Zendesk (ZEN) 10-Q 4 May 20 2020 Q1 Quarterly report Financial data

Cover Page

Cover Page - shares	3 Months Ended
	Mar. 31, 2020	Apr. 30, 2020
Cover [Abstract]
Document Type	10-Q
Document Quarterly Report	true
Document Period End Date	Mar. 31, 2020
Document Transition Report	false
Entity File Number	001-36456
Entity Registrant Name	ZENDESK, INC.
Entity Incorporation, State or Country Code	DE
Entity Tax Identification Number	26-4411091
Entity Address, Address Line One	1019 Market Street
Entity Address, City or Town	San Francisco
Entity Address, State or Province	CA
Entity Address, Postal Zip Code	94103
City Area Code	415
Local Phone Number	418-7506
Title of 12(b) Security	Common Stock, par value $0.01 per share
Trading Symbol	ZEN
Security Exchange Name	NYSE
Entity Current Reporting Status	Yes
Entity Interactive Data Current	Yes
Entity Filer Category	Large Accelerated Filer
Smaller Reporting Company	false
Emerging Growth Company	false
Entity Shell Company	false
Entity Common Stock, Shares Outstanding		114,225,954
Amendment Flag	false
Document Fiscal Year Focus	2020
Document Fiscal Period Focus	Q1
Entity Central Index Key	0001463172
Current Fiscal Year End Date	--12-31

CONDENSED CONSOLIDATED BALANCE

CONDENSED CONSOLIDATED BALANCE SHEETS - USD ($) $ in Thousands	Mar. 31, 2020	Dec. 31, 2019
Current assets:
Cash and cash equivalents	$ 199,092	$ 196,591
Marketable securities	269,003	286,958
Accounts receivable, net of allowance for doubtful accounts of $5,796 and $2,846 as of March 31, 2020 and December 31, 2019, respectively	101,027	127,808
Deferred costs	38,215	35,619
Prepaid expenses and other current assets	45,785	45,847
Total current assets	653,122	692,823
Marketable securities, noncurrent	369,091	361,948
Property and equipment, net	103,017	102,090
Deferred costs, noncurrent	36,520	35,230
Lease right-of-use assets	96,307	89,983
Goodwill and intangible assets, net	204,093	206,883
Other assets	26,640	25,632
Total assets	1,488,790	1,514,589
Current liabilities:
Accounts payable	26,227	38,376
Accrued liabilities	42,629	36,347
Accrued compensation and related benefits	61,996	61,512
Deferred revenue	301,402	320,642
Lease liabilities	21,253	21,804
Total current liabilities	453,507	478,681
Convertible senior notes, net	490,014	483,464
Deferred revenue, noncurrent	1,941	3,320
Lease liabilities, noncurrent	86,535	83,478
Other liabilities	6,850	7,662
Total liabilities	1,038,847	1,056,605
Commitments and contingencies (Note 9)
Stockholders’ equity:
Preferred stock	0	0
Common stock	1,139	1,130
Additional paid-in capital	1,200,521	1,155,044
Accumulated other comprehensive income (loss)	(10,152)	591
Accumulated deficit	(741,565)	(698,781)
Total stockholders’ equity	449,943	457,984
Total liabilities and stockholders’ equity	$ 1,488,790	$ 1,514,589

CONDENSED CONSOLIDATED BALANC_2

CONDENSED CONSOLIDATED BALANCE SHEETS (Parenthetical) - USD ($) $ in Thousands	Mar. 31, 2020	Dec. 31, 2019
Statement of Financial Position [Abstract]
Allowance for doubtful accounts	$ 5,796	$ 2,846

CONDENSED CONSOLIDATED STATEMEN

CONDENSED CONSOLIDATED STATEMENTS OF OPERATIONS - USD ($) shares in Thousands, $ in Thousands		3 Months Ended
		Mar. 31, 2020	Mar. 31, 2019
Income Statement [Abstract]
Revenue		$ 237,475	$ 181,484
Cost of revenue	[1]	59,702	55,654
Gross profit		177,773	125,830
Operating expenses:
Research and development	[1]	60,421	46,791
Sales and marketing	[1]	124,310	91,700
General and administrative	[1]	34,326	31,253
Total operating expenses	[1]	219,057	169,744
Operating loss		(41,284)	(43,914)
Other income (expense), net:
Interest income		4,570	5,472
Interest expense		(6,887)	(6,544)
Other income, net		2,334	700
Total other income (expense), net		17	(372)
Loss before provision for income taxes		(41,267)	(44,286)
Provision for income taxes		1,516	434
Net loss		$ (42,783)	$ (44,720)
Net loss per share, basic and diluted (usd per share)		$ (0.38)	$ (0.41)
Weighted-average shares used to compute net loss per share, basic and diluted (in shares)		113,538	108,630
[1]	Includes share-based compensation expense as follows: Three Months Ended 2020 2019 Cost of revenue $ 5,059 $ 4,937 Research and development 12,626 11,636 Sales and marketing 16,559 12,399 General and administrative 7,838 7,685

CONDENSED CONSOLIDATED STATEM_2

CONDENSED CONSOLIDATED STATEMENTS OF OPERATIONS (Parenthetical) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2020	Mar. 31, 2019
Share-based compensation	$ 42,082	$ 36,657
Cost of revenue
Share-based compensation	5,059	4,937
Research and development
Share-based compensation	12,626	11,636
Sales and marketing
Share-based compensation	16,559	12,399
General and administrative
Share-based compensation	$ 7,838	$ 7,685

CONDENSED CONSOLIDATED STATEM_3

CONDENSED CONSOLIDATED STATEMENTS OF COMPREHENSIVE LOSS - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2020	Mar. 31, 2019
Statement of Comprehensive Income [Abstract]
Net loss	$ (42,783)	$ (44,720)
Other comprehensive income (loss), before tax:
Net unrealized gain (loss) on available-for-sale investments	(3,395)	3,342
Net unrealized gain (loss) on derivative instruments	(7,348)	1,124
Other comprehensive income (loss), before tax	(10,743)	4,466
Tax effect	0	(1,072)
Other comprehensive income (loss), net of tax	(10,743)	3,394
Comprehensive loss	$ (53,526)	$ (41,326)

CONDENSED CONSOLIDATED STATEM_4

CONDENSED CONSOLIDATED STATEMENTS OF STOCKHOLDERS' EQUITY - USD ($) shares in Thousands, $ in Thousands	Total	Common Stock	Additional Paid-In Capital	Accumulated Other Comprehensive Income (Loss)	Accumulated Deficit
Beginning balance (in shares) at Dec. 31, 2018		108,037
Beginning balance at Dec. 31, 2018	$ 416,921	$ 1,080	$ 950,693	$ (5,724)	$ (529,128)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Issuance of common stock upon exercise of stock options (in shares)		376
Issuance of common stock upon exercise of stock options	8,438	$ 4	8,434
Issuance of common stock for settlement of RSUs and PRSUs (in shares)		847
Issuance of common stock for settlement of RSUs and PRSUs	(2,417)	$ 8	(2,425)
Share-based compensation	37,329		37,329
Other comprehensive income (loss), net of tax	3,394			3,394
Net loss	(44,720)				(44,720)
Ending balance (in shares) at Mar. 31, 2019		109,260
Ending balance at Mar. 31, 2019	418,945	$ 1,092	994,031	(2,330)	(573,848)
Beginning balance (in shares) at Dec. 31, 2019		113,081
Beginning balance at Dec. 31, 2019	$ 457,984	$ 1,130	1,155,044	591	(698,781)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Issuance of common stock upon exercise of stock options (in shares)	175	175
Issuance of common stock upon exercise of stock options	$ 4,001	$ 2	3,999
Issuance of common stock for settlement of RSUs and PRSUs (in shares)		720
Issuance of common stock for settlement of RSUs and PRSUs	(1,897)	$ 7	(1,904)
Share-based compensation	43,382		43,382
Other comprehensive income (loss), net of tax	(10,743)			(10,743)
Net loss	(42,783)				(42,783)
Ending balance (in shares) at Mar. 31, 2020		113,976
Ending balance at Mar. 31, 2020	$ 449,943	$ 1,139	$ 1,200,521	$ (10,152)	$ (741,565)

CONDENSED CONSOLIDATED STATEM_5

CONDENSED CONSOLIDATED STATEMENTS OF CASH FLOWS - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2020	Mar. 31, 2019
Cash flows from operating activities
Net loss	$ (42,783)	$ (44,720)
Adjustments to reconcile net loss to net cash provided by (used in) operating activities:
Depreciation and amortization	11,240	8,732
Share-based compensation	42,082	36,657
Amortization of deferred costs	9,965	6,918
Amortization of debt discount and issuance costs	6,549	6,188
Other	2,061	394
Changes in operating assets and liabilities:
Accounts receivable	26,023	(6,966)
Prepaid expenses and other current assets	1,743	(3,774)
Deferred costs	(13,448)	(10,190)
Lease right-of-use assets	4,975	4,373
Other assets and liabilities	(232)	(498)
Accounts payable	(10,323)	15,655
Accrued liabilities	(662)	2,512
Accrued compensation and related benefits	(9,541)	(4,629)
Deferred revenue	(21,464)	12,149
Lease liabilities	(8,794)	(3,832)
Net cash provided by (used in) operating activities	(2,609)	18,969
Cash flows from investing activities
Purchases of property and equipment	(9,938)	(9,258)
Internal-use software development costs	(3,058)	(1,213)
Purchases of marketable securities	(121,430)	(145,142)
Proceeds from maturities of marketable securities	74,231	47,265
Proceeds from sales of marketable securities	54,784	91,562
Purchases of strategic investments	(1,500)	(500)
Net cash used in investing activities	(6,911)	(17,286)
Cash flows from financing activities
Proceeds from exercises of employee stock options	4,001	8,437
Proceeds from employee stock purchase plan	10,115	8,415
Taxes paid related to net share settlement of share-based awards	(1,897)	(2,416)
Net cash provided by financing activities	12,219	14,436
Effect of exchange rate changes on cash, cash equivalents and restricted cash	16	33
Net increase in cash, cash equivalents and restricted cash	2,715	16,152
Cash, cash equivalents and restricted cash at beginning of period	199,897	128,876
Cash, cash equivalents and restricted cash at end of period	202,612	145,028
Reconciliation of cash, cash equivalents and restricted cash to condensed consolidated balance sheets
Total cash, cash equivalents and restricted cash	202,612	145,028
Supplemental cash flow data
Cash paid for interest	719	719
Cash paid for taxes	657	700
Non-cash investing and financing activities
Balance of property and equipment in accounts payable and accrued expenses	4,801	2,411
Property and equipment acquired through tenant improvement allowances	0	349
Internal-Use Software Development Costs
Non-cash investing and financing activities
Share-based compensation capitalized in deferred costs and in internal-use software development costs	850	375
Deferred Costs
Non-cash investing and financing activities
Share-based compensation capitalized in deferred costs and in internal-use software development costs	$ 404	$ 297

Overview and Basis of Presentat

Overview and Basis of Presentation	3 Months Ended
	Mar. 31, 2020
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, solutions that are intended to help organizations and their customers build better experiences. Our customer experience solutions are 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. With our origins in customer service, we have evolved our offerings over time to product and platform solutions that work together to help organizations understand the broader customer journey, improve communications across all channels, and engage where and when it’s needed most. 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, 2019, filed with the SEC on February 13, 2020. 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. The consolidated balance sheet as of December 31, 2019 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, stockholders' equity, 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, 2020 . 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 estimate of variable consideration related to revenue recognition; • the estimate of credit losses for accounts receivable and marketable securities; • the fair value and useful lives of acquired intangible assets; • the capitalization and useful life of capitalized costs to obtain customer contracts; • the valuation of strategic investments; • the useful lives of property and equipment; • the capitalization and useful lives of internal-use software; • the lease term and incremental borrowing rate for lease liabilities; • the fair value of our convertible senior notes; • the fair value of asset retirement obligations; • the fair value and expense recognition for certain share-based awards; • the preparation of financial forecasts used in currency hedging; • the recognition and measurement of legal contingencies; and • the recognition of tax benefits and forecasts used to determine our effective tax rate. In December 2019, the novel coronavirus and resulting disease (“COVID-19”) was reported and in March 2020 the World Health Organization declared it a pandemic. The extent of the impact of COVID-19 on our operational and financial performance will depend on certain developments, including the duration and spread of the outbreak, impact on our customers and our sales cycles, and impact on our employees, as discussed in more detail the Overview section. During the quarter, this uncertainty resulted in a higher level of judgment related to our estimates and assumptions concerning variable consideration related to revenue recognition, the estimate of credit losses for accounts receivable, and impairment of strategic investments. As of the date of issuance of the financial statements, we are not aware of any specific event or circumstance that would require us to update our estimates, judgments, or revise the carrying value of our assets or liabilities. These estimates may change, as new events occur and additional information is obtained, and are recognized in the consolidated financial statements as soon as they become known. Actual results could differ from those estimates and any such differences may be material to our financial statements. Accounts Receivable and Allowance for Doubtful Accounts Accounts receivable are recorded at the invoiced amount, net of allowance for doubtful accounts. The allowance is based upon historical loss patterns, the age of each past due invoice, and an evaluation of the potential risk of loss associated with delinquent accounts. The allowance also reflects current market conditions and reasonable and supportable forecasts of future economic conditions. As of March 31, 2020 , our allowance reflects increased collectibility concerns stemming from the COVID-19 pandemic and may increase in future periods as we ascertain further impacts to our customers and business. The allowance for doubtful accounts was $6 million and $3 million as of March 31, 2020 and December 31, 2019, respectively. Accounts receivable deemed uncollectable are charged against the allowance for doubtful accounts when identified. The balance of accounts receivable also includes contract assets, which are recorded when revenue is recognized in advance of invoicing. Concentrations of Risk As of March 31, 2020 and December 31, 2019, 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 months ended March 31, 2020 or 2019 . Recently Issued Accounting Pronouncements In December 2019, the FASB issued ASU 2019-12, regarding ASC Topic 740 “ Income Taxes, ” which simplifies certain aspects of accounting for income taxes. The guidance is effective for annual reporting periods beginning after December 15, 2020, including interim periods within that reporting period. Early adoption is permitted. We are currently evaluating the impact of the adoption of this standard on our consolidated financial statements. Recently Adopted Accounting Pronouncements In June 2016, the Financial Accounting Standards Board, or FASB, issued ASU 2016-13, including subsequent amendments, regarding ASC Topic 326 “ Measurement of Credit Losses on Financial Instruments, ” which modifies the accounting methodology for most financial instruments. The guidance establishes a new “expected loss model” that requires entities to estimate current expected credit losses on financial instruments by using all practical and relevant information. Additionally, any expected credit losses are to be reflected as allowances rather than reductions in the amortized cost of available-for-sale debt securities. We adopted this standard in the first quarter of 2020. The adoption did not have a material effect on our consolidated financial statements. In connection with the adoption, for purposes of identifying and measuring impairment, the policy election was made to exclude accrued interest from both the fair value and amortized cost basis of our available-for-sale debt securities. Such accrued interest is recorded in prepaid expenses and other current assets. In January 2017, the FASB issued ASU 2017-04, regarding ASC Topic 350 “ Simplifying the Test for Goodwill Impairment, ” which simplifies the required methodology to calculate an impairment charge for goodwill. We adopted this standard in the first quarter of 2020. The adoption did not have an effect on our consolidated financial statements. In August 2018, the FASB issued ASU 2018-13, regarding ASC Topic 820 “ Fair Value Measurement, ” which modifies the disclosure requirements for fair value measurements for certain types of investments. We adopted this standard in the first quarter of 2020. The adoption did not have an effect on our consolidated financial statements.

Business Combinations

Business Combinations	3 Months Ended
	Mar. 31, 2020
Business Combinations [Abstract]
Business Combinations	Business Combinations Smooch Technologies Holdings ULC On May 14, 2019, we completed the acquisition of Smooch Technologies Holdings ULC, or Smooch, a developer of messaging technology. We acquired Smooch for purchase consideration of $72 million in cash. In connection with the acquisition in the second quarter of 2019, we incurred transaction costs of $3 million within general and administrative expenses and share-based compensation expense of $5 million , primarily within general and administrative expenses, resulting from the accelerated vesting of certain unvested Smooch stock options because post-combination service requirements were eliminated. The fair value of assets acquired and liabilities assumed was based on a preliminary valuation, and our estimates and assumptions are subject to change within the measurement period. The primary area that remains preliminary relates to the evaluation of certain tax-related items. The total purchase consideration was allocated to the assets acquired and liabilities assumed as set forth below (in thousands). During the three months ended March 31, 2020 , we made certain immaterial adjustments to the preliminary purchase price allocation, which are reflected in the table below. The excess of the purchase price over the net assets acquired was recorded as goodwill. Goodwill generated from the acquisition is primarily attributable to assembled workforce and expected growth from the expansion of the scope of and market opportunity for our products. 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. As a result of the structure of the transaction, the balance of goodwill is deductible in the U.S. over 15 years for income tax purposes. Net tangible assets $ 1,974 Net deferred tax liability (1,194 ) Identifiable intangible assets: Developed technology 8,000 Customer relationships 3,900 Backlog 1,000 Goodwill 58,317 Total purchase consideration $ 71,997 The developed technology, customer relationships, and backlog intangible assets were assigned useful lives of 5.5 , 8.0 , and 2.0 years, respectively. In connection with the acquisition, we granted cash-based retention awards to certain employees of Smooch, which vest over a required service period. The awards will be recorded as expense and were not included in the total purchase consideration. From the date of the acquisition, the results of operations of Smooch 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 Smooch are not material to our consolidated financial statements in any period presented.

Financial Instruments

Financial Instruments	3 Months Ended
	Mar. 31, 2020
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 based on the three-tier fair value hierarchy (in thousands): Fair Value Measurement at Level 1 Level 2 Total Description Corporate bonds $ — $ 401,130 $ 401,130 Money market funds 125,936 — 125,936 Asset-backed securities — 118,816 118,816 U.S. Treasury securities — 78,854 78,854 Agency securities — 26,670 26,670 Commercial paper — 12,624 12,624 Total $ 125,936 $ 638,094 $ 764,030 Included in cash and cash equivalents $ 125,936 Included in marketable securities $ 638,094 Fair Value Measurement at Level 1 Level 2 Total Description Corporate bonds $ — $ 418,005 $ 418,005 Asset-backed securities — 124,046 124,046 U.S. Treasury securities — 94,731 94,731 Money market funds 70,455 — 70,455 Commercial paper — 13,548 13,548 Certificates of deposit and time deposits — 1,144 1,144 Agency securities — 920 920 Total $ 70,455 $ 652,394 $ 722,849 Included in cash and cash equivalents $ 73,943 Included in marketable securities $ 648,906 As of March 31, 2020 and December 31, 2019 , there were no securities within Level 3 of the fair value hierarchy. There were no transfers between fair value measurement levels during the three months ended March 31, 2020 . As of March 31, 2020 , gross unrealized gains and losses for marketable securities were $3 million and $2 million , respectively. The aggregate amortized cost basis for cash equivalents and marketable securities was $763 million and excludes accrued interest of $3 million . The aggregate fair value of securities with unrealized losses was $246 million . As of December 31, 2019 , gross unrealized gains and losses for marketable securities were $4 million and no t material, respectively. The aggregate amortized cost basis for cash equivalents and marketable securities as of December 31, 2019 was $719 million and excludes accrued interest of $4 million . The aggregate fair value of securities with unrealized losses was $45 million . Unrealized losses for securities that have been in an unrealized loss position for more than 12 months as of March 31, 2020 and December 31, 2019 were no t material. We have no t recorded an allowance for credit losses, as we believe any such losses would be immaterial based on the high-grade credit rating for each of our marketable securities as of the end of each period. We intend to hold our marketable securities to maturity and it is unlikely that they would be sold before their cost bases are recovered. The following table classifies our marketable securities by contractual maturity (in thousands): March 31, December 31, Due in one year or less $ 269,003 $ 286,958 Due after one year and within five years 369,091 361,948 Total $ 638,094 $ 648,906 As of March 31, 2020 and December 31, 2019 , the balances of strategic investments without readily determinable fair values were $12 million and $11 million , respectively. There have been no adjustments to the carrying values of strategic investments resulting from impairments or observable price changes. 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 of 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. We include time value related to our cash flow hedges for effectiveness testing purposes and the entire change in the unrecognized value of our hedge contracts is recorded in accumulated other comprehensive income (loss), or AOCI. As of March 31, 2020 , the balance of AOCI included an unrecognized net loss of $6 million related to the changes in the fair value of foreign currency forward contracts designated as cash flow hedges. We expect to reclassify a net loss of $7 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 (in thousands): March 31, 2020 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 $ 3,852 Accrued liabilities $ 10,751 Total $ 3,852 $ 10,751 December 31, 2019 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 $ 2,385 Accrued liabilities $ 1,975 Total $ 2,385 $ 1,975 Our foreign currency forward contracts had a total notional value of $318 million and $260 million as of March 31, 2020 and December 31, 2019 , respectively. We have a master netting arrangement with each of our counterparties, which permit net settlement of multiple, separate derivative contracts with a single payment. GAAP 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. We do not enter into any derivative contracts for trading or speculative purposes. As of March 31, 2020 and December 31, 2019 , there was no cash collateral posted with counterparties. All derivatives have been designated as hedging instruments. The following table presents information about our foreign currency forward contracts on our condensed consolidated statements of operations for the three months ended March 31, 2020 and 2019 (in thousands): Gain (Loss) Reclassified from AOCI into Earnings Three Months Ended March 31, Classification 2020 2019 Revenue $ 397 $ 443 Cost of revenue (321 ) (474 ) Research and development (281 ) (434 ) Sales and marketing (562 ) (790 ) General and administrative (174 ) (276 ) Total $ (941 ) $ (1,531 ) The loss recognized in AOCI related to foreign currency forward contracts was $8 million and no t material for the three months ended March 31, 2020 and 2019 , respectively. The cash flow effects related to foreign currency forward contracts are included within operating activities on our consolidated statements of cash flows. Convertible Senior Notes As of March 31, 2020 , the fair value of our convertible senior notes was $686 million . The fair value was determined based on the quoted price of the convertible senior notes in an inactive market on the last traded day of the quarter and has been classified as Level 2 in the fair value hierarchy. Based on the closing price of our common stock of $64.01 on the last trading day of the quarter, the if-converted value of our convertible senior notes exceeded the principal amount of $575 million as of March 31, 2020 .

Costs to Obtain Customer Contra

Costs to Obtain Customer Contracts	3 Months Ended
	Mar. 31, 2020
Revenue from Contract with Customer [Abstract]
Costs to Obtain Customer Contracts	Costs to Obtain Customer Contracts The balances of deferred costs to obtain customer contracts were $75 million and $71 million as of March 31, 2020 and December 31, 2019 , respectively. Amortization expense for these deferred costs was $10 million and $7 million for the three months ended March 31, 2020 and 2019 , respectively. There were no impairment losses related to these deferred costs for the periods presented. The changes in the balances of deferred revenue are as follows (in thousands): Three Months Ended March 31, 2020 2019 Balance, beginning of period $ 323,962 $ 247,962 Billings 216,856 193,118 Subscription and services revenue (224,059 ) (172,852 ) Other revenue* (13,416 ) (8,632 ) Balance, end of period $ 303,343 $ 259,596 *Other revenue primarily includes implementation and training services, Talk usage, and amounts from contract assets. For the three months ended March 31, 2020 and 2019 , the majority of revenue recognized was from the deferred revenue balances at the beginning of each period. The aggregate balance of remaining performance obligations as of March 31, 2020 was $673 million . We expect to recognize $489 million of the balance as revenue in the next 12 months and the remainder thereafter. The aggregate balance of remaining performance obligations represents contracted revenue that has not yet been recognized, including contracted revenue from renewals, and does not include contract amounts which are cancelable by the customer and amounts associated with optional renewal periods.

Property and Equipment

Property and Equipment	3 Months Ended
	Mar. 31, 2020
Property, Plant and Equipment [Abstract]
Property and Equipment	Property and Equipment Property and equipment, net consists of the following (in thousands): March 31, December 31, Leasehold improvements $ 86,593 $ 83,968 Capitalized internal-use software 40,647 38,437 Computer equipment and licensed software and patents 28,539 27,309 Furniture and fixtures 17,072 16,332 Construction in progress 10,337 8,647 Total 183,188 174,693 Less: accumulated depreciation and amortization (80,171 ) (72,603 ) Property and equipment, net $ 103,017 $ 102,090 Depreciation expense was $7 million and $5 million for the three months ended March 31, 2020 and 2019 , respectively. Amortization expense of capitalized internal-use software was $2 million for each of the three months ended March 31, 2020 and 2019 . The carrying values of capitalized internal-use software as of March 31, 2020 and December 31, 2019 were $25 million and $23 million , respectively, including $9 million and $8 million in construction in progress, respectively.

Leases

Leases	3 Months Ended
	Mar. 31, 2020
Leases [Abstract]
Leases	Leases We lease office space under noncancelable operating leases with various expiration dates. Additionally, we are the sublessor for certain office space. All of our office leases are classified as operating leases with lease expense recognized on a straight-line basis over the lease term. Lease right-of-use assets and liabilities are recognized at the commencement date based on the present value of lease payments over the lease term. As our leases do not provide an implicit rate, we use our incremental borrowing rate based on the information available at the commencement date in determining the present value of lease payments. The lease right-of-use assets also include any lease payments made and exclude lease incentives such as tenant improvement allowances. Options to extend the lease term are included in the lease term when it is reasonably certain that we will exercise the extension option. Our operating leases typically include non-lease components such as common-area maintenance costs. We have elected to include non-lease components with lease payments for the purpose of calculating lease right-of-use assets and liabilities, to the extent that they are fixed. Non-lease components that are not fixed are expensed as incurred as variable lease payments. Leases with a term of one year or less are not recognized on our consolidated balance sheet; we recognize lease expense for these leases on a straight-line basis over the lease term. The following tables present information about leases on our consolidated balance sheet (in thousands): March 31, 2020 December 31, 2019 Assets Lease right-of-use assets $ 96,307 $ 89,983 Liabilities Lease liabilities 21,253 21,804 Lease liabilities, noncurrent 86,535 83,478 As of March 31, 2020 , the weighted average remaining lease term was 6.2 years and the weighted average discount rate was 4.9% . The following table presents information about leases on our consolidated statement of operations (in thousands): Three Months Ended March 31, 2020 2019 Operating lease expense $ 6,343 $ 5,045 Short-term lease expense 185 874 Variable lease expense 1,543 885 Sublease income (464 ) (401 ) The following table presents supplemental cash flow information about our leases (in thousands): Three Months Ended March 31, 2020 2019 Cash paid for amounts included in the measurement of lease liabilities $ 9,552 $ 4,176 Operating lease assets obtained in exchange for new lease liabilities 11,316 19,550 As of March 31, 2020 , remaining maturities of lease liabilities are as follows: Remainder of 2020 $ 18,460 2021 26,074 2022 23,744 2023 16,079 2024 7,357 Thereafter 32,748 Total lease payments 124,462 Less imputed interest 16,674 Total $ 107,788 The table above excludes future payments of $10 million related to signed leases that have not yet commenced.

Goodwill and Acquired Intangibl

Goodwill and Acquired Intangible Assets	3 Months Ended
	Mar. 31, 2020
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 three months ended March 31, 2020 are as follows (in thousands): Balance as of December 31, 2019 $ 169,647 Goodwill adjustments 15 Balance as of March 31, 2020 $ 169,662 Acquired intangible assets subject to amortization consist of the following (in thousands): As of March 31, 2020 Cost Accumulated Amortization Net Weighted Average Remaining Useful Life (In years) Developed technology $ 39,000 $ (16,197 ) $ 22,803 4.7 Customer relationships 15,210 (4,582 ) 10,628 4.6 Backlog 3,200 (2,200 ) 1,000 0.8 $ 57,410 $ (22,979 ) $ 34,431 As of December 31, 2019 Cost Accumulated Amortization Net Weighted Average Remaining Useful Life (In years) Developed technology $ 39,000 $ (14,492 ) $ 24,508 4.9 Customer relationships 15,210 (3,882 ) 11,328 4.8 Backlog 3,200 (1,800 ) 1,400 1.0 $ 57,410 $ (20,174 ) $ 37,236 Amortization expense of acquired intangible assets was $3 million and $2 million for the three months ended March 31, 2020 and 2019 , respectively. Estimated future amortization expense as of March 31, 2020 is as follows (in thousands): Remainder of 2020 $ 6,505 2021 7,600 2022 7,435 2023 6,656 2024 4,615 Thereafter 1,620 $ 34,431

0.25% Convertible Senior Notes

0.25% Convertible Senior Notes and Capped Call	3 Months Ended
	Mar. 31, 2020
Debt Disclosure [Abstract]
0.25% Convertible Senior Notes and Capped Call	0.25% Convertible Senior Notes and Capped Call In March 2018, we issued $575 million aggregate principal amount of 0.25% convertible senior notes due March 15, 2023 in a private offering (the “Notes”). The Notes are unsecured obligations and bear interest at a fixed rate of 0.25% per annum, payable semi-annually in arrears on March 15 and September 15 of each year, commencing on September 15, 2018. The total net proceeds from the offering, after deducting initial purchase discounts and estimated debt issuance costs, were approximately $561 million . Each $1,000 principal amount of the Notes will initially be convertible into 15.8554 shares of our common stock, the “Conversion Option,” which is equivalent to an initial conversion price of approximately $63.07 per share, subject to adjustment upon the occurrence of specified events. The Notes will be convertible at the option of the holders at any time prior to the close of business on the business day immediately preceding December 15, 2022, only under the following circumstances: (1) during any calendar quarter commencing after the calendar quarter ending on June 30, 2018 (and only during such calendar quarter), if the last reported sale price of our common stock for at least 20 trading days (whether or not consecutive) during a period of 30 consecutive trading days ending on the last trading day of the immediately preceding calendar quarter is greater than or equal to 130% of the conversion price on each applicable trading day; (2) during the five business day period after any five consecutive trading day period, the “Measurement Period,” in which the trading price per $1,000 principal amount of notes for each trading day of the Measurement Period was less than 98% of the product of the last reported sale price of our common stock and the conversion rate on each such trading day; or (3) upon the occurrence of specified corporate events (as set forth in the indenture). On or after December 15, 2022 until the close of business on the second scheduled trading day immediately preceding the maturity date, holders may convert their Notes at any time, regardless of the foregoing circumstances. Upon conversion, we will pay or deliver, as the case may be, cash, shares of our common stock or a combination of cash and shares of our common stock, at our election. If certain specified fundamental changes occur (as set forth in the indenture governing the Notes) prior to the maturity date, holders of the Notes may require us to repurchase for cash all or any portion of their notes at a repurchase price equal to 100% of the principal amount of the Notes to be repurchased, plus accrued and unpaid interest to, but excluding, the fundamental change repurchase date. In addition, if specific corporate events occur prior to the applicable maturity date, we will increase the conversion rate for a holder who elects to convert their notes in connection with such a corporate event in certain circumstances. It is our current intent and policy to settle conversions through combination settlement with a specified dollar amount of $1,000 per $1,000 principal amount of Notes. During the three months ended March 31, 2020 , the conditions allowing holders of the Notes to convert were not met. The Notes are therefore not convertible during the three months ending June 30, 2020, and are classified as a noncurrent liability as of March 31, 2020. To-date, we have received one request for conversion for an immaterial amount of Notes. In accounting for the transaction, the Notes were separated into liability and equity components. The carrying amount of the liability component was calculated by measuring the fair value of a similar debt instrument that does not have an associated conversion feature. The carrying amount of the equity component representing the Conversion Option was $125 million and was determined by deducting the fair value of the liability component from the par value of the Notes. The equity component was recorded in additional paid-in capital and is not remeasured as long as it continues to meet the conditions for equity classification. The excess of the principal amount of the liability component over its carrying amount, the “Debt Discount,” is amortized to interest expense over the contractual term of the Notes at an effective interest rate of 5.26% . In accounting for the debt issuance costs of $14 million related to the Notes, we allocated the total amount incurred to the liability and equity components of the Notes based on their relative values. Issuance costs attributable to the liability component were $11 million and are amortized to interest expense using the effective interest method over the contractual term of the Notes. Issuance costs attributable to the equity component were netted with the equity component in additional paid-in capital. The net carrying amount of the liability component of the Notes is as follows (in thousands): March 31, December 31, Principal $ 575,000 $ 575,000 Unamortized Debt Discount (77,979 ) (84,037 ) Unamortized issuance costs (7,007 ) (7,499 ) Net carrying amount $ 490,014 $ 483,464 The net carrying amount of the equity component of the Notes is as follows (in thousands): March 31, December 31, Debt Discount for Conversion Option $ 124,976 $ 124,976 Issuance costs (2,948 ) (2,948 ) Net carrying amount $ 122,028 $ 122,028 Interest expense related to the Notes is as follows (in thousands): Three Months Ended March 31, 2020 2019 Contractual interest expense $ 359 $ 356 Amortization of Debt Discount 6,057 5,751 Amortization of issuance costs 492 437 Total interest expense $ 6,908 $ 6,544 In connection with the pricing of the Notes, we entered into privately negotiated capped call transactions with certain counterparties, the “Capped Calls.” The Capped Calls each have an initial strike price of approximately $63.07 per share, subject to certain adjustments, which correspond to the initial conversion price of the Notes. The Capped Calls have initial cap prices of $95.20 per share, subject to certain adjustments. The Capped Calls cover, subject to anti-dilution adjustments, approximately 9.1 million shares of our common stock. Conditions that cause adjustments to the initial strike price of the Capped Calls mirror conditions that result in corresponding adjustments for the Notes. The Capped Calls are generally intended to reduce or offset the potential dilution to our common stock upon any conversion of the Notes with such reduction or offset, as the case may be, subject to a cap based on the cap price. For accounting purposes, the Capped Calls are separate transactions, and not part of the terms of the Notes. As these transactions meet certain accounting criteria, the Capped Calls are recorded in stockholders' equity and are not accounted for as derivatives. The cost of $64 million incurred in connection with the Capped Calls was recorded as a reduction to additional paid-in capital. The net impact to our stockholders' equity, included in additional paid-in capital, of the above components of the Notes is as follows (in thousands): Conversion Option $ 124,976 Purchase of Capped Calls (63,940 ) Issuance costs (2,948 ) Net deferred tax liability (13,784 ) Total $ 44,304

Commitments and Contingencies

Commitments and Contingencies	3 Months Ended
	Mar. 31, 2020
Commitments and Contingencies Disclosure [Abstract]
Commitments and Contingencies	Commitments and Contingencies Commitments As of March 31, 2020 , 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, 2019. Litigation and Loss Contingencies We accrue estimates for resolution of legal and other contingencies when losses are probable and estimable. These estimates are reviewed at least quarterly and adjusted to reflect the impacts of negotiations, estimated settlements, legal rulings, advice of legal counsel, and other information and events pertaining to a particular matter. On October 24, 2019 and November 7, 2019, purported stockholders of the Company filed two putative class action complaints in the United States District Court for the Northern District of California, entitled Charles Reidinger v. Zendesk, Inc., et al., 3:19-cv-06968-CRB and Ho v. Zendesk, Inc., et al., No. 3:19-cv-07361-WHA, respectively, against the Company and certain of the Company’s executive officers. The complaints are nearly identical and allege violations of Section 10(b) and Section 20(a) of the Securities Exchange Act of 1934, as amended, purportedly on behalf of all persons who purchased Zendesk, Inc. common stock between February 6, 2019 and October 1, 2019, inclusive. The claims are based upon allegations that the defendants misrepresented and/or omitted material information in certain of our prior public filings. To this point, no discovery has occurred in these cases. The court has appointed a lead plaintiff and consolidated the various lawsuits into a single action (Case No. 3:19-cv-06968-CRB), and lead plaintiff filed its amended complaint on April 14, 2020 asserting the same alleged violations of securities laws as the initial complaints. The class action is still in the preliminary stages, and it is not possible for the Company to quantify the extent of potential liability to the individual defendants, if any. Management believes that the lawsuit lacks merit and intends to vigorously defend the actions. We cannot predict the outcome of or estimate the possible loss or range of loss from the above described matter. From time to time, we may be subject to other legal proceedings, claims, investigations, and government inquiries in the ordinary course of business. We have received, and may in the future continue to receive, claims from third parties asserting, among other things, infringement of their intellectual property rights, labor and employment rights, defamation, privacy, and contractual rights. In general, the resolution of a legal matter could prevent the Company from offering its service to others, could be material to the Company’s financial condition or cash flows, or both, or could otherwise adversely affect the Company’s operating results. The outcomes of legal proceedings and other contingencies are inherently unpredictable and subject to significant uncertainties. As a result, the Company is not able to reasonably estimate the amount or range of possible losses in excess of any amounts accrued, including losses that could arise as a result of application of non-monetary remedies, with respect to the contingencies it faces. In management’s opinion, resolution of all current matters is not expected to have a material adverse impact on 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	3 Months Ended
	Mar. 31, 2020
Equity [Abstract]
Common Stock and Stockholders' Equity	Common Stock and Stockholders’ Equity Common Stock As of March 31, 2020 and December 31, 2019 , there were 400 million shares of common stock authorized for issuance with a par value of $0.01 per share and 114.0 million and 113.1 million shares were issued and outstanding, respectively. Preferred Stock As of each of March 31, 2020 and December 31, 2019 , there were 10 million shares of preferred stock authorized for issuance with a par value of $0.01 per share and no shares of preferred stock were issued or outstanding. 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. During the three months ended March 31, 2020 , no shares of common stock were purchased under the ESPP. Pursuant to the terms of the ESPP, the number of shares reserved under the ESPP increased by 1.1 million shares on January 1, 2020. As of March 31, 2020 , 5.5 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 5.7 million shares on January 1, 2020. As of March 31, 2020 , we had 15.7 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 of common stock. 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 share-based award activity for the three months ended March 31, 2020 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 Aggregate Intrinsic Value (In years) Outstanding — January 1, 2020 11,613 4,860 $ 24.08 5.85 $ 255,536 5,361 $ 55.00 $ 410,804 Increase in authorized shares 5,654 Stock options granted (456 ) 456 88.73 RSUs granted (1,398 ) 1,398 83.85 Stock options exercised (175 ) 22.93 RSUs vested (694 ) 49.96 Stock options forfeited or canceled 12 (12 ) 30.18 RSUs forfeited or canceled 212 (212 ) 55.23 RSUs forfeited or canceled and unavailable for grant (7 ) 23.44 PRSUs forfeited 25 Outstanding — March 31, 2020 15,662 5,129 $ 29.85 5.97 $ 189,715 5,846 $ 62.53 $ 374,201 The restricted stock units, or RSUs, 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 market price of our common stock on the last trading day of the reporting period and the exercise price of outstanding, in-the-money options. The total intrinsic value of stock options exercised during the three months ended March 31, 2020 and 2019 was $10 million and $21 million , respectively. The intrinsic value for options exercised represents the difference between the exercise price and the market value on the date of exercise. The weighted-average grant date fair value of stock options granted during the three months ended March 31, 2020 and 2019 was $31.63 and $28.65 , respectively. The total fair value of RSUs vested during the three months ended March 31, 2020 and 2019 was $55 million and $63 million , respectively. The fair value of RSUs vested represents market value on the vesting date. The weighted-average grant date fair value of RSUs granted during the three months ended March 31, 2020 and 2019 was $83.85 , and $64.88 , respectively. As of March 31, 2020 , we had a total of $385 million in future expense related to our stock options and RSUs to be recognized over a weighted average period of 2.9 years. Performance Restricted Stock Units During the three months ended September 30, 2018 , the compensation committee of our board of directors granted performance-based restricted stock units, or PRSUs, representing 0.2 million shares of common stock, the substantial majority of which were granted in connection with the acquisition of FutureSimple Inc. The PRSUs vest in four semi-annual tranches through March 2021. The PRSUs include a service condition and a performance condition related to the attainment of semi-annual performance targets approved and communicated in advance of each performance period. For each of the three months ended March 31, 2020 and 2019 , we recorded $1 million of share-based compensation expense related to the PRSUs. For the three months ended March 31, 2020 and 2019 , 26 thousand and no PRSUs were vested, respectively. The total future expense related to the PRSUs will be based on the fair value of the underlying shares on the grant date for each performance tranche.

Deferred Revenue and Performanc

Deferred Revenue and Performance Obligations	3 Months Ended
	Mar. 31, 2020
Revenue from Contract with Customer [Abstract]
Deferred Revenue and Performance Obligations	Costs to Obtain Customer Contracts The balances of deferred costs to obtain customer contracts were $75 million and $71 million as of March 31, 2020 and December 31, 2019 , respectively. Amortization expense for these deferred costs was $10 million and $7 million for the three months ended March 31, 2020 and 2019 , respectively. There were no impairment losses related to these deferred costs for the periods presented. The changes in the balances of deferred revenue are as follows (in thousands): Three Months Ended March 31, 2020 2019 Balance, beginning of period $ 323,962 $ 247,962 Billings 216,856 193,118 Subscription and services revenue (224,059 ) (172,852 ) Other revenue* (13,416 ) (8,632 ) Balance, end of period $ 303,343 $ 259,596 *Other revenue primarily includes implementation and training services, Talk usage, and amounts from contract assets. For the three months ended March 31, 2020 and 2019 , the majority of revenue recognized was from the deferred revenue balances at the beginning of each period. The aggregate balance of remaining performance obligations as of March 31, 2020 was $673 million . We expect to recognize $489 million of the balance as revenue in the next 12 months and the remainder thereafter. The aggregate balance of remaining performance obligations represents contracted revenue that has not yet been recognized, including contracted revenue from renewals, and does not include contract amounts which are cancelable by the customer and amounts associated with optional renewal periods.

Net Loss Per Share

Net Loss Per Share	3 Months Ended
	Mar. 31, 2020
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 those related to outstanding share-based awards and our convertible senior notes, 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 2020 2019 Net loss $ (42,783 ) $ (44,720 ) Weighted-average shares used to compute basic and diluted net loss per share 113,538 108,630 Net loss per share, basic and diluted $ (0.38 ) $ (0.41 ) The anti-dilutive securities excluded from the shares used to calculate diluted net loss per share are as follows (in thousands): As of March 31, 2020 2019 Shares subject to outstanding common stock options and employee stock purchase plan 5,429 6,167 Restricted stock units 5,846 7,028 Shares related to convertible senior notes 1,749 1,283 13,024 14,478 The shares related to convertible senior notes in the table above are calculated based on the average market price of our common stock for the three months ended March 31, 2020 and 2019, respectively. We expect to settle the principal amount of the convertible senior notes in cash and therefore use the treasury stock method for calculating any potential dilutive effect of the conversion spread on diluted net income per share, if applicable. The conversion spread has a dilutive impact on diluted net income per share when the average market price of our common stock for a given reporting period exceeds the initial conversion price of $63.07 per share for the convertible senior notes. Based on the initial conversion price, potential dilution related to the convertible senior notes is approximately 9.1 million shares. The convertible senior notes will not be convertible during the three months ending June 30, 2020.

Income Taxes

Income Taxes	3 Months Ended
	Mar. 31, 2020
Income Tax Disclosure [Abstract]
Income Taxes	Income Taxes We reported $2 million and immaterial income tax expense for the three months ended March 31, 2020 and 2019 , respectively. 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	3 Months Ended
	Mar. 31, 2020
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 2020 2019 United States $ 124,037 $ 94,901 EMEA 67,919 52,075 APAC 25,575 19,476 Other 19,944 15,032 Total $ 237,475 $ 181,484 Long-Lived Assets The following table presents our long-lived assets by geographic area (in thousands): As of As of United States $ 98,152 $ 91,532 EMEA: Republic of Ireland 41,210 42,500 Other EMEA 3,274 3,725 Total EMEA 44,484 46,225 APAC: Singapore 24,393 25,988 Other APAC 7,119 5,362 Total APAC 31,512 31,350 Other 471 417 Total $ 174,619 $ 169,524 The table above includes property and equipment and lease right-of-use assets and excludes capitalized internal-use software and intangible assets.

Overview and Basis of Present_2

Overview and Basis of Presentation (Policies)	3 Months Ended
	Mar. 31, 2020
Organization, Consolidation and Presentation of Financial Statements [Abstract]
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, 2019, filed with the SEC on February 13, 2020. 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. The consolidated balance sheet as of December 31, 2019 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, stockholders' equity, 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, 2020 .
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 estimate of variable consideration related to revenue recognition; • the estimate of credit losses for accounts receivable and marketable securities; • the fair value and useful lives of acquired intangible assets; • the capitalization and useful life of capitalized costs to obtain customer contracts; • the valuation of strategic investments; • the useful lives of property and equipment; • the capitalization and useful lives of internal-use software; • the lease term and incremental borrowing rate for lease liabilities; • the fair value of our convertible senior notes; • the fair value of asset retirement obligations; • the fair value and expense recognition for certain share-based awards; • the preparation of financial forecasts used in currency hedging; • the recognition and measurement of legal contingencies; and • the recognition of tax benefits and forecasts used to determine our effective tax rate. In December 2019, the novel coronavirus and resulting disease (“COVID-19”) was reported and in March 2020 the World Health Organization declared it a pandemic. The extent of the impact of COVID-19 on our operational and financial performance will depend on certain developments, including the duration and spread of the outbreak, impact on our customers and our sales cycles, and impact on our employees, as discussed in more detail the Overview section. During the quarter, this uncertainty resulted in a higher level of judgment related to our estimates and assumptions concerning variable consideration related to revenue recognition, the estimate of credit losses for accounts receivable, and impairment of strategic investments. As of the date of issuance of the financial statements, we are not aware of any specific event or circumstance that would require us to update our estimates, judgments, or revise the carrying value of our assets or liabilities. These estimates may change, as new events occur and additional information is obtained, and are recognized in the consolidated financial statements as soon as they become known. Actual results could differ from those estimates and any such differences may be material to our financial statements.
Accounts Receivable and Allowance for Doubtful Accounts	Accounts receivable are recorded at the invoiced amount, net of allowance for doubtful accounts. The allowance is based upon historical loss patterns, the age of each past due invoice, and an evaluation of the potential risk of loss associated with delinquent accounts. The allowance also reflects current market conditions and reasonable and supportable forecasts of future economic conditions. As of March 31, 2020 , our allowance reflects increased collectibility concerns stemming from the COVID-19 pandemic and may increase in future periods as we ascertain further impacts to our customers and business. The allowance for doubtful accounts was $6 million and $3 million as of March 31, 2020 and December 31, 2019, respectively. Accounts receivable deemed uncollectable are charged against the allowance for doubtful accounts when identified. The balance of accounts receivable also includes contract assets, which are recorded when revenue is recognized in advance of invoicing.
Concentrations of Risk	As of March 31, 2020 and December 31, 2019, 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 months ended March 31, 2020 or 2019 .
Recently Issued and Adopted Accounting Pronouncements	In December 2019, the FASB issued ASU 2019-12, regarding ASC Topic 740 “ Income Taxes, ” which simplifies certain aspects of accounting for income taxes. The guidance is effective for annual reporting periods beginning after December 15, 2020, including interim periods within that reporting period. Early adoption is permitted. We are currently evaluating the impact of the adoption of this standard on our consolidated financial statements. Recently Adopted Accounting Pronouncements In June 2016, the Financial Accounting Standards Board, or FASB, issued ASU 2016-13, including subsequent amendments, regarding ASC Topic 326 “ Measurement of Credit Losses on Financial Instruments, ” which modifies the accounting methodology for most financial instruments. The guidance establishes a new “expected loss model” that requires entities to estimate current expected credit losses on financial instruments by using all practical and relevant information. Additionally, any expected credit losses are to be reflected as allowances rather than reductions in the amortized cost of available-for-sale debt securities. We adopted this standard in the first quarter of 2020. The adoption did not have a material effect on our consolidated financial statements. In connection with the adoption, for purposes of identifying and measuring impairment, the policy election was made to exclude accrued interest from both the fair value and amortized cost basis of our available-for-sale debt securities. Such accrued interest is recorded in prepaid expenses and other current assets. In January 2017, the FASB issued ASU 2017-04, regarding ASC Topic 350 “ Simplifying the Test for Goodwill Impairment, ” which simplifies the required methodology to calculate an impairment charge for goodwill. We adopted this standard in the first quarter of 2020. The adoption did not have an effect on our consolidated financial statements. In August 2018, the FASB issued ASU 2018-13, regarding ASC Topic 820 “ Fair Value Measurement, ” which modifies the disclosure requirements for fair value measurements for certain types of investments. We adopted this standard in the first quarter of 2020. The adoption did not have an effect on our consolidated financial statements.
Leases	Lease right-of-use assets and liabilities are recognized at the commencement date based on the present value of lease payments over the lease term. As our leases do not provide an implicit rate, we use our incremental borrowing rate based on the information available at the commencement date in determining the present value of lease payments. The lease right-of-use assets also include any lease payments made and exclude lease incentives such as tenant improvement allowances. Options to extend the lease term are included in the lease term when it is reasonably certain that we will exercise the extension option. Our operating leases typically include non-lease components such as common-area maintenance costs. We have elected to include non-lease components with lease payments for the purpose of calculating lease right-of-use assets and liabilities, to the extent that they are fixed. Non-lease components that are not fixed are expensed as incurred as variable lease payments. Leases with a term of one year or less are not recognized on our consolidated balance sheet; we recognize lease expense for these leases on a straight-line basis over the lease term.

Business Combinations (Tables)

Business Combinations (Tables)	3 Months Ended
	Mar. 31, 2020
Business Combinations [Abstract]
Summary of Assets Acquired and Liabilities Assumed	Net tangible assets $ 1,974 Net deferred tax liability (1,194 ) Identifiable intangible assets: Developed technology 8,000 Customer relationships 3,900 Backlog 1,000 Goodwill 58,317 Total purchase consideration $ 71,997

Financial Instruments (Tables)

Financial Instruments (Tables)	3 Months Ended
	Mar. 31, 2020
Fair Value Disclosures [Abstract]
Schedule of 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 based on the three-tier fair value hierarchy (in thousands): Fair Value Measurement at Level 1 Level 2 Total Description Corporate bonds $ — $ 401,130 $ 401,130 Money market funds 125,936 — 125,936 Asset-backed securities — 118,816 118,816 U.S. Treasury securities — 78,854 78,854 Agency securities — 26,670 26,670 Commercial paper — 12,624 12,624 Total $ 125,936 $ 638,094 $ 764,030 Included in cash and cash equivalents $ 125,936 Included in marketable securities $ 638,094 Fair Value Measurement at Level 1 Level 2 Total Description Corporate bonds $ — $ 418,005 $ 418,005 Asset-backed securities — 124,046 124,046 U.S. Treasury securities — 94,731 94,731 Money market funds 70,455 — 70,455 Commercial paper — 13,548 13,548 Certificates of deposit and time deposits — 1,144 1,144 Agency securities — 920 920 Total $ 70,455 $ 652,394 $ 722,849 Included in cash and cash equivalents $ 73,943 Included in marketable securities $ 648,906
Schedule of Marketable Securities Classified by Contractual Maturity	The following table classifies our marketable securities by contractual maturity (in thousands): March 31, December 31, Due in one year or less $ 269,003 $ 286,958 Due after one year and within five years 369,091 361,948 Total $ 638,094 $ 648,906
Schedule of Derivative Instruments on Consolidated Balance Sheets	The following tables present information about our derivative instruments on our consolidated balance sheets (in thousands): March 31, 2020 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 $ 3,852 Accrued liabilities $ 10,751 Total $ 3,852 $ 10,751 December 31, 2019 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 $ 2,385 Accrued liabilities $ 1,975 Total $ 2,385 $ 1,975
Schedule of Derivative Instruments on Statement of Operations	The following table presents information about our foreign currency forward contracts on our condensed consolidated statements of operations for the three months ended March 31, 2020 and 2019 (in thousands): Gain (Loss) Reclassified from AOCI into Earnings Three Months Ended March 31, Classification 2020 2019 Revenue $ 397 $ 443 Cost of revenue (321 ) (474 ) Research and development (281 ) (434 ) Sales and marketing (562 ) (790 ) General and administrative (174 ) (276 ) Total $ (941 ) $ (1,531 )

Property and Equipment (Tables)

Property and Equipment (Tables)	3 Months Ended
	Mar. 31, 2020
Property, Plant and Equipment [Abstract]
Components of Property and Equipment	Property and equipment, net consists of the following (in thousands): March 31, December 31, Leasehold improvements $ 86,593 $ 83,968 Capitalized internal-use software 40,647 38,437 Computer equipment and licensed software and patents 28,539 27,309 Furniture and fixtures 17,072 16,332 Construction in progress 10,337 8,647 Total 183,188 174,693 Less: accumulated depreciation and amortization (80,171 ) (72,603 ) Property and equipment, net $ 103,017 $ 102,090

Leases (Tables)

Leases (Tables)	3 Months Ended
	Mar. 31, 2020
Leases [Abstract]
Schedule of Lease Impact on Balance Sheet	The following tables present information about leases on our consolidated balance sheet (in thousands): March 31, 2020 December 31, 2019 Assets Lease right-of-use assets $ 96,307 $ 89,983 Liabilities Lease liabilities 21,253 21,804 Lease liabilities, noncurrent 86,535 83,478
Schedule of Lease Cost and Supplemental Cash Flow Information	The following table presents information about leases on our consolidated statement of operations (in thousands): Three Months Ended March 31, 2020 2019 Operating lease expense $ 6,343 $ 5,045 Short-term lease expense 185 874 Variable lease expense 1,543 885 Sublease income (464 ) (401 ) The following table presents supplemental cash flow information about our leases (in thousands): Three Months Ended March 31, 2020 2019 Cash paid for amounts included in the measurement of lease liabilities $ 9,552 $ 4,176 Operating lease assets obtained in exchange for new lease liabilities 11,316 19,550
Schedule of Maturities of Leases	As of March 31, 2020 , remaining maturities of lease liabilities are as follows: Remainder of 2020 $ 18,460 2021 26,074 2022 23,744 2023 16,079 2024 7,357 Thereafter 32,748 Total lease payments 124,462 Less imputed interest 16,674 Total $ 107,788

Goodwill and Acquired Intangi_2

Goodwill and Acquired Intangible Assets (Tables)	3 Months Ended
	Mar. 31, 2020
Goodwill and Intangible Assets Disclosure [Abstract]
Schedule of Carrying Amount of Goodwill	The changes in the carrying amount of goodwill for the three months ended March 31, 2020 are as follows (in thousands): Balance as of December 31, 2019 $ 169,647 Goodwill adjustments 15 Balance as of March 31, 2020 $ 169,662
Summary of Intangible Assets Acquired	Acquired intangible assets subject to amortization consist of the following (in thousands): As of March 31, 2020 Cost Accumulated Amortization Net Weighted Average Remaining Useful Life (In years) Developed technology $ 39,000 $ (16,197 ) $ 22,803 4.7 Customer relationships 15,210 (4,582 ) 10,628 4.6 Backlog 3,200 (2,200 ) 1,000 0.8 $ 57,410 $ (22,979 ) $ 34,431 As of December 31, 2019 Cost Accumulated Amortization Net Weighted Average Remaining Useful Life (In years) Developed technology $ 39,000 $ (14,492 ) $ 24,508 4.9 Customer relationships 15,210 (3,882 ) 11,328 4.8 Backlog 3,200 (1,800 ) 1,400 1.0 $ 57,410 $ (20,174 ) $ 37,236
Summary of Estimated Future Amortization Expense	Estimated future amortization expense as of March 31, 2020 is as follows (in thousands): Remainder of 2020 $ 6,505 2021 7,600 2022 7,435 2023 6,656 2024 4,615 Thereafter 1,620 $ 34,431

0.25% Convertible Senior Note_2

0.25% Convertible Senior Notes and Capped Call (Tables)	3 Months Ended
	Mar. 31, 2020
Debt Disclosure [Abstract]
Schedule of Net Carrying Amount of Liability and Equity Component of Convertible Notes	The net impact to our stockholders' equity, included in additional paid-in capital, of the above components of the Notes is as follows (in thousands): Conversion Option $ 124,976 Purchase of Capped Calls (63,940 ) Issuance costs (2,948 ) Net deferred tax liability (13,784 ) Total $ 44,304 The net carrying amount of the liability component of the Notes is as follows (in thousands): March 31, December 31, Principal $ 575,000 $ 575,000 Unamortized Debt Discount (77,979 ) (84,037 ) Unamortized issuance costs (7,007 ) (7,499 ) Net carrying amount $ 490,014 $ 483,464 The net carrying amount of the equity component of the Notes is as follows (in thousands): March 31, December 31, Debt Discount for Conversion Option $ 124,976 $ 124,976 Issuance costs (2,948 ) (2,948 ) Net carrying amount $ 122,028 $ 122,028
Schedule of Interest Expense	Interest expense related to the Notes is as follows (in thousands): Three Months Ended March 31, 2020 2019 Contractual interest expense $ 359 $ 356 Amortization of Debt Discount 6,057 5,751 Amortization of issuance costs 492 437 Total interest expense $ 6,908 $ 6,544

Common Stock and Stockholders_2

Common Stock and Stockholders' Equity (Tables)	3 Months Ended
	Mar. 31, 2020
Equity [Abstract]
Summary of Stock Option and RSU Award Activity	A summary of our share-based award activity for the three months ended March 31, 2020 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 Aggregate Intrinsic Value (In years) Outstanding — January 1, 2020 11,613 4,860 $ 24.08 5.85 $ 255,536 5,361 $ 55.00 $ 410,804 Increase in authorized shares 5,654 Stock options granted (456 ) 456 88.73 RSUs granted (1,398 ) 1,398 83.85 Stock options exercised (175 ) 22.93 RSUs vested (694 ) 49.96 Stock options forfeited or canceled 12 (12 ) 30.18 RSUs forfeited or canceled 212 (212 ) 55.23 RSUs forfeited or canceled and unavailable for grant (7 ) 23.44 PRSUs forfeited 25 Outstanding — March 31, 2020 15,662 5,129 $ 29.85 5.97 $ 189,715 5,846 $ 62.53 $ 374,201

Deferred Revenue and Performa_2

Deferred Revenue and Performance Obligations (Tables)	3 Months Ended
	Mar. 31, 2020
Revenue from Contract with Customer [Abstract]
Schedule of Changes in Balance of Deferred Revenue	The changes in the balances of deferred revenue are as follows (in thousands): Three Months Ended March 31, 2020 2019 Balance, beginning of period $ 323,962 $ 247,962 Billings 216,856 193,118 Subscription and services revenue (224,059 ) (172,852 ) Other revenue* (13,416 ) (8,632 ) Balance, end of period $ 303,343 $ 259,596 *Other revenue primarily includes implementation and training services, Talk usage, and amounts from contract assets.

Net Loss Per Share (Tables)

Net Loss Per Share (Tables)	3 Months Ended
	Mar. 31, 2020
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 2020 2019 Net loss $ (42,783 ) $ (44,720 ) Weighted-average shares used to compute basic and diluted net loss per share 113,538 108,630 Net loss per share, basic and diluted $ (0.38 ) $ (0.41 )
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 March 31, 2020 2019 Shares subject to outstanding common stock options and employee stock purchase plan 5,429 6,167 Restricted stock units 5,846 7,028 Shares related to convertible senior notes 1,749 1,283 13,024 14,478

Geographic Information (Tables)

Geographic Information (Tables)	3 Months Ended
	Mar. 31, 2020
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 2020 2019 United States $ 124,037 $ 94,901 EMEA 67,919 52,075 APAC 25,575 19,476 Other 19,944 15,032 Total $ 237,475 $ 181,484
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 $ 98,152 $ 91,532 EMEA: Republic of Ireland 41,210 42,500 Other EMEA 3,274 3,725 Total EMEA 44,484 46,225 APAC: Singapore 24,393 25,988 Other APAC 7,119 5,362 Total APAC 31,512 31,350 Other 471 417 Total $ 174,619 $ 169,524

Overview and Basis of Present_3

Overview and Basis of Presentation - (Details) - USD ($) $ in Millions	Mar. 31, 2020	Dec. 31, 2019
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Allowance for doubtful accounts	$ 6	$ 3

Business Combinations - Narrati

Business Combinations - Narrative (Details) - Smooch Technologies Holding ULC - USD ($) $ in Millions	May 14, 2019	Jun. 30, 2019
Business Acquisition [Line Items]
Cash consideration	$ 72
Transaction costs associated with transaction		$ 3
Share based compensation expense as a result of acquisition		$ 5
Amortization period for goodwill acquired and eligible for income tax deductions	15 years
Developed technology
Business Acquisition [Line Items]
Acquired intangible assets weighted average useful life	5 years 6 months
Customer relationships
Business Acquisition [Line Items]
Acquired intangible assets weighted average useful life	8 years
Backlog
Business Acquisition [Line Items]
Acquired intangible assets weighted average useful life	2 years

Business Combinations - Summary

Business Combinations - Summary of Assets Acquired and Liabilities Assumed (Details) - USD ($) $ in Thousands	Mar. 31, 2020	Dec. 31, 2019	May 14, 2019
Business Acquisition [Line Items]
Goodwill	$ 169,662	$ 169,647
Smooch Technologies Holding ULC
Business Acquisition [Line Items]
Net tangible assets			$ 1,974
Net deferred tax liability			(1,194)
Goodwill			58,317
Total purchase price			71,997
Developed technology | Smooch Technologies Holding ULC
Business Acquisition [Line Items]
Identifiable intangible assets:			8,000
Customer relationships | Smooch Technologies Holding ULC
Business Acquisition [Line Items]
Identifiable intangible assets:			3,900
Backlog | Smooch Technologies Holding ULC
Business Acquisition [Line Items]
Identifiable intangible assets:			$ 1,000

Financial Instruments - Financi

Financial Instruments - Financial Assets Measured at Fair Value on Recurring Basis (Details) - USD ($) $ in Thousands	Mar. 31, 2020	Dec. 31, 2019
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Included in marketable securities	$ 638,094	$ 648,906
Fair Value Measurements, Recurring
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Total fair value of financial assets	764,030	722,849
Included in cash and cash equivalents	125,936	73,943
Included in marketable securities	638,094	648,906
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	401,130	418,005
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	125,936	70,455
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	118,816	124,046
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	78,854	94,731
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	26,670	920
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	12,624	13,548
Fair Value Measurements, Recurring | Certificates of deposit and time deposits
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Total fair value of financial assets		1,144
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	125,936	70,455
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	125,936	70,455
Fair Value Measurements, Recurring | Level 1 | Asset-backed securities
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 | U.S. Treasury securities
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 | Agency securities
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 | Commercial paper
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 | Certificates of deposit and time deposits
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Total fair value of financial assets		0
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	638,094	652,394
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	401,130	418,005
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
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	118,816	124,046
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	78,854	94,731
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	26,670	920
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	$ 12,624	13,548
Fair Value Measurements, Recurring | Level 2 | Certificates of deposit and time deposits
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Total fair value of financial assets		$ 1,144

Financial Instruments - Narrati

Financial Instruments - Narrative (Details) - USD ($)	3 Months Ended		12 Months Ended
	Mar. 31, 2020	Mar. 31, 2019	Dec. 31, 2019	Dec. 31, 2018
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Gross unrealized gains	$ 3,000,000		$ 4,000,000
Gross unrealized losses	2,000,000		0
Amortized cost of cash equivalents and marketable securities	763,000,000		719,000,000
Accrued interest	3,000,000		4,000,000
Aggregate fair value of securities with unrealized losses	246,000,000		45,000,000
Unrealized losses recognized by securities in continuous loss position for twelve months or longer	0		0
Allowance for credit losses	0		0
Balance of strategic investment	12,000,000		11,000,000
Adjustments to carrying value of strategic investments	0
Unrealized loss in accumulated other comprehensive loss	(449,943,000)	$ (418,945,000)	(457,984,000)	$ (416,921,000)
Cash collateral posted	$ 0		0
Closing price of common stock (usd per share)	$ 64.01
Level 3
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Fair value of financial assets	$ 0		0
Shares related to convertible senior notes | Convertible Debt
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Convertible debt, if-convertible value in excess of principal amount	575,000,000
Shares related to convertible senior notes | Convertible Debt | Level 2
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Fair value	686,000,000
Foreign Currency Forward Contracts
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Reclassification of net loss	7,000,000
Notional value	318,000,000		$ 260,000,000
Gain (loss) recognized in AOCI	$ (8,000,000)	$ 0
Foreign Currency Forward Contracts | Maximum
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Derivative, maturity	15 months
AOCI, Derivative Qualifying as Hedge, Excluded Component, Parent | Foreign Currency Forward Contracts
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Unrealized loss in accumulated other comprehensive loss	$ (6,000,000)

Financial Instruments - Marketa

Financial Instruments - Marketable Securities by Contractual Maturity (Details) - USD ($) $ in Thousands	Mar. 31, 2020	Dec. 31, 2019
Fair Value Disclosures [Abstract]
Due in one year or less	$ 269,003	$ 286,958
Due after one year and within five years	369,091	361,948
Total	$ 638,094	$ 648,906

Financial Instruments - Schedul

Financial Instruments - Schedule of Derivative Instruments on Consolidated Balance Sheets (Details) - Designated as Hedging Instrument - Level 2 - USD ($) $ in Thousands	Mar. 31, 2020	Dec. 31, 2019
Derivatives Fair Value [Line Items]
Asset Derivatives	$ 3,852	$ 2,385
Liability Derivatives	10,751	1,975
Foreign Currency Forward Contracts | Other current assets
Derivatives Fair Value [Line Items]
Asset Derivatives	3,852	2,385
Foreign Currency Forward Contracts | Accrued liabilities
Derivatives Fair Value [Line Items]
Liability Derivatives	$ 10,751	$ 1,975

Financial Instruments - Sched_2

Financial Instruments - Schedule of Derivative Instruments on Statement of Operations (Details) - Foreign Currency Forward Contracts - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2020	Mar. 31, 2019
Derivative Instruments Gain Loss [Line Items]
Gain (Loss) Reclassified from AOCI into Earnings	$ (941)	$ (1,531)
Revenue
Derivative Instruments Gain Loss [Line Items]
Gain (Loss) Reclassified from AOCI into Earnings	397	443
Cost of revenue
Derivative Instruments Gain Loss [Line Items]
Gain (Loss) Reclassified from AOCI into Earnings	(321)	(474)
Research and development
Derivative Instruments Gain Loss [Line Items]
Gain (Loss) Reclassified from AOCI into Earnings	(281)	(434)
Sales and marketing
Derivative Instruments Gain Loss [Line Items]
Gain (Loss) Reclassified from AOCI into Earnings	(562)	(790)
General and administrative
Derivative Instruments Gain Loss [Line Items]
Gain (Loss) Reclassified from AOCI into Earnings	$ (174)	$ (276)

Costs to Obtain Customer Cont_2

Costs to Obtain Customer Contracts (Details) - USD ($)	3 Months Ended
	Mar. 31, 2020	Mar. 31, 2019	Dec. 31, 2019
Revenue from Contract with Customer [Abstract]
Deferred costs to obtain customer contracts	$ 75,000,000		$ 71,000,000
Amortization of deferred costs	9,965,000	$ 6,918,000
Impairment related to deferred costs	$ 0	$ 0

Property and Equipment - Compon

Property and Equipment - Components of Property and Equipment (Details) - USD ($) $ in Thousands	Mar. 31, 2020	Dec. 31, 2019
Property, Plant and Equipment [Line Items]
Total	$ 183,188	$ 174,693
Less: accumulated depreciation and amortization	(80,171)	(72,603)
Property and equipment, net	103,017	102,090
Leasehold improvements
Property, Plant and Equipment [Line Items]
Total	86,593	83,968
Capitalized internal-use software
Property, Plant and Equipment [Line Items]
Total	40,647	38,437
Computer equipment and licensed software and patents
Property, Plant and Equipment [Line Items]
Total	28,539	27,309
Furniture and fixtures
Property, Plant and Equipment [Line Items]
Total	17,072	16,332
Construction in progress
Property, Plant and Equipment [Line Items]
Total	$ 10,337	$ 8,647

Property and Equipment - Narrat

Property and Equipment - Narrative (Details) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2020	Mar. 31, 2019	Dec. 31, 2019
Property, Plant and Equipment [Abstract]
Depreciation expense	$ 7	$ 5
Amortization expense of capitalized internal-use software	2	$ 2
Carrying value of capitalized internal-use software	25		$ 23
Capitalized internal-use software included in construction in progress	$ 8		$ 9

Leases - Schedule of Lease Impa

Leases - Schedule of Lease Impact on Balance Sheet (Details) - USD ($) $ in Thousands	Mar. 31, 2020	Dec. 31, 2019	Mar. 31, 2019
Assets
Lease right-of-use assets	$ 96,307	$ 89,983	$ 99,000
Liabilities
Lease liabilities	21,253	21,804
Lease liabilities, noncurrent	$ 86,535	$ 83,478

Leases - Narrative (Details)

Leases - Narrative (Details) $ in Millions	Mar. 31, 2020USD ($)
Leases [Abstract]
Weighted average remaining lease term	6 years 2 months 12 days
Weighted average discount rate	4.90%
Operating lease payments for leases that have not yet commenced	$ 10

Leases - Schedule of Lease Cost

Leases - Schedule of Lease Cost (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2020	Mar. 31, 2019
Leases [Abstract]
Operating lease expense	$ 6,343	$ 5,045
Short-term lease expense	185	874
Variable lease expense	1,543	885
Sublease income	$ (464)	$ (401)

Leases - Schedule of Supplement

Leases - Schedule of Supplemental Cash Flow Information (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2020	Mar. 31, 2019
Leases [Abstract]
Cash paid for amounts included in the measurement of lease liabilities	$ 9,552	$ 4,176
Operating lease assets obtained in exchange for new lease liabilities	$ 11,316	$ 19,550

Leases - Schedule of Maturities

Leases - Schedule of Maturities of Leases (Details) - USD ($) $ in Thousands	Mar. 31, 2020	Mar. 31, 2019
Lessee, Operating Lease, Liability, Payment, Due [Abstract]
Remainder of 2020	$ 18,460
2021	26,074
2022	23,744
2023	16,079
2024	7,357
Thereafter	32,748
Total lease payments	124,462
Less imputed interest	16,674
Total	$ 107,788	$ 114,000

Goodwill and Acquired Intangi_3

Goodwill and Acquired Intangible Assets - Schedule of Carrying Amount of Goodwill (Details) $ in Thousands	3 Months Ended
	Mar. 31, 2020USD ($)
Goodwill [Roll Forward]
Balance as of December 31, 2019	$ 169,647
Goodwill adjustments	15
Balance as of March 31, 2020	$ 169,662

Goodwill and Acquired Intangi_4

Goodwill and Acquired Intangible Assets - Acquired Intangible Assets Subject to Amortization (Details) - USD ($) $ in Thousands	3 Months Ended	12 Months Ended
	Mar. 31, 2020	Dec. 31, 2019
Finite Lived Intangible Assets [Line Items]
Cost	$ 57,410	$ 57,410
Accumulated Amortization	(22,979)	(20,174)
Net	34,431	37,236
Developed technology
Finite Lived Intangible Assets [Line Items]
Cost	39,000	39,000
Accumulated Amortization	(16,197)	(14,492)
Net	$ 22,803	$ 24,508
Weighted Average Remaining Useful Life	4 years 8 months 12 days	4 years 10 months 24 days
Customer relationships
Finite Lived Intangible Assets [Line Items]
Cost	$ 15,210	$ 15,210
Accumulated Amortization	(4,582)	(3,882)
Net	$ 10,628	$ 11,328
Weighted Average Remaining Useful Life	4 years 7 months 6 days	4 years 9 months 18 days
Backlog
Finite Lived Intangible Assets [Line Items]
Cost	$ 3,200	$ 3,200
Accumulated Amortization	(2,200)	(1,800)
Net	$ 1,000	$ 1,400
Weighted Average Remaining Useful Life	24 days	1 year

Goodwill and Acquired Intangi_5

Goodwill and Acquired Intangible Assets - Narrative (Details) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2020	Mar. 31, 2019
Goodwill and Intangible Assets Disclosure [Abstract]
Amortization expense	$ 3	$ 2

Goodwill and Acquired Intangi_6

Goodwill and Acquired Intangible Assets - Estimated Future Amortization Expense (Details) - USD ($) $ in Thousands	Mar. 31, 2020	Dec. 31, 2019
Goodwill and Intangible Assets Disclosure [Abstract]
Remainder of 2020	$ 6,505
2021	7,600
2022	7,435
2023	6,656
2024	4,615
Thereafter	1,620
Total estimated future amortization expense	$ 34,431	$ 37,236

0.25% Convertible Senior Note_3

0.25% Convertible Senior Notes and Capped Call - Narrative (Details) - Convertible Debt - Shares related to convertible senior notes $ / shares in Units, shares in Millions	1 Months Ended	3 Months Ended
	Mar. 31, 2018USD ($)day$ / sharesshares	Mar. 31, 2020USD ($)	Dec. 31, 2019USD ($)
Debt Instrument [Line Items]
Aggregate principal amount	$ 575,000,000
Interest rate	0.25%
Proceeds from issuance of convertible senior notes, net of issuance costs	$ 561,000,000
Initial conversion rate of common stock		0.0158554
Conversion price (usd per share) | $ / shares	$ 63.07
Limitation on sale of common stock, sale price threshold, number of trading days | day	20
Limitation on sale of common stock, sale price threshold, trading period | day	30
Threshold percentage of stock price trigger	130.00%
Number of consecutive business days	5 days
Percentage of closing sale price in excess of convertible notes	98.00%
Redemption price percentage	100.00%
Conversion Option	$ 125,000,000	$ 124,976,000	$ 124,976,000
Effective interest rate		5.26%
Debt issuance costs, gross		$ 14,000,000
Issuance costs attributable to the liability component	$ 11,000,000	7,007,000	$ 7,499,000
Capped calls, initial cap price (in usd per share) | $ / shares	$ 95.20
Number of shares covered by cap call (in shares) | shares	9.1
Cost incurred related to capped calls	$ (64,000,000)	(44,304,000)
Net deferred tax liability related to cap call		$ 13,784,000

0.25% Convertible Senior Note_4

0.25% Convertible Senior Notes and Capped Call - Schedule of Net Carrying Amount of Liability and Equity Component of Convertible Notes (Details) - Convertible Debt - Shares related to convertible senior notes - USD ($) $ in Thousands	Mar. 31, 2020	Dec. 31, 2019	Mar. 31, 2018
Net Carrying Amount of Liability Component of Convertible Notes [Abstract]
Principal	$ 575,000	$ 575,000
Unamortized Debt Discount	(77,979)	(84,037)
Unamortized issuance costs	(7,007)	(7,499)	$ (11,000)
Net carrying amount	490,014	483,464
Net Carrying Amount of Equity Component of Convertible Notes [Abstract]
Debt Discount for Conversion Option	124,976	124,976	$ 125,000
Issuance costs	(2,948)	(2,948)
Net carrying amount	$ 122,028	$ 122,028

0.25% Convertible Senior Note_5

0.25% Convertible Senior Notes and Capped Call - Schedule of Interest Expense (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2020	Mar. 31, 2019
Debt Instrument [Line Items]
Total interest expense	$ 6,887	$ 6,544
Convertible Debt | Shares related to convertible senior notes
Debt Instrument [Line Items]
Contractual interest expense	359	356
Amortization of Debt Discount	6,057	5,751
Amortization of issuance costs	492	437
Total interest expense	$ 6,908	$ 6,544

0.25% Convertible Senior Note_6

0.25% Convertible Senior Notes and Capped Call - Summary of Impact to Stockholder's Equity (Details) - Convertible Debt - Shares related to convertible senior notes - USD ($) $ in Thousands	1 Months Ended	3 Months Ended
	Mar. 31, 2018	Mar. 31, 2020	Dec. 31, 2019
Debt Instrument [Line Items]
Conversion Option	$ 125,000	$ 124,976	$ 124,976
Purchase of Capped Calls		(63,940)
Issuance costs		(2,948)	$ (2,948)
Net deferred tax liability		(13,784)
Net impact to stockholder's equity	$ 64,000	$ 44,304

Common Stock and Stockholders_3

Common Stock and Stockholders' Equity - Narrative (Details) $ / shares in Units, $ in Millions	Jan. 01, 2020shares	May 06, 2016shares	Mar. 31, 2020USD ($)number_of_semi_annual_tranchesoffering_period$ / sharesshares	Mar. 31, 2019USD ($)$ / sharesshares	Dec. 31, 2019$ / sharesshares
Class Of Stock [Line Items]
Common stock, shares authorized (in shares)			400,000,000		400,000,000
Common stock, par value (usd per share) | $ / shares			$ 0.01		$ 0.01
Common stock, shares issued (in shares)			114,000,000		113,100,000
Common stock, shares outstanding (in shares)			114,000,000		113,100,000
Preferred stock, shares authorized (in shares)			10,000,000		10,000,000
Preferred stock, par value (usd per share) | $ / shares			$ 0.01		$ 0.01
Preferred stock, shares issued (in shares)			0		0
Preferred stock, shares outstanding (in shares)			0		0
Increase in authorized shares (in shares)			5,654,000
Shares of common stock available for issuance (in shares)			15,662,000		11,613,000
Stock options granted (in shares)		1,200,000	456,000
Intrinsic value of options exercised (usd per share) | $			$ 10	$ 21
Weighted-average grant date fair value of stock options (usd per share) | $ / shares			$ 31.63	$ 28.65
Future period share-based compensation expense | $			$ 385
Future period share-based compensation expense, period to recognized			2 years 10 months 24 days
Employee Stock Option
Class Of Stock [Line Items]
Offering period			18 months
Number of offering periods | offering_period			3,000
Length of purchase period			6 months
Restricted Stock Units
Class Of Stock [Line Items]
Intrinsic value of shares vested | $			$ 55	$ 63
Weighted average grant date fair value (usd per share) | $ / shares			$ 83.85	$ 64.88
Shares granted (in shares)			1,398,000
Number of shares vested (in shares)			694,000
Performance Restricted Stock Units
Class Of Stock [Line Items]
Number of vesting periods | number_of_semi_annual_tranches			4
2009 Stock Option and Grant Plan
Class Of Stock [Line Items]
Shares of common stock available for issuance (in shares)			0
2014 Plan | Employee Stock Option
Class Of Stock [Line Items]
Increase in authorized shares (in shares)	5,700,000
Shares of common stock available for issuance (in shares)			15,700,000
PSU Retention Plan | Performance Restricted Stock Units
Class Of Stock [Line Items]
Shares granted (in shares)				200,000
Share-based compensation expense | $			$ 1	$ 1
Number of shares vested (in shares)			26,000	0
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%
Increase in authorized shares (in shares)	1,100,000
Shares of common stock available for issuance (in shares)			5,500,000

Common Stock and Stockholders_4

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	Mar. 31, 2020	Mar. 31, 2019	Dec. 31, 2019
Shares Available for Grant
Outstanding at beginning of period (in shares)		11,613
Increase in authorized shares (in shares)		5,654
Stock options granted (in shares)		(456)
Granted (in shares)		(1,398)
Stock options forfeited or canceled (in shares)		12
Forfeited or canceled (in shares)		212
Outstanding at end of period (in shares)		15,662		11,613
Number of Shares
Balance at the beginning of the period (in shares)		4,860
Stock options granted (in shares)	1,200	456
Stock options exercised (in shares)		(175)
Stock options forfeited or canceled (in shares)		(12)
Balance at the end of the period (in shares)		5,129		4,860
Weighted Average Exercise Price
Balance at the beginning of the period (usd per share)		$ 24.08
Stock options granted (usd per share)		88.73
Stock options exercised (usd per share)		22.93
Stock options forfeited or canceled (usd per share)		30.18
Balance at the end of the period (usd per share)		$ 29.85		$ 24.08
Weighted Average Remaining Contractual Term
Weighted average remaining contractual term		5 years 11 months 19 days		5 years 10 months 6 days
Aggregate Intrinsic Value
Aggregate intrinsic value, options		$ 189,715		$ 255,536
Aggregate intrinsic value, restricted stock units		$ 374,201		$ 410,804
Restricted Stock Units
Outstanding RSUs
Balance at the beginning of the period (in shares)		5,361
RSUs granted (in shares)		1,398
RSUs vested (in shares)		(694)
RSUs forfeited or canceled (in shares)		(212)
RSUs forfeited and unavailable for grant (in shares)		(7)
Balance at the end of the period (in shares)		5,846		5,361
Weighted Average Grant Date Fair Value
Balance at the beginning of the period (usd per share)		$ 55
Weighted average grant date fair value, RSUs granted (usd per share)		83.85	$ 64.88
Weighted average grant date fair value, RSUs vested (usd per share)		49.96
Weighted average grant date fair value, RSUs forfeited or canceled (usd per share)		55.23
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)		$ 62.53		$ 55
Performance Restricted Stock Units
Shares Available for Grant
Forfeited or canceled (in shares)		25

Deferred Revenue and Performa_3

Deferred Revenue and Performance Obligations - Schedule of Changes in Balance of Deferred Revenue (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2020	Mar. 31, 2019
Change in Contract with Customer, Liability [Abstract]
Balance, beginning of period	$ 323,962	$ 247,962
Billings	216,856	193,118
Subscription and services revenue	(224,059)	(172,852)
Other revenue	(13,416)	(8,632)
Balance, end of period	$ 303,343	$ 259,596

Deferred Revenue and Performa_4

Deferred Revenue and Performance Obligations - Performance Obligations (Details) $ in Millions	Mar. 31, 2020USD ($)
Revenue from Contract with Customer [Abstract]
Performance obligations expected to be satisfied	$ 673
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2020-04-01
Revenue from Contract with Customer [Abstract]
Performance obligations expected to be satisfied	$ 489
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items]
Performance obligations expected to be satisfied, expected timing	1 year

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
	Mar. 31, 2020	Mar. 31, 2019
Earnings Per Share [Abstract]
Net loss	$ (42,783)	$ (44,720)
Weighted-average shares used to compute basic and diluted net loss per share (in shares)	113,538	108,630
Net loss per share, basic and diluted (usd per share)	$ (0.38)	$ (0.41)

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	3 Months Ended
	Mar. 31, 2020	Mar. 31, 2019
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Antidilutive securities excluded from computation of earnings per share amount (in shares)	13,024	14,478
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)	5,429	6,167
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)	5,846	7,028
Shares related to convertible senior notes
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Antidilutive securities excluded from computation of earnings per share amount (in shares)	1,749	1,283

Net Loss Per Share - Narrative

Net Loss Per Share - Narrative (Details) - $ / shares shares in Millions	3 Months Ended
	Mar. 31, 2020	Mar. 31, 2018
Debt Instrument [Line Items]
Potential dilution based on initial conversion price (in shares)	9.1
Convertible Debt | Shares related to convertible senior notes
Debt Instrument [Line Items]
Conversion price (usd per share)		$ 63.07

Income Taxes - Narrative (Detai

Income Taxes - Narrative (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2020	Mar. 31, 2019
Income Tax Disclosure [Abstract]
Income tax expense (benefit)	$ 1,516	$ 434

Geographic Information - Narrat

Geographic Information - Narrative (Details)	3 Months Ended
	Mar. 31, 2020segment
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
	Mar. 31, 2020	Mar. 31, 2019
Revenues From External Customers And Long Lived Assets [Line Items]
Revenue	$ 237,475	$ 181,484
United States
Revenues From External Customers And Long Lived Assets [Line Items]
Revenue	124,037	94,901
EMEA
Revenues From External Customers And Long Lived Assets [Line Items]
Revenue	67,919	52,075
APAC
Revenues From External Customers And Long Lived Assets [Line Items]
Revenue	25,575	19,476
Other
Revenues From External Customers And Long Lived Assets [Line Items]
Revenue	$ 19,944	$ 15,032

Geographic Information - Sche_2

Geographic Information - Schedule of Long-Lived Assets by Geographic Areas (Details) - USD ($) $ in Thousands	Mar. 31, 2020	Dec. 31, 2019
Revenues From External Customers And Long Lived Assets [Line Items]
Long-lived assets	$ 174,619	$ 169,524
United States
Revenues From External Customers And Long Lived Assets [Line Items]
Long-lived assets	98,152	91,532
Republic of Ireland
Revenues From External Customers And Long Lived Assets [Line Items]
Long-lived assets	41,210	42,500
Other EMEA
Revenues From External Customers And Long Lived Assets [Line Items]
Long-lived assets	3,274	3,725
EMEA
Revenues From External Customers And Long Lived Assets [Line Items]
Long-lived assets	44,484	46,225
Singapore
Revenues From External Customers And Long Lived Assets [Line Items]
Long-lived assets	24,393	25,988
Other APAC
Revenues From External Customers And Long Lived Assets [Line Items]
Long-lived assets	7,119	5,362
APAC
Revenues From External Customers And Long Lived Assets [Line Items]
Long-lived assets	31,512	31,350
Other
Revenues From External Customers And Long Lived Assets [Line Items]
Long-lived assets	$ 471	$ 417

Uncategorized Items - zen10-qq1

Label	Element	Value
Restricted Cash, Noncurrent	us-gaap_RestrictedCashNoncurrent	$ 719,000
Restricted Cash, Noncurrent	us-gaap_RestrictedCashNoncurrent	723,000
Restricted Cash, Current	us-gaap_RestrictedCashCurrent	1,891,000
Restricted Cash, Current	us-gaap_RestrictedCashCurrent	$ 2,797,000