended				6 Months Ended	9 Months Ended
	Jun. 30, 2018USD ($)	Sep. 30, 2018USD ($)	Jun. 30, 2018USD ($)	Mar. 31, 2018USD ($)	Sep. 30, 2017USD ($)	Jun. 30, 2018USD ($)	Sep. 30, 2018USD ($)agreement	Sep. 30, 2017USD ($)	Dec. 31, 2015USD ($)
Derivative Instruments, Gain (Loss) [Line Items]
Interest expense		$ 37,527,000			$ 35,848,000		$ 111,923,000	$ 121,022,000
Unrealized gain (loss) on cash flow hedge, net of taxes of $48 and $256, and $(182) and $626 for the three and nine months ended September 30, 2017 and 2018, respectively		812,000	$ 144,000	$ 1,041,000	83,000	$ 1,184,000	1,996,000	(309,000)
Unrealized gain (loss) arising during period, tax		256,000			$ 48,000		$ 626,000	$ (182,000)
Cash Flow Hedging
Derivative Instruments, Gain (Loss) [Line Items]
Number of interest rate cap agreements | agreement							2
Interest rate cap period							3 years
Interest Rate Cap Entered Into December 2015
Derivative Instruments, Gain (Loss) [Line Items]
Fair value of the interest rate contracts		1,000,000					$ 1,000,000
Interest Rate Cap Entered Into December 2015 | Reclassification out of Accumulated Other Comprehensive Income
Derivative Instruments, Gain (Loss) [Line Items]
Derivative loss to be reclassified as increase to interest expense in the next twelve months		100,000					100,000
Interest Rate Cap Entered Into December 2015 | Cash Flow Hedging
Derivative Instruments, Gain (Loss) [Line Items]
Notional amount outstanding									$ 500,000,000
Interest Rate Cap Entered Into December 2015 | Cash Flow Hedging | Designated as Hedging Instrument
Derivative Instruments, Gain (Loss) [Line Items]
Unrealized gain (loss) on cash flow hedge, net of taxes of $48 and $256, and $(182) and $626 for the three and nine months ended September 30, 2017 and 2018, respectively							1,900,000
Unrealized gain (loss) arising during period, tax							100,000
Interest Rate Cap Entered Into December 2015 | Cash Flow Hedging | Reclassification out of Accumulated Other Comprehensive Income | Designated as Hedging Instrument
Derivative Instruments, Gain (Loss) [Line Items]
Interest expense		600,000					1,200,000
Interest Rate Cap Entered Into June 2018
Derivative Instruments, Gain (Loss) [Line Items]
Interest rate cap period	3 years
Fair value of the interest rate contracts		5,900,000					5,900,000
Interest Rate Cap Entered Into June 2018 | Reclassification out of Accumulated Other Comprehensive Income
Derivative Instruments, Gain (Loss) [Line Items]
Derivative loss to be reclassified as increase to interest expense in the next twelve months		1,700,000					1,700,000
Interest Rate Cap Entered Into June 2018 | Cash Flow Hedging
Derivative Instruments, Gain (Loss) [Line Items]
Notional amount outstanding	$ 800,000,000		$ 800,000,000			$ 800,000,000
Interest Rate Cap Entered Into June 2018 | Cash Flow Hedging | Designated as Hedging Instrument
Derivative Instruments, Gain (Loss) [Line Items]
Unrealized gain (loss) on cash flow hedge, net of taxes of $48 and $256, and $(182) and $626 for the three and nine months ended September 30, 2017 and 2018, respectively							700,000
Unrealized gain (loss) arising during period, tax							200,000
Interest Rate Cap Entered Into June 2018 | Cash Flow Hedging | Reclassification out of Accumulated Other Comprehensive Income | Designated as Hedging Instrument
Derivative Instruments, Gain (Loss) [Line Items]
Interest expense		$ 400,000					$ 500,000

Goodwill and Other Intangible_3

Goodwill and Other Intangible Assets - Changes in Goodwill Balances (Detail) $ in Thousands	9 Months Ended
	Sep. 30, 2018USD ($)
Goodwill [Roll Forward]
Goodwill, beginning balance	$ 1,850,582
Foreign translation impact	(1,318)
Goodwill, ending balance	1,849,264
Web Presence
Goodwill [Roll Forward]
Goodwill, beginning balance	1,216,419
Foreign translation impact	(1,318)
Goodwill, ending balance	1,215,101
Email Marketing
Goodwill [Roll Forward]
Goodwill, beginning balance	604,305
Foreign translation impact	0
Goodwill, ending balance	604,305
Domain
Goodwill [Roll Forward]
Goodwill, beginning balance	29,858
Foreign translation impact	0
Goodwill, ending balance	$ 29,858

Goodwill and Other Intangible_4

Goodwill and Other Intangible Assets - Summary of Other Intangible Assets (Detail) - USD ($) $ in Thousands	9 Months Ended	12 Months Ended
	Sep. 30, 2018	Dec. 31, 2017
Finite-Lived Intangible Assets [Line Items]
Gross Carrying Amount	$ 1,142,895	$ 1,144,468
Accumulated Amortization	765,225	689,028
Net Carrying Amount	377,670	455,440
Domain names available for sale
Finite-Lived Intangible Assets [Line Items]
Gross Carrying Amount	30,855	30,458
Accumulated Amortization	9,091	7,221
Net Carrying Amount	$ 21,764	$ 23,237
Weighted average useful life	Indefinite	Indefinite
Developed technology
Finite-Lived Intangible Assets [Line Items]
Gross Carrying Amount	$ 284,312	$ 285,911
Accumulated Amortization	173,203	149,514
Net Carrying Amount	$ 111,109	$ 136,397
Weighted average useful life	7 years	7 years
Subscriber relationships
Finite-Lived Intangible Assets [Line Items]
Gross Carrying Amount	$ 659,376	$ 659,732
Accumulated Amortization	472,625	431,938
Net Carrying Amount	$ 186,751	$ 227,794
Weighted average useful life	7 years	7 years
Trade-names
Finite-Lived Intangible Assets [Line Items]
Gross Carrying Amount	$ 134,046	$ 134,054
Accumulated Amortization	81,740	73,019
Net Carrying Amount	$ 52,306	$ 61,035
Weighted average useful life	8 years	8 years
Intellectual property
Finite-Lived Intangible Assets [Line Items]
Gross Carrying Amount	$ 34,306	$ 34,313
Accumulated Amortization	28,566	27,336
Net Carrying Amount	$ 5,740	$ 6,977
Weighted average useful life	5 years	5 years

Goodwill and Other Intangible_5

Goodwill and Other Intangible Assets - Additional Information (Detail) - USD ($)	3 Months Ended		9 Months Ended
	Sep. 30, 2018	Sep. 30, 2017	Sep. 30, 2018	Sep. 30, 2017
Goodwill and Intangible Assets Disclosure [Abstract]
Impairment of other intangible assets			$ 0	$ 0
Amortization of other intangible assets	$ 26,177,000	$ 35,347,000	$ 77,890,000	$ 104,554,000

Investments - Additional Inform

Investments - Additional Information (Detail) - USD ($) $ in Thousands	1 Months Ended	3 Months Ended		9 Months Ended
	May 31, 2014	Sep. 30, 2018	Sep. 30, 2017	Sep. 30, 2018	Sep. 30, 2017	Dec. 31, 2017	Jan. 31, 2012
Schedule of Equity Method Investments [Line Items]
Investments		$ 15,266		$ 15,266		$ 15,267
Accounts payable		$ 10,812		$ 10,812		11,058
Proportionate share exceed of the company's consolidated assets or income		10.00%		10.00%
Bluezone Labs, LLC
Schedule of Equity Method Investments [Line Items]
Amount of investment for acquisition							$ 300
Ownership interest							25.00%
Purchase of products and services		$ 200	$ 400	$ 900	$ 1,300
Accounts payable		0		0		100
Prepaid expense		$ 100		$ 100		$ 700
Automattic
Schedule of Equity Method Investments [Line Items]
Investment made on asset	$ 15,000
Percentage of outstanding shares invested	5.00%
Minimum
Schedule of Equity Method Investments [Line Items]
Voting interest		20.00%		20.00%
Maximum
Schedule of Equity Method Investments [Line Items]
Voting interest		50.00%		50.00%

Notes Payable - Schedule of Lon

Notes Payable - Schedule of Long Term Debt (Details) - USD ($) $ in Thousands	Sep. 30, 2018	Dec. 31, 2017
Long-Term Debt [Line Items]
Total	$ 1,824,042	$ 1,892,245
Current maturities	31,606	33,945
Excluding current maturities	1,792,436	1,858,300
2018 First Lien Term Loan
Long-Term Debt [Line Items]
Total	1,493,131	0
Current maturities	31,606
Excluding current maturities	1,461,525
2017 First Lien Term Loan
Long-Term Debt [Line Items]
Total	0	1,563,197
Current maturities	0	33,945
Excluding current maturities	0	1,529,252
Notes
Long-Term Debt [Line Items]
Total	330,911	329,048
Current maturities	0	0
Excluding current maturities	330,911	329,048
Revolving credit facilities
Long-Term Debt [Line Items]
Total	$ 0	$ 0

Notes Payable - Additional Info

Notes Payable - Additional Information (Detail)	Jun. 20, 2018USD ($)	Jun. 14, 2017USD ($)	Feb. 09, 2016USD ($)	Sep. 30, 2018USD ($)	Jun. 30, 2018USD ($)	Sep. 30, 2017USD ($)	Jun. 30, 2017USD ($)	Sep. 30, 2018USD ($)repaymentprepayment	Sep. 30, 2017USD ($)	Jan. 30, 2017USD ($)
Long-Term Debt [Line Items]
Repayments of long-term debt								$ 1,656,094,000	$ 1,733,147,000
Line of credit facility, unused capacity, commitment fee percentage				0.50%		0.50%		0.50%	0.50%
Interest expense				$ 37,527,000		$ 35,848,000		$ 111,923,000	$ 121,022,000
Interest expense and service fees				34,469,000		32,551,000		101,575,000	105,371,000
Financing costs expensed				0		$ 0	$ 5,500,000	1,228,000	$ 5,487,000
Revolving Credit Facility
Long-Term Debt [Line Items]
Revolving credit facility maximum borrowing amount			$ 165,000,000	$ 165,000,000				$ 165,000,000
Commitment fee percentage			0.50%
2018 First Lien Term Loan
Long-Term Debt [Line Items]
Original note balance	$ 1,580,300,000
Debt instrument revised LIBOR rate	3.75%
Reference rate	2.75%
Basis revised spread on LIBOR rate	1.00%
Basis spread on reference rate	2.00%
Number of mandatory repayments | repayment								2
Repayments of long-term debt								$ 7,900,000
Unamortized debt issuance expense					$ 400,000
Interest expense and service fees					300,000
Financing costs expensed					1,200,000
2018 First Lien Term Loan | London Interbank Offered Rate (LIBOR)
Long-Term Debt [Line Items]
Basis spread on variable rate	1.00%
2018 First Lien Term Loan | Federal Funds Effective Rate
Long-Term Debt [Line Items]
Basis spread on variable rate	0.50%
2017 First Lien Term Loan
Long-Term Debt [Line Items]
Original note balance		$ 1,697,300,000
Debt issue price		99.75%
Debt instrument revised LIBOR rate		4.00%
Reference rate		3.00%
Basis revised spread on LIBOR rate		1.00%
Basis spread on reference rate		2.00%
Number of mandatory repayments | repayment								1
Repayments of long-term debt	$ 1,580,300,000							$ 8,500,000
Number of voluntary prepayments | prepayment								1
Voluntary prepayments								$ 17,000,000
Debt issuance costs, gross							4,200,000
Unamortized debt issuance expense							900,000
2017 First Lien Term Loan | London Interbank Offered Rate (LIBOR)
Long-Term Debt [Line Items]
Basis spread on variable rate		1.00%
2017 First Lien Term Loan | Federal Funds Effective Rate
Long-Term Debt [Line Items]
Basis spread on variable rate		0.50%
2016 Revolver Commitments Maturing June 2023 | Revolving Credit Facility
Long-Term Debt [Line Items]
Revolving credit facility maximum borrowing amount					106,200,000
2016 Revolver Commitments Maturing February 2021 | Revolving Credit Facility
Long-Term Debt [Line Items]
Revolving credit facility maximum borrowing amount					$ 58,750,000
2013 First Lien Term Loan
Long-Term Debt [Line Items]
Interest expense and service fees							$ 1,000,000
Alternate Base Rate Loans | Revolving Credit Facility | Federal Funds Effective Rate
Long-Term Debt [Line Items]
Basis spread on variable rate			0.50%
Alternate Base Rate Loans | Non-extended Revolving Loan
Long-Term Debt [Line Items]
Basis revised spread on LIBOR rate			3.00%
Alternate Base Rate Loans | Extended Revolving Loan
Long-Term Debt [Line Items]
Basis revised spread on LIBOR rate			2.25%
LIBOR Based Interest Rate Loan | Revolving Credit Facility | London Interbank Offered Rate (LIBOR)
Long-Term Debt [Line Items]
Basis revised spread on LIBOR rate			1.00%
LIBOR Based Interest Rate Loan | Non-extended Revolving Loan
Long-Term Debt [Line Items]
Reference rate			4.00%
LIBOR Based Interest Rate Loan | Extended Revolving Loan
Long-Term Debt [Line Items]
Reference rate			3.25%
Notes
Long-Term Debt [Line Items]
Original note balance			$ 350,000,000
Redemption price, percentage								101.00%
Par value percentage			98.065%
Interest rate, stated percentage			10.875%	10.875%		10.875%		10.875%	10.875%
Senior notes										$ 350,000,000
Voluntary Prepayment Number One | 2018 First Lien Term Loan
Long-Term Debt [Line Items]
Number of voluntary prepayments | prepayment								1
Voluntary prepayments								$ 17,000,000
Voluntary Prepayment Number Two | 2018 First Lien Term Loan
Long-Term Debt [Line Items]
Number of voluntary prepayments | prepayment								1
Voluntary prepayments								$ 17,500,000

Notes Payable - Schedule of 201

Notes Payable - Schedule of 2018 First Lien Term Loan (Details) - USD ($) $ in Thousands	Sep. 30, 2018	Dec. 31, 2017
Long-Term Debt [Line Items]
Long-term debt, gross	$ 1,880,002
Deferred financing costs	(33,515)	$ (37,736)
Total	1,824,042	1,892,245
Current maturities	31,606	33,945
Excluding current maturities	1,792,436	1,858,300
2018 First Lien Term Loan
Long-Term Debt [Line Items]
Long-term debt, gross	1,530,002
Unamortized deferred financing costs	(19,594)
Deferred financing costs	(17,277)
Total	1,493,131	$ 0
Current maturities	31,606
Excluding current maturities	$ 1,461,525

Notes Payable-Schedule of 2017

Notes Payable-Schedule of 2017 First Lien Term Loan (Details) - USD ($) $ in Thousands	Sep. 30, 2018	Dec. 31, 2017
Long-Term Debt [Line Items]
Long-term debt, gross	$ 1,880,002
Deferred financing costs	(33,515)	$ (37,736)
Total	1,824,042	1,892,245
Current maturities	31,606	33,945
Excluding current maturities	1,792,436	1,858,300
2017 First Lien Term Loan
Long-Term Debt [Line Items]
Long-term debt, gross	0	1,605,792
Unamortized deferred financing costs	0	(22,456)
Deferred financing costs	0	(20,139)
Total	0	1,563,197
Current maturities	0	33,945
Excluding current maturities	$ 0	$ 1,529,252

Notes Payable - Schedule of Sen

Notes Payable - Schedule of Senior Notes (Details) - USD ($) $ in Thousands	Sep. 30, 2018	Dec. 31, 2017
Long-Term Debt [Line Items]
Long-term debt, gross	$ 1,880,002
Deferred financing costs	(33,515)	$ (37,736)
Total	1,824,042	1,892,245
Current maturities	31,606	33,945
Long-term debt, excluding current maturities	1,792,436	1,858,300
Notes
Long-Term Debt [Line Items]
Long-term debt, gross	350,000	350,000
Unamortized deferred financing costs	(13,921)	(15,280)
Deferred financing costs	(5,168)	(5,672)
Total	330,911	329,048
Current maturities	0	0
Long-term debt, excluding current maturities	$ 330,911	$ 329,048

Notes Payable - Summary of Futu

Notes Payable - Summary of Future Debt Maturities (Detail) $ in Thousands	Sep. 30, 2018USD ($)
Debt Disclosure [Abstract]
(Remainder of) 2018	$ 7,902
2,019	31,606
2,020	31,606
2,021	31,606
2,022	31,606
Thereafter	1,745,676
Total	$ 1,880,002

Notes Payable - Schedule of Int

Notes Payable - Schedule of Interest Rates and Interest Expense (Detail) - USD ($) $ in Thousands	3 Months Ended			9 Months Ended
	Sep. 30, 2018	Sep. 30, 2017	Jun. 30, 2017	Sep. 30, 2018	Sep. 30, 2017	Feb. 09, 2016
Long-Term Debt [Line Items]
Line of credit facility, unused capacity, commitment fee percentage	0.50%	0.50%		0.50%	0.50%
Interest expense and service fees	$ 34,469	$ 32,551		$ 101,575	$ 105,371
Loss on early extinguishment of debt	0	0		331	992
Financing costs expensed	0	0	$ 5,500	1,228	5,487
Amortization of deferred financing fees	1,722	1,873		4,708	5,403
Amortization of original issue discounts	1,083	1,059		3,209	2,791
Amortization of net present value of deferred consideration	60	127		311	504
Other interest expense	193	238		561	474
Interest expense	$ 37,527	$ 35,848		$ 111,923	$ 121,022
Notes
Long-Term Debt [Line Items]
Interest rate, stated percentage	10.875%	10.875%		10.875%	10.875%	10.875%
Minimum
Long-Term Debt [Line Items]
Debt instrument LIBOR rate	5.81%	5.14%		5.46%	5.14%
Maximum
Long-Term Debt [Line Items]
Debt instrument LIBOR rate	6.07%	5.32%		6.32%	6.68%

Stockholders' Equity - Addition

Stockholders' Equity - Additional Information (Detail)	9 Months Ended
	Sep. 30, 2018vote
Equity [Abstract]
Number of votes per share	1

Stockholders' Equity - Summary

Stockholders' Equity - Summary of Changes in Stockholders' Equity (Detail) - USD ($) $ in Thousands	Jan. 01, 2018	Sep. 30, 2018	Jun. 30, 2018	Mar. 31, 2018	Sep. 30, 2017	Jun. 30, 2018	Sep. 30, 2018	Sep. 30, 2017	Dec. 31, 2017
Increase (Decrease) in Stockholder's Equity [Roll Forward]
Stockholders' equity attributable to parent, beginning balance	$ 83,005			$ 83,005		$ 83,005	$ 83,005
Stock-based compensation							21,932
Reclassification of stock-compensation liability award							250
Stock option exercises							756
Foreign currency translation adjustment		$ (644)	$ (2,425)	580	$ 1,070	(1,845)	(2,489)	$ 2,984
Unrealized gain on derivative		812	$ 144	$ 1,041	83	$ 1,184	1,996	(309)
Net loss attributable to Endurance International Group Holdings, Inc.		(6,335)			$ (40,264)		(8,236)	$ (114,781)
Stockholders' equity attributable to parent, ending balance		$ 156,598					$ 156,598
Accounting Standards Update 2014-09
Increase (Decrease) in Stockholder's Equity [Roll Forward]
Adjustment to beginning retained earnings resulting from adoption of ASC 606, net of tax impact of $7.0 million									$ 59,384
Tax Impact of ASC 606	$ 7,000

Stock-Based Compensation - Addi

Stock-Based Compensation - Additional Information (Detail) - USD ($) $ / shares in Units, $ in Thousands	Aug. 11, 2017	Feb. 09, 2016	Sep. 30, 2018	Sep. 30, 2017	Mar. 31, 2017	Sep. 30, 2018	Sep. 30, 2017	Dec. 31, 2017	Dec. 31, 2015
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Common stock, par value (in usd per share)			$ 0.0001			$ 0.0001		$ 0.0001
Stock-based compensation expense			$ 7,550	$ 19,580		$ 21,932	$ 48,749
Restricted Stock Awards
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Compensation cost not yet recognized			43,700			43,700
Stock Option Awards
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Compensation cost not yet recognized			$ 8,900			$ 8,900
2016 Performance Based Awards
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Stock-based compensation expense					$ 1,200
Chief Executive Officer | 2015 Performance Based Award
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Award shares granted for vesting (in shares)									3,693,754
Vested period of award shares									3 years
Number of RSUs expected to vest (in shares)								1,661,439
Performance award shares forfeited (in shares)								2,032,315
Chief Financial Officer | 2016 Performance Based Awards
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Award shares granted for vesting (in shares)					223,214
Chief Operating Officer | 2016 Performance Based Awards
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Award shares granted for vesting (in shares)					260,416
Chief Administrative Officer | 2016 Performance Based Awards
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Award shares granted for vesting (in shares)					148,810
2013 Stock Incentive Plan
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Common stock reserved for future awards (in shares)			38,000,000			38,000,000
Shares available for grant (in shares)			16,722,969			16,722,969
Stock options, granted (in shares)						611,010
2013 Stock Incentive Plan | Restricted Stock Awards
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Award shares granted for vesting (in shares)						0
Vested (in shares)						819,886
Vesting period						4 years
Compensation cost not yet recognized, period for recognition						2 years 1 month 6 days
Performance award shares forfeited (in shares)						2,134,075
2013 Stock Incentive Plan | Stock Option Awards
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Compensation cost not yet recognized, period for recognition						1 year 7 months 9 days
2013 Stock Incentive Plan | Restricted Stock Units
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Award shares granted for vesting (in shares)						3,846,567
Vested (in shares)						1,185,704
Performance award shares forfeited (in shares)						394,763
2017 CEO Award
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Stock-based compensation expense	$ 10,375						$ 2,200
2017 CEO Award | Restricted Stock Units
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Number of RSUs expected to vest (in shares)			750,000			750,000
2017 CEO Award | Chief Executive Officer | Stock Option Awards
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Award shares granted for vesting (in shares)	612,419
Vested period of award shares	3 years
2017 CEO Award | Chief Executive Officer | Restricted Stock Units
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Award shares granted for vesting (in shares)	1,032,500
Vested (in shares)	282,500
Vested period of award shares	3 years
2011 Stock Incentive Plan
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Common stock reserved for future awards (in shares)		10,000,000
Shares available for grant (in shares)			8,390,174			8,390,174
Common stock, par value (in usd per share)		$ 0.01
Stock options, granted (in shares)						0
2011 Stock Incentive Plan | Stock Option Awards
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Stock options, granted (in shares)		2,143,987
2011 Stock Incentive Plan | Restricted Stock Units
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Award shares granted for vesting (in shares)		2,202,846				41,379
Vested (in shares)						516,600
Performance award shares forfeited (in shares)						92,030
Share-based Compensation Award, Tranche One | 2017 CEO Award | Stock Option Awards
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Awards expected to vest outstanding (percent)			33.30%			33.30%
Share-based Compensation Award, Tranche One | 2017 CEO Award | Restricted Stock Units
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Number of RSUs expected to vest (in shares)			250,000			250,000
Share-based Compensation Award, Tranche Two | 2017 CEO Award | Restricted Stock Units
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Number of RSUs expected to vest (in shares)			250,000,000			250,000,000
Share-based Compensation Award, Tranche Three | 2017 CEO Award | Restricted Stock Units
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Number of RSUs expected to vest (in shares)			250,000,000			250,000,000
Minimum | 2013 Stock Incentive Plan | Restricted Stock Units
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Vesting period						3 years
Maximum | 2011 Stock Incentive Plan | Restricted Stock Units
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Vesting period						4 years

Stock-Based Compensation - Summ

Stock-Based Compensation - Summary of Total Stock-Based Compensation Expense (Detail) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2018	Sep. 30, 2017	Sep. 30, 2018	Sep. 30, 2017
Common Stock Options Restricted Stock Warrants And Changes In Capitalization [Line Items]
Stock-based compensation expense	$ 7,550	$ 19,580	$ 21,932	$ 48,749
2011 And 2013 Stock Incentive Plan
Common Stock Options Restricted Stock Warrants And Changes In Capitalization [Line Items]
Stock-based compensation expense	7,550	19,579	21,932	48,749
Cost of revenue | 2011 And 2013 Stock Incentive Plan
Common Stock Options Restricted Stock Warrants And Changes In Capitalization [Line Items]
Stock-based compensation expense	828	1,553	3,223	4,720
Sales and marketing | 2011 And 2013 Stock Incentive Plan
Common Stock Options Restricted Stock Warrants And Changes In Capitalization [Line Items]
Stock-based compensation expense	1,478	2,263	4,009	7,027
Engineering and development | 2011 And 2013 Stock Incentive Plan
Common Stock Options Restricted Stock Warrants And Changes In Capitalization [Line Items]
Stock-based compensation expense	1,237	1,807	3,519	4,707
General and administrative | 2011 And 2013 Stock Incentive Plan
Common Stock Options Restricted Stock Warrants And Changes In Capitalization [Line Items]
Stock-based compensation expense	$ 4,007	$ 13,956	$ 11,181	$ 32,295

Stock-Based Compensation - Su_2

Stock-Based Compensation - Summary of Stock Options (Detail) $ / shares in Units, $ in Thousands	9 Months Ended
	Sep. 30, 2018USD ($)$ / sharesshares
2013 Stock Incentive Plan
Stock Options
Beginning balance stock options, outstanding (in shares) | shares	8,575,150
Stock options, granted (in shares) | shares	611,010
Stock options, exercised (in shares) | shares	(19,049)
Stock options, forfeited (in shares) | shares	(304,382)
Stock options, expired (in shares) | shares	(1,516,912)
Ending balance stock options, outstanding (in shares) | shares	7,345,817
Stock options, exercisable (in shares) | shares	5,475,357
Stock options, expected to vest after September 30, 2017 (in shares) | shares	1,870,460
Stock options, exercisable as of March 31, 2017 and expected to vest thereafter (in shares) | shares	7,345,817
Weighted- Average Exercise Price
Weighted - average exercise price, outstanding (in usd per share)	$ 12.30
Weighted - average exercise price, granted (in usd per share)	7.50
Weighted - average exercise price, exercised (in usd per share)	8.09
Weighted - average exercise price, forfeited (in usd per share)	12.79
Weighted - average exercise price, expired (in usd per share)	13.56
Weighted - average exercise price, outstanding (in usd per share)	11.63
Weighted - average exercise price exercisable at March 31, 2017 (in usd per share)	12.39
Weighted - average exercise price, expected to vest after March 31, 2017 (in usd per share)	9.39
Weighted - average exercise price, exercisable as of March 31, 2017 and expected to vest thereafter (in usd per share)	$ 11.63
Weighted - average remaining contractual term, outstanding	5 years 36 days
Weighted - average remaining contractual term, exercisable at March 31, 2017	3 years 10 months 28 days
Weighted - average remaining contractual term, expected to vest after March 31, 2017	8 years 4 months 26 days
Weighted - average remaining contractual term, exercisable as of March 31, 2017 and expected to vest thereafter	5 years 36 days
Aggregate intrinsic value, outstanding | $	$ 1,600
Aggregate intrinsic value, exercisable at March 31, 2017 | $	283
Aggregate intrinsic value, expected to vest after March 31, 2017 | $	1,317
Aggregate intrinsic value, exercisable as of March 31, 2017 and expected to vest thereafter | $	$ 1,600
Estimated fair value of the Company's common stock (in usd per share)	$ 8.80
2011 Stock Incentive Plan
Stock Options
Beginning balance stock options, outstanding (in shares) | shares	888,260
Stock options, granted (in shares) | shares	0
Stock options, exercised (in shares) | shares	(92,229)
Stock options, forfeited (in shares) | shares	(10,256)
Stock options, expired (in shares) | shares	(38,652)
Ending balance stock options, outstanding (in shares) | shares	747,123
Stock options, exercisable (in shares) | shares	563,823
Stock options, expected to vest after September 30, 2017 (in shares) | shares	183,300
Stock options, exercisable as of March 31, 2017 and expected to vest thereafter (in shares) | shares	747,123
Weighted- Average Exercise Price
Weighted - average exercise price, outstanding (in usd per share)	$ 8.75
Weighted - average exercise price, granted (in usd per share)	0
Weighted - average exercise price, exercised (in usd per share)	6.53
Weighted - average exercise price, forfeited (in usd per share)	10.47
Weighted - average exercise price, expired (in usd per share)	9.21
Weighted - average exercise price, outstanding (in usd per share)	8.98
Weighted - average exercise price exercisable at March 31, 2017 (in usd per share)	8.76
Weighted - average exercise price, expected to vest after March 31, 2017 (in usd per share)	9.65
Weighted - average exercise price, exercisable as of March 31, 2017 and expected to vest thereafter (in usd per share)	$ 8.98
Weighted - average remaining contractual term, outstanding	3 years 8 months 15 days
Weighted - average remaining contractual term, exercisable at March 31, 2017	3 years 6 months 2 days
Weighted - average remaining contractual term, expected to vest after March 31, 2017	4 years 2 months
Weighted - average remaining contractual term, exercisable as of March 31, 2017 and expected to vest thereafter	3 years 8 months 15 days
Aggregate intrinsic value, outstanding | $	$ 546
Aggregate intrinsic value, exercisable at March 31, 2017 | $	499
Aggregate intrinsic value, expected to vest after March 31, 2017 | $	47
Aggregate intrinsic value, exercisable as of March 31, 2017 and expected to vest thereafter | $	$ 546
Estimated fair value of the Company's common stock (in usd per share)	$ 8.80

Stock-Based Compensation - Su_3

Stock-Based Compensation - Summary of Restricted Stock Awards and Restricted Stock Units (Detail) - $ / shares	Feb. 09, 2016	Sep. 30, 2018
Restricted Stock Awards | 2013 Stock Incentive Plan
Restricted Stock Units
Non-vested, beginning balance (in shares)		3,432,946
Granted (in shares)		0
Vested (in shares)		(819,886)
Canceled (in shares)		(2,134,075)
Non-vested, ending balance (in shares)		478,985
Weighted Average Grant Date Fair Value
Weighted average grant date fair value, non-vested, beginning balance (in usd per share)		$ 13.79
Weighted average grant date fair value, granted (in usd per share)		0
Weighted average grant date fair value, vested (in usd per share)		12.29
Weighted average grant date fair value, canceled (in usd per share)		14.85
Weighted average grant date fair value, non-vested, ending balance (in usd per share)		$ 11.62
Restricted Stock Units | 2011 Stock Incentive Plan
Restricted Stock Units
Non-vested, beginning balance (in shares)		1,541,141
Granted (in shares)	2,202,846	41,379
Vested (in shares)		(516,600)
Canceled (in shares)		(92,030)
Non-vested, ending balance (in shares)		973,890
Weighted Average Grant Date Fair Value
Weighted average grant date fair value, non-vested, beginning balance (in usd per share)		$ 8.30
Weighted average grant date fair value, granted (in usd per share)		7.25
Weighted average grant date fair value, vested (in usd per share)		8.38
Weighted average grant date fair value, canceled (in usd per share)		8.53
Weighted average grant date fair value, non-vested, ending balance (in usd per share)		$ 8.20
Restricted Stock Units | 2013 Stock Incentive Plan
Restricted Stock Units
Non-vested, beginning balance (in shares)		3,004,137
Granted (in shares)		3,846,567
Vested (in shares)		(1,185,704)
Canceled (in shares)		(394,763)
Non-vested, ending balance (in shares)		5,270,237
Weighted Average Grant Date Fair Value
Weighted average grant date fair value, non-vested, beginning balance (in usd per share)		$ 7.93
Weighted average grant date fair value, granted (in usd per share)		7.55
Weighted average grant date fair value, vested (in usd per share)		9.08
Weighted average grant date fair value, canceled (in usd per share)		7.78
Weighted average grant date fair value, non-vested, ending balance (in usd per share)		$ 7.67

Accumulated Other Comprehensi_3

Accumulated Other Comprehensive Income (Details) $ in Thousands	9 Months Ended
	Sep. 30, 2018USD ($)
AOCI Attributable to Parent, Net of Tax [Roll Forward]
Stockholders' equity attributable to parent, beginning balance	$ 83,005
Other comprehensive income (loss)	(493)
Stockholders' equity attributable to parent, ending balance	156,598
Foreign Currency Translation Adjustments
AOCI Attributable to Parent, Net of Tax [Roll Forward]
Stockholders' equity attributable to parent, beginning balance	696
Other comprehensive income (loss)	(2,489)
Stockholders' equity attributable to parent, ending balance	(1,793)
Unrealized Gains (Losses) on Cash Flow Hedges
AOCI Attributable to Parent, Net of Tax [Roll Forward]
Stockholders' equity attributable to parent, beginning balance	(1,237)
Other comprehensive income (loss)	1,996
Stockholders' equity attributable to parent, ending balance	759
AOCI Attributable to Parent
AOCI Attributable to Parent, Net of Tax [Roll Forward]
Stockholders' equity attributable to parent, beginning balance	(541)
Stockholders' equity attributable to parent, ending balance	$ (1,034)

Revenue - Narrative (Details)

Revenue - Narrative (Details) - USD ($)	3 Months Ended		9 Months Ended
	Sep. 30, 2018	Sep. 30, 2017	Sep. 30, 2018	Sep. 30, 2017	Dec. 31, 2017
Revenue, Initial Application Period Cumulative Effect Transition [Line Items]
Revenue	$ 283,770,000	$ 295,222,000	$ 862,896,000	$ 882,617,000
Contract impairment loss	0		0
Credit loss expense	0		0
Accounting Standards Update 2014-09
Revenue, Initial Application Period Cumulative Effect Transition [Line Items]
Adjustment to beginning retained earnings resulting from adoption of ASC 606, net of tax impact of $7.0 million					$ 59,384,000
Difference between Revenue Guidance in Effect before and after Topic 606 | Accounting Standards Update 2014-09
Revenue, Initial Application Period Cumulative Effect Transition [Line Items]
Revenue	(573,000)		(1,221,000)
Customer acquisition costs	$ 0		$ 500,000

Revenue - Disaggregation of Rev

Revenue - Disaggregation of Revenue (Details) - USD ($) $ in Thousands	3 Months Ended	9 Months Ended
	Sep. 30, 2018	Sep. 30, 2018
Disaggregation of Revenue [Line Items]
Revenue from contract with customer	$ 283,770	$ 862,896
Subscriber revenue
Disaggregation of Revenue [Line Items]
Revenue from contract with customer	275,066	835,768
Non-subscriber revenue
Disaggregation of Revenue [Line Items]
Revenue from contract with customer	8,704	27,128
Domestic
Disaggregation of Revenue [Line Items]
Revenue from contract with customer	206,566	626,966
International
Disaggregation of Revenue [Line Items]
Revenue from contract with customer	77,204	235,930
Direct revenue from subscribers | Subscriber revenue
Disaggregation of Revenue [Line Items]
Revenue from contract with customer	252,596	766,089
Professional services | Subscriber revenue
Disaggregation of Revenue [Line Items]
Revenue from contract with customer	3,789	11,436
Reseller revenue | Subscriber revenue
Disaggregation of Revenue [Line Items]
Revenue from contract with customer	18,681	58,243
MDF | Non-subscriber revenue
Disaggregation of Revenue [Line Items]
Revenue from contract with customer	2,592	6,949
Premium domains | Non-subscriber revenue
Disaggregation of Revenue [Line Items]
Revenue from contract with customer	5,070	15,893
Domain parking | Non-subscriber revenue
Disaggregation of Revenue [Line Items]
Revenue from contract with customer	1,042	4,286
Web Presence
Disaggregation of Revenue [Line Items]
Revenue from contract with customer	149,871	457,603
Web Presence | Subscriber revenue
Disaggregation of Revenue [Line Items]
Revenue from contract with customer	147,497	450,899
Web Presence | Non-subscriber revenue
Disaggregation of Revenue [Line Items]
Revenue from contract with customer	2,374	6,704
Web Presence | Domestic
Disaggregation of Revenue [Line Items]
Revenue from contract with customer	100,065	306,724
Web Presence | International
Disaggregation of Revenue [Line Items]
Revenue from contract with customer	49,806	150,879
Web Presence | Direct revenue from subscribers | Subscriber revenue
Disaggregation of Revenue [Line Items]
Revenue from contract with customer	138,869	424,321
Web Presence | Professional services | Subscriber revenue
Disaggregation of Revenue [Line Items]
Revenue from contract with customer	3,387	10,091
Web Presence | Reseller revenue | Subscriber revenue
Disaggregation of Revenue [Line Items]
Revenue from contract with customer	5,241	16,487
Web Presence | MDF | Non-subscriber revenue
Disaggregation of Revenue [Line Items]
Revenue from contract with customer	2,199	6,012
Web Presence | Premium domains | Non-subscriber revenue
Disaggregation of Revenue [Line Items]
Revenue from contract with customer	3	70
Web Presence | Domain parking | Non-subscriber revenue
Disaggregation of Revenue [Line Items]
Revenue from contract with customer	172	622
Email Marketing
Disaggregation of Revenue [Line Items]
Revenue from contract with customer	102,111	306,712
Email Marketing | Subscriber revenue
Disaggregation of Revenue [Line Items]
Revenue from contract with customer	101,970	306,248
Email Marketing | Non-subscriber revenue
Disaggregation of Revenue [Line Items]
Revenue from contract with customer	141	464
Email Marketing | Domestic
Disaggregation of Revenue [Line Items]
Revenue from contract with customer	93,992	281,717
Email Marketing | International
Disaggregation of Revenue [Line Items]
Revenue from contract with customer	8,119	24,995
Email Marketing | Direct revenue from subscribers | Subscriber revenue
Disaggregation of Revenue [Line Items]
Revenue from contract with customer	100,816	302,583
Email Marketing | Professional services | Subscriber revenue
Disaggregation of Revenue [Line Items]
Revenue from contract with customer	299	1,045
Email Marketing | Reseller revenue | Subscriber revenue
Disaggregation of Revenue [Line Items]
Revenue from contract with customer	855	2,620
Email Marketing | MDF | Non-subscriber revenue
Disaggregation of Revenue [Line Items]
Revenue from contract with customer	141	464
Email Marketing | Premium domains | Non-subscriber revenue
Disaggregation of Revenue [Line Items]
Revenue from contract with customer	0	0
Email Marketing | Domain parking | Non-subscriber revenue
Disaggregation of Revenue [Line Items]
Revenue from contract with customer	0	0
Domain Name Business
Disaggregation of Revenue [Line Items]
Revenue from contract with customer	31,788	98,581
Domain Name Business | Subscriber revenue
Disaggregation of Revenue [Line Items]
Revenue from contract with customer	25,599	78,621
Domain Name Business | Non-subscriber revenue
Disaggregation of Revenue [Line Items]
Revenue from contract with customer	6,189	19,960
Domain Name Business | Domestic
Disaggregation of Revenue [Line Items]
Revenue from contract with customer	12,509	38,525
Domain Name Business | International
Disaggregation of Revenue [Line Items]
Revenue from contract with customer	19,279	60,056
Domain Name Business | Direct revenue from subscribers | Subscriber revenue
Disaggregation of Revenue [Line Items]
Revenue from contract with customer	12,911	39,185
Domain Name Business | Professional services | Subscriber revenue
Disaggregation of Revenue [Line Items]
Revenue from contract with customer	103	300
Domain Name Business | Reseller revenue | Subscriber revenue
Disaggregation of Revenue [Line Items]
Revenue from contract with customer	12,585	39,136
Domain Name Business | MDF | Non-subscriber revenue
Disaggregation of Revenue [Line Items]
Revenue from contract with customer	252	473
Domain Name Business | Premium domains | Non-subscriber revenue
Disaggregation of Revenue [Line Items]
Revenue from contract with customer	5,067	15,823
Domain Name Business | Domain parking | Non-subscriber revenue
Disaggregation of Revenue [Line Items]
Revenue from contract with customer	$ 870	$ 3,664

Redeemable Non-Controlling In_2

Redeemable Non-Controlling Interest - Additional Information (Detail) - USD ($) $ in Thousands	Jul. 07, 2017	Sep. 30, 2018	Sep. 30, 2017	Sep. 30, 2018	Sep. 30, 2017	Jul. 01, 2017	Jul. 14, 2016	May 16, 2016	Jan. 06, 2016	Aug. 31, 2014
Redeemable Noncontrolling Interest [Line Items]
Reduced accretion value						$ 14,200
Accretion in excess of fair value		$ 0	$ 0	$ 0	$ 7,247
WZ (UK) Ltd.
Redeemable Noncontrolling Interest [Line Items]
Ownership interest							86.40%	77.50%	57.50%	49.00%
Payments to acquire business	$ 25,000

Income Taxes - Additional Infor

Income Taxes - Additional Information (Detail) - USD ($) $ in Thousands	3 Months Ended				6 Months Ended	9 Months Ended		12 Months Ended
	Sep. 30, 2018	Jun. 30, 2018	Mar. 31, 2018	Sep. 30, 2017	Jun. 30, 2018	Sep. 30, 2018	Sep. 30, 2017	Dec. 31, 2017
Operating Loss Carryforwards [Line Items]
Provisional income tax expense (benefit) due to change in tax rate								$ 16,900
Income tax expense	$ 11,715	$ (946)	$ (1,943)	$ 2,982	$ (2,889)	$ 8,826	$ 11,384
Valuation allowance increase (decrease)						7,900
Unrecognized tax benefits that would impact effective tax rate								1,100
Unrecognized tax benefits	2,900					2,900		1,100
Deferred federal and state deferred tax expense (benefit)	12,900			1,900		8,900	7,300
Federal and state current income taxes	100			200		500	2,600
Provision for foreign tax	(1,600)			700		(800)	2,300
Foreign deferred tax expense (benefit)	$ (300)			$ (200)		$ (200)	$ 800
Amount of net operating loss carry-forwards available to offset future U.S. federal taxable income								236,300
Amount of net operating loss carry-forwards available to offset future state taxable income								168,300
Loss carry-forwards available to future foreign taxable income								26,700
Domestic Tax Authority
Operating Loss Carryforwards [Line Items]
Deferred tax assets, capital loss carryforwards								3,400
Tax credit carryforward								17,600
State and Local Jurisdiction
Operating Loss Carryforwards [Line Items]
Deferred tax assets, capital loss carryforwards								1,400
Tax credit carryforward								12,300
CHINA
Operating Loss Carryforwards [Line Items]
Loss carry-forwards available to future foreign taxable income								700
NETHERLANDS
Operating Loss Carryforwards [Line Items]
Loss carry-forwards available to future foreign taxable income								12,600
United Kingdom
Operating Loss Carryforwards [Line Items]
Loss carry-forwards available to future foreign taxable income								13,200
SINGAPORE
Operating Loss Carryforwards [Line Items]
Loss carry-forwards available to future foreign taxable income								200
Adjustment
Operating Loss Carryforwards [Line Items]
Worthless stock loss								$ 78,000
Income tax expense		(2,596)	(4,560)		(7,156)
Originally Filed
Operating Loss Carryforwards [Line Items]
Income tax expense		$ 1,650	$ 2,617		$ 4,267

Severance and Other Exit Cost_2

Severance and Other Exit Costs - Additional Information (Detail)	Feb. 09, 2016position	Jan. 31, 2018position	Jan. 31, 2017position	Sep. 30, 2018USD ($)	Sep. 30, 2018USD ($)position	Sep. 30, 2018USD ($)	Dec. 31, 2017USD ($)
Employee Severance
Restructuring Cost and Reserve [Line Items]
Severance costs incurred						$ 2,978,000
Accrued reserve				$ 1,000,000	$ 1,000,000	1,000,000	$ 3,668,000
Payments for restructuring						5,646,000
Facilities Closing
Restructuring Cost and Reserve [Line Items]
Facilities charge						43,000
Accrued reserve				4,290,000	$ 4,290,000	4,290,000	$ 6,005,000
Payments for restructuring						2,080,000
Sublease income received						322,000
2018 Restructuring Plan
Restructuring Cost and Reserve [Line Items]
Number of positions eliminated | position		71			95
Severance costs incurred				100,000		3,000,000
2018 Restructuring Plan | Employee Severance
Restructuring Cost and Reserve [Line Items]
Accrued reserve				600,000	$ 600,000	600,000
Payments for restructuring				600,000		2,400,000
2017 Restructuring Plan
Restructuring Cost and Reserve [Line Items]
Number of positions eliminated | position			660
Severance costs incurred				0		0
2017 Restructuring Plan | Employee Severance
Restructuring Cost and Reserve [Line Items]
Accrued reserve				400,000	400,000	400,000
Payments for restructuring				500,000		3,300,000
2017 Restructuring Plan | Facilities Closing
Restructuring Cost and Reserve [Line Items]
Facilities charge				0		200,000
Accrued reserve				0	0	0
Payments for restructuring				0		100,000
2016 Restructuring Plan
Restructuring Cost and Reserve [Line Items]
Number of positions eliminated | position	265
2016 Restructuring Plan | Employee Severance
Restructuring Cost and Reserve [Line Items]
Accrued reserve				0	0	0
Constant Contact, Inc. | 2017 Restructuring Plan
Restructuring Cost and Reserve [Line Items]
Number of positions eliminated | position			50
Email Marketing | Facilities Closing
Restructuring Cost and Reserve [Line Items]
Facilities charge				100,000		200,000
Accrued reserve				4,300,000	$ 4,300,000	4,300,000
Payments for restructuring				$ 500,000		$ 1,500,000

Severance and Other Exit Cost_3

Severance and Other Exit Costs - Summary of Aggregate Activity Related to Company's Facilities Exit Costs Accrual and Severance Accrual (Detail) $ in Thousands	9 Months Ended
	Sep. 30, 2018USD ($)
Employee Severance
Restructuring Reserve [Roll Forward]
Beginning Balance	$ 3,668
Severance charges	2,978
Cash paid	(5,646)
Ending Balance	1,000
Facilities Closing
Restructuring Reserve [Roll Forward]
Beginning Balance	6,005
Facility adjustments	43
Sublease income received	322
Cash paid	(2,080)
Ending Balance	$ 4,290

Severance and Other Exit Cost_4

Severance and Other Exit Costs - Summary of Total Restructuring Charges Recorded in the Consolidated Statements of Operations and Comprehensive Loss (Detail) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2018	Sep. 30, 2017	Sep. 30, 2018	Sep. 30, 2017
Restructuring Cost and Reserve [Line Items]
Total restructuring charges	$ 197	$ 4,489	$ 3,021	$ 14,584
Cost of revenue
Restructuring Cost and Reserve [Line Items]
Total restructuring charges	37	449	1,443	3,892
Sales and marketing
Restructuring Cost and Reserve [Line Items]
Total restructuring charges	17	1,011	133	3,260
Engineering and development
Restructuring Cost and Reserve [Line Items]
Total restructuring charges	33	271	389	1,349
General and administrative
Restructuring Cost and Reserve [Line Items]
Total restructuring charges	$ 110	$ 2,758	$ 1,056	$ 6,083

Commitments and Contingencies -

Commitments and Contingencies - Additional Information (Detail)	Jun. 30, 2017USD ($)	Aug. 07, 2015defendant	Sep. 30, 2018USD ($)	Mar. 31, 2018USD ($)	Sep. 30, 2018USD ($)	Sep. 30, 2017USD ($)	Jun. 30, 2018USD ($)
Loss Contingencies [Line Items]
Minimum revenue requirement from single customer per year	$ 500
Legal settlement reserve			$ (935,000)		$ 7,325,000	$ 0
Machado vs Endurance and McGee vs Constant Contact
Loss Contingencies [Line Items]
Legal settlement reserve				$ 8,500,000
Loss contingency accrual			$ 7,300,000		$ 7,300,000		$ 8,300,000
Constant Contact, Inc. | McGee vs Constant Contact
Loss Contingencies [Line Items]
Number of defendants | defendant		2

Related Party Transactions - Ad

Related Party Transactions - Additional Information (Detail) - USD ($) $ in Thousands	Dec. 09, 2015	Sep. 30, 2018	Sep. 30, 2017	Sep. 30, 2018	Sep. 30, 2017	Dec. 31, 2017	Dec. 31, 2016
Related Party Transaction [Line Items]
Prepaid expenses and other current assets		$ 27,101		$ 27,101		$ 29,327
Amount included in accounts receivable		$ 14,105		$ 14,105		15,945
Former Chief Executive Officer
Related Party Transaction [Line Items]
Common stock outstanding ownership percentage		5.00%		5.00%
Immediate Family Member of Management or Principal Owner
Related Party Transaction [Line Items]
Amount included in accounts payable and accrued expense		$ 2,200		$ 2,200		1,500
Related party transaction expense		3,800	$ 3,850	12,185	$ 11,100
Chief Executive Officer and a Director
Related Party Transaction [Line Items]
Amount included in accounts payable and accrued expense		1,200		1,200		1,300
Prepaid expenses and other current assets		100		100		200
Amount included in accounts receivable		1,000		1,000		700
Related party transaction expense		$ 540	$ 950	2,555	$ 2,250
Goldman, Sachs & Co.
Related Party Transaction [Line Items]
Related party transaction expense				$ 300		$ 500
Interest rate cap period	3 years
Interest Rate Cap Premium | Goldman, Sachs & Co.
Related Party Transaction [Line Items]
Amounts of related party transaction							$ 3,000

Related Party Transactions - Su

Related Party Transactions - Summary of Related Party Transactions (Detail) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2018	Sep. 30, 2017	Sep. 30, 2018	Sep. 30, 2017
Related Party Transaction [Line Items]
Revenue	$ (283,770)	$ (295,222)	$ (862,896)	$ (882,617)
Sales and marketing	63,831	66,276	197,733	211,154
Engineering and development	22,683	19,882	64,559	60,393
General and administrative	25,693	51,269	95,212	130,929
Immediate Family Member of Management or Principal Owner
Related Party Transaction [Line Items]
Cost of revenue	3,330	3,100	10,555	9,100
Sales and marketing	160	500	605	1,000
Engineering and development	290	200	960	850
General and administrative	20	50	65	150
Total related party transaction expense, net	3,800	3,850	12,185	11,100
Chief Executive Officer and a Director
Related Party Transaction [Line Items]
Revenue	(1,430)	(1,050)	(4,075)	(2,150)
Revenue (contra)	1,800	1,850	6,140	4,050
Total related party transaction impact to revenue	370	800	2,065	1,900
Cost of revenue	170	150	490	350
Total related party transaction expense, net	$ 540	$ 950	$ 2,555	$ 2,250

Segment Information - Additiona

Segment Information - Additional Information (Details) $ in Millions	3 Months Ended	9 Months Ended	12 Months Ended
	Dec. 31, 2017Segment	Sep. 30, 2018Segment	Dec. 31, 2017USD ($)Segment	Sep. 30, 2017Segment	Dec. 31, 2016USD ($)
Segment Reporting Information [Line Items]
Number of reportable segments | Segment		3		2
Web Presence
Segment Reporting Information [Line Items]
Number of reportable segments | Segment	2		2
Gross Profit | Reclassification of Expenses Between Segments | Web Presence
Segment Reporting Information [Line Items]
Reclassification between segments			$ (6.9)		$ (3)
Gross Profit | Reclassification of Expenses Between Segments | Domain
Segment Reporting Information [Line Items]
Reclassification between segments			6.9		3
EBITDA | Reclassification of Expenses Between Segments | Web Presence
Segment Reporting Information [Line Items]
Reclassification between segments			(6.9)		(3)
EBITDA | Reclassification of Expenses Between Segments | Domain
Segment Reporting Information [Line Items]
Reclassification between segments			$ 6.9		$ 3

Segment Information - Schedule

Segment Information - Schedule of Segment Information (Details) - USD ($) $ in Thousands	3 Months Ended				6 Months Ended	9 Months Ended
	Sep. 30, 2018	Jun. 30, 2018	Mar. 31, 2018	Sep. 30, 2017	Jun. 30, 2018	Sep. 30, 2018	Sep. 30, 2017
Segment Reporting Information [Line Items]
Revenue	$ 283,770			$ 295,222		$ 862,896	$ 882,617
Gross profit	154,825			136,357		469,299	428,420
Net loss	(6,335)	$ 627	$ (2,528)	(40,264)	$ (1,901)	(8,236)	(107,257)
Interest expense, net	37,238			35,645		111,203	120,516
Income tax expense	11,715	$ (946)	$ (1,943)	2,982	$ (2,889)	8,826	11,384
Depreciation	11,889			13,571		36,753	40,733
Amortization of other intangible assets	26,177			35,347		77,890	104,554
Stock-based compensation	7,550			19,580		21,932	48,749
Restructuring expenses	197			4,489		3,021	14,584
Transaction expenses and charges	0			0		0	773
(Gain) loss of unconsolidated entities				(33)		2	(72)
Impairment of other long-lived assets				14,448			14,448
SEC investigations reserve				8,000			8,000
Shareholder litigation reserve	(935)					7,325	0
Adjusted EBITDA	87,496			93,765		258,716	256,412
Intercompany revenue	2,500			2,500		7,600	8,100
Web Presence
Segment Reporting Information [Line Items]
Revenue	149,871			159,530		457,603	483,661
Gross profit	75,074			77,032		225,149	229,186
Net loss	(7,565)			(20,403)		(20,549)	(67,226)
Interest expense, net	18,132			14,686		53,503	50,877
Income tax expense	6,136			798		960	12,645
Depreciation	8,401			9,399		24,769	27,401
Amortization of other intangible assets	11,941			14,884		35,812	44,431
Stock-based compensation	1,569			15,510		12,066	38,023
Restructuring expenses	54			3,468		1,654	8,944
Transaction expenses and charges							0
(Gain) loss of unconsolidated entities				(33)		2	(72)
Impairment of other long-lived assets				600			600
SEC investigations reserve				4,323			4,323
Shareholder litigation reserve	(768)					4,780	0
Adjusted EBITDA	37,900			43,232		112,997	119,946
Email Marketing
Segment Reporting Information [Line Items]
Revenue	102,111			101,526		306,712	298,401
Gross profit	71,356			65,286		214,909	188,181
Net loss	6,596			2,202		22,350	(8,026)
Interest expense, net	17,128			20,514		50,866	68,212
Income tax expense	4,179			1,323		8,009	(4,821)
Depreciation	2,538			3,233		9,090	10,632
Amortization of other intangible assets	13,384			18,770		39,716	55,697
Stock-based compensation	4,472			1,668		7,168	5,392
Restructuring expenses	141			682		723	4,743
Transaction expenses and charges							773
(Gain) loss of unconsolidated entities				0		0	0
Impairment of other long-lived assets				0			0
SEC investigations reserve				2,751			2,751
Shareholder litigation reserve	0					1,500	0
Adjusted EBITDA	48,438			51,143		139,422	135,353
Domain
Segment Reporting Information [Line Items]
Revenue	31,788			34,166		98,581	100,555
Gross profit	8,395			(5,961)		29,241	11,053
Net loss	(5,366)			(22,063)		(10,037)	(32,005)
Interest expense, net	1,978			445		6,834	1,427
Income tax expense	1,400			861		(143)	3,560
Depreciation	950			939		2,894	2,700
Amortization of other intangible assets	852			1,693		2,362	4,426
Stock-based compensation	1,509			2,402		2,698	5,334
Restructuring expenses	2			339		644	897
Transaction expenses and charges							0
(Gain) loss of unconsolidated entities				0		0	0
Impairment of other long-lived assets				13,848			13,848
SEC investigations reserve				926			926
Shareholder litigation reserve	(167)					1,045	0
Adjusted EBITDA	$ 1,158			$ (610)		$ 6,297	$ 1,113

Segment Information - Schedul_2

Segment Information - Schedule of Error Correction (Details) - USD ($) $ in Thousands	3 Months Ended				6 Months Ended	9 Months Ended
	Sep. 30, 2018	Jun. 30, 2018	Mar. 31, 2018	Sep. 30, 2017	Jun. 30, 2018	Sep. 30, 2018	Sep. 30, 2017
Segment Reporting Information [Line Items]
Gross profit	$ 154,825			$ 136,357		$ 469,299	$ 428,420
Net loss	(6,335)	$ 627	$ (2,528)	(40,264)	$ (1,901)	(8,236)	(107,257)
Adjusted EBITDA	87,496			93,765		258,716	256,412
Web Presence
Segment Reporting Information [Line Items]
Gross profit	75,074			77,032		225,149	229,186
Net loss	(7,565)			(20,403)		(20,549)	(67,226)
Adjusted EBITDA	37,900			43,232		112,997	119,946
Domain
Segment Reporting Information [Line Items]
Gross profit	8,395			(5,961)		29,241	11,053
Net loss	(5,366)			(22,063)		(10,037)	(32,005)
Adjusted EBITDA	$ 1,158			(610)		$ 6,297	1,113
(as reported)
Segment Reporting Information [Line Items]
Net loss		$ (1,969)	$ (7,088)		$ (9,057)
(as reported) | Web Presence
Segment Reporting Information [Line Items]
Gross profit				75,097			224,300
Net loss				(22,416)			(73,346)
Adjusted EBITDA				41,297			115,060
(as reported) | Domain
Segment Reporting Information [Line Items]
Gross profit				(4,026)			15,939
Net loss				(20,050)			(25,885)
Adjusted EBITDA				$ 1,325			$ 5,999

Supplemental Guarantor Financ_3

Supplemental Guarantor Financial Information - Additional Information (Details)	3 Months Ended
	Dec. 31, 2016USD ($)guarantor	Feb. 29, 2016USD ($)
Guarantor Obligations [Line Items]
Number of guarantors sold | guarantor	2
Notes
Guarantor Obligations [Line Items]
Senior notes		$ 350,000,000
Interest rate, stated percentage		10.875%
CardStar | Guarantor Subsidiaries
Guarantor Obligations [Line Items]
Proceeds from sale of assets	$ 100,000

Supplemental Guarantor Financ_4

Supplemental Guarantor Financial Information - Condensed Consolidated Balance Sheets (Details) - USD ($) $ in Thousands	Sep. 30, 2018	Jun. 30, 2018	Mar. 31, 2018	Dec. 31, 2017
Current assets:
Cash and cash equivalents	$ 89,674			$ 66,493
Restricted cash	1,832			2,625
Accounts receivable	14,105			15,945
Prepaid domain name registry fees	57,114			53,805
Prepaid commissions	41,744			0
Prepaid expenses and other current assets	27,101			29,327
Total current assets	231,570			168,195
Intercompany receivables, net	0			0
Property and equipment—net	79,315			95,452
Goodwill	1,849,264			1,850,582
Other intangible assets—net	377,670			455,440
Investment in subsidiaries	0			0
Prepaid commissions, net of current portion	42,081			0
Other assets	38,503			31,417
Total assets	2,618,403			2,601,086
Current liabilities:
Accounts payable	10,812			11,058
Accrued expenses and other current liabilities	89,066			108,479
Deferred revenue	380,564			361,940
Current portion of notes payable	31,606			33,945
Current portion of capital lease obligations	7,595			7,630
Deferred consideration, short-term	2,386			4,365
Total current liabilities	522,029			527,417
Long-term deferred revenue	96,419			90,972
Notes payable	1,792,436			1,858,300
Capital lease obligations—long term	2,067			7,719
Deferred consideration	1,342			3,551
Other long-term liabilities	47,512			30,122
Total liabilities	2,461,805	$ 2,482,950	$ 2,529,059	2,518,081
Equity	156,598	154,915	148,749	83,005
Total liabilities and stockholders’ equity	2,618,403	$ 2,637,865	$ 2,677,808	2,601,086
Reportable Legal Entities | Parent
Current assets:
Cash and cash equivalents	207			92
Restricted cash	0			0
Accounts receivable	0			0
Prepaid domain name registry fees	0			0
Prepaid commissions	0
Prepaid expenses and other current assets	0			(12)
Total current assets	207			80
Intercompany receivables, net	34,278			33,637
Property and equipment—net	0			0
Goodwill	0			0
Other intangible assets—net	0			0
Investment in subsidiaries	122,114			49,288
Prepaid commissions, net of current portion	0
Other assets	0			0
Total assets	156,599			83,005
Current liabilities:
Accounts payable	0			0
Accrued expenses and other current liabilities	0			0
Deferred revenue	0			0
Current portion of notes payable	0			0
Current portion of capital lease obligations	0			0
Deferred consideration, short-term	0			0
Total current liabilities	0			0
Long-term deferred revenue	0			0
Notes payable	0			0
Capital lease obligations—long term	0			0
Deferred consideration	0			0
Other long-term liabilities	0			0
Total liabilities	0			0
Equity	156,599			83,005
Total liabilities and stockholders’ equity	156,599			83,005
Reportable Legal Entities | Issuer
Current assets:
Cash and cash equivalents	2			2
Restricted cash	0			0
Accounts receivable	0			0
Prepaid domain name registry fees	0			0
Prepaid commissions	0
Prepaid expenses and other current assets	174			86
Total current assets	176			88
Intercompany receivables, net	441,001			606,834
Property and equipment—net	0			0
Goodwill	0			0
Other intangible assets—net	0			0
Investment in subsidiaries	1,510,592			1,355,013
Prepaid commissions, net of current portion	0
Other assets	9,742			3,639
Total assets	1,961,511			1,965,574
Current liabilities:
Accounts payable	0			0
Accrued expenses and other current liabilities	15,197			24,509
Deferred revenue	0			0
Current portion of notes payable	31,606			33,945
Current portion of capital lease obligations	0			0
Deferred consideration, short-term	0			0
Total current liabilities	46,803			58,454
Long-term deferred revenue	0			0
Notes payable	1,792,436			1,858,300
Capital lease obligations—long term	0			0
Deferred consideration	0			0
Other long-term liabilities	158			(468)
Total liabilities	1,839,397			1,916,286
Equity	122,114			49,288
Total liabilities and stockholders’ equity	1,961,511			1,965,574
Reportable Legal Entities | Guarantor Subsidiaries
Current assets:
Cash and cash equivalents	59,890			54,473
Restricted cash	1,731			2,472
Accounts receivable	11,906			12,386
Prepaid domain name registry fees	32,729			28,291
Prepaid commissions	41,085
Prepaid expenses and other current assets	18,361			20,062
Total current assets	165,702			117,684
Intercompany receivables, net	(354,298)			(498,213)
Property and equipment—net	66,772			81,693
Goodwill	1,673,851			1,673,851
Other intangible assets—net	376,441			450,778
Investment in subsidiaries	74,478			37,200
Prepaid commissions, net of current portion	41,346
Other assets	22,351			21,373
Total assets	2,066,643			1,884,366
Current liabilities:
Accounts payable	10,239			9,532
Accrued expenses and other current liabilities	69,493			75,819
Deferred revenue	330,178			309,395
Current portion of notes payable	0			0
Current portion of capital lease obligations	7,595			7,630
Deferred consideration, short-term	2,386			4,365
Total current liabilities	419,891			406,741
Long-term deferred revenue	86,133			81,199
Notes payable	0			0
Capital lease obligations—long term	2,067			7,719
Deferred consideration	1,342			3,551
Other long-term liabilities	46,618			30,143
Total liabilities	556,051			529,353
Equity	1,510,592			1,355,013
Total liabilities and stockholders’ equity	2,066,643			1,884,366
Reportable Legal Entities | Non-Guarantor Subsidiaries
Current assets:
Cash and cash equivalents	29,575			11,926
Restricted cash	101			153
Accounts receivable	2,199			3,559
Prepaid domain name registry fees	24,385			25,514
Prepaid commissions	659
Prepaid expenses and other current assets	8,566			9,191
Total current assets	65,485			50,343
Intercompany receivables, net	(120,981)			(142,258)
Property and equipment—net	12,543			13,759
Goodwill	175,413			176,731
Other intangible assets—net	1,229			4,662
Investment in subsidiaries	0			0
Prepaid commissions, net of current portion	735
Other assets	6,410			6,405
Total assets	140,834			109,642
Current liabilities:
Accounts payable	573			1,526
Accrued expenses and other current liabilities	4,376			8,151
Deferred revenue	50,386			52,545
Current portion of notes payable	0			0
Current portion of capital lease obligations	0			0
Deferred consideration, short-term	0			0
Total current liabilities	55,335			62,222
Long-term deferred revenue	10,286			9,773
Notes payable	0			0
Capital lease obligations—long term	0			0
Deferred consideration	0			0
Other long-term liabilities	736			447
Total liabilities	66,357			72,442
Equity	74,477			37,200
Total liabilities and stockholders’ equity	140,834			109,642
Eliminations
Current assets:
Cash and cash equivalents	0			0
Restricted cash	0			0
Accounts receivable	0			0
Prepaid domain name registry fees	0			0
Prepaid commissions	0
Prepaid expenses and other current assets	0			0
Total current assets	0			0
Intercompany receivables, net	0			0
Property and equipment—net	0			0
Goodwill	0			0
Other intangible assets—net	0			0
Investment in subsidiaries	(1,707,184)			(1,441,501)
Prepaid commissions, net of current portion	0
Other assets	0			0
Total assets	(1,707,184)			(1,441,501)
Current liabilities:
Accounts payable	0			0
Accrued expenses and other current liabilities	0			0
Deferred revenue	0			0
Current portion of notes payable	0			0
Current portion of capital lease obligations	0			0
Deferred consideration, short-term	0			0
Total current liabilities	0			0
Long-term deferred revenue	0			0
Notes payable	0			0
Capital lease obligations—long term	0			0
Deferred consideration	0			0
Other long-term liabilities	0			0
Total liabilities	0			0
Equity	(1,707,184)			(1,441,501)
Total liabilities and stockholders’ equity	$ (1,707,184)			$ (1,441,501)

Supplemental Guarantor Financ_5

Supplemental Guarantor Financial Information - Consolidated Statements of Operations and Comprehensive Income (Loss) (Details) - USD ($) $ in Thousands	3 Months Ended				6 Months Ended	9 Months Ended
	Sep. 30, 2018	Jun. 30, 2018	Mar. 31, 2018	Sep. 30, 2017	Jun. 30, 2018	Sep. 30, 2018	Sep. 30, 2017
Income Statement [Abstract]
Revenue	$ 283,770			$ 295,222		$ 862,896	$ 882,617
Cost of revenue	128,945			158,865		393,597	454,197
Gross profit	154,825			136,357		469,299	428,420
Operating expense:
Sales and marketing	63,831			66,276		197,733	211,154
Engineering and development	22,683			19,882		64,559	60,393
General and administrative	25,693			51,269		95,212	130,929
Transaction costs							773
Total operating expense	112,207			137,427		357,504	403,249
(Loss) income from operations	42,618			(1,070)		111,795	25,171
Interest expense and other income, net	37,238			36,245		111,203	121,116
(Loss) income before income taxes and equity earnings of unconsolidated entities	5,380	$ (344)	$ (4,444)	(37,315)	$ (4,788)	592	(95,945)
Income tax expense	11,715	(946)	(1,943)	2,982	(2,889)	8,826	11,384
Loss before equity earnings of unconsolidated entities	(6,335)	602	(2,501)	(40,297)	(1,899)	(8,234)	(107,329)
Equity (income) loss of unconsolidated entities, net of tax	0	(25)	27	(33)	2	2	(72)
Net loss	(6,335)	627	(2,528)	(40,264)	(1,901)	(8,236)	(107,257)
Net loss attributable to non-controlling interest	0			0			7,524
Net loss attributable to Endurance International Group Holdings, Inc.	(6,335)			(40,264)		(8,236)	(114,781)
Comprehensive income (loss):
Foreign currency translation adjustment	(644)	(2,425)	580	1,070	(1,845)	(2,489)	2,984
Unrealized gain on derivative	812	144	1,041	83	1,184	1,996	(309)
Total comprehensive (loss) income	(6,167)	$ (1,654)	$ (907)	(39,111)	$ (2,562)	(8,729)	(112,106)
Eliminations
Income Statement [Abstract]
Revenue	(1,348)			(1,782)		(4,710)	(4,510)
Cost of revenue	(1,348)			(1,334)		(4,710)	(3,642)
Gross profit	0			(448)		0	(868)
Operating expense:
Sales and marketing	0			0		0	(3)
Engineering and development	0			0		0	0
General and administrative	0			(605)		0	(605)
Transaction costs							0
Total operating expense	0			(605)		0	(608)
(Loss) income from operations	0			157		0	(260)
Interest expense and other income, net	0			0		0	0
(Loss) income before income taxes and equity earnings of unconsolidated entities	0			157		0	(260)
Income tax expense	0			0		0	0
Loss before equity earnings of unconsolidated entities	0			157		0	(260)
Equity (income) loss of unconsolidated entities, net of tax	17,460			(58,817)		106,794	(138,647)
Net loss	(17,460)			58,974		(106,794)	138,387
Net loss attributable to non-controlling interest							0
Net loss attributable to Endurance International Group Holdings, Inc.	(17,460)			58,974		(106,794)	138,387
Comprehensive income (loss):
Foreign currency translation adjustment	0			0		0	0
Unrealized gain on derivative	0			0		0	0
Total comprehensive (loss) income	(17,460)			58,974		(106,794)	138,387
Parent Company | Reportable Legal Entities
Income Statement [Abstract]
Revenue	0			0		0	0
Cost of revenue	0			0		0	0
Gross profit	0			0		0	0
Operating expense:
Sales and marketing	0			0		0	0
Engineering and development	0			0		0	0
General and administrative	(11)			0		(11)	0
Transaction costs							0
Total operating expense	(11)			0		(11)	0
(Loss) income from operations	11			0		11	0
Interest expense and other income, net	0			0		0	0
(Loss) income before income taxes and equity earnings of unconsolidated entities	11			0		11	0
Income tax expense	0			0		0	0
Loss before equity earnings of unconsolidated entities	11			0		11	0
Equity (income) loss of unconsolidated entities, net of tax	6,346			40,422		8,247	106,999
Net loss	(6,335)			(40,422)		(8,236)	(106,999)
Net loss attributable to non-controlling interest							0
Net loss attributable to Endurance International Group Holdings, Inc.	(6,335)			(40,422)		(8,236)	(106,999)
Comprehensive income (loss):
Foreign currency translation adjustment	0			0		0	0
Unrealized gain on derivative	0			0		0	0
Total comprehensive (loss) income	(6,335)			(40,422)		(8,236)	(106,999)
Issuer | Reportable Legal Entities
Income Statement [Abstract]
Revenue	0			0		0	0
Cost of revenue	0			0		0	0
Gross profit	0			0		0	0
Operating expense:
Sales and marketing	0			0		0	0
Engineering and development	0			0		0	0
General and administrative	52			56		169	166
Transaction costs							0
Total operating expense	52			56		169	166
(Loss) income from operations	(52)			(56)		(169)	(166)
Interest expense and other income, net	37,305			35,661		111,051	120,313
(Loss) income before income taxes and equity earnings of unconsolidated entities	(37,357)			(35,717)		(111,220)	(120,479)
Income tax expense	(8,891)			(13,201)		(26,470)	(44,512)
Loss before equity earnings of unconsolidated entities	(28,466)			(22,516)		(84,750)	(75,967)
Equity (income) loss of unconsolidated entities, net of tax	(22,120)			17,906		(76,503)	31,033
Net loss	(6,346)			(40,422)		(8,247)	(107,000)
Net loss attributable to non-controlling interest							0
Net loss attributable to Endurance International Group Holdings, Inc.	(6,346)			(40,422)		(8,247)	(107,000)
Comprehensive income (loss):
Foreign currency translation adjustment	0			0		0	0
Unrealized gain on derivative	812			83		1,996	(309)
Total comprehensive (loss) income	(5,534)			(40,339)		(6,251)	(107,309)
Guarantor Subsidiaries | Reportable Legal Entities
Income Statement [Abstract]
Revenue	258,388			266,985		783,611	788,806
Cost of revenue	110,808			139,044		338,885	392,447
Gross profit	147,580			127,941		444,726	396,359
Operating expense:
Sales and marketing	60,341			61,376		187,175	195,392
Engineering and development	20,524			17,412		58,850	51,053
General and administrative	24,187			50,353		124,317	123,736
Transaction costs							773
Total operating expense	105,052			129,141		370,342	370,954
(Loss) income from operations	42,528			(1,200)		74,384	25,405
Interest expense and other income, net	74			756		539	1,150
(Loss) income before income taxes and equity earnings of unconsolidated entities	42,454			(1,956)		73,845	24,255
Income tax expense	22,020			15,494		35,897	54,744
Loss before equity earnings of unconsolidated entities	20,434			(17,450)		37,948	(30,489)
Equity (income) loss of unconsolidated entities, net of tax	(1,686)			456		(38,554)	543
Net loss	22,120			(17,906)		76,502	(31,032)
Net loss attributable to non-controlling interest							7,524
Net loss attributable to Endurance International Group Holdings, Inc.	22,120			(17,906)		76,502	(38,556)
Comprehensive income (loss):
Foreign currency translation adjustment	0			0		0	0
Unrealized gain on derivative	0			0		0	0
Total comprehensive (loss) income	22,120			(17,906)		76,502	(38,556)
Non-Guarantor Subsidiaries | Reportable Legal Entities
Income Statement [Abstract]
Revenue	26,730			30,019		83,995	98,321
Cost of revenue	19,485			21,155		59,422	65,392
Gross profit	7,245			8,864		24,573	32,929
Operating expense:
Sales and marketing	3,490			4,900		10,558	15,765
Engineering and development	2,159			2,470		5,709	9,340
General and administrative	1,465			1,465		(29,263)	7,632
Transaction costs							0
Total operating expense	7,114			8,835		(12,996)	32,737
(Loss) income from operations	131			29		37,569	192
Interest expense and other income, net	(141)			(172)		(387)	(347)
(Loss) income before income taxes and equity earnings of unconsolidated entities	272			201		37,956	539
Income tax expense	(1,414)			689		(601)	1,152
Loss before equity earnings of unconsolidated entities	1,686			(488)		38,557	(613)
Equity (income) loss of unconsolidated entities, net of tax	0			0		18	0
Net loss	1,686			(488)		38,539	(613)
Net loss attributable to non-controlling interest							0
Net loss attributable to Endurance International Group Holdings, Inc.	1,686			(488)		38,539	(613)
Comprehensive income (loss):
Foreign currency translation adjustment	(644)			1,070		(2,489)	2,984
Unrealized gain on derivative	0			0		0	0
Total comprehensive (loss) income	$ 1,042			$ 582		$ 36,050	$ 2,371

Supplemental Guarantor Financ_6

Supplemental Guarantor Financial Information - Condensed Consolidated Statements of Cash Flows (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended	9 Months Ended
	Sep. 30, 2018	Mar. 31, 2018	Jun. 30, 2018	Sep. 30, 2018	Sep. 30, 2017
Condensed Cash Flow Statements, Captions [Line Items]
Net cash (used in) provided by operating activities	$ 51,341	$ 52,360	$ 82,252	$ 133,593	$ 128,866
Cash flows from investing activities:
Purchases of property and equipment				(22,343)	(32,095)
Proceeds from note receivable					0
Proceeds from sale of property and equipment				6	292
Purchases of intangible assets				0	(1,966)
Net cash used in investing activities				(22,337)	(33,769)
Cash flows from financing activities:
Proceeds from issuance of term loan and notes, net of original issue discounts				1,580,305	1,693,007
Repayment of notes payable and revolver				(1,656,094)	(1,733,147)
Payment of financing costs				(1,580)	(6,304)
Payment of deferred consideration				(4,500)	(5,408)
Payment of redeemable non-controlling interest liability				0	(25,000)
Principal payments on capital lease obligations				(5,609)	(5,679)
Proceeds from exercise of stock options				756	1,548
Intercompany loans and investments				0	0
Net cash used in financing activities				(86,722)	(80,983)
Net effect of exchange rate on cash and cash equivalents and restricted cash				(2,146)	2,156
Net increase in cash and cash equivalents and restricted cash				22,388	16,270
Cash and cash equivalents and restricted cash:
Beginning of period		69,118	69,118	69,118	56,898
End of period	91,506			91,506	73,168
Eliminations
Condensed Cash Flow Statements, Captions [Line Items]
Net cash (used in) provided by operating activities				0	0
Cash flows from investing activities:
Purchases of property and equipment				0	0
Proceeds from note receivable					0
Proceeds from sale of property and equipment				0	0
Purchases of intangible assets					0
Net cash used in investing activities				0	0
Cash flows from financing activities:
Proceeds from issuance of term loan and notes, net of original issue discounts				0	0
Repayment of notes payable and revolver				0	0
Payment of financing costs				0	0
Payment of deferred consideration				0	0
Payment of redeemable non-controlling interest liability					0
Principal payments on capital lease obligations				0	0
Proceeds from exercise of stock options				0	0
Intercompany loans and investments				0	0
Net cash used in financing activities				0	0
Net effect of exchange rate on cash and cash equivalents and restricted cash				0	0
Net increase in cash and cash equivalents and restricted cash				0	0
Cash and cash equivalents and restricted cash:
Beginning of period		0	0	0	0
End of period	0			0	0
Parent Company | Reportable Legal Entities
Condensed Cash Flow Statements, Captions [Line Items]
Net cash (used in) provided by operating activities				0	(32)
Cash flows from investing activities:
Purchases of property and equipment				0	0
Proceeds from note receivable					0
Proceeds from sale of property and equipment				0	0
Purchases of intangible assets					0
Net cash used in investing activities				0	0
Cash flows from financing activities:
Proceeds from issuance of term loan and notes, net of original issue discounts				0	0
Repayment of notes payable and revolver				0	0
Payment of financing costs				0	0
Payment of deferred consideration				0	0
Payment of redeemable non-controlling interest liability					0
Principal payments on capital lease obligations				0	0
Proceeds from exercise of stock options				756	1,548
Intercompany loans and investments				(641)	(1,058)
Net cash used in financing activities				115	490
Net effect of exchange rate on cash and cash equivalents and restricted cash				0	0
Net increase in cash and cash equivalents and restricted cash				115	458
Cash and cash equivalents and restricted cash:
Beginning of period		92	92	92	3
End of period	207			207	461
Issuer | Reportable Legal Entities
Condensed Cash Flow Statements, Captions [Line Items]
Net cash (used in) provided by operating activities				(88,464)	(72,687)
Cash flows from investing activities:
Purchases of property and equipment				0	0
Proceeds from note receivable					0
Proceeds from sale of property and equipment				0	0
Purchases of intangible assets					0
Net cash used in investing activities				0	0
Cash flows from financing activities:
Proceeds from issuance of term loan and notes, net of original issue discounts				1,580,305	1,693,007
Repayment of notes payable and revolver				(1,656,094)	(1,733,147)
Payment of financing costs				(1,580)	(6,304)
Payment of deferred consideration				0	0
Payment of redeemable non-controlling interest liability					0
Principal payments on capital lease obligations				0	0
Proceeds from exercise of stock options				0	0
Intercompany loans and investments				165,833	119,128
Net cash used in financing activities				88,464	72,684
Net effect of exchange rate on cash and cash equivalents and restricted cash				0	0
Net increase in cash and cash equivalents and restricted cash				0	(3)
Cash and cash equivalents and restricted cash:
Beginning of period		2	2	2	4
End of period	2			2	1
Guarantor Subsidiaries | Reportable Legal Entities
Condensed Cash Flow Statements, Captions [Line Items]
Net cash (used in) provided by operating activities				180,852	204,768
Cash flows from investing activities:
Purchases of property and equipment				(22,159)	(28,140)
Proceeds from note receivable					0
Proceeds from sale of property and equipment				6	292
Purchases of intangible assets					(1,932)
Net cash used in investing activities				(22,153)	(29,780)
Cash flows from financing activities:
Proceeds from issuance of term loan and notes, net of original issue discounts				0	0
Repayment of notes payable and revolver				0	0
Payment of financing costs				0	0
Payment of deferred consideration				(4,500)	(4,550)
Payment of redeemable non-controlling interest liability					(25,000)
Principal payments on capital lease obligations				(5,609)	(5,679)
Proceeds from exercise of stock options				0	0
Intercompany loans and investments				(143,914)	(124,060)
Net cash used in financing activities				(154,023)	(159,289)
Net effect of exchange rate on cash and cash equivalents and restricted cash				0	0
Net increase in cash and cash equivalents and restricted cash				4,676	15,699
Cash and cash equivalents and restricted cash:
Beginning of period		56,945	56,945	56,945	41,654
End of period	61,621			61,621	57,353
Non-Guarantor Subsidiaries | Reportable Legal Entities
Condensed Cash Flow Statements, Captions [Line Items]
Net cash (used in) provided by operating activities				41,205	(3,183)
Cash flows from investing activities:
Purchases of property and equipment				(184)	(3,955)
Proceeds from note receivable					0
Proceeds from sale of property and equipment				0	0
Purchases of intangible assets					(34)
Net cash used in investing activities				(184)	(3,989)
Cash flows from financing activities:
Proceeds from issuance of term loan and notes, net of original issue discounts				0	0
Repayment of notes payable and revolver				0	0
Payment of financing costs				0	0
Payment of deferred consideration				0	(858)
Payment of redeemable non-controlling interest liability					0
Principal payments on capital lease obligations				0	0
Proceeds from exercise of stock options				0	0
Intercompany loans and investments				(21,278)	5,990
Net cash used in financing activities				(21,278)	5,132
Net effect of exchange rate on cash and cash equivalents and restricted cash				(2,146)	2,156
Net increase in cash and cash equivalents and restricted cash				17,597	116
Cash and cash equivalents and restricted cash:
Beginning of period		$ 12,079	$ 12,079	12,079	15,237
End of period	$ 29,676			$ 29,676	$ 15,353