Zendesk (ZEN) 10-Q 3 Nov 17 2017 Q3 Quarterly report Financial data

Document and Entity Information

Document and Entity Information - shares	9 Months Ended
	Sep. 30, 2017	Oct. 31, 2017
Document And Entity Information [Abstract]
Document Type	10-Q
Amendment Flag	false
Document Period End Date	Sep. 30, 2017
Document Fiscal Year Focus	2,017
Document Fiscal Period Focus	Q3
Trading Symbol	ZEN
Entity Registrant Name	Zendesk, Inc.
Entity Central Index Key	1,463,172
Current Fiscal Year End Date	--12-31
Entity Filer Category	Large Accelerated Filer
Entity Common Stock, Shares Outstanding		101,507,140

CONDENSED CONSOLIDATED BALANCE

CONDENSED CONSOLIDATED BALANCE SHEETS - USD ($) $ in Thousands	Sep. 30, 2017	Dec. 31, 2016
Current assets:
Cash and cash equivalents	$ 92,603	$ 93,677
Marketable securities	133,959	131,190
Accounts receivable, net of allowance for doubtful accounts of $751 and $1,269 as of September 30, 2017 and December 31, 2016, respectively	51,465	37,343
Prepaid expenses and other current assets	24,318	17,608
Total current assets	302,345	279,818
Marketable securities, noncurrent	90,263	75,168
Property and equipment, net	59,600	62,731
Goodwill and intangible assets, net	67,779	53,296
Other assets	9,350	4,272
Total assets	529,337	475,285
Current liabilities:
Accounts payable	11,212	4,555
Accrued liabilities	21,588	19,106
Accrued compensation and related benefits	26,325	20,281
Deferred revenue	154,163	123,276
Total current liabilities	213,288	167,218
Deferred revenue, noncurrent	1,727	1,257
Other liabilities	8,152	7,382
Total liabilities	223,167	175,857
Commitments and contingencies (Note 6)
Stockholders’ equity:
Preferred stock	0	0
Common stock	1,010	971
Additional paid-in capital	711,301	624,026
Accumulated other comprehensive loss	(2,205)	(5,197)
Accumulated deficit	(403,936)	(319,720)
Treasury stock, at cost (none and 0.5 million shares as of September 30, 2017 and December 31, 2016, respectively)	0	(652)
Total stockholders’ equity	306,170	299,428
Total liabilities and stockholders’ equity	$ 529,337	$ 475,285

CONDENSED CONSOLIDATED BALANCE3

CONDENSED CONSOLIDATED BALANCE SHEETS (Parenthetical) - USD ($) $ in Thousands, shares in Millions	Sep. 30, 2017	Dec. 31, 2016
Statement of Financial Position [Abstract]
Allowance for doubtful accounts	$ 751	$ 1,269
Treasury stock, shares (in shares)	0	0.5

CONDENSED CONSOLIDATED STATEMEN

CONDENSED CONSOLIDATED STATEMENTS OF OPERATIONS - USD ($) shares in Thousands, $ in Thousands		3 Months Ended				9 Months Ended
		Sep. 30, 2017		Sep. 30, 2016		Sep. 30, 2017	Sep. 30, 2016
Income Statement [Abstract]
Revenue		$ 112,786		$ 80,717		$ 307,066	$ 223,376
Cost of revenue	[1]	33,693		23,866		92,464	68,318
Gross profit		79,093		56,851		214,602	155,058
Operating expenses:
Research and development	[1]	29,358		22,953		84,512	66,683
Sales and marketing	[1]	56,778		43,899		156,707	119,421
General and administrative	[1]	21,398		16,212		59,502	48,149
Total operating expenses		107,534	[1]	83,064	[1]	300,721	234,253	[1]
Operating loss		(28,441)		(26,213)		(86,119)	(79,195)
Other income, net		619		681		1,345	745
Loss before provision for (benefit from) income taxes		(27,822)		(25,532)		(84,774)	(78,450)
Provision for (benefit from) income taxes		(133)		294		(786)	800
Net loss		$ (27,689)		$ (25,826)		$ (83,988)	$ (79,250)
Net loss per share, basic and diluted (usd per share)		$ (0.28)		$ (0.27)		$ (0.85)	$ (0.86)
Weighted-average shares used to compute net loss per share, basic and diluted (in shares)		100,659		94,085		99,203	92,274
[1]	Includes share-based compensation expense as follows: Three Months EndedSeptember 30, Nine Months EndedSeptember 30,2017 2016 2017 2016Cost of revenue$2,408 $1,919 $6,668 $5,355Research and development7,776 7,172 22,273 20,548Sales and marketing6,716 6,657 18,362 17,780General and administrative5,619 4,247 15,502 12,654

CONDENSED CONSOLIDATED STATEME5

CONDENSED CONSOLIDATED STATEMENTS OF OPERATIONS (Parenthetical) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2017	Sep. 30, 2016	Sep. 30, 2017	Sep. 30, 2016
Share-based compensation expense			$ 62,805	$ 56,337
Cost of revenue
Share-based compensation expense	$ 2,408	$ 1,919	6,668	5,355
Research and development
Share-based compensation expense	7,776	7,172	22,273	20,548
Sales and marketing
Share-based compensation expense	6,716	6,657	18,362	17,780
General and administrative
Share-based compensation expense	$ 5,619	$ 4,247	$ 15,502	$ 12,654

CONDENSED CONSOLIDATED STATEME6

CONDENSED CONSOLIDATED STATEMENTS OF COMPREHENSIVE LOSS - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2017	Sep. 30, 2016	Sep. 30, 2017	Sep. 30, 2016
Statement of Comprehensive Income [Abstract]
Net loss	$ (27,689)	$ (25,826)	$ (83,988)	$ (79,250)
Other comprehensive gain, before tax:
Net change in unrealized gain (loss) on available-for-sale investments	80	(35)	213	80
Foreign currency translation gain (loss)	0	(227)	824	570
Net change in unrealized gain (loss) on derivative instruments	344	416	3,692	139
Other comprehensive gain, before tax	424	154	4,729	789
Tax effect	(156)	(61)	(1,737)	(295)
Other comprehensive gain, net of tax	268	93	2,992	494
Comprehensive loss	$ (27,421)	$ (25,733)	$ (80,996)	$ (78,756)

CONDENSED CONSOLIDATED STATEME7

CONDENSED CONSOLIDATED STATEMENTS OF CASH FLOWS - USD ($) $ in Thousands	9 Months Ended
	Sep. 30, 2017	Sep. 30, 2016
Cash flows from operating activities
Net loss	$ (83,988)	$ (79,250)
Adjustments to reconcile net loss to net cash provided by operating activities
Depreciation and amortization	24,263	20,000
Share-based compensation	62,805	56,337
Excess tax benefit from share-based award activity	0	(133)
Other	380	1,219
Changes in operating assets and liabilities:
Accounts receivable	(15,039)	(11,782)
Prepaid expenses and other current assets	(5,109)	(7,401)
Other assets and liabilities	(5,513)	(1,829)
Accounts payable	7,237	(2,220)
Accrued liabilities	6,843	2,645
Accrued compensation and related benefits	1,503	812
Deferred revenue	31,357	25,596
Net cash provided by operating activities	24,739	3,994
Cash flows from investing activities
Purchases of property and equipment	(13,334)	(12,494)
Internal-use software development costs	(5,237)	(4,313)
Purchases of marketable securities	(135,279)	(216,640)
Proceeds from maturities of marketable securities	88,960	23,971
Proceeds from sale of marketable securities	28,144	39,244
Cash paid for the acquisition of Outbound, net of cash acquired	(16,470)	0
Net cash used in investing activities	(53,216)	(170,232)
Cash flows from financing activities
Proceeds from exercise of employee stock options	18,550	19,886
Proceeds from employee stock purchase plan	10,980	8,704
Taxes paid related to net share settlement of share-based awards	(2,415)	(626)
Principal payment on debt	0	(323)
Excess tax benefit from share-based award activity	0	133
Net cash provided by financing activities	27,115	27,774
Effect of exchange rate changes on cash and cash equivalents	288	(173)
Net decrease in cash and cash equivalents	(1,074)	(138,637)
Cash and cash equivalents at beginning of period	93,677	216,226
Cash and cash equivalents at end of period	92,603	77,589
Supplemental cash flow data:
Cash paid for income taxes and interest	1,532	968
Non-cash investing and financing activities:
Share-based compensation capitalized in internal-use software development costs	1,984	1,761
Balance of property and equipment in accounts payable and accrued expenses	1,384	2,466
Property and equipment acquired through tenant improvement allowances	437	64
Vesting of early exercised stock options	$ 317	$ 509

Overview and Basis of Presentat

Overview and Basis of Presentation	9 Months Ended
	Sep. 30, 2017
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Overview and Basis of Presentation	Overview and Basis of Presentation Company and Background Zendesk was founded in Denmark in 2007 and reincorporated in Delaware in April 2009. We are a software development company that provides software as a service, or SaaS, products that are intended to help organizations and their customers build better relationships. With our origins in customer service, we have evolved our offerings over time to a family of products that work together to help organizations understand their customers, improve communications, and engage where and when it’s needed most. Our product family is built upon a modern architecture that enables us and our customers to rapidly innovate, adapt our technology in novel ways, and easily integrate with other products and applications. References to Zendesk, the “Company,” “our,” or “we” in these notes refer to Zendesk, Inc. and its subsidiaries on a consolidated basis. Basis of Presentation These unaudited condensed consolidated financial statements have been prepared in accordance with United States generally accepted accounting principles, or GAAP, and applicable rules and regulations of the Securities and Exchange Commission, or SEC, regarding interim financial reporting. Certain information and note disclosures normally included in the financial statements prepared in accordance with GAAP have been condensed or omitted pursuant to such rules and regulations. Therefore, these condensed consolidated financial statements should be read in conjunction with the audited consolidated financial statements and notes included in our Annual Report on Form 10-K for the year ended December 31, 2016, filed with the SEC on February 27, 2017. There have been no changes to our significant accounting policies described in the Annual Report on Form 10-K that have had a material impact on our condensed consolidated financial statements and related notes, except as described below. In the first quarter of 2017, we changed our accounting policy for share-based compensation to recognize forfeitures as they occur, as permitted by Accounting Standards Update, or ASU, 2016-09. Refer to Recently Adopted Accounting Pronouncements below for a more detailed discussion. The consolidated balance sheet as of December 31, 2016 included herein was derived from the audited financial statements as of that date. The unaudited condensed consolidated financial statements reflect all normal recurring adjustments necessary to present fairly our financial position, results of operations, comprehensive loss, and cash flows for the interim periods, but are not necessarily indicative of the results of operations to be anticipated for the full year ending December 31, 2017 . Use of Estimates The preparation of our consolidated financial statements in conformity with GAAP requires management to make certain estimates, judgments, and assumptions that affect the reported amounts of assets and liabilities and disclosure of contingent assets and liabilities at the date of the financial statements, as well as the reported amounts of revenue and expenses during the reported periods. Significant items subject to such estimates and assumptions include the fair value of share-based awards, acquired intangible assets, goodwill and unrecognized tax benefits, the useful lives of acquired intangible assets and property and equipment, the capitalization and estimated useful life of capitalized internal-use software, and financial forecasts used in currency hedging. These estimates are based on information available as of the date of the financial statements; therefore, actual results could differ from those estimates. Concentrations of Risk As of September 30, 2017 , no customers represented 10% or greater of our total accounts receivable balance. There were no customers that individually exceeded 10% of our revenue during the three and nine months ended September 30, 2017 or 2016 . Recently Issued Accounting Pronouncements In May 2014, the Financial Accounting Standards Board, or the FASB, issued new revenue guidance that provides principles for recognizing revenue to which an entity expects to be entitled for the transfer of promised goods or services to customers. The guidance also requires the deferral of incremental costs to acquire contracts with customers. As currently issued and amended, the new guidance is effective for annual reporting periods beginning after December 15, 2017, including interim periods within that reporting period, though early adoption is permitted for annual reporting periods beginning after December 15, 2016. The guidance may be applied retrospectively to each prior period presented (full retrospective method), or with the cumulative effect recognized as of the date of initial adoption (modified retrospective method). We currently intend to adopt using the full retrospective method; however, our decision has not been finalized. We have completed a preliminary assessment to determine the effect of adoption on our existing revenue arrangements and are nearing final conclusions. We are continuing to progress in the implementation of our new revenue recognition systems. As a result of adoption, we also expect to capitalize a significant portion of our sales commissions and other incremental costs to acquire contracts, which we historically expensed as incurred, resulting in an increase in deferred costs recognized on our balance sheet. We have not yet concluded the useful life of our capitalized costs, which will affect the classification and magnitude of the deferred costs at each reporting period. We are nearing the completion of our analysis to quantify the total effect of adoption on our consolidated financial statements. To meet the incremental disclosure requirements of the new guidance, we are also developing processes that will enable our ability to disclose backlog. In February 2016, the FASB issued ASU 2016-02, regarding Accounting Standards Codification, or ASC, Topic 842 “ Leases. ” This new standard requires lessees to recognize most leases on their balance sheets as lease liabilities with corresponding right-of-use assets and eliminates certain real estate-specific provisions. The new guidance is effective for annual reporting periods beginning after December 15, 2018, including interim periods within that reporting period. Early adoption is permitted. We are currently evaluating the effect of this standard on our consolidated financial statements. In August 2017, the FASB issued ASU 2017-12, regarding ASC Topic 815 "Derivatives and Hedging." This amendment simplifies various aspects of hedge accounting, including measurement and presentation of hedge ineffectiveness and certain documentation and assessment requirements. The amendment also makes more hedging strategies eligible for hedge accounting. The guidance is effective for annual reporting periods beginning after December 15, 2018, including interim periods within that reporting period. Early adoption is permitted. We are currently evaluating the effect of this standard on our consolidated financial statements. Recently Adopted Accounting Pronouncements In March 2016, the FASB issued ASU 2016-09, regarding ASC Topic 718 “ Compensation - Stock Compensation. ” This amendment changes certain aspects of accounting for share-based awards to employees, including the recognition of income tax effects of awards when the awards vest or are settled, requirements on net share settlement to cover tax withholding, and accounting for forfeitures. We adopted the standard in the first quarter of 2017. As required by the new standard, we now recognize excess tax effects from share-based awards as a component of provision for income taxes in our statement of operations when awards vest or are settled. Upon adoption, we recorded a deferred tax asset of $52.8 million to reflect, on a modified retrospective basis, the previously unrecognized excess tax benefits; however, the deferred tax asset was fully offset by a valuation allowance, resulting in no impact to our consolidated financial statements. In our statement of cash flows, we no longer classify excess tax benefits as a reduction from operating cash flows. This change was made prospectively beginning with the quarter ended March 31, 2017. We also elected to account for forfeitures as they occur; therefore, share-based compensation expense for the three and nine months ended September 30, 2017 has been calculated based on actual forfeitures in our consolidated statement of operations, rather than our previous approach, which was net of estimated forfeitures. The cumulative-effect adjustment of this change on a modified retrospective basis was not material. Share-based compensation expense for the three and nine months ended September 30, 2016 was recorded net of estimated forfeitures. In October 2016, the FASB issued ASU 2016-16, “ Income Taxes - Intra-Entity Transfers of Assets Other Than Inventory, ” which requires entities to recognize the income tax consequences of an intra-entity transfer of an asset other than inventory when the transfer occurs. The new guidance is effective for annual reporting periods beginning after December 15, 2017. Early adoption is permitted as of the beginning of an annual reporting period. The new standard must be adopted using a modified retrospective basis, with the cumulative effect recognized as of the date of adoption. We early adopted the standard in the first quarter of 2017. Upon adoption, we recorded a deferred tax asset of $6.2 million to reflect the previously unrecognized tax benefits; however, the deferred tax asset was fully offset by a valuation allowance, resulting in no impact to our consolidated financial statements. In May 2017, the FASB issued ASU 2017-09, regarding ASC Topic 718 “ Compensation - Stock Compensation: Scope of Modification Accounting. ” This amendment clarified what changes to terms or conditions of share-based awards require an entity to apply modification accounting. The new guidance is effective for annual reporting periods beginning after December 15, 2017, including interim periods within that reporting period. We early adopted this standard in the second quarter of 2017 on a prospective basis, as permitted by the standard. The adoption did not have a material effect on our consolidated financial statements.

Business Combination

Business Combination	9 Months Ended
	Sep. 30, 2017
Business Combinations [Abstract]
Business Combination	Business Combination On April 27, 2017, we completed the acquisition of Outbound Solutions, Inc., or Outbound, a provider of software that enables companies to deliver intelligent, behavior-based messages across multiple channels. We acquired Outbound for purchase consideration of $16.6 million in cash. As of September 30, 2017, we finalized our purchase accounting for the acquisition. The total purchase consideration was allocated to the assets acquired and liabilities assumed as set forth below (in thousands). The excess of the purchase price over the net assets acquired was recorded as goodwill. Goodwill generated from the acquisition is primarily attributable to expected growth from the expansion of the scope of and market opportunity for our products. Goodwill is no t deductible for income tax purposes. Goodwill will not be amortized but instead will be tested for impairment at least annually and more frequently if certain indicators of impairment are present. Net tangible assets acquired $ 96 Net deferred tax liability recognized (492 ) Identifiable intangible assets: Developed technology 3,200 Customer relationships 410 Goodwill 13,350 Total purchase price $ 16,564 The developed technology and customer relationship intangible assets were assigned useful lives of 6.5 and 3.5 years, respectively. From the date of the acquisition, the results of operations of Outbound have been included in and are immaterial to our consolidated financial statements. Pro forma revenue and results of operations have not been presented because the historical results of Outbound are not material to our consolidated financial statements in any period presented.

Financial Instruments

Financial Instruments	9 Months Ended
	Sep. 30, 2017
Fair Value Disclosures [Abstract]
Financial Instruments	Financial Instruments Investments The following tables present information about our financial assets measured at fair value on a recurring basis as of September 30, 2017 and December 31, 2016 based on the three-tier fair value hierarchy (in thousands): Fair Value Measurement at Level 1 Level 2 Total Description Corporate bonds $ — $ 152,888 152,888 U.S. treasury securities — 28,434 28,434 Asset-backed securities — 24,471 24,471 Commercial paper — 15,397 15,397 Money market funds 12,354 — 12,354 Agency securities — 8,532 8,532 Total $ 12,354 $ 229,722 $ 242,076 Included in cash and cash equivalents $ 17,854 Included in marketable securities $ 224,222 Fair Value Measurement at Level 1 Level 2 Total Description Corporate bonds $ — $ 124,930 $ 124,930 Asset-backed securities — 32,567 32,567 U.S. treasury securities — 30,585 30,585 Commercial paper — 9,787 9,787 Agency securities — 8,489 8,489 Money market funds 3,545 $ — $ 3,545 Total $ 3,545 $ 206,358 $ 209,903 Included in cash and cash equivalents $ 3,545 Included in marketable securities $ 206,358 As of September 30, 2017 and December 31, 2016 , there were no securities within Level 3 of the fair value hierarchy. There were no transfers between fair value measurement levels during the three and nine months ended September 30, 2017 . Gross unrealized gains and losses for cash equivalents and marketable securities as of September 30, 2017 and December 31, 2016 were no t material. Unrealized losses for securities that have been in an unrealized loss position for more than 12 months as of September 30, 2017 and December 31, 2016 were not material. The following table classifies our marketable securities by contractual maturity as of September 30, 2017 and December 31, 2016 (in thousands): September 30, December 31, Due in one year or less $ 133,959 $ 131,190 Due after one year 90,263 75,168 Total $ 224,222 $ 206,358 For our other financial instruments, including accounts receivable, accounts payable, and other current liabilities, the carrying amounts approximate their fair values due to the relatively short maturity of these balances. Derivative Instruments and Hedging Our foreign currency exposures typically arise from expenditures associated with foreign operations and sales in foreign currencies for subscriptions to our products. To mitigate the effect of foreign currency fluctuations on our future cash flows and earnings, we enter into foreign currency forward contracts with certain financial institutions and designate those contracts as cash flow hedges. Our foreign currency forward contracts generally have maturities of 15 months or less. As of September 30, 2017 , the balance of accumulated other comprehensive loss included an unrecognized net gain of $0.7 million related to the effective portion of changes in the fair value of foreign currency forward contracts designated as cash flow hedges. We expect to reclassify a net gain of $0.9 million into earnings over the next 12 months associated with our cash flow hedges. The following tables present information about our derivative instruments on our consolidated balance sheets as of September 30, 2017 and December 31, 2016 (in thousands): September 30, 2017 Asset Derivatives Liability Derivatives Derivative Instrument Balance Sheet Location Fair Value (Level 2) Balance Sheet Location Fair Value (Level 2) Foreign currency forward contracts Other current assets $ 2,459 Accrued liabilities $ 1,873 Total $ 2,459 $ 1,873 December 31, 2016 Asset Derivatives Liability Derivatives Derivative Instrument Balance Sheet Location Fair Value (Level 2) Balance Sheet Location Fair Value (Level 2) Foreign currency forward contracts Other current assets $ 868 Accrued liabilities $ 4,280 Total $ 868 $ 4,280 Our foreign currency forward contracts had a total notional value of $119.4 million and $79.6 million as of September 30, 2017 and December 31, 2016 , respectively. We have a master netting arrangement with each of our counterparties, which permits net settlement of multiple, separate derivative contracts with a single payment. We may also be required to exchange cash collateral with certain of our counterparties on a regular basis. ASC 815 permits companies to present the fair value of derivative instruments on a net basis according to master netting arrangements. We have elected to present our derivative instruments on a gross basis in our consolidated financial statements. As of September 30, 2017 and December 31, 2016 , our balances of cash collateral posted with counterparties were none and $1.1 million , respectively. The following table presents information about our derivative instruments on the statement of operations for the three and nine months ended September 30, 2017 and 2016 (in thousands): Three Months Ended September 30, 2017 Nine Months Ended September 30, 2017 Hedging Instrument Location of Gain (Loss) Reclassified into Earnings Gain Recognized in AOCI Gain Reclassified from AOCI into Earnings Gain Recognized in AOCI Loss Reclassified from AOCI into Earnings Foreign currency forward contracts Revenue, cost of revenue, operating expenses $ 629 $ 285 $ 3,117 $ (575 ) Total $ 629 $ 285 $ 3,117 $ (575 ) Three Months Ended September 30, 2016 Nine Months Ended September 30, 2016 Hedging Instrument Location of Loss Reclassified into Earnings Gain Recognized in AOCI Loss Reclassified from AOCI into Earnings Loss Recognized in AOCI Loss Reclassified from AOCI into Earnings Foreign currency forward contracts Revenue, cost of revenue, operating expenses $ 207 $ (209 ) $ (218 ) $ (357 ) Total $ 207 $ (209 ) $ (218 ) $ (357 ) All derivatives have been designated as hedging instruments. Amounts recognized in earnings related to excluded time value and hedge ineffectiveness for the three and nine months ended September 30, 2017 and 2016 were not material .

Property and Equipment

Property and Equipment	9 Months Ended
	Sep. 30, 2017
Property, Plant and Equipment [Abstract]
Property and Equipment	Property and Equipment Property and equipment, net consists of the following (in thousands): September 30, December 31, Hosting equipment $ 37,423 $ 35,018 Capitalized internal-use software 30,449 25,773 Leasehold improvements 28,117 25,396 Computer equipment and licensed software and patents 15,122 11,879 Furniture and fixtures 9,496 8,014 Construction in progress 7,070 7,993 Total 127,677 114,073 Less: accumulated depreciation and amortization (68,077 ) (51,342 ) Property and equipment, net $ 59,600 $ 62,731 Depreciation expense was $5.3 million and $4.1 million for the three months ended September 30, 2017 and 2016 , respectively, and $15.1 million and $11.8 million for the nine months ended September 30, 2017 and 2016 , respectively. Amortization expense of capitalized internal-use software was $1.8 million for each of the three months ended September 30, 2017 and 2016 , and $6.0 million and $5.2 million for the nine months ended September 30, 2017 and 2016 , respectively. The carrying value of capitalized internal-use software at September 30, 2017 and December 31, 2016 was $16.4 million and $15.4 million , respectively, including $6.7 million and $5.4 million in construction in progress, respectively.

Goodwill and Acquired Intangibl

Goodwill and Acquired Intangible Assets	9 Months Ended
	Sep. 30, 2017
Goodwill and Intangible Assets Disclosure [Abstract]
Goodwill and Acquired Intangible Assets	Goodwill and Acquired Intangible Assets The changes in the carrying amount of goodwill for the nine months ended September 30, 2017 are as follows (in thousands): Balance as of December 31, 2016 $ 45,347 Goodwill acquired 13,350 Foreign currency translation adjustments 434 Balance as of September 30, 2017 $ 59,131 Acquired intangible assets subject to amortization as of September 30, 2017 and December 31, 2016 consist of the following (in thousands): As of September 30, 2017 Cost Accumulated Amortization Foreign Currency Translation Adjustments Net Weighted Average Remaining Useful Life (In years) Developed technology $ 17,200 $ (9,225 ) $ (93 ) $ 7,882 3.9 Customer relationships 2,210 (1,414 ) (30 ) 766 2.4 $ 19,410 $ (10,639 ) $ (123 ) $ 8,648 As of December 31, 2016 Cost Accumulated Amortization Foreign Currency Translation Adjustments Net Weighted Average Remaining Useful Life (In years) Developed technology $ 14,000 $ (6,584 ) $ (169 ) $ 7,247 2.9 Customer relationships 1,800 (1,044 ) (53 ) 703 2.3 $ 15,800 $ (7,628 ) $ (222 ) $ 7,950 Amortization expense of acquired intangible assets was $1.0 million for each of the three months ended September 30, 2017 and 2016 , and $3.0 million and $2.9 million for the nine months ended September 30, 2017 and 2016 , respectively. Estimated future amortization expense as of September 30, 2017 is as follows (in thousands): Remainder of 2017 $ 741 2018 2,735 2019 2,676 2020 1,102 2021 492 Thereafter 902 $ 8,648

Commitments and Contingencies

Commitments and Contingencies	9 Months Ended
	Sep. 30, 2017
Commitments and Contingencies Disclosure [Abstract]
Commitments and Contingencies	Commitments and Contingencies Contractual Obligations We lease office space under noncancelable operating leases with various expiration dates. Certain of the office space lease agreements contain rent holidays or rent escalation provisions. Rent holiday and rent escalation provisions are considered in determining the straight-line expense to be recorded over the lease term. The lease term begins on the date of initial possession of the leased property for purposes of recognizing lease expense on a straight-line basis over the term of the lease. Rent expense was $2.8 million and $2.6 million for the three months ended September 30, 2017 and 2016 , respectively, and $8.3 million and $7.2 million for the nine months ended September 30, 2017 and 2016 , respectively. Except as discussed below, there were no material changes in our commitments under contractual obligations, as disclosed in our audited consolidated financial statements for the year ended December 31, 2016. During the nine months ended September 30, 2017 , we entered into three operating lease agreements for which the remaining anticipated amount of rent to be paid over the noncancelable terms of the leases is approximately $76.9 million as of September 30, 2017 . During the nine months ended September 30, 2017 , we entered into two agreements with cloud infrastructure providers for which we have remaining purchase obligations of approximately $15.6 million as of September 30, 2017 . The following table summarizes our remaining obligations under the three operating lease agreements and the two agreements with cloud infrastructure providers discussed above as of September 30, 2017 (in thousands): Total Less than 1 Year 1 to 3 Years 3 to 5 Years More than 5 Years Operating lease obligations $ 76,909 $ 1,477 $ 18,131 $ 19,409 $ 37,892 Purchase obligations $ 15,559 8,392 7,167 — — Litigation and Loss Contingencies We accrue estimates for resolution of legal and other contingencies when losses are probable and estimable. From time to time, we may become a party to litigation and subject to claims that arise in the ordinary course of business, including intellectual property claims, labor and employment claims, threatened claims, breach of contract claims, tax, and other matters. We currently have no material pending litigation. We are not currently aware of any litigation matters or loss contingencies that would be expected to have a material adverse effect on our business, consolidated balance sheets, results of operations, comprehensive loss, or cash flows. Indemnifications In the ordinary course of business, we enter into contractual arrangements under which we agree to provide indemnification of varying scope and terms to customers, business partners, and other parties with respect to certain matters, including, but not limited to, losses arising out of the breach of such agreements, intellectual property infringement claims made by third parties, and other liabilities relating to or arising from our products or our acts or omissions. In these circumstances, payment may be conditional on the other party making a claim pursuant to the procedures specified in the particular contract. Further, our obligations under these agreements may be limited in terms of time and/or amount, and in some instances, we may have recourse against third parties for certain payments. In addition, we have indemnification agreements with our directors and executive officers that require us, among other things, to indemnify them against certain liabilities that may arise by reason of their status or service as directors or officers. The terms of such obligations may vary. To date, we have not incurred any material costs, and we have not accrued any liabilities in our consolidated financial statements, as a result of these obligations. Certain of our product offerings include service-level agreements warranting defined levels of uptime reliability and performance, which permit those customers to receive credits for future services in the event that we fail to meet those levels. To date, we have not accrued for any significant liabilities in our consolidated financial statements as a result of these service-level agreements.

Common Stock and Stockholders'

Common Stock and Stockholders' Equity	9 Months Ended
	Sep. 30, 2017
Equity [Abstract]
Common Stock and Stockholders' Equity	Common Stock and Stockholders’ Equity Common Stock As of September 30, 2017 and December 31, 2016 , there were 400 million shares authorized for issuance with a par value of $0.01 per share. There were 101.1 million and 97.2 million shares of common stock issued and 101.1 million and 96.7 million shares outstanding as of September 30, 2017 and December 31, 2016 , respectively. Included within the number of shares issued and outstanding were approximately 14 thousand and 0.1 million shares of common stock subject to repurchase, as of September 30, 2017 and December 31, 2016 , respectively. Preferred Stock As of each of September 30, 2017 and December 31, 2016 , 10.0 million shares of preferred stock were authorized for issuance with a par value of $0.01 per share and no shares of preferred stock were issued or outstanding. Treasury Stock During the nine months ended September 30, 2017, we retired all 0.5 million of our treasury shares, which had been classified as treasury stock, at cost in the stockholders’ equity section of our consolidated balance sheet. Employee Equity Plans Employee Stock Purchase Plan Under our Employee Stock Purchase Plan, or ESPP, eligible employees are granted options to purchase shares of our common stock through payroll deductions. The ESPP provides for 18-month offering periods, which include three six-month purchase periods. At the end of each purchase period, employees are able to purchase shares at 85% of the lower of the fair market value of our common stock at the beginning of an offering period or the fair market value of our common stock at the end of the purchase period. For the three and nine months ended September 30, 2017 , none and 0.4 million shares of common stock were purchased under the ESPP, respectively. Pursuant to the terms of the ESPP, the number of shares reserved under the ESPP increased by 1.0 million shares on January 1, 2017. As of September 30, 2017 , 3.9 million shares of common stock were available for issuance under the ESPP. Stock Option and Grant Plans Our board of directors adopted the 2009 Stock Option and Grant Plan, or the 2009 Plan, in July 2009. The 2009 Plan was terminated in connection with our initial public offering in May 2014, and accordingly, no shares are available for issuance under this plan. The 2009 Plan continues to govern outstanding awards granted thereunder. Our 2014 Stock Option and Incentive Plan, or the 2014 Plan, serves as the successor to our 2009 Plan. Pursuant to the terms of the 2014 Plan, the number of shares reserved for issuance under the 2014 Plan increased by 4.8 million shares on January 1, 2017. As of September 30, 2017 , we had 8.1 million shares of common stock available for future grants under the 2014 Plan. On May 6, 2016, the compensation committee of our board of directors granted equity awards representing 1.2 million shares. These awards were granted outside of the 2014 Plan pursuant to an exemption provided for “employment inducement awards” within the meaning of Section 303A.08 of the New York Stock Exchange Listed Company Manual and accordingly did not require approval from our stockholders. A summary of our stock option and restricted stock unit, or RSU, activity for the nine months ended September 30, 2017 is as follows (in thousands, except per share information): Options Outstanding RSUs Outstanding Shares Available for Grant Number of Shares Weighted Average Exercise Price Weighted Average Remaining Contractual Term Aggregate Intrinsic Value Outstanding RSUs Weighted Average Grant Date Fair Value (In years) Outstanding — January 1, 2017 6,039 8,479 $ 14.52 7.49 $ 66,449 6,936 $ 20.81 Increase in authorized shares 4,833 Stock options granted (998 ) 998 27.03 RSUs granted (3,068 ) 3,068 27.69 Stock options exercised (1,771 ) 10.47 RSUs vested (2,343 ) 20.11 Stock options forfeited or canceled 288 (288 ) 23.81 RSUs forfeited or canceled 995 (995 ) 22.11 RSUs forfeited or canceled and unavailable for grant (202 ) 23.44 Stock options forfeited or canceled and unavailable for grant (200 ) 23.44 Outstanding — September 30, 2017 8,089 7,218 $ 16.63 7.21 $ 90,199 6,464 $ 24.05 The RSUs and stock options forfeited or canceled and unavailable for grant relate to our employment inducement awards. The aggregate intrinsic value for options outstanding represents the difference between the closing stock price of our common stock and the exercise price of outstanding, in-the-money options. As of September 30, 2017 , we had a total of $184.5 million in future share-based compensation expense related to all equity awards to be recognized over a weighted average period of 2.7 years.

Net Loss Per Share

Net Loss Per Share	9 Months Ended
	Sep. 30, 2017
Earnings Per Share [Abstract]
Net Loss Per Share	Net Loss Per Share Basic net loss per share is computed by dividing net loss by the weighted-average number of shares of common stock outstanding during the period. Diluted net loss per share is computed by giving effect to all potential shares of common stock, including outstanding share-based awards, to the extent dilutive. Basic and diluted net loss per share were the same for each period presented as the inclusion of all potential common stock outstanding would have been anti-dilutive. The following table presents the calculation of basic and diluted net loss per share for the periods presented (in thousands, except per share data): Three Months Ended Nine Months Ended 2017 2016 2017 2016 Net loss $ (27,689 ) $ (25,826 ) $ (83,988 ) $ (79,250 ) Weighted-average shares used to compute basic and diluted net loss per share 100,659 94,085 99,203 92,274 Net loss per share, basic and diluted $ (0.28 ) $ (0.27 ) $ (0.85 ) $ (0.86 ) The anti-dilutive securities excluded from the shares used to calculate diluted net loss per share are as follows (in thousands): As of September 30, 2017 2016 Shares subject to outstanding common stock options and employee stock purchase plan 7,488 9,753 Restricted stock units 6,464 7,565 13,952 17,318

Income Taxes

Income Taxes	9 Months Ended
	Sep. 30, 2017
Income Tax Disclosure [Abstract]
Income Taxes	Income Taxes Our effective tax rates for each of the three and nine months ended September 30, 2017 and 2016 were approximately 1% or less. The effective tax rate for each period differs from the statutory rate primarily as a result of not recognizing a deferred tax asset for U.S. losses due to having a full valuation allowance against U.S. deferred tax assets.

Geographic Information

Geographic Information	9 Months Ended
	Sep. 30, 2017
Segment Reporting [Abstract]
Geographic Information	Geographic Information Our chief operating decision maker reviews the financial information presented on a consolidated basis for purposes of allocating resources and evaluating our financial performance. Accordingly, we have determined that we operate in a single reporting segment. Revenue The following table presents our revenue by geographic area, as determined based on the billing address of our customers (in thousands): Three Months Ended Nine Months Ended 2017 2016 2017 2016 United States $ 59,455 $ 43,587 $ 163,971 $ 121,222 EMEA 32,447 22,601 87,338 62,208 Other 20,884 14,529 55,757 39,946 Total $ 112,786 $ 80,717 $ 307,066 $ 223,376 Long-Lived Assets The following table presents our long-lived assets by geographic area (in thousands): As of As of United States $ 25,395 $ 26,372 EMEA: Republic of Ireland 4,788 5,703 Other EMEA 5,423 6,834 Total EMEA 10,211 12,537 APAC 7,486 8,357 Total $ 43,092 $ 47,266 The carrying values of capitalized internal-use software and intangible assets are excluded from the balance of long-lived assets presented in the table above.

Overview and Basis of Present18

Overview and Basis of Presentation (Policies)	9 Months Ended
	Sep. 30, 2017
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Basis of Presentation	Basis of Presentation These unaudited condensed consolidated financial statements have been prepared in accordance with United States generally accepted accounting principles, or GAAP, and applicable rules and regulations of the Securities and Exchange Commission, or SEC, regarding interim financial reporting. Certain information and note disclosures normally included in the financial statements prepared in accordance with GAAP have been condensed or omitted pursuant to such rules and regulations. Therefore, these condensed consolidated financial statements should be read in conjunction with the audited consolidated financial statements and notes included in our Annual Report on Form 10-K for the year ended December 31, 2016, filed with the SEC on February 27, 2017. There have been no changes to our significant accounting policies described in the Annual Report on Form 10-K that have had a material impact on our condensed consolidated financial statements and related notes, except as described below. In the first quarter of 2017, we changed our accounting policy for share-based compensation to recognize forfeitures as they occur, as permitted by Accounting Standards Update, or ASU, 2016-09. Refer to Recently Adopted Accounting Pronouncements below for a more detailed discussion. The consolidated balance sheet as of December 31, 2016 included herein was derived from the audited financial statements as of that date. The unaudited condensed consolidated financial statements reflect all normal recurring adjustments necessary to present fairly our financial position, results of operations, comprehensive loss, and cash flows for the interim periods, but are not necessarily indicative of the results of operations to be anticipated for the full year ending December 31, 2017 .
Use of Estimates	Use of Estimates The preparation of our consolidated financial statements in conformity with GAAP requires management to make certain estimates, judgments, and assumptions that affect the reported amounts of assets and liabilities and disclosure of contingent assets and liabilities at the date of the financial statements, as well as the reported amounts of revenue and expenses during the reported periods. Significant items subject to such estimates and assumptions include the fair value of share-based awards, acquired intangible assets, goodwill and unrecognized tax benefits, the useful lives of acquired intangible assets and property and equipment, the capitalization and estimated useful life of capitalized internal-use software, and financial forecasts used in currency hedging. These estimates are based on information available as of the date of the financial statements; therefore, actual results could differ from those estimates.
Recently Issued and Adopted Accounting Pronouncements	Recently Issued Accounting Pronouncements In May 2014, the Financial Accounting Standards Board, or the FASB, issued new revenue guidance that provides principles for recognizing revenue to which an entity expects to be entitled for the transfer of promised goods or services to customers. The guidance also requires the deferral of incremental costs to acquire contracts with customers. As currently issued and amended, the new guidance is effective for annual reporting periods beginning after December 15, 2017, including interim periods within that reporting period, though early adoption is permitted for annual reporting periods beginning after December 15, 2016. The guidance may be applied retrospectively to each prior period presented (full retrospective method), or with the cumulative effect recognized as of the date of initial adoption (modified retrospective method). We currently intend to adopt using the full retrospective method; however, our decision has not been finalized. We have completed a preliminary assessment to determine the effect of adoption on our existing revenue arrangements and are nearing final conclusions. We are continuing to progress in the implementation of our new revenue recognition systems. As a result of adoption, we also expect to capitalize a significant portion of our sales commissions and other incremental costs to acquire contracts, which we historically expensed as incurred, resulting in an increase in deferred costs recognized on our balance sheet. We have not yet concluded the useful life of our capitalized costs, which will affect the classification and magnitude of the deferred costs at each reporting period. We are nearing the completion of our analysis to quantify the total effect of adoption on our consolidated financial statements. To meet the incremental disclosure requirements of the new guidance, we are also developing processes that will enable our ability to disclose backlog. In February 2016, the FASB issued ASU 2016-02, regarding Accounting Standards Codification, or ASC, Topic 842 “ Leases. ” This new standard requires lessees to recognize most leases on their balance sheets as lease liabilities with corresponding right-of-use assets and eliminates certain real estate-specific provisions. The new guidance is effective for annual reporting periods beginning after December 15, 2018, including interim periods within that reporting period. Early adoption is permitted. We are currently evaluating the effect of this standard on our consolidated financial statements. In August 2017, the FASB issued ASU 2017-12, regarding ASC Topic 815 "Derivatives and Hedging." This amendment simplifies various aspects of hedge accounting, including measurement and presentation of hedge ineffectiveness and certain documentation and assessment requirements. The amendment also makes more hedging strategies eligible for hedge accounting. The guidance is effective for annual reporting periods beginning after December 15, 2018, including interim periods within that reporting period. Early adoption is permitted. We are currently evaluating the effect of this standard on our consolidated financial statements. Recently Adopted Accounting Pronouncements In March 2016, the FASB issued ASU 2016-09, regarding ASC Topic 718 “ Compensation - Stock Compensation. ” This amendment changes certain aspects of accounting for share-based awards to employees, including the recognition of income tax effects of awards when the awards vest or are settled, requirements on net share settlement to cover tax withholding, and accounting for forfeitures. We adopted the standard in the first quarter of 2017. As required by the new standard, we now recognize excess tax effects from share-based awards as a component of provision for income taxes in our statement of operations when awards vest or are settled. Upon adoption, we recorded a deferred tax asset of $52.8 million to reflect, on a modified retrospective basis, the previously unrecognized excess tax benefits; however, the deferred tax asset was fully offset by a valuation allowance, resulting in no impact to our consolidated financial statements. In our statement of cash flows, we no longer classify excess tax benefits as a reduction from operating cash flows. This change was made prospectively beginning with the quarter ended March 31, 2017. We also elected to account for forfeitures as they occur; therefore, share-based compensation expense for the three and nine months ended September 30, 2017 has been calculated based on actual forfeitures in our consolidated statement of operations, rather than our previous approach, which was net of estimated forfeitures. The cumulative-effect adjustment of this change on a modified retrospective basis was not material. Share-based compensation expense for the three and nine months ended September 30, 2016 was recorded net of estimated forfeitures. In October 2016, the FASB issued ASU 2016-16, “ Income Taxes - Intra-Entity Transfers of Assets Other Than Inventory, ” which requires entities to recognize the income tax consequences of an intra-entity transfer of an asset other than inventory when the transfer occurs. The new guidance is effective for annual reporting periods beginning after December 15, 2017. Early adoption is permitted as of the beginning of an annual reporting period. The new standard must be adopted using a modified retrospective basis, with the cumulative effect recognized as of the date of adoption. We early adopted the standard in the first quarter of 2017. Upon adoption, we recorded a deferred tax asset of $6.2 million to reflect the previously unrecognized tax benefits; however, the deferred tax asset was fully offset by a valuation allowance, resulting in no impact to our consolidated financial statements. In May 2017, the FASB issued ASU 2017-09, regarding ASC Topic 718 “ Compensation - Stock Compensation: Scope of Modification Accounting. ” This amendment clarified what changes to terms or conditions of share-based awards require an entity to apply modification accounting. The new guidance is effective for annual reporting periods beginning after December 15, 2017, including interim periods within that reporting period. We early adopted this standard in the second quarter of 2017 on a prospective basis, as permitted by the standard. The adoption did not have a material effect on our consolidated financial statements.

Business Combination (Tables)

Business Combination (Tables)	9 Months Ended
	Sep. 30, 2017
Business Combinations [Abstract]
Summary of Assets Acquired and Liabilities Assumed	Goodwill will not be amortized but instead will be tested for impairment at least annually and more frequently if certain indicators of impairment are present. Net tangible assets acquired $ 96 Net deferred tax liability recognized (492 ) Identifiable intangible assets: Developed technology 3,200 Customer relationships 410 Goodwill 13,350 Total purchase price $ 16,564

Financial Instruments (Tables)

Financial Instruments (Tables)	9 Months Ended
	Sep. 30, 2017
Fair Value Disclosures [Abstract]
Assets Measured at Fair Value on Recurring Basis	The following tables present information about our financial assets measured at fair value on a recurring basis as of September 30, 2017 and December 31, 2016 based on the three-tier fair value hierarchy (in thousands): Fair Value Measurement at Level 1 Level 2 Total Description Corporate bonds $ — $ 152,888 152,888 U.S. treasury securities — 28,434 28,434 Asset-backed securities — 24,471 24,471 Commercial paper — 15,397 15,397 Money market funds 12,354 — 12,354 Agency securities — 8,532 8,532 Total $ 12,354 $ 229,722 $ 242,076 Included in cash and cash equivalents $ 17,854 Included in marketable securities $ 224,222 Fair Value Measurement at Level 1 Level 2 Total Description Corporate bonds $ — $ 124,930 $ 124,930 Asset-backed securities — 32,567 32,567 U.S. treasury securities — 30,585 30,585 Commercial paper — 9,787 9,787 Agency securities — 8,489 8,489 Money market funds 3,545 $ — $ 3,545 Total $ 3,545 $ 206,358 $ 209,903 Included in cash and cash equivalents $ 3,545 Included in marketable securities $ 206,358
Schedule of Marketable Securities Classified by Contractual Maturity	The following table classifies our marketable securities by contractual maturity as of September 30, 2017 and December 31, 2016 (in thousands): September 30, December 31, Due in one year or less $ 133,959 $ 131,190 Due after one year 90,263 75,168 Total $ 224,222 $ 206,358
Schedule of Derivative Instruments on Consolidated Balance Sheets	The following tables present information about our derivative instruments on our consolidated balance sheets as of September 30, 2017 and December 31, 2016 (in thousands): September 30, 2017 Asset Derivatives Liability Derivatives Derivative Instrument Balance Sheet Location Fair Value (Level 2) Balance Sheet Location Fair Value (Level 2) Foreign currency forward contracts Other current assets $ 2,459 Accrued liabilities $ 1,873 Total $ 2,459 $ 1,873 December 31, 2016 Asset Derivatives Liability Derivatives Derivative Instrument Balance Sheet Location Fair Value (Level 2) Balance Sheet Location Fair Value (Level 2) Foreign currency forward contracts Other current assets $ 868 Accrued liabilities $ 4,280 Total $ 868 $ 4,280
Schedule of Derivative Instruments on Statement of Operations	The following table presents information about our derivative instruments on the statement of operations for the three and nine months ended September 30, 2017 and 2016 (in thousands): Three Months Ended September 30, 2017 Nine Months Ended September 30, 2017 Hedging Instrument Location of Gain (Loss) Reclassified into Earnings Gain Recognized in AOCI Gain Reclassified from AOCI into Earnings Gain Recognized in AOCI Loss Reclassified from AOCI into Earnings Foreign currency forward contracts Revenue, cost of revenue, operating expenses $ 629 $ 285 $ 3,117 $ (575 ) Total $ 629 $ 285 $ 3,117 $ (575 ) Three Months Ended September 30, 2016 Nine Months Ended September 30, 2016 Hedging Instrument Location of Loss Reclassified into Earnings Gain Recognized in AOCI Loss Reclassified from AOCI into Earnings Loss Recognized in AOCI Loss Reclassified from AOCI into Earnings Foreign currency forward contracts Revenue, cost of revenue, operating expenses $ 207 $ (209 ) $ (218 ) $ (357 ) Total $ 207 $ (209 ) $ (218 ) $ (357 )

Property and Equipment (Tables)

Property and Equipment (Tables)	9 Months Ended
	Sep. 30, 2017
Property, Plant and Equipment [Abstract]
Components of Property and Equipment	Property and equipment, net consists of the following (in thousands): September 30, December 31, Hosting equipment $ 37,423 $ 35,018 Capitalized internal-use software 30,449 25,773 Leasehold improvements 28,117 25,396 Computer equipment and licensed software and patents 15,122 11,879 Furniture and fixtures 9,496 8,014 Construction in progress 7,070 7,993 Total 127,677 114,073 Less: accumulated depreciation and amortization (68,077 ) (51,342 ) Property and equipment, net $ 59,600 $ 62,731

Goodwill and Acquired Intangi22

Goodwill and Acquired Intangible Assets (Tables)	9 Months Ended
	Sep. 30, 2017
Goodwill and Intangible Assets Disclosure [Abstract]
Summary of Changes in Carrying Amount of Goodwill	The changes in the carrying amount of goodwill for the nine months ended September 30, 2017 are as follows (in thousands): Balance as of December 31, 2016 $ 45,347 Goodwill acquired 13,350 Foreign currency translation adjustments 434 Balance as of September 30, 2017 $ 59,131
Summary of Intangible Assets Acquired	Acquired intangible assets subject to amortization as of September 30, 2017 and December 31, 2016 consist of the following (in thousands): As of September 30, 2017 Cost Accumulated Amortization Foreign Currency Translation Adjustments Net Weighted Average Remaining Useful Life (In years) Developed technology $ 17,200 $ (9,225 ) $ (93 ) $ 7,882 3.9 Customer relationships 2,210 (1,414 ) (30 ) 766 2.4 $ 19,410 $ (10,639 ) $ (123 ) $ 8,648 As of December 31, 2016 Cost Accumulated Amortization Foreign Currency Translation Adjustments Net Weighted Average Remaining Useful Life (In years) Developed technology $ 14,000 $ (6,584 ) $ (169 ) $ 7,247 2.9 Customer relationships 1,800 (1,044 ) (53 ) 703 2.3 $ 15,800 $ (7,628 ) $ (222 ) $ 7,950
Summary of Estimated Future Amortization Expense	Estimated future amortization expense as of September 30, 2017 is as follows (in thousands): Remainder of 2017 $ 741 2018 2,735 2019 2,676 2020 1,102 2021 492 Thereafter 902 $ 8,648

Commitments and Contingencies (

Commitments and Contingencies (Tables)	9 Months Ended
	Sep. 30, 2017
Commitments and Contingencies Disclosure [Abstract]
Summary of Remaining Obligations Under Operating Lease Agreements	The following table summarizes our remaining obligations under the three operating lease agreements and the two agreements with cloud infrastructure providers discussed above as of September 30, 2017 (in thousands): Total Less than 1 Year 1 to 3 Years 3 to 5 Years More than 5 Years Operating lease obligations $ 76,909 $ 1,477 $ 18,131 $ 19,409 $ 37,892 Purchase obligations $ 15,559 8,392 7,167 — —

Common Stock and Stockholders24

Common Stock and Stockholders' Equity (Tables)	9 Months Ended
	Sep. 30, 2017
Equity [Abstract]
Summary of Stock Option and RSU Award Activity	A summary of our stock option and restricted stock unit, or RSU, activity for the nine months ended September 30, 2017 is as follows (in thousands, except per share information): Options Outstanding RSUs Outstanding Shares Available for Grant Number of Shares Weighted Average Exercise Price Weighted Average Remaining Contractual Term Aggregate Intrinsic Value Outstanding RSUs Weighted Average Grant Date Fair Value (In years) Outstanding — January 1, 2017 6,039 8,479 $ 14.52 7.49 $ 66,449 6,936 $ 20.81 Increase in authorized shares 4,833 Stock options granted (998 ) 998 27.03 RSUs granted (3,068 ) 3,068 27.69 Stock options exercised (1,771 ) 10.47 RSUs vested (2,343 ) 20.11 Stock options forfeited or canceled 288 (288 ) 23.81 RSUs forfeited or canceled 995 (995 ) 22.11 RSUs forfeited or canceled and unavailable for grant (202 ) 23.44 Stock options forfeited or canceled and unavailable for grant (200 ) 23.44 Outstanding — September 30, 2017 8,089 7,218 $ 16.63 7.21 $ 90,199 6,464 $ 24.05

Net Loss Per Share (Tables)

Net Loss Per Share (Tables)	9 Months Ended
	Sep. 30, 2017
Earnings Per Share [Abstract]
Schedule of Computation of Basic and Diluted Net Loss per Share	The following table presents the calculation of basic and diluted net loss per share for the periods presented (in thousands, except per share data): Three Months Ended Nine Months Ended 2017 2016 2017 2016 Net loss $ (27,689 ) $ (25,826 ) $ (83,988 ) $ (79,250 ) Weighted-average shares used to compute basic and diluted net loss per share 100,659 94,085 99,203 92,274 Net loss per share, basic and diluted $ (0.28 ) $ (0.27 ) $ (0.85 ) $ (0.86 )
Schedule of Anti-Dilutive Securities Excluded from the Diluted per Share Calculation	The anti-dilutive securities excluded from the shares used to calculate diluted net loss per share are as follows (in thousands): As of September 30, 2017 2016 Shares subject to outstanding common stock options and employee stock purchase plan 7,488 9,753 Restricted stock units 6,464 7,565 13,952 17,318

Geographic Information (Tables)

Geographic Information (Tables)	9 Months Ended
	Sep. 30, 2017
Segment Reporting [Abstract]
Schedule of Revenue by Geographic Areas	The following table presents our revenue by geographic area, as determined based on the billing address of our customers (in thousands): Three Months Ended Nine Months Ended 2017 2016 2017 2016 United States $ 59,455 $ 43,587 $ 163,971 $ 121,222 EMEA 32,447 22,601 87,338 62,208 Other 20,884 14,529 55,757 39,946 Total $ 112,786 $ 80,717 $ 307,066 $ 223,376
Schedule of Long-Lived Assets by Geographic Areas	The following table presents our long-lived assets by geographic area (in thousands): As of As of United States $ 25,395 $ 26,372 EMEA: Republic of Ireland 4,788 5,703 Other EMEA 5,423 6,834 Total EMEA 10,211 12,537 APAC 7,486 8,357 Total $ 43,092 $ 47,266

Overview and Basis of Present27

Overview and Basis of Presentation - Additional Information (Details) - USD ($) $ in Millions	3 Months Ended	9 Months Ended
	Sep. 30, 2017	Sep. 30, 2017	Mar. 31, 2017
Accounting Standards Update 2016-16
Subsidiary, Sale of Stock [Line Items]
Deferred tax asset, gross			$ 52.8
Deferred tax asset valuation allowance			52.8
Accounts Receivable | Customer Concentration Risk
Subsidiary, Sale of Stock [Line Items]
Concentration risk (percent)		10.00%
Sales Revenue, Net | Customer Concentration Risk
Subsidiary, Sale of Stock [Line Items]
Concentration risk (percent)	10.00%	10.00%
Adjustments for New Accounting Principle, Early Adoption | Accounting Standards Update 2016-16
Subsidiary, Sale of Stock [Line Items]
Deferred tax asset, gross			$ 6.2

Business Combination - Narrativ

Business Combination - Narrative (Details) - Outbound Solutions Inc	Apr. 27, 2017USD ($)
Business Acquisition [Line Items]
Cash consideration	$ 16,600,000
Goodwill expected to be tax deductible	$ 0
Developed technology
Business Acquisition [Line Items]
Acquired intangible assets weighted average useful life	6 years 6 months
Customer relationships
Business Acquisition [Line Items]
Acquired intangible assets weighted average useful life	3 years 6 months

Business Combination - Summary

Business Combination - Summary of Assets Acquired and Liabilities Assumed (Details) - USD ($) $ in Thousands	Sep. 30, 2017	Apr. 27, 2017	Dec. 31, 2016
Business Acquisition [Line Items]
Goodwill	$ 59,131		$ 45,347
Outbound Solutions Inc
Business Acquisition [Line Items]
Net tangible assets acquired		$ 96
Net deferred tax liability recognized		(492)
Goodwill		13,350
Total purchase price		16,564
Developed technology | Outbound Solutions Inc
Business Acquisition [Line Items]
Identifiable intangible assets:		3,200
Customer relationships | Outbound Solutions Inc
Business Acquisition [Line Items]
Identifiable intangible assets:		$ 410

Financial Instruments - Financi

Financial Instruments - Financial Assets Measured at Fair Value on Recurring Basis (Details) - USD ($) $ in Thousands	Sep. 30, 2017	Dec. 31, 2016
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Included in marketable securities	$ 224,222	$ 206,358
Fair Value Measurements, Recurring
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Total fair value of financial assets	242,076	209,903
Included in cash and cash equivalents	17,854	3,545
Included in marketable securities	224,222	206,358
Fair Value Measurements, Recurring | Corporate bonds
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Total fair value of financial assets	152,888	124,930
Fair Value Measurements, Recurring | U.S. treasury securities
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Total fair value of financial assets	28,434	30,585
Fair Value Measurements, Recurring | Asset-backed securities
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Total fair value of financial assets	24,471	32,567
Fair Value Measurements, Recurring | Commercial paper
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Total fair value of financial assets	15,397	9,787
Fair Value Measurements, Recurring | Agency securities
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Total fair value of financial assets	8,532	8,489
Fair Value Measurements, Recurring | Money market funds
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Total fair value of financial assets	12,354	3,545
Fair Value Measurements, Recurring | Level 1
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Total fair value of financial assets	12,354	3,545
Fair Value Measurements, Recurring | Level 1 | Corporate bonds
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Total fair value of financial assets	0	0
Fair Value Measurements, Recurring | Level 1 | Money market funds
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Total fair value of financial assets	12,354	3,545
Fair Value Measurements, Recurring | Level 2
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Total fair value of financial assets	229,722	206,358
Fair Value Measurements, Recurring | Level 2 | Corporate bonds
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Total fair value of financial assets	152,888	124,930
Fair Value Measurements, Recurring | Level 2 | U.S. treasury securities
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Total fair value of financial assets	28,434	30,585
Fair Value Measurements, Recurring | Level 2 | Asset-backed securities
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Total fair value of financial assets	24,471	32,567
Fair Value Measurements, Recurring | Level 2 | Commercial paper
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Total fair value of financial assets	15,397	9,787
Fair Value Measurements, Recurring | Level 2 | Agency securities
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Total fair value of financial assets	8,532	8,489
Fair Value Measurements, Recurring | Level 2 | Money market funds
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Total fair value of financial assets	$ 0	$ 0

Financial Instruments - Additio

Financial Instruments - Additional Information (Details) - USD ($)	9 Months Ended
	Sep. 30, 2017	Dec. 31, 2016
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Securities that were in an unrealized loss position for more than 12 months.	$ 0	$ 0
Cash collateral posted	0	1,100,000
Foreign currency forward contracts
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Unrealized loss in accumulated other comprehensive loss	700,000
Reclassification from accumulated other comprehensive income into earnings over next 12 month	900,000
Notional value	119,400,000	79,600,000
Level 3
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Securities within Level 3 of the fair value hierarchy	$ 0	$ 0
Maximum | Foreign currency forward contracts
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Derivative, maturity	15 months

Financial Instruments - Marketa

Financial Instruments - Marketable Securities by Contractual Maturity (Details) - USD ($) $ in Thousands	Sep. 30, 2017	Dec. 31, 2016
Fair Value Disclosures [Abstract]
Due in one year or less	$ 133,959	$ 131,190
Due after one year	90,263	75,168
Total	$ 224,222	$ 206,358

Financial Instruments - Schedul

Financial Instruments - Schedule of Derivative Instruments on Consolidated Balance Sheets (Details) - Designated as Hedging Instrument - Level 2 - USD ($) $ in Thousands	Sep. 30, 2017	Dec. 31, 2016
Derivatives Fair Value [Line Items]
Asset Derivatives	$ 2,459	$ 868
Liability Derivatives	1,873	4,280
Foreign currency forward contracts | Other current assets
Derivatives Fair Value [Line Items]
Asset Derivatives	2,459	868
Foreign currency forward contracts | Accrued liabilities
Derivatives Fair Value [Line Items]
Liability Derivatives	$ 1,873	$ 4,280

Financial Instruments - Sched34

Financial Instruments - Schedule of Derivative Instruments on Statement of Operations (Details) - Designated as Hedging Instrument - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2017	Sep. 30, 2016	Sep. 30, 2017	Sep. 30, 2016
Derivative Instruments Gain Loss [Line Items]
Gain Recognized in AOCI	$ 629	$ 207	$ 3,117	$ (218)
Loss Reclassified from AOCI into Earnings	285	(209)	(575)	(357)
Revenue, cost of revenue, operating expenses | Foreign currency forward contracts
Derivative Instruments Gain Loss [Line Items]
Gain Recognized in AOCI	629	207	3,117	(218)
Loss Reclassified from AOCI into Earnings	$ 285	$ (209)	$ (575)	$ (357)

Property and Equipment - Compon

Property and Equipment - Components of Property and Equipment (Details) - USD ($) $ in Thousands	Sep. 30, 2017	Dec. 31, 2016
Property Plant And Equipment [Line Items]
Total	$ 127,677	$ 114,073
Less: accumulated depreciation and amortization	(68,077)	(51,342)
Property and equipment, net	59,600	62,731
Hosting equipment
Property Plant And Equipment [Line Items]
Total	37,423	35,018
Capitalized internal-use software
Property Plant And Equipment [Line Items]
Total	30,449	25,773
Leasehold improvements
Property Plant And Equipment [Line Items]
Total	28,117	25,396
Computer equipment and licensed software and patents
Property Plant And Equipment [Line Items]
Total	15,122	11,879
Furniture and fixtures
Property Plant And Equipment [Line Items]
Total	9,496	8,014
Construction in progress
Property Plant And Equipment [Line Items]
Total	$ 7,070	$ 7,993

Property and Equipment - Additi

Property and Equipment - Additional Information (Details) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2017	Sep. 30, 2016	Sep. 30, 2017	Sep. 30, 2016	Dec. 31, 2016
Property, Plant and Equipment [Abstract]
Depreciation expense	$ 5.3	$ 4.1	$ 15.1	$ 11.8
Amortization expense of capitalized internal-use software	1.8	$ 1.8	6	$ 5.2
Carrying value of capitalized internal-use software	16.4		16.4		$ 15.4
Capitalized internal-use software included in construction in progress	$ 6.7		$ 6.7		$ 5.4

Goodwill and Acquired Intangi37

Goodwill and Acquired Intangible Assets - Changes in Carrying Amount of Goodwill (Details) $ in Thousands	9 Months Ended
	Sep. 30, 2017USD ($)
Goodwill [Roll Forward]
Balance as of December 31, 2016	$ 45,347
Goodwill acquired	13,350
Foreign currency translation adjustments	434
Balance as of September 30, 2017	$ 59,131

Goodwill and Acquired Intangi38

Goodwill and Acquired Intangible Assets - Acquired Intangible Assets Subject to Amortization (Details) - USD ($) $ in Thousands	9 Months Ended	12 Months Ended
	Sep. 30, 2017	Dec. 31, 2016
Finite Lived Intangible Assets [Line Items]
Cost	$ 19,410	$ 15,800
Accumulated Amortization	(10,639)	(7,628)
Foreign Currency Translation Adjustments	(123)	(222)
Net	8,648	7,950
Developed technology
Finite Lived Intangible Assets [Line Items]
Cost	17,200	14,000
Accumulated Amortization	(9,225)	(6,584)
Foreign Currency Translation Adjustments	(93)	(169)
Net	$ 7,882	$ 7,247
Weighted Average Remaining Useful Life	3 years 10 months 24 days	2 years 10 months 24 days
Customer relationships
Finite Lived Intangible Assets [Line Items]
Cost	$ 2,210	$ 1,800
Accumulated Amortization	(1,414)	(1,044)
Foreign Currency Translation Adjustments	(30)	(53)
Net	$ 766	$ 703
Weighted Average Remaining Useful Life	2 years 4 months 24 days	2 years 3 months 2 days

Goodwill and Acquired Intangi39

Goodwill and Acquired Intangible Assets - Additional Information (Details) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2017	Sep. 30, 2016	Sep. 30, 2017	Sep. 30, 2016
Goodwill and Intangible Assets Disclosure [Abstract]
Amortization expense	$ 1	$ 1	$ 3	$ 2.9

Goodwill and Acquired Intangi40

Goodwill and Acquired Intangible Assets - Estimated Future Amortization Expense (Details) - USD ($) $ in Thousands	Sep. 30, 2017	Dec. 31, 2016
Goodwill and Intangible Assets Disclosure [Abstract]
Remainder of 2017	$ 741
2,018	2,735
2,019	2,676
2,020	1,102
2,021	492
Thereafter	902
Net	$ 8,648	$ 7,950

Commitments and Contingencies -

Commitments and Contingencies - Additional Information (Details) - USD ($) $ in Thousands	1 Months Ended	3 Months Ended		9 Months Ended
	Nov. 30, 2017	Sep. 30, 2017	Sep. 30, 2016	Sep. 30, 2017	Sep. 30, 2016
Other Commitments [Line Items]
Rent expense		$ 2,800	$ 2,600	$ 8,300	$ 7,200
Operating Leases, Future Minimum Payments Due, Rolling Maturity [Abstract]
Total amount of rent to be paid		76,909		76,909
Operating lease obligations less than one year		1,477		1,477
Operating lease obligations one to three years		18,131		18,131
Operating lease obligations three to five years		19,409		19,409
Operating lease obligations more than five years		37,892		37,892
Cloud Infrastructure Agreements
Purchase Obligation, Fiscal Year Maturity [Abstract]
Purchase obligations		15,559		15,559
Purchase obligations due in less than one year		8,392		8,392
Purchase obligations due one to three years		7,167		7,167
Purchase obligations due three to five years		0		0
Purchase obligations due after year five		$ 0		$ 0
Cloud Infrastructure Agreements | Subsequent Event
Other Commitments [Line Items]
Purchase obligation recognition period	3 years
Purchase Obligation, Fiscal Year Maturity [Abstract]
Purchase obligations	$ 69,800

Common Stock and Stockholders42

Common Stock and Stockholders' Equity - Additional Information (Details) - USD ($) $ / shares in Units, $ in Millions	Jan. 01, 2017	May 06, 2016	Sep. 30, 2017	Sep. 30, 2017	Dec. 31, 2016
Class Of Stock [Line Items]
Common stock, shares authorized (in shares)			400,000,000	400,000,000	400,000,000
Common stock, par value (usd per share)			$ 0.01	$ 0.01	$ 0.01
Common stock, shares issued (in shares)			101,100,000	101,100,000	97,200,000
Common stock, shares outstanding (in shares)			101,100,000	101,100,000	96,700,000
Common stock shares outstanding, subject to repurchase (in shares)			14,000	14,000	100,000
Preferred stock, shares authorized (in shares)			10,000,000	10,000,000	10,000,000
Preferred stock, shares outstanding (in shares)			0	0	0
Preferred stock, par value (usd per share)			$ 0.01	$ 0.01	$ 0.01
Preferred stock, shares issued (in shares)			0	0	0
Retired treasury shares (in shares)				500,000
Increase in authorized shares (in shares)				4,833,000
Shares of common stock available for issuance (in shares)			8,089,000	8,089,000	6,039,000
Stock options granted (in shares)		1,200,000		998,000
Future period share-based compensation expense			$ 184.5	$ 184.5
Future period share-based compensation expense, period to recognized				2 years 8 months 12 days
Employee Stock Purchase Plan Awards
Class Of Stock [Line Items]
Offering period				18 months
2009 Stock Option and Grant Plan
Class Of Stock [Line Items]
Shares of common stock available for issuance (in shares)			0	0
2014 Plan | Employee Stock Option
Class Of Stock [Line Items]
Increase in authorized shares (in shares)	4,800,000
Shares of common stock available for issuance (in shares)			8,100,000	8,100,000
Employee Stock Purchase Plan
Class Of Stock [Line Items]
Percentage of purchase price of shares lower of the fair market value of common stock employees are able to purchase shares				85.00%
Common shares purchased (in shares)			0	400,000
Increase in authorized shares (in shares)	1,000,000
Shares of common stock available for issuance (in shares)			3,900,000	3,900,000

Common Stock and Stockholders43

Common Stock and Stockholders' Equity - Summary of Stock Option and RSU Award Activity (Details) - USD ($) $ / shares in Units, shares in Thousands, $ in Thousands	May 06, 2016	Sep. 30, 2017	Dec. 31, 2016
Shares Available for Grant
Outstanding — January 1, 2017		6,039
Increase in authorized shares, shares		4,833
Stock options granted, shares		(998)
RSUs granted, shares		(3,068)
Stock options forfeited or canceled, shares		288
RSUs forfeited or canceled, shares		995
Outstanding — September 30, 2017		8,089	6,039
Number of Shares
Balance at the beginning of the period, shares		8,479
Stock options granted, shares	1,200	998
Stock options exercised, shares		(1,771)
Stock options forfeited or canceled, shares		(288)
Stock options forfeited and unavailable for grant, shares		(200)
Balance at the end of the period, shares		7,218	8,479
Weighted-Average Exercise Price
Balance at the beginning of the period (usd per share)		$ 14.52
Stock options granted (usd per share)		27.03
Stock options exercised (usd per share)		10.47
Stock options forfeited or canceled (usd per share)		23.81
Stock options forfeited and unavailable for grant (usd per share)		23.44
Balance at the end of the period (usd per share)		$ 16.63	$ 14.52
Weighted Average Remaining Contractual Term
Weighted Average Remaining Contractual Term		7 years 2 months 15 days	7 years 5 months 27 days
Aggregate Intrinsic Value
Aggregate intrinsic value, beginning		$ 66,449
Aggregate intrinsic value, ending		$ 90,199	$ 66,449
RSUs Outstanding
Outstanding RSUs
Balance at the beginning of the period, shares		6,936
RSUs granted, shares		3,068
RSUs vested, shares		(2,343)
RSUs forfeited or canceled, shares		(995)
RSUs forfeited and unavailable for grant, shares		(202)
Balance at the end of the period, shares		6,464	6,936
Weighted-Average Grant Date Fair Value
Balance at the beginning of the period (usd per share)		$ 20.81
Weighted average grant date fair value, RSUs granted (usd per share)		27.69
Weighted average grant date fair value, RSUs vested (usd per share)		20.11
Weighted average grant date fair value, RSUs forfeited or canceled (usd per share)		22.11
Weighted average grant date fair value, forfeited and unavailable for grant (usd per share)		23.44
Balance at the end of the period (usd per share)		$ 24.05	$ 20.81

Net Loss per Share - Computatio

Net Loss per Share - Computation of Basic and Diluted Net Loss per Share of Common Stock (Details) - USD ($) $ / shares in Units, shares in Thousands, $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2017	Sep. 30, 2016	Sep. 30, 2017	Sep. 30, 2016
Earnings Per Share [Abstract]
Net loss	$ (27,689)	$ (25,826)	$ (83,988)	$ (79,250)
Weighted-average shares used to compute basic and diluted net loss per share	100,659	94,085	99,203	92,274
Net loss per share, basic and diluted (usd per share)	$ (0.28)	$ (0.27)	$ (0.85)	$ (0.86)

Net Loss per Share - Schedule o

Net Loss per Share - Schedule of Anti-Dilutive Securities Excluded from the Diluted per Share Calculation (Details) - shares shares in Thousands	9 Months Ended
	Sep. 30, 2017	Sep. 30, 2016
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Antidilutive securities excluded from computation of earnings per share amount (in shares)	13,952	17,318
Shares subject to outstanding common stock options and employee stock purchase plan
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Antidilutive securities excluded from computation of earnings per share amount (in shares)	7,488	9,753
Restricted stock units
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Antidilutive securities excluded from computation of earnings per share amount (in shares)	6,464	7,565

Income Taxes - Additional Infor

Income Taxes - Additional Information (Details)	3 Months Ended		9 Months Ended
	Sep. 30, 2017	Sep. 30, 2016	Sep. 30, 2017	Sep. 30, 2016
Income Tax Disclosure [Abstract]
Effective income tax rate, percent, less than	1.00%	1.00%	1.00%	1.00%

Geographic Information - Additi

Geographic Information - Additional Information (Details)	9 Months Ended
	Sep. 30, 2017segments
Segment Reporting [Abstract]
Number of reportable segments	1

Geographic Information - Schedu

Geographic Information - Schedule of Revenue by Geographic Areas (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2017	Sep. 30, 2016	Sep. 30, 2017	Sep. 30, 2016
Revenues From External Customers And Long Lived Assets [Line Items]
Revenue	$ 112,786	$ 80,717	$ 307,066	$ 223,376
United States
Revenues From External Customers And Long Lived Assets [Line Items]
Revenue	59,455	43,587	163,971	121,222
EMEA
Revenues From External Customers And Long Lived Assets [Line Items]
Revenue	32,447	22,601	87,338	62,208
Other
Revenues From External Customers And Long Lived Assets [Line Items]
Revenue	$ 20,884	$ 14,529	$ 55,757	$ 39,946

Geographic Information - Sche49

Geographic Information - Schedule of Long-Lived Assets by Geographic Areas (Details) - USD ($) $ in Thousands	Sep. 30, 2017	Dec. 31, 2016
Revenues From External Customers And Long Lived Assets [Line Items]
Long-lived assets	$ 43,092	$ 47,266
United States
Revenues From External Customers And Long Lived Assets [Line Items]
Long-lived assets	25,395	26,372
Republic of Ireland
Revenues From External Customers And Long Lived Assets [Line Items]
Long-lived assets	4,788	5,703
Other EMEA
Revenues From External Customers And Long Lived Assets [Line Items]
Long-lived assets	5,423	6,834
EMEA
Revenues From External Customers And Long Lived Assets [Line Items]
Long-lived assets	10,211	12,537
APAC
Revenues From External Customers And Long Lived Assets [Line Items]
Long-lived assets	$ 7,486	$ 8,357