Five9 (FIVN) 10-Q 27 Jul 21 2021 Q2 Quarterly report Financial data

Cover Page

Cover Page - shares	6 Months Ended
	Jun. 30, 2021	Jul. 23, 2021
Cover [Abstract]
Document Type	10-Q
Document Quarterly Report	true
Document Period End Date	Jun. 30, 2021
Document Transition Report	false
Entity File Number	001-36383
Entity Registrant Name	Five9, Inc.
Entity Incorporation, State or Country Code	DE
Entity Tax Identification Number	94-3394123
Entity Address, Address Line One	3001 Bishop Drive
Entity Address, Address Line Two	Suite 350
Entity Address, City or Town	San Ramon
Entity Address, State or Province	CA
Entity Address, Postal Zip Code	94583
City Area Code	925
Local Phone Number	201-2000
Title of 12(b) Security	Common stock, par value $0.001 per share
Trading Symbol	FIVN
Security Exchange Name	NASDAQ
Entity Current Reporting Status	Yes
Entity Interactive Data Current	Yes
Entity Filer Category	Large Accelerated Filer
Entity Small Business	false
Entity Emerging Growth Company	false
Entity Shell Company	false
Entity Common Stock, Shares Outstanding		67,699,681
Entity Central Index Key	0001288847
Current Fiscal Year End Date	--12-31
Document Fiscal Year Focus	2021
Document Fiscal Period Focus	Q2
Amendment Flag	false

Condensed Consolidated Balance

Condensed Consolidated Balance Sheets - USD ($) $ in Thousands	Jun. 30, 2021	Dec. 31, 2020
Current assets:
Cash and cash equivalents	$ 175,199	$ 220,372
Marketable investments	390,986	383,171
Accounts receivable, net	53,811	48,731
Prepaid expenses and other current assets	22,110	16,149
Deferred contract acquisition costs, net	26,791	20,695
Total current assets	668,897	689,118
Property and equipment, net	63,107	51,213
Operating lease right-of-use assets	46,966	9,010
Intangible assets, net	45,790	51,684
Goodwill	165,420	165,420
Marketable investments	72,758	42,127
Other assets	3,089	3,236
Deferred contract acquisition costs, net — less current portion	69,689	51,934
Total assets	1,135,716	1,063,742
Current liabilities:
Accounts payable	17,632	17,145
Accrued and other current liabilities	74,024	44,450
Operating lease liabilities	7,758	3,912
Accrued federal fees	5,138	3,745
Sales tax liabilities	1,588	1,714
Finance lease liabilities	36	612
Deferred revenue	33,237	31,983
Total current liabilities	139,413	103,561
Convertible senior notes	773,588	643,316
Sales tax liabilities — less current portion	867	857
Operating lease liabilities — less current portion	46,029	5,379
Other long-term liabilities	13,113	31,465
Total liabilities	973,010	784,578
Commitments and contingencies
Stockholders’ equity:
Common stock	68	67
Additional paid-in capital	366,637	476,941
Accumulated other comprehensive income	299	335
Accumulated deficit	(204,298)	(198,179)
Total stockholders’ equity	162,706	279,164
Total liabilities and stockholders’ equity	$ 1,135,716	$ 1,063,742

Condensed Consolidated Statemen

Condensed Consolidated Statements of Operations and Comprehensive Loss (Unaudited) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2021	Jun. 30, 2020	Jun. 30, 2021	Jun. 30, 2020
Income Statement [Abstract]
Revenue	$ 143,782	$ 99,792	$ 281,664	$ 194,880
Cost of revenue	64,395	42,453	124,198	82,490
Gross profit	79,387	57,339	157,466	112,390
Operating expenses:
Research and development	24,648	17,208	46,769	32,397
Sales and marketing	46,024	32,231	90,823	62,391
General and administrative	22,909	16,129	45,154	30,787
Total operating expenses	93,581	65,568	182,746	125,575
Loss from operations	(14,194)	(8,229)	(25,280)	(13,185)
Other (expense) income, net:
Interest expense	(2,118)	(5,734)	(4,056)	(9,218)
Loss on early extinguishment of debt	0	(5,794)	0	(5,794)
Other (expense) and interest income	(353)	829	(178)	1,901
Total other (expense) income, net	(2,471)	(10,699)	(4,234)	(13,111)
Loss before income taxes	(16,665)	(18,928)	(29,514)	(26,296)
Benefit from income taxes	(135)	(2,876)	(652)	(2,807)
Net loss	$ (16,530)	$ (16,052)	$ (28,862)	$ (23,489)
Net loss per share:
Basic (in USD per share)	$ (0.25)	$ (0.25)	$ (0.43)	$ (0.38)
Diluted (in USD per share)	$ (0.25)	$ (0.25)	$ (0.43)	$ (0.38)
Shares used in computing net loss per share:
Basic (in shares)	67,292,000	63,282,000	67,008,000	62,494,000
Diluted (in shares)	67,292,000	63,282,000	67,008,000	62,494,000
Comprehensive Loss:
Net loss	$ (16,530)	$ (16,052)	$ (28,862)	$ (23,489)
Other comprehensive (loss) income	(80)	(626)	(36)	428
Comprehensive loss	$ (16,610)	$ (16,678)	$ (28,898)	$ (23,061)

Condensed Consolidated Statem_2

Condensed Consolidated Statement of Stockholders' Equity (Unaudited) - USD ($) shares in Thousands, $ in Thousands	Total	Cumulative Effect, Period of Adoption, Adjustment	[1]	Common Stock	Additional Paid-In Capital	Additional Paid-In CapitalCumulative Effect, Period of Adoption, Adjustment	[1]	Accumulated Other Comprehensive Income	Accumulated Deficit	Accumulated DeficitCumulative Effect, Period of Adoption, Adjustment	[1]
Beginning balance at Dec. 31, 2019	$ 196,458			$ 61	$ 351,870			$ 576	$ (156,049)
Beginning balance (in shares) at Dec. 31, 2019				61,544
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Equity component of issuance of the 2025 convertible senior notes, net of issuance costs	154,363				154,363
Purchase of capped calls related to the 2025 convertible senior notes	(90,448)				(90,448)
Equity component from conversion of the 2023 convertible senior notes	(293,809)				(293,809)
Issuance of common stock upon partial conversion of the 2023 convertible senior notes	268,573			$ 3	268,570
Issuance of common stock upon partial conversion of the 2023 convertible senior notes (in shares)				2,724
Issuance of common stock upon exercise of stock options	6,080				6,080
Issuance of common stock upon exercise of stock options (in shares)				321
Issuance of common stock upon vesting of restricted stock units	1			$ 1
Issuance of common stock upon vesting of restricted stock units (in shares)				604
Issuance of common stock under ESPP (in shares)				103
Issuance of common stock under ESPP	5,666				5,666
Stock-based compensation	30,585				30,585
Other comprehensive (loss) income	428							428
Net loss	(23,489)								(23,489)
Ending balance at Jun. 30, 2020	254,408			$ 65	432,877			1,004	(179,538)
Ending balance (in shares) at Jun. 30, 2020				65,296
Beginning balance at Dec. 31, 2019	196,458			$ 61	351,870			576	(156,049)
Beginning balance (in shares) at Dec. 31, 2019				61,544
Ending balance at Dec. 31, 2020	$ 279,164	$ (145,669)		$ 67	476,941	$ (168,412)		335	(198,179)	$ 22,743
Ending balance (in shares) at Dec. 31, 2020				66,496
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Accounting Standards Update [Extensible Enumeration]	ASU 2020-06
Beginning balance at Mar. 31, 2020	$ 206,466			$ 62	368,260			1,630	(163,486)
Beginning balance (in shares) at Mar. 31, 2020				61,992
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Equity component of issuance of the 2025 convertible senior notes, net of issuance costs	154,363				154,363
Purchase of capped calls related to the 2025 convertible senior notes	(90,448)				(90,448)
Equity component from conversion of the 2023 convertible senior notes	(293,809)				(293,809)
Issuance of common stock upon partial conversion of the 2023 convertible senior notes	268,573			$ 3	268,570
Issuance of common stock upon partial conversion of the 2023 convertible senior notes (in shares)				2,724
Issuance of common stock upon exercise of stock options	3,484				3,484
Issuance of common stock upon exercise of stock options (in shares)				161
Issuance of common stock upon vesting of restricted stock units (in shares)				316
Issuance of common stock under ESPP (in shares)				103
Issuance of common stock under ESPP	5,666				5,666
Stock-based compensation	16,791				16,791
Other comprehensive (loss) income	(626)							(626)
Net loss	(16,052)								(16,052)
Ending balance at Jun. 30, 2020	254,408			$ 65	432,877			1,004	(179,538)
Ending balance (in shares) at Jun. 30, 2020				65,296
Beginning balance at Dec. 31, 2020	279,164	$ (145,669)		$ 67	476,941	$ (168,412)		335	(198,179)	$ 22,743
Beginning balance (in shares) at Dec. 31, 2020				66,496
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Issuance of common stock upon partial conversion of the 2023 convertible senior notes	(275)				(275)
Issuance of common stock upon partial conversion of the 2023 convertible senior notes (in shares)				325
Partial unwind of capped calls and retirement of common stock related to the 2023 convertible senior notes	7				7
Partial unwind of capped calls and retirement of common stock related to the 2023 convertible senior notes (in shares)				(47)
Issuance of common stock upon exercise of stock options	4,439				4,439
Issuance of common stock upon exercise of stock options (in shares)				246
Issuance of common stock upon vesting of restricted stock units	1			$ 1
Issuance of common stock upon vesting of restricted stock units (in shares)				596
Issuance of common stock under ESPP (in shares)				68
Issuance of common stock under ESPP	8,128				8,128
Stock-based compensation	45,809				45,809
Other comprehensive (loss) income	(36)							(36)
Net loss	(28,862)
Ending balance at Jun. 30, 2021	162,706			$ 68	366,637			299	(204,298)
Ending balance (in shares) at Jun. 30, 2021				67,684
Beginning balance at Mar. 31, 2021	144,206			$ 67	331,528			379	(187,768)
Beginning balance (in shares) at Mar. 31, 2021				67,029
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Issuance of common stock upon partial conversion of the 2023 convertible senior notes	(149)				(149)
Issuance of common stock upon partial conversion of the 2023 convertible senior notes (in shares)				182
Partial unwind of capped calls and retirement of common stock related to the 2023 convertible senior notes	5				5
Partial unwind of capped calls and retirement of common stock related to the 2023 convertible senior notes (in shares)				(28)
Issuance of common stock upon exercise of stock options	2,224				2,224
Issuance of common stock upon exercise of stock options (in shares)				123
Issuance of common stock upon vesting of restricted stock units	1			$ 1
Issuance of common stock upon vesting of restricted stock units (in shares)				310
Issuance of common stock under ESPP (in shares)				68
Issuance of common stock under ESPP	8,128				8,128
Stock-based compensation	24,901				24,901
Other comprehensive (loss) income	(80)							(80)
Net loss	(16,530)
Ending balance at Jun. 30, 2021	$ 162,706			$ 68	$ 366,637			$ 299	$ (204,298)
Ending balance (in shares) at Jun. 30, 2021				67,684
[1]	Effective January 1, 2021, the Company adopted ASU 2020-06. Accordingly, the Company recorded a net reduction to opening accumulated deficit of $22.7 million and a net reduction to opening additional paid-in capital of $168.4 million as of January 1, 2021 due to the cumulative impact of adopting this new standard. See Note 1 for more information.

Condensed Consolidated Statem_3

Condensed Consolidated Statements of Cash Flows (Unaudited) - USD ($) $ in Thousands	6 Months Ended
	Jun. 30, 2021	Jun. 30, 2020
Cash flows from operating activities:
Net loss	$ (28,862)	$ (23,489)
Adjustments to reconcile net loss to net cash provided by operating activities:
Depreciation and amortization	18,414	11,213
Amortization of operating lease right-of-use assets	4,473	2,786
Amortization of deferred contract acquisition costs	11,468	7,305
Amortization of premium on marketable investments	3,521	630
Provision for doubtful accounts	337	353
Stock-based compensation	45,809	30,585
Amortization of discount and issuance costs on convertible senior notes	1,959	8,571
Loss on early extinguishment of debt	0	5,794
Change in fair of value of contingent consideration	5,200	0
Tax benefit of valuation allowance associated with an acquisition	0	(2,910)
Other	226	82
Changes in operating assets and liabilities:
Accounts receivable	(5,526)	(2,119)
Prepaid expenses and other current assets	(5,962)	(7,065)
Deferred contract acquisition costs	(35,319)	(19,153)
Other assets	147	(1,604)
Accounts payable	1,725	2,553
Accrued and other current liabilities	23,343	9,561
Accrued federal fees and sales tax liabilities	1,277	(945)
Deferred revenue	(2,118)	3,292
Other liabilities	(14,955)	(281)
Net cash provided by operating activities	25,157	25,159
Cash flows from investing activities:
Purchases of marketable investments	(325,628)	(460,899)
Proceeds from maturities of marketable investments	283,605	167,850
Purchases of property and equipment	(19,477)	(14,891)
Cash paid to acquire Virtual Observer	0	(28,313)
Cash paid to acquire substantially all of the assets of Whendu	0	(100)
Net cash used in investing activities	(61,500)	(336,353)
Cash flows from financing activities:
Proceeds from issuance of convertible senior notes, net of issuance costs	0	728,812
Payments for capped call transactions	0	(90,448)
Repurchase of a portion of 2023 convertible senior notes, net of costs	(17,622)	(181,462)
Proceeds from exercise of common stock options	4,439	6,080
Proceeds from sale of common stock under ESPP	8,128	5,666
Payment of holdback related to the Virtual Observer acquisition	(3,200)	0
Payments of finance leases	(575)	(2,195)
Net cash (used in) provided by financing activities	(8,830)	466,453
Net (decrease) increase in cash and cash equivalents	(45,173)	155,259
Cash and cash equivalents:
Beginning of period	220,372	77,976
End of period	175,199	233,235
Supplemental disclosures of cash flow data:
Cash paid for interest	1,912	305
Cash paid for income taxes	163	141
Non-cash investing and financing activities:
Equipment purchased and unpaid at period-end	7,818	2,838
Capitalization of leasehold improvements and furniture and fixtures through non-cash lease incentive	4,815	0
Acquisition and related transaction costs accrued at period-end	$ 0	$ 3,700

Description of Business and Sum

Description of Business and Summary of Significant Accounting Policies	6 Months Ended
	Jun. 30, 2021
Accounting Policies [Abstract]
Description of Business and Summary of Significant Accounting Policies	Description of Business and Summary of Significant Accounting Policies Five9, Inc. and its wholly-owned subsidiaries (the “Company”) is a provider of cloud software for contact centers. The Company was incorporated in Delaware in 2001 and is headquartered in San Ramon, California. The Company has offices in Europe, Asia and Australia, which primarily provide research, development, sales, marketing, and client support services. Proposed Merger with Zoom On July 16, 2021, the Company entered into an Agreement and Plan of Merger (the “Merger Agreement”) by and among the Company, Zoom Video Communications, Inc., a Delaware corporation (“Zoom”) and Summer Merger Sub, Inc., a Delaware corporation and a direct, wholly owned subsidiary of Zoom (“Merger Sub”). Pursuant to the Merger Agreement, and upon the terms and subject to the conditions therein, at the effective time of the merger, Merger Sub will merge with and into the Company (the “Merger”), with the Company surviving the Merger and continuing as a wholly owned subsidiary of Zoom. See Note 14 for additional details. Basis of Presentation The accompanying condensed consolidated financial statements have been prepared in accordance with generally accepted accounting principles in the United States (“GAAP”) and applicable rules and regulations of the Securities and Exchange Commission (“SEC”) regarding interim financial reporting. Certain information and note disclosures normally included in 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 consolidated financial statements and notes included in the Company’s Annual Report on Form 10-K for the year ended December 31, 2020. In the opinion of management, the condensed consolidated financial statements reflect all adjustments, which are normal and recurring in nature, necessary for fair financial statement presentation. All intercompany transactions and balances have been eliminated in consolidation. Certain prior period amounts within operating activities in the condensed consolidated statements of cash flows have been reclassified to conform to the current period presentation. The condensed consolidated balance sheet and the consolidated statement of stockholders' equity included in this Quarterly Report as of June 30, 2021 differ from the Form 10-K for the year ended December 31, 2020 as it reflects an immaterial error correction due to the reclassification of $2.3 million from treasury stock to additional paid-in-capital. This reclassification was from the shares received for the partial unwind of capped calls related to the 2023 convertible senior notes. Use of Estimates The preparation of condensed consolidated financial statements in accordance with GAAP requires management to make estimates and assumptions that affect the reported amounts of assets and liabilities and disclosure of contingent assets and liabilities at the date of the condensed consolidated financial statements and the reported amounts of revenue and expenses during the reporting period. The significant estimates made by management affect revenue and related reserves, as well as the fair value of liabilities assumed through business combinations. Management periodically evaluates such estimates and they are adjusted prospectively based upon such periodic evaluation. Actual results could differ from those estimates. Significant Accounting Policies The Company’s significant accounting policies are disclosed in its Annual Report on Form 10-K for the year ended December 31, 2020. Recently Adopted Accounting Pronouncements In August 2020, the FASB issued ASU No. 2020-06, Debt-Debt with Conversion and Other Options (Subtopic 470-20) and Derivatives and Hedging-Contracts in Entity’s Own Equity (Subtopic 815-40): Accounting for Convertible Instruments and Contracts in an Entity’s Own Equity ("ASU 2020-06"), which simplifies the accounting for convertible instruments by removing the separation models for (1) convertible debt with a cash conversion feature and (2) convertible instruments with a beneficial conversion feature. The Company elected to early adopt ASU 2020-06 as of January 1, 2021 using a modified retrospective transition method. Applying the transition guidance, the Company was required to apply the guidance to all impacted financial instruments that were outstanding as of January 1, 2021 with the cumulative effect recognized as an adjustment to the opening balance of accumulated deficit. As a result of early adopting ASU 2020-06, the Company made certain adjustments to its accounting for the outstanding 0.125% convertible senior notes due 2023 (the "2023 convertible senior notes") and the outstanding 0.500% convertible senior notes due 2025 (the "2025 convertible senior notes", and, together with the 2023 convertible senior notes, the "convertible senior notes"). The adoption of ASU 2020-06 resulted in the re-combination of the liability and equity components of the convertible senior notes into a single liability instrument, which required the Company to record a $168.4 million decrease in additional paid in capital from the derecognition of the separated equity components of these notes, a $145.7 million increase in debt from the derecognition of the discount associated with the separated equity components of the convertible senior notes, and a $22.7 million cumulative effect decrease to the opening balance of its accumulated deficit as of January 1, 2021 upon transition. Interest expense recognized in future periods will be reduced as a result of accounting for the convertible senior notes as a single liability instrument. Since the Company had a net loss for the three and six months ended June 30, 2021, the convertible senior notes were determined to be anti-dilutive and therefore had no impact to basic or diluted net loss per share for the periods as a result of adopting ASU 2020-06. In December 2019, the FASB issued ASU No. 2019-12, Income Taxes (Topic 740): Simplifying the Accounting for Income Taxes (“ASU 2019-12”), which amends its guidance to simplify the accounting for income taxes by, among other things, removing exceptions to certain general principles in Topic 740, Income Taxes. The standard is effective for the Company beginning in the first quarter of 2021. The Company has adopted ASU 2019-12 and concluded that the impact on its condensed consolidated financial statements was immaterial. Recent Accounting Pronouncements Not Yet Effective The Company has reviewed or is in the process of evaluating all issued, but not yet effective, accounting pronouncements and does not believe the future adoption of any such accounting pronouncements will cause a material impact on its condensed consolidated financial position, operating results or cash flows.

Revenue

Revenue	6 Months Ended
	Jun. 30, 2021
Revenue from Contract with Customer [Abstract]
Revenue	Revenue Contract Balances The following table provides information about accounts receivable, net, deferred contract acquisition costs, net, contract assets and contract liabilities from contracts with customers (in thousands): June 30, 2021 December 31, 2020 Accounts receivable, net $ 53,811 $ 48,731 Deferred contract acquisition costs, net: Current $ 26,791 $ 20,695 Non-current 69,689 51,934 Total deferred contract acquisition costs, net $ 96,480 $ 72,629 Contract assets and contract liabilities: Contract assets (included in prepaid expenses and other current assets) $ 1,654 $ 1,297 Contract liabilities (deferred revenue) 33,237 31,983 Contract liabilities (deferred revenue) (included in other long-term liabilities) 2,592 3,373 Net contract liabilities $ (34,175) $ (34,059) The Company receives payments from customers based upon billing cycles. Invoice payment terms are usually 30 days or less. Accounts receivable are recorded when the right to consideration becomes unconditional. Deferred contract acquisition costs are recorded when incurred and are amortized over an estimated customer benefit period of five years. The Company’s contract assets consist of unbilled amounts typically resulting from professional services revenue recognition when it exceeds the total amounts billed to the customer. The Company’s contract liabilities consist of advance payments and billings in excess of revenue recognized. In the three and six months ended June 30, 2021, the Company recognized revenue of $5.0 million and $25.3 million, respectively, related to its contract liabilities at December 31, 2020. Remaining Performance Obligations As of June 30, 2021, the aggregate amount of the total transaction price allocated in contracts with original duration of greater than one year to the remaining performance obligations was $443.0 million. The Company expects to recognize revenue on approximately three-fourths of the remaining performance obligation over the next 24 months, with the balance recognized thereafter. The Company has elected the optional exemption, which allows for the exclusion of the amounts for remaining performance obligations that are part of contracts with an original expected duration of one year or less. Such remaining performance obligations represent unsatisfied or partially unsatisfied performance obligations pursuant to ASC 606.

Investments and Fair Value Meas

Investments and Fair Value Measurements	6 Months Ended
	Jun. 30, 2021
Fair Value Disclosures [Abstract]
Investments and Fair Value Measurements	Investments and Fair Value Measurements Marketable Investments The Company’s marketable investments have been classified and accounted for as available-for-sale. The Company’s marketable investments as of June 30, 2021 and December 31, 2020 were as follows (in thousands): June 30, 2021 Short-Term Marketable Investments Cost Gross Unrealized Gains Gross Unrealized Losses Fair Value Certificates of deposit $ 1,788 $ 1 $ — $ 1,789 U.S. treasury 237,848 21 (4) 237,865 U.S. agency securities 76,909 12 (3) 76,918 Commercial paper 40,358 — — 40,358 Municipal bonds 25,236 2 (2) 25,236 Corporate bonds 8,821 1 (2) 8,820 Total $ 390,960 $ 37 $ (11) $ 390,986 June 30, 2021 Long-term Marketable Investments Cost Gross Unrealized Gains Gross Unrealized Losses Fair Value Certificates of deposit $ 509 $ 1 $ — $ 510 U.S. treasury 2,994 — — 2,994 U.S. agency securities 53,252 — (31) 53,221 Municipal bonds 14,858 3 (2) 14,859 Corporate bonds 1,174 — — 1,174 Total $ 72,787 $ 4 $ (33) $ 72,758 December 31, 2020 Short-Term Marketable Investments Cost Gross Unrealized Gains Gross Unrealized Losses Fair Value Certificates of deposit $ 3,479 $ 1 $ — $ 3,480 U.S. treasury 287,315 41 (4) 287,352 U.S. agency securities 67,227 12 (6) 67,233 Commercial paper 5,093 — — 5,093 Municipal bonds 2,684 1 (1) 2,684 Corporate bonds 17,323 6 — 17,329 Total $ 383,121 $ 61 $ (11) $ 383,171 December 31, 2020 Long-term Marketable Investments Cost Gross Unrealized Gains Gross Unrealized Losses Fair Value U.S. treasury $ 10,189 $ — $ — $ 10,189 U.S. agency securities 31,469 9 (1) 31,477 Municipal bonds 461 — — 461 Total $ 42,119 $ 9 $ (1) $ 42,127 The following table presents the gross unrealized losses and the fair value for those marketable investments that were in an unrealized loss position for less than 12 months as of June 30, 2021 and December 31, 2020 (in thousands): June 30, 2021 December 31, 2020 Gross Unrealized Losses Fair Value Gross Unrealized Losses Fair Value U.S. treasury $ (4) $ 48,266 $ (4) $ 78,549 U.S. agency securities (34) 81,845 (7) 39,443 Municipal bonds (4) 17,263 (1) 1,201 Corporate bonds (2) 7,444 (1) 1,347 Total $ (44) $ 154,818 $ (13) $ 120,540 Although the Company had certain available-for-sale debt securities in an unrealized loss position as of June 30, 2021, no impairment loss was recorded since it did not intend to sell them, did not anticipate a need to sell them, and the decline in fair value was not due to any credit-related factors. The amortized cost and fair values of the Company’s marketable investments by contractual maturity as of June 30, 2021 and December 31, 2020 were as follows (in thousands): June 30, 2021 December 31, 2020 Cost Fair Value Cost Fair Value Due within one year $ 390,960 $ 390,986 $ 383,121 $ 383,171 Due after one year 72,787 72,758 42,119 42,127 Total $ 463,747 $ 463,744 $ 425,240 $ 425,298 Fair Value Measurements The Company carries cash equivalents and marketable investments at fair value. Fair value is based on the price that would be received from selling an asset or paid to transfer a liability in an orderly transaction between market participants at the measurement date. Fair value is estimated by applying the following hierarchy, which prioritizes the inputs used to measure fair value into three levels and bases the categorization within the hierarchy upon the lowest level of input that is available and significant to the fair value measurement: Level 1 — Observable inputs, which include unadjusted quoted prices in active markets for identical assets or liabilities. Level 2 — Observable inputs other than Level 1 inputs, such as quoted prices in markets that are not active, or other inputs that are observable or can be corroborated by observable market data for substantially the full term of the assets or liabilities. Level 3 — Unobservable inputs that are supported by little or no market activity and that are based on management’s assumptions, including fair value measurements determined by using pricing models, discounted cash flow methodologies or similar techniques. The Company determined the fair value of its Level 1 financial instruments, which are traded in active markets, using quoted market prices for identical instruments. Marketable investments classified within Level 2 of the fair value hierarchy are valued based on other observable inputs, including broker or dealer quotations or alternative pricing sources. When quoted prices in active markets for identical assets or liabilities are not available, the Company relies on non-binding quotes from its investment managers, which are based on proprietary valuation models of independent pricing services. These models generally use inputs such as observable market data, quoted market prices for similar instruments, historical pricing trends of a security as relative to its peers. To validate the fair value determination provided by its investment managers, the Company reviews the pricing movement in the context of overall market trends and trading information from its investment managers. The Company performs routine procedures such as comparing prices obtained from independent source to ensure that appropriate fair values are recorded. The following tables set forth the Company’s assets measured at fair value by level within the fair value hierarchy (in thousands): June 30, 2021 Level 1 Level 2 Level 3 Total Assets Cash equivalents Money market funds $ 53,799 $ — $ — $ 53,799 Municipal bonds — 14,644 — 14,644 Total cash equivalents $ 53,799 $ 14,644 $ — $ 68,443 Marketable investments (short and long term) Certificates of deposit $ — $ 2,299 $ — $ 2,299 U.S. treasury 240,859 — — 240,859 U.S. agency securities and government sponsored securities — 130,139 — 130,139 Commercial paper — 40,358 — 40,358 Municipal bonds — 40,095 — 40,095 Corporate bonds — 9,994 — 9,994 Total marketable investments $ 240,859 $ 222,885 $ — $ 463,744 Liabilities Contingent consideration $ — $ — $ 23,300 $ 23,300 December 31, 2020 Level 1 Level 2 Level 3 Total Assets Cash equivalents Money market funds $ 89,888 $ — $ — $ 89,888 U.S. treasury 39,997 — — 39,997 Total cash equivalents $ 129,885 $ — $ — $ 129,885 Marketable investments (short and long-term) Certificates of deposit $ — $ 3,480 $ — $ 3,480 U.S. treasury 297,540 — — 297,540 U.S. agency securities — 98,711 — 98,711 Commercial paper — 5,093 — 5,093 Municipal bonds — 3,145 — 3,145 Corporate bonds — 17,329 — 17,329 Total marketable investments $ 297,540 $ 127,758 $ — $ 425,298 Liabilities Contingent consideration $ — $ — $ 18,100 $ 18,100 As of June 30, 2021 and December 31, 2020, the estimated fair value of the Company’s outstanding 2023 convertible senior notes was $184.2 million and $253.1 million, respectively. As of June 30, 2021 and December 31, 2020, the estimated fair value of the Company's outstanding 2025 convertible senior notes was $1,108.2 million and $1,098.5 million, respectively. The fair values were determined based on the quoted price of the convertible senior notes in an inactive market on the last trading day of the reporting period and have been classified as Level 2 in the fair value hierarchy. See Note 6 for further information on the Company’s convertible senior notes. As part of the agreement to acquire Inference Solutions Inc. ("Inference") in November 2020, the Company may be obligated to pay contingent earn out consideration of up to $24.0 million based upon achievement of certain milestones and relative thresholds during the earn out measurement period which ends on December 31, 2021. The fair value of the contingent consideration arrangement, estimated to be $23.3 million as of June 30, 2021, is classified within Level 3 and is determined using a probability-based scenario analysis approach. The resulting probability-weighted contingent consideration amounts were discounted based on the Company’s estimated cost of debt. Future changes in the achievement of certain milestones and relative thresholds could result in a material change to the fair value of the contingent consideration, and such changes will be recorded in general and administrative expense in the consolidated statements of operations and comprehensive loss. During the three and six months ended June 30, 2021, the Company recognized $2.7 million and $5.2 million, respectively, of contingent consideration expense due to an increase in fair value of the contingent consideration as a result of the estimated achievement of the forecast (and reduced uncertainty about making a payment), the shorter time to payment, and a decrease in the cost of debt. A reconciliation of the beginning and ending balance for contingent consideration consisted of the following (in thousands): Three Months Ended June 30, 2021 Six Months Ended June 30, 2021 Balance, beginning of period $ 20,600 $ 18,100 Change in fair value of contingent consideration 2,700 5,200 Balance, end of period $ 23,300 $ 23,300 There were no assets or liabilities measured at fair value on a non-recurring basis as of June 30, 2021 and December 31, 2020.

Financial Statement Components

Financial Statement Components	6 Months Ended
	Jun. 30, 2021
Financial Statement Components [Abstract]
Financial Statement Components	Financial Statement Components Cash and cash equivalents consisted of the following (in thousands): June 30, 2021 December 31, 2020 Cash $ 106,756 $ 90,487 Money market funds 53,799 89,888 U.S. treasury — 39,997 Municipal bonds 14,644 — Total cash and cash equivalents $ 175,199 $ 220,372 Accounts receivable, net consisted of the following (in thousands): June 30, 2021 December 31, 2020 Trade accounts receivable $ 48,501 $ 42,366 Unbilled trade accounts receivable, net of advance client deposits 5,451 6,492 Allowance for doubtful accounts (141) (127) Accounts receivable, net $ 53,811 $ 48,731 Prepaid expenses and other current assets consisted of the following (in thousands): June 30, 2021 December 31, 2020 Prepaid expenses $ 13,724 $ 9,816 Other current assets 6,732 5,036 Contract assets 1,654 1,297 Prepaid expenses and other current assets $ 22,110 $ 16,149 Property and equipment, net consisted of the following (in thousands): June 30, 2021 December 31, 2020 Computer and network equipment $ 101,047 $ 89,763 Computer software 32,694 25,888 Internal-use software development costs 500 500 Furniture and fixtures 3,964 3,372 Leasehold improvements 5,531 2,335 Property and equipment 143,736 121,858 Accumulated depreciation and amortization (80,629) (70,645) Property and equipment, net $ 63,107 $ 51,213 Depreciation and amortization expense associated with property and equipment was $6.7 million and $12.5 million, respectively, for the three and six months ended June 30, 2021. Depreciation and amortization expense associated with property and equipment was $4.5 million and $8.4 million, respectively, for the three and six months ended June 30, 2020. Property and equipment capitalized under finance lease obligations consists primarily of computer and network equipment and was as follows (in thousands): June 30, 2021 December 31, 2020 Gross $ 44,009 $ 45,021 Less: accumulated depreciation and amortization (42,211) (41,908) Total $ 1,798 $ 3,113 Accrued and other current liabilities consisted of the following (in thousands): June 30, 2021 December 31, 2020 Accrued expenses $ 15,068 $ 15,217 Accrued compensation and benefits 35,656 29,233 Contingent consideration 23,300 — Accrued and other current liabilities $ 74,024 $ 44,450 Other long-term liabilities consisted of the following (in thousands): June 30, 2021 December 31, 2020 Deferred revenue $ 2,592 $ 3,373 Deferred tax liabilities 3,511 4,438 Other long-term liabilities 7,010 5,554 Contingent consideration — 18,100 Other long-term liabilities $ 13,113 $ 31,465

Goodwill and Intangible Assets

Goodwill and Intangible Assets	6 Months Ended
	Jun. 30, 2021
Goodwill and Intangible Assets Disclosure [Abstract]
Goodwill and Intangible Assets	Goodwill and Intangible Assets Goodwill There was no activity in the Company's goodwill balance during the six months ended June 30, 2021. Intangible Assets The following table summarizes the activity in the Company's intangible assets balance during the three and six months ended June 30, 2021 (in thousands): Three Months Ended June 30, 2021 Six Months Ended June 30, 2021 Beginning of the period $ 48,737 $ 51,684 Amortization (2,947) (5,894) End of the period $ 45,790 $ 45,790 The components of intangible assets were as follows (in thousands): June 30, 2021 December 31, 2020 Gross Carrying Amount Accumulated Amortization Net Carrying Amount Weighted Average Remaining Amortization period (Years) Gross Carrying Amount Accumulated Amortization Net Carrying Amount Weighted Average Remaining Amortization period (Years) Developed technology $ 56,214 $ (12,291) $ 43,923 4.5 $ 56,214 $ (6,761) $ 49,453 4.9 Acquired workforce 470 (256) 214 1.4 470 (177) 293 1.9 Customer relationships 1,600 (261) 1,339 4.2 1,600 (101) 1,499 4.7 Trademarks 500 (186) 314 1.3 500 (61) 439 1.8 Total $ 58,784 $ (12,994) $ 45,790 4.4 $ 58,784 $ (7,100) $ 51,684 4.9 Amortization expense for intangible assets was $2.9 million and $5.9 million during the three and six months ended June 30, 2021, respectively. Amortization expense for intangible assets was $1.7 million and $2.8 million during the three and six months ended June 30, 2020, respectively. The increase in amortization expense during the three and six months ended June 30, 2021 was due to the acquisition of intangible assets from Inference in November 2020 and Virtual Observer in April 2020. As of June 30, 2021, the expected future amortization expense for intangible assets was as follows (in thousands): Period Expected Future Amortization Expense Remaining 2021 $ 5,893 2022 11,704 2023 10,870 2024 7,527 2025 5,596 Thereafter 4,200 Total $ 45,790

Debt

Debt	6 Months Ended
	Jun. 30, 2021
Debt Disclosure [Abstract]
Debt	Debt 2025 Convertible Senior Notes and Related Capped Call Transactions In May and June 2020, the Company issued $747.5 million aggregate principal amount of the 2025 convertible senior notes in a private offering, which aggregate principal amount included the exercise in full of the initial purchasers’ option to purchase up to an additional $97.5 million principal amount of the 2025 convertible senior notes. The 2025 convertible senior notes mature on June 1, 2025 and bear interest at a fixed rate of 0.500% per annum, payable semiannually in arrears on June 1 and December 1 of each year, beginning on December 1, 2020. In addition, under the terms of the 2025 convertible senior notes, the Company is obligated to pay additional interest on the 2025 convertible senior notes at a rate equal to 0.500% per annum for the period from June 13, 2021 through July 8, 2021, after which such additional interest is no longer payable. The total net proceeds from the issuance of the 2025 convertible senior notes, after deducting initial purchasers' discounts and commissions and estimated debt issuance costs, were approximately $728.8 million. Each $1,000 principal amount of the 2025 convertible senior notes is initially convertible into 7.4437 shares of the Company’s common stock (the “2025 Conversion Option”), which is equivalent to an initial conversion price of approximately $134.34 per share of common stock, subject to adjustment upon the occurrence of specified events. The initial conversion price represents a premium of approximately 30% to the $103.34 per share closing price of the Company’s common stock on The Nasdaq Global Market on May 21, 2020. The 2025 convertible senior notes are convertible, in multiples of $1,000 principal amount, at the option of the holders prior to the close of business on the business day immediately preceding March 1, 2025, only under the following circumstances: (1) during any calendar quarter commencing after the calendar quarter ending on September 30, 2020 (and only during such calendar quarter), if the last reported sale price of the Company’s common stock for at least 20 trading days (whether or not consecutive) during a period of 30 consecutive trading days ending on, and including, 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 “2025 Measurement Period”) in which the trading price (as defined in the 2025 Indenture governing the 2025 convertible senior notes) per $1,000 principal amount of the 2025 convertible senior notes for each trading day of the 2025 Measurement Period was less than 98% of the product of the last reported sale price of the Company’s common stock and the conversion rate in effect on each such trading day; (3) if the Company calls any or all of the 2025 convertible senior notes for redemption, at any time prior to the close of business on the second scheduled trading day immediately preceding the redemption date; or (4) upon the occurrence of specified corporate events. On or after March 1, 2025 until the close of business on the second scheduled trading day immediately preceding the maturity date, holders may convert all or any portion of their 2025 convertible senior notes, in multiples of $1,000 principal amount, at the option of the holder regardless of the foregoing circumstances. Upon conversion, the Company will pay or deliver, as the case may be, cash, shares of the Company’s common stock or a combination of cash and shares of the Company’s common stock, at the Company’s election. If the Company undergoes a fundamental change (as defined in the indenture governing the 2025 convertible senior notes), subject to certain conditions, holders may require the Company to repurchase for cash all or any portion of their 2025 convertible senior notes, in principal amounts of $1,000 or a multiple thereof, at a fundamental change repurchase price equal to 100% of the principal amount of the 2025 convertible senior notes to be repurchased, plus accrued and unpaid interest, if any, to, but excluding, the fundamental change repurchase date. In addition, following certain corporate events or if the Company issues a notice of redemption, it will, under certain circumstances, increase the conversion rate for holders who elect to convert their notes in connection with such corporate event or during the relevant redemption period. There have been no changes to the initial conversion price of the 2025 convertible senior notes since issuance. The closing market price of the Company's common stock of $183.39 per share on June 30, 2021, the last trading day during the three months ended June 30, 2021, was greater than $174.64 per share, which represents 130% of the initial conversion price of $134.34 per share. However, the last reported sale price of the Company’s common stock for at least 20 trading days (whether or not consecutive) during a period of 30 consecutive trading days ending on, and including, the last trading day, June 30, 2021, was not greater than or equal to 130% of the initial conversion price. As such, during the three months ended June 30, 2021, the conditions allowing holders of the 2025 convertible senior notes to convert were not met. The 2025 convertible senior notes are therefore not convertible for the three months ending September 30, 2021. The Company may not redeem the 2025 convertible senior notes prior to June 6, 2023. The Company may redeem for cash all or any portion of the 2025 convertible senior notes, at its option, on or after June 6, 2023 and prior to March 1, 2025 if the last reported sale price of its common stock has been at least 130% of the conversion price then in effect for at least 20 trading days (whether or not consecutive) during any 30 consecutive trading day period (including the last trading day of such period) ending not more than two trading days immediately preceding the date on which the Company provides notice of redemption at a redemption price equal to 100% of the principal amount of the 2025 convertible senior notes to be redeemed, plus accrued and unpaid interest, if any, to, but excluding, the redemption date. No sinking fund is provided for the 2025 convertible senior notes. The 2025 convertible senior notes are the Company’s senior unsecured obligations and rank senior in right of payment to any of the Company’s indebtedness that is expressly subordinated in right of payment to the 2025 convertible senior notes; equal in right of payment to any of the Company’s unsecured indebtedness that is not so subordinated (including the 2023 convertible senior notes); effectively junior in right of payment to any of the Company’s secured indebtedness to the extent of the value of the assets securing such indebtedness; and structurally junior to all indebtedness and other liabilities (including trade payables) of the Company’s subsidiaries. Prior to the adoption of ASU 2020-06 on January 1, 2021 and in accounting for the issuance of the 2025 convertible senior notes, the 2025 convertible senior 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 2025 Conversion Option was $158.3 million and was determined by deducting the fair value of the liability component from the par value of the 2025 convertible senior notes. The equity component was recorded in additional paid-in-capital and was not re-measured as long as it continued to meet the conditions for equity classification. The excess of the principal amount of the liability component over its carrying amount (the “Debt Discount”) was amortized to interest expense over the contractual term of the 2025 convertible senior notes at an effective interest rate of 5.76%. Prior to the adoption of ASU 2020-06 on January 1, 2021 and in accounting for the debt issuance costs of $18.7 million related to the 2025 convertible senior notes, the Company allocated the total amount incurred to the liability and equity components of the 2025 convertible senior notes based on their relative values. Issuance costs attributable to the liability component were $14.7 million and were amortized to interest expense using the effective interest method over the contractual term of the 2025 convertible senior notes. Issuance costs attributable to the equity component were netted with the equity component in additional paid-in-capital. On January 1, 2021, the Company elected to early adopt ASU 2020-06 based on a modified retrospective transition method. Under such transition, prior-period information has not been retrospectively adjusted. In accounting for the 2025 convertible senior notes after adoption of ASU 2020-06, the 2025 convertible senior notes are accounted for as a single liability, and the carrying amount of the 2025 convertible senior notes is $732.8 million as of June 30, 2021, with principal of $747.5 million, net of issuance cost of $14.7 million. The 2025 senior convertible notes were classified as long term liabilities as of June 30, 2021. The issuance cost related to the 2025 convertible senior notes is being amortized to interest expense over the contractual term of the 2025 convertible senior notes at an effective interest rate 1.0%. The net carrying amount of the 2025 convertible senior notes as of June 30, 2021 (post-ASU 2020-06 adoption) and as of December 31, 2020 (pre-ASU 2020-06 adoption) was as follows (in thousands): June 30, 2021 December 31, 2020 Principal $ 747,500 $ 747,500 Unamortized debt discount — (141,792) Unamortized issuance costs (14,707) (13,192) Net carrying amount $ 732,793 $ 592,516 The net carrying amount of the equity component of the 2025 convertible senior notes as of June 30, 2021 (post-ASU 2020-06 adoption) and as of December 31, 2020 (pre-ASU 2020-06 adoption) was as follows (in thousands): June 30, 2021 December 31, 2020 Equity component $ — $ 158,321 Issuance costs — (3,958) Net carrying amount $ — $ 154,363 Interest expense related to the 2025 convertible senior notes was as follows (in thousands): Three Months Ended Six Months Ended June 30, 2021 June 30, 2020 June 30, 2021 June 30, 2020 Contractual interest expense $ 1,121 $ 362 $ 2,055 $ 362 Amortization of debt discount — 2,528 — 2,528 Amortization of issuance costs 912 235 1,802 235 Total interest expense $ 2,033 $ 3,125 $ 3,857 $ 3,125 In connection with the issuance of the 2025 convertible senior notes, the Company entered into privately negotiated capped call transactions (the “2025 Capped Call Transactions”) with certain financial institutions. The 2025 Capped Call Transactions are expected generally to reduce the potential dilution to the Company’s common stock in connection with any conversion of the 2025 convertible senior notes and/or offset any cash payments the Company is required to make in excess of the principal amount of converted 2025 convertible senior notes, as the case may be, with such reduction and/or offset subject to a cap based on the cap price. The initial cap price of the 2025 Capped Call Transactions was $206.68 per share and is subject to certain adjustments under the terms of the 2025 Capped Call Transactions. The 2025 Capped Call Transactions cover, subject to anti-dilution adjustments, approximately 5.6 million shares of the Company’s common stock. For accounting purposes, the 2025 Capped Call Transactions are separate transactions, and not integrated with the issuance of the 2025 convertible senior notes. As these transactions meet certain accounting criteria, the 2025 Capped Call Transactions are recorded in stockholders’ equity and are not accounted for as derivatives. The cost to the Company of the 2025 Capped Call Transactions was $90.5 million during the year ended December 31, 2020, which was recorded as a reduction to additional paid-in capital. Maturity of the Company’s 2025 convertible senior notes as of June 30, 2021 was as follows (in thousands): Period Amount to Mature 2025 (Maturity date of June 1, 2025) $ 747,500 Total $ 747,500 2023 Convertible Senior Notes and Related Capped Call Transactions In May 2018, the Company issued $258.8 million aggregate principal amount of 2023 convertible senior notes in a private offering. The 2023 convertible senior notes mature on May 1, 2023 and bear interest at a fixed rate of 0.125% per annum, payable semiannually in arrears on May 1 and November 1 of each year. The total net proceeds from the offering, after deducting initial purchasers' discounts and commissions and estimated debt issuance costs, was approximately $250.8 million. In May 2020, the Company used part of the net proceeds from the issuance of the 2025 convertible senior notes to repurchase, exchange or otherwise retire approximately $181.0 million aggregate principal amount of the 2023 convertible senior notes in privately-negotiated transactions for aggregate consideration of $449.6 million, consisting of $181.0 million in cash and 2,723,581 shares of the Company’s common stock (the "2023 Note Repurchase Transactions"). As of June 30, 2021, after giving effect to the 2023 Note Repurchase Transactions and other settlements upon conversion requests, approximately $41.3 million aggregate principal amount of 2023 convertible senior notes remained outstanding. The 2023 Note Repurchase Transactions were accounted for as a debt extinguishment. Pursuant to ASC Subtopic 470-20 under existing accounting rules prior to ASU 2020-06 adoption, total consideration for the 2023 Note Repurchase Transactions was separated into liability and equity components by estimating the fair value of a similar liability without a conversion option and assigning the residual value to the equity component. The gain or loss on extinguishment of the debt was subsequently determined by comparing the repurchase consideration allocated to the liability component to the sum of the carrying value of the liability component, net of the proportionate amounts of unamortized debt discount and the remaining unamortized debt issuance costs. Of the $449.6 million in aggregate consideration paid by the Company in connection with the 2023 Note Repurchase Transactions, $155.8 million and $293.8 million were allocated to the debt and equity components, respectively, using an effective interest rate of 5.32% to determine the fair value of the liability component. This interest rate was based on the income and market-based approaches used to determine the effective interest rate of the 2023 convertible senior notes, adjusted for the remaining term of the 2023 convertible senior notes. As of the settlement of the 2023 Note Repurchase Transactions, the carrying value of the 2023 convertible senior notes subject to the 2023 Note Repurchase Transactions, net of unamortized debt discount and issuance costs, was $150.4 million. The Company also incurred approximately $0.5 million in third party transaction costs related to the 2023 Note Repurchase Transactions. These costs were allocated to the liability and equity components in proportion to the allocation of consideration transferred at settlement and accounted for as debt extinguishment costs and equity reacquisition costs, respectively. The 2023 Note Repurchase Transactions resulted in a $5.8 million loss on early debt extinguishment in the second quarter of fiscal 2020, of which $2.7 million consisted of unamortized debt issuance costs. Each $1,000 principal amount of the 2023 convertible senior notes was initially convertible into 24.4978 shares of the Company’s common stock (the “2023 Conversion Option”), which is equivalent to an initial conversion price of approximately $40.82 per share of common stock, subject to adjustment upon the occurrence of specified events. The 2023 convertible senior notes are convertible, in multiples of $1,000 principal amount, at the option of the holders at any time prior to the close of business on the business day immediately preceding November 1, 2022, only under the following circumstances: (1) during any calendar quarter commencing after the calendar quarter ended on September 30, 2018 (and only during such calendar quarter), if the last reported sale price of the Company’s common stock for at least 20 trading days (whether or not consecutive) during a period of 30 consecutive trading days ending on, and including, 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 “2023 Measurement Period”) in which the trading price (as defined in the indenture governing the 2023 convertible senior notes) per $1,000 principal amount of the 2023 convertible senior notes for each trading day of the 2023 Measurement Period was less than 98% of the product of the last reported sale price of the Company’s common stock and the conversion rate in effect on each such trading day; (3) if the Company calls any or all of the 2023 convertible senior notes for redemption, at any time prior to the close of business on the second scheduled trading day immediately preceding the redemption date; or (4) upon the occurrence of specified corporate events. On or after November 1, 2022 until the close of business on the second scheduled trading day immediately preceding the maturity date, holders may convert all or any portion of their 2023 convertible senior notes, in multiples of $1,000 principal amount, at the option of the holder regardless of the foregoing circumstances. Upon conversion, the Company will pay or deliver, as the case may be, cash, shares of the Company’s common stock or a combination of cash and shares of the Company’s common stock, at the Company’s election. If the Company undergoes a fundamental change (as defined in the indenture governing the 2023 convertible senior notes), subject to certain conditions, holders may require the Company to repurchase for cash all or any portion of their 2023 convertible senior notes, in principal amounts of $1,000 or a multiple thereof, at a fundamental change repurchase price equal to 100% of the principal amount of the 2023 convertible senior notes to be repurchased, plus accrued and unpaid interest, if any, to, but excluding, the fundamental change repurchase date. In addition, following certain corporate events that occur prior to the maturity date or if the Company issues a notice of redemption, it will, under certain circumstances, increase the conversion rate for holders who elect to convert their 2023 convertible senior notes in connection with such corporate event or during the relevant redemption period. There have been no changes to the initial conversion price of the 2023 convertible senior notes since issuance. During each of the quarters from the third quarter of 2019 through the second quarter of 2021, one of the triggers for convertibility of the 2023 convertible senior notes was triggered as the last reported sale price of the Company’s common stock was greater than $53.07 per share, which represents 130% of the initial conversion price of $40.82 per share, for at least 20 trading days in the period of 30 consecutive trading days ended on, and including, the last trading day of the quarter for each quarter of 2020 and for the first and second quarters of 2021. As a result, the 2023 convertible senior notes were convertible, in multiples of $1,000 principal amount, at the option of the 2023 convertible senior note holders between October 1, 2019 to June 30, 2021, and are also currently convertible between July 1, 2021 to September 30, 2021. Whether the 2023 convertible senior notes will be convertible after September 30, 2021 will depend on the continued satisfaction of this condition or other conversion conditions in the future. During the six months ended June 30, 2021, the Company paid $17.6 million in cash and issued 324,575 shares of its common stock to settle aggregate principal amount of $17.6 million of its 2023 convertible senior notes. As of June 30, 2021, approximately $41.3 million aggregate principal amount of our 2023 convertible senior notes remained outstanding. The conversions that occurred prior to January 1, 2021 resulted in a $1.2 million loss on early debt extinguishment. The conversions that occurred during the six months ended June 30, 2021 were subject to ASU 2020-06 and such conversions were accounted for as contractual conversions, which did not result in any gain or loss upon their settlement. During 2020, the Company received 15,714 shares from the partial unwind of capped calls resulting from the settlement of its 2023 convertible senior notes. The receipt of the 15,714 shares reduced the number of common shares outstanding. During the six months ended June 30, 2021, the Company received an additional 46,724 shares from the partial unwind of capped calls resulting from the settlement of its 2023 convertible senior notes. The receipt of the 46,724 shares reduced the number of common shares outstanding. In addition, on or prior to June 30, 2021, the Company received elections to convert aggregate principal amount of $1.2 million of its 2023 convertible senior notes that remain unsettled as of the end of the second quarter of 2021. The Company expects to settle these conversions in cash or a combination of cash and shares during the second half of 2021. The Company has the option to settle any future election conversion notices in cash, shares, or a combination of cash and shares. The 2023 convertible senior notes became redeemable at the Company's option on May 5, 2021. The Company may redeem for cash all or any portion of the 2023 convertible senior notes, at its option, if the last reported sale price of its common stock has been at least 130% of the conversion price then in effect for at least 20 trading days (whether or not consecutive) during any 30 consecutive trading day period (including the last trading day of such period) ending not more than two trading days immediately preceding the date on which the Company provides notice of redemption at a redemption price equal to 100% of the principal amount of the 2023 convertible senior notes to be redeemed, plus accrued and unpaid interest, if any, to, but excluding, the redemption date. No sinking fund is provided for the 2023 convertible senior notes. The 2023 convertible senior notes are the Company’s senior unsecured obligations and rank senior in right of payment to any of the Company’s indebtedness that is expressly subordinated in right of payment to the 2023 convertible senior notes; equal in right of payment to any of the Company’s unsecured indebtedness that is not so subordinated (including the 2025 convertible senior notes); effectively junior in right of payment to any of the Company’s secured indebtedness to the extent of the value of the assets securing such indebtedness; and structurally junior to all indebtedness and other liabilities (including trade payables) of the Company’s subsidiaries. Prior to the adoption of ASU 2020-06 on January 1, 2021 and in accounting for the issuance of the 2023 convertible senior notes, the 2023 convertible senior 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 equity component was recorded in additional paid-in-capital and was not re-measured as long as it continued to meet the conditions for equity classification. The excess of the principal amount of the liability component over its carrying amount (the "Debt Discount") was amortized to interest expense over the contractual term of the 2023 convertible senior notes at an effective interest rate of 6.39%. Prior to the adoption of ASU 2020-06 on January 1, 2021 and in accounting for the debt issuance costs of $8.0 million related to the 2023 convertible senior notes, the Company allocated the total amount incurred to the liability and equity components of the 2023 convertible senior notes based on their relative values. Issuance costs attributable to the liability component were $6.0 million and were amortized to interest expense using the effective interest method over the contractual term of the 2023 convertible senior notes. Issuance costs attributable to the equity component were netted with the equity component in additional paid-in-capital. After the adoption of ASU 2020-06, the 2023 convertible senior notes are accounted for as a single liability, and the carrying amount of the 2023 convertible senior notes was $40.8 million as of June 30, 2021, with principal of $41.3 million , net of issuance cost of $0.5 million. The 2023 senior convertible notes were classified as long term liabilities during the six months ended on June 30, 2021. The issuance cost related to the 2023 convertible senior notes is being amortized to interest expense over the contractual term of the 2023 convertible senior notes at an effective interest rate 0.76%. The net carrying amount of the 2023 convertible senior notes as of June 30, 2021 (post-ASU 2020-06 adoption) and as of December 31, 2020 (pre-ASU 2020-06 adoption) was as follows (in thousands): June 30, 2021 December 31, 2020 Principal $ 41,278 $ 58,867 Unamortized debt discount — (7,367) Unamortized issuance costs (483) (700) Net carrying amount $ 40,795 $ 50,800 The net carrying amount of the equity component of the 2023 convertible senior notes as of June 30, 2021 (post-ASU 2020-06 adoption) and as of December 31, 2020 (pre-ASU 2020-06 adoption) was as follows (in thousands): June 30, 2021 December 31, 2020 Equity component $ — $ 14,505 Issuance costs — (455) Net carrying amount $ — $ 14,050 Interest expense related to the 2023 convertible senior notes was as follows (in thousands): Three Months Ended Six Months Ended June 30, 2021 June 30, 2020 June 30, 2021 June 30, 2020 Contractual interest expense $ 6 $ 60 $ 23 $ 141 Amortization of debt discount — 2,272 — 5,304 Amortization of issuance costs 73 216 157 504 Total interest expense $ 79 $ 2,548 $ 180 $ 5,949 In connection with the issuance of the 2023 convertible senior notes, the Company entered into privately negotiated capped call transactions (the “2023 Capped Call Transactions”) with certain financial institutions. The 2023 Capped Call Transactions are expected generally to reduce the potential dilution to the Company’s common stock upon any conversion of the 2023 convertible senior notes and/or offset any cash payments the Company is required to make in excess of the principal amount of converted 2023 convertible senior notes, as the case may be, with such reduction and/or offset subject to a cap based on the cap price. The initial cap price of the 2023 Capped Call Transactions was $62.80 per share, and is subject to certain adjustments under the terms of the 2023 Capped Call Transactions. The 2023 Capped Call Transactions cover, subject to anti-dilution adjustments, approximately 6.3 million shares of the Company’s common stock. For accounting purposes, the 2023 Capped Call Transactions are separate transactions, and not integrated with the issuance of the 2023 convertible senior notes. As these transactions meet certain accounting criteria, the 2023 Capped Call Transactions are recorded in stockholders’ equity and are not accounted for as derivatives. The cost of $31.4 million incurred in connection with the 2023 Capped Call Transactions was recorded as a reduction to additional paid-in capital. In connection with the 2023 Note Repurchase Transactions, the Company amended the 2023 Capped Call Transactions such that the portion associated with the 2023 convertible senior notes subject to the 2023 Note Repurchase Transactions would remain outstanding notwithstanding the retirement of $181.0 million aggregate principal amount of 2023 convertible senior notes. Following such amendment, the 2023 Capped Call Transactions continue to meet the accounting criteria to be recorded in stockholders’ equity and are not accounted for as derivatives. Maturity of the Company’s 2023 convertible senior notes as of June 30, 2021 was as follows (in thousands): Period Amount to Mature 2023 (Maturity date of May 1, 2023) $ 41,278 Total $ 41,278

Stockholders' Equity

Stockholders' Equity	6 Months Ended
	Jun. 30, 2021
Equity [Abstract]
Stockholders' Equity	Stockholders’ Equity Capital Structure Common Stock The Company is authorized to issue 450,000,000 shares of common stock with a par value of $0.001 per share. As of June 30, 2021 and December 31, 2020, the Company had 67,683,848 and 66,496,060 shares of common stock issued and outstanding, respectively. During the three and six months ended June 30, 2021, the Company issued 181,560 shares and 324,575 shares, respectively, of common stock in connection with 2023 convertible senior note settlements. During the three and six months ended June 30, 2021, the Company also received 27,938 and 46,724 shares, respectively, from the partial unwind of capped calls resulting from the settlement of its 2023 convertible senior notes. The receipt of the 27,938 shares and 46,724 shares during the three and six months ended June 30, 2021, respectively, reduced the number of common shares outstanding. See Note 6 for further details. Preferred Stock The Company is authorized to designate and issue up to 5,000,000 shares of preferred stock with a par value of $0.001 per share in one or more series without stockholder approval and to fix the rights, preferences, privileges and restrictions thereof. As of June 30, 2021 and December 31, 2020, there were no shares of preferred stock issued and outstanding. Common Stock Reserved for Future Issuance Shares of common stock reserved for future issuance related to outstanding equity awards and employee equity incentive plans were as follows (in thousands): June 30, 2021 Stock options outstanding 2,129 Restricted stock units outstanding 2,273 Shares available for future grant under 2014 Plan 14,165 Shares available for future issuance under ESPP 3,129 Total shares of common stock reserved 21,696 Stock Options A summary of the Company’s stock option activity during the six months ended June 30, 2021 is as follows (in thousands, except years and per share data): Number of Weighted Weighted Aggregate Outstanding as of December 31, 2020 2,255 $ 26.33 Options granted (weighted average grant date fair value of $81.48 per share) 130 180.76 Options exercised (246) 18.05 Options forfeited or expired (10) 82.62 Outstanding as of June 30, 2021 2,129 $ 36.47 5.3 $ 312,868 The aggregate intrinsic value amounts are computed based on the difference between the exercise price of the stock options and the fair market value of the Company’s common stock of $183.39 per share as of June 30, 2021 for all in-the-money stock options outstanding. Restricted Stock Units A summary of the Company’s restricted stock unit ("RSU"), activity during the six months ended June 30, 2021 is as follows (in thousands, except per share data): Number of Shares Weighted Average Grant Date Fair Value Per Share Outstanding as of December 31, 2020 2,267 $ 65.42 RSUs granted 691 179.79 RSUs vested and released (596) 58.11 RSUs forfeited (89) 83.94 Outstanding as of June 30, 2021 2,273 100.80 Stock-Based Compensation Stock-based compensation expense was as follows (in thousands): Three Months Ended Six Months Ended June 30, 2021 June 30, 2020 June 30, 2021 June 30, 2020 Cost of revenue $ 3,781 $ 2,499 $ 6,886 $ 4,488 Research and development 6,152 3,684 10,915 6,491 Sales and marketing 8,208 5,265 14,979 9,371 General and administrative 6,760 5,343 13,029 10,235 Total stock-based compensation $ 24,901 $ 16,791 $ 45,809 $ 30,585 As of June 30, 2021, unrecognized stock-based compensation expense by award type and their expected weighted-average recognition periods are summarized in the following table (in thousands, except years). Stock Option RSU ESPP Unrecognized stock-based compensation expense $ 26,930 $ 217,556 $ 1,907 Weighted-average amortization period 2.7 years 3.1 years 0.4 years The weighted-average assumptions used to value stock options granted during the periods presented were as follows: Stock Options Three Months Ended Six Months Ended June 30, 2021 June 30, 2020 June 30, 2021 June 30, 2020 Expected term (years) 6.0 6.0 6.0 6.0 Volatility 47 % 48 % 47 % 47 % Risk-free interest rate 1.0 % 0.4 % 1.0 % 1.1 % Dividend yield (1) — — — — (1) The Company has not paid, and does not anticipate paying, cash dividends on its shares of common stock. Accordingly, the expected dividend yield is zero.

Net Loss Per Share

Net Loss Per Share	6 Months Ended
	Jun. 30, 2021
Earnings Per Share [Abstract]
Net Loss Per Share	Net Loss Per ShareBasic net loss per share is calculated by dividing net loss by the weighted average number of shares of common stock outstanding during the period, and excludes any dilutive effects of employee stock-based awards and potential shares upon conversion of the convertible senior notes. Diluted net loss per share is computed giving effect to all potentially dilutive shares of common stock, including common stock issuable upon exercise of stock options, vesting of restricted stock units and shares of common stock issuable upon conversion of convertible senior notes. As the Company had net losses for the three and six months ended June 30, 2021 and 2020, all potentially issuable shares of common stock were determined to be anti-dilutive. The following table presents the calculation of basic and diluted net loss per share (in thousands, except per share data): Three Months Ended Six Months Ended June 30, 2021 June 30, 2020 June 30, 2021 June 30, 2020 Net loss $ (16,530) $ (16,052) $ (28,862) $ (23,489) Weighted-average shares used in computing basic and diluted net loss per share 67,292 63,282 67,008 62,494 Basic and diluted net loss per share $ (0.25) $ (0.25) $ (0.43) $ (0.38) The following securities were excluded from the calculation of diluted net loss per share because their effect would have been anti-dilutive (in thousands): Three Months Ended Six Months Ended June 30, 2021 June 30, 2020 June 30, 2021 June 30, 2020 Stock options 2,129 2,431 2,129 2,431 Restricted stock units 2,273 2,753 2,273 2,753 Convertible senior notes (1) 6,708 1,106 6,796 984 Total 11,110 6,290 11,198 6,168 (1) Anti-dilutive convertible senior notes were calculated under the if-converted method for the three and six months ended June 30, 2021 due to the adoption of ASU 2020-06 and under the treasury stock method for the three and six months ended June 30, 2020. Prior to the adoption of ASU 2020-06, the Company used the treasury stock method for calculating any potential dilutive effect of the conversion spread of its convertible senior notes. The conversion spread had a dilutive impact for the 2023 convertible senior notes during the three and six months ended June 30, 2020 since the average market price of the Company’s common stock during the period exceeded the initial conversion price of $40.82 per share. However, the potential shares of common stock issuable upon the conversion of the 2023 convertible senior notes were excluded from the calculation of diluted net loss per share because their effect would have been anti-dilutive.

Income Taxes

Income Taxes	6 Months Ended
	Jun. 30, 2021
Income Tax Disclosure [Abstract]
Income Taxes	Income Taxes The benefit from income taxes for the three and six months ended June 30, 2021 was approximately $(0.1) million and $(0.7) million, respectively. The benefit from income taxes for the three and six months ended June 30, 2020 was approximately $(2.9) million and $(2.8) million, respectively. The benefit from income taxes for the three and six months ended June 30, 2021 consisted primarily of a foreign income tax benefit offset by domestic state minimum taxes. The benefit from income taxes for the three and six months ended June 30, 2020 consisted primarily of foreign income taxes, a benefit from the reduction of the valuation allowance due to purchase accounting related to the Virtual Observer acquisition, offset by domestic state minimum taxes. For the three and six months ended June 30, 2021, the benefit from income taxes differed from the statutory amount primarily due to state and foreign income taxes and the Company realizing no benefit for current year domestic losses due to maintaining a full valuation allowance against its domestic net deferred tax assets. For the three and six months ended June 30, 2020, the provision for income taxes differed from the statutory amount primarily due to reduction in the valuation allowance resulting from the recording of deferred tax liabilities related to the Virtual Observer acquisition. The realization of tax benefits of deferred tax assets is dependent upon future levels of taxable income, of an appropriate character, in the periods the items are expected to be deductible or taxable. Based on the available objective evidence, the Company does not believe it is more likely than not that the net deferred tax assets will be realizable. Accordingly, the Company has provided a full valuation allowance against the domestic net deferred tax assets as of June 30, 2021 and December 31, 2020. The Company intends to maintain the remaining valuation allowance until sufficient positive evidence exists to support a reversal of, or decrease in, the valuation allowance. During the three and six months ended June 30, 2021, there were no material changes to the total amount of unrecognized tax benefits.

Commitments and Contingencies

Commitments and Contingencies	6 Months Ended
	Jun. 30, 2021
Commitments and Contingencies Disclosure [Abstract]
Commitments and Contingencies	Commitments and Contingencies Commitments The Company’s principal commitments consist of future payment obligations under its convertible senior notes, finance leases to finance data centers and other computer and networking equipment purchases, operating leases for office facilities, cloud services agreement, and agreements with third parties to provide co-location hosting, telecommunication usage and equipment maintenance services. These commitments as of December 31, 2020 are disclosed in the Company’s Annual Report on Form 10-K for the year ended December 31, 2020, and did not change materially during the six months ended June 30, 2021, except for certain hosting and telecommunications agreements, cloud service agreements, the convertible senior notes, the contingent consideration described in Note 3, and the operating leases described in Note 12. As of June 30, 2021, the Company’s commitment under various hosting and telecommunications agreements totaled $11.8 million for terms ranging up to 60 months. These agreements require the Company to make monthly payments over the service term in exchange for certain network services. In September 2020, the Company entered into a cloud services agreement for a term of three years and a total commitment of $12.5 million. As of June 30, 2021, the total remaining commitment was approximately $7.5 million, of which approximately $5.0 million and $2.5 million is expected to be paid for the remainder of 2021 and 2022, respectively. In June 2021, the Company entered into an additional cloud services agreement for a term of three years and a total commitment of $5.0 million, of which $1.1 million is expected to be paid in 2021, $1.7 million in 2022, and $2.2 million in 2023. As of June 30, 2021, $788.8 million of aggregate principal of the convertible senior notes were outstanding. The 2023 convertible senior notes and the 2025 convertible senior notes are due on May 1, 2023 and June 1, 2025, respectively. See Note 6 for more information concerning the convertible senior notes. Legal Matters The Company is involved in various legal and regulatory matters arising in the normal course of business. In management’s opinion, resolution of these matters is not expected to have a material impact on the Company’s consolidated results of operations, cash flows, or its financial position. However, due to the uncertain nature of legal matters, an unfavorable resolution of a matter could materially affect the Company’s future consolidated results of operations, cash flows or financial position in a particular period. The Company expenses legal fees as incurred. Indemnification Agreements

Geographical Information

Geographical Information	6 Months Ended
	Jun. 30, 2021
Segment Reporting [Abstract]
Geographical Information	Geographical Information The following table summarizes revenues by geographic region based on client billing address (in thousands): Three Months Ended Six Months Ended June 30, 2021 June 30, 2020 June 30, 2021 June 30, 2020 United States $ 131,257 $ 91,784 $ 257,143 $ 179,215 International 12,525 8,008 24,521 15,665 Total revenue $ 143,782 $ 99,792 $ 281,664 $ 194,880 The following table summarizes total property and equipment, net in the respective locations (in thousands): June 30, 2021 December 31, 2020 United States $ 54,748 $ 43,339 International 8,359 7,874 Property and equipment, net $ 63,107 $ 51,213

Leases

Leases	6 Months Ended
	Jun. 30, 2021
Leases [Abstract]
Leases	Leases The Company has leases for offices, data centers and computer and networking equipment that expire at various dates through 2031. The Company’s leases have remaining terms of one three The Company's Bishop Ranch Lease commenced on February 1, 2021, has a lease term of 10 years, and has a total commitment over its term of $46.4 million, which was the primary component of the increase in operating lease costs, operating lease right-of-use assets and operating lease liabilities for the three and six months ended June 30, 2021. The components of lease expenses were as follows (in thousands): Three Months Ended Six Months Ended June 30, 2021 June 30, 2020 June 30, 2021 June 30, 2020 Operating lease cost $ 2,517 $ 1,515 $ 5,185 $ 3,031 Finance lease cost: Amortization of right-of-use assets $ 544 $ 982 $ 1,261 $ 2,120 Interest on finance lease liabilities 5 63 18 145 Total finance lease cost $ 549 $ 1,045 $ 1,279 $ 2,265 Supplemental cash flow information related to leases was as follows (in thousands): Three Months Ended Six Months Ended June 30, 2021 June 30, 2020 June 30, 2021 June 30, 2020 Cash paid for amounts included in the measurement of lease liabilities: Operating cash used in operating leases $ (1,370) $ (1,607) $ (3,408) $ (3,190) Financing cash used in finance leases (119) (966) (575) (2,195) Right of use assets obtained in exchange for lease obligations: Operating leases 4,090 364 42,429 4,256 Finance leases — — — — Supplemental balance sheet information related to leases was as follows (in thousands): June 30, 2021 December 31, 2020 Operating leases Operating lease right-of-use assets $ 46,966 $ 9,010 Operating lease liabilities $ 7,758 $ 3,912 Operating lease liabilities — less current portion 46,029 5,379 Total operating lease liabilities $ 53,787 $ 9,291 Finance leases Property and equipment, gross $ 44,009 $ 45,021 Less: accumulated depreciation and amortization (42,211) (41,908) Property and equipment, net $ 1,798 $ 3,113 Finance lease liabilities: Finance leases $ 36 $ 612 Finance lease liabilities — less current portion — — Total finance lease liabilities $ 36 $ 612 Weighted average remaining terms were as follows (in years): June 30, 2021 December 31, 2020 Weighted average remaining lease term Operating leases 7.9 2.6 Finance leases 0.2 0.5 Weighted average discount rates were as follows: June 30, 2021 December 31, 2020 Weighted average discount rate Operating leases 3.2 % 4.5 % Finance leases 12.3 % 7.9 % Maturities of lease liabilities were as follows (in thousands): Year Ending December 31, Operating Leases Finance Leases Remaining 2021 $ 3,807 $ 37 2022 10,312 — 2023 8,799 — 2024 6,016 — 2025 4,916 — Thereafter 27,360 Total future minimum lease payments 61,210 37 Less: imputed interest (7,423) (1) Total $ 53,787 $ 36 As of June 30, 2021, the Company entered into additional data center operating leases that had not yet commenced, representing a total commitment over their terms of $1.8 million. These operating leases are expected to commence during the third quarter of 2021 with lease terms of three years.
Leases	Leases The Company has leases for offices, data centers and computer and networking equipment that expire at various dates through 2031. The Company’s leases have remaining terms of one three The Company's Bishop Ranch Lease commenced on February 1, 2021, has a lease term of 10 years, and has a total commitment over its term of $46.4 million, which was the primary component of the increase in operating lease costs, operating lease right-of-use assets and operating lease liabilities for the three and six months ended June 30, 2021. The components of lease expenses were as follows (in thousands): Three Months Ended Six Months Ended June 30, 2021 June 30, 2020 June 30, 2021 June 30, 2020 Operating lease cost $ 2,517 $ 1,515 $ 5,185 $ 3,031 Finance lease cost: Amortization of right-of-use assets $ 544 $ 982 $ 1,261 $ 2,120 Interest on finance lease liabilities 5 63 18 145 Total finance lease cost $ 549 $ 1,045 $ 1,279 $ 2,265 Supplemental cash flow information related to leases was as follows (in thousands): Three Months Ended Six Months Ended June 30, 2021 June 30, 2020 June 30, 2021 June 30, 2020 Cash paid for amounts included in the measurement of lease liabilities: Operating cash used in operating leases $ (1,370) $ (1,607) $ (3,408) $ (3,190) Financing cash used in finance leases (119) (966) (575) (2,195) Right of use assets obtained in exchange for lease obligations: Operating leases 4,090 364 42,429 4,256 Finance leases — — — — Supplemental balance sheet information related to leases was as follows (in thousands): June 30, 2021 December 31, 2020 Operating leases Operating lease right-of-use assets $ 46,966 $ 9,010 Operating lease liabilities $ 7,758 $ 3,912 Operating lease liabilities — less current portion 46,029 5,379 Total operating lease liabilities $ 53,787 $ 9,291 Finance leases Property and equipment, gross $ 44,009 $ 45,021 Less: accumulated depreciation and amortization (42,211) (41,908) Property and equipment, net $ 1,798 $ 3,113 Finance lease liabilities: Finance leases $ 36 $ 612 Finance lease liabilities — less current portion — — Total finance lease liabilities $ 36 $ 612 Weighted average remaining terms were as follows (in years): June 30, 2021 December 31, 2020 Weighted average remaining lease term Operating leases 7.9 2.6 Finance leases 0.2 0.5 Weighted average discount rates were as follows: June 30, 2021 December 31, 2020 Weighted average discount rate Operating leases 3.2 % 4.5 % Finance leases 12.3 % 7.9 % Maturities of lease liabilities were as follows (in thousands): Year Ending December 31, Operating Leases Finance Leases Remaining 2021 $ 3,807 $ 37 2022 10,312 — 2023 8,799 — 2024 6,016 — 2025 4,916 — Thereafter 27,360 Total future minimum lease payments 61,210 37 Less: imputed interest (7,423) (1) Total $ 53,787 $ 36 As of June 30, 2021, the Company entered into additional data center operating leases that had not yet commenced, representing a total commitment over their terms of $1.8 million. These operating leases are expected to commence during the third quarter of 2021 with lease terms of three years.

Acquisitions

Acquisitions	6 Months Ended
	Jun. 30, 2021
Business Combination and Asset Acquisition [Abstract]
Acquisitions	Acquisitions Inference Solutions On November 18, 2020, the Company acquired all of the issued and outstanding shares of Inference for total consideration of approximately $156.7 million. The total consideration comprised of $137.0 million in cash, net of cash acquired, and $18.1 million in estimated fair value of contingent earn out consideration. The contingent earn out consideration is up to $24.0 million and is based upon achievement of certain milestones and relative thresholds during the earn out measurement period which ends on December 31, 2021. The range of amounts that the Company could pay under the contingent consideration arrangement is between $0.0 million and $24.0 million. The fair value of the contingent earn out consideration is estimated to be $23.3 million as of June 30, 2021. See Note 3 for additional information regarding the contingent consideration arrangement. This acquisition, which was accounted for as a business combination, is intended to accelerate the Company’s AI position through the addition of Inference’s widely deployed IVA platform. The excess of the purchase price over identifiable intangible assets and net tangible assets in the amount of $131.0 million was allocated to goodwill, which is not deductible for tax purposes. The fair values assigned to assets acquired and liabilities assumed are based on management’s best estimates and assumptions as of the reporting date and are considered preliminary pending finalization of tax liabilities assumed including calculation of deferred tax assets and liabilities. During the measurement period, which may be up to one year from the acquisition date, the Company may record adjustments to the fair value of these tangible and intangible assets acquired and liabilities assumed, with the corresponding offset to goodwill. The following table presents the preliminary allocation of the purchase price at the acquisition date (in thousands): Cash $ 1,394 Property and equipment acquired 124 Other assets acquired 2,238 Acquired technology 28,600 Customer relationships 1,100 Trade name and trademarks 400 Goodwill 130,976 Total assets acquired 164,832 Liabilities assumed (3,525) Deferred tax liability (4,616) Total consideration $ 156,691 Total consideration (net of cash acquired) $ 155,297 The acquired technology, customer relationships, and trade name will be amortized on a straight-line basis over their assigned useful lives of six years, five years, and two years, respectively. The Company used the income approach to estimate the fair value of intangible assets acquired. In connection with this acquisition, the Company incurred approximately $2.9 million of acquisition costs in 2020, and incurred an additional $0.0 million and $0.3 million in the three and six months ended June 30, 2021, respectively, which have been expensed as incurred and included in general and administrative expense in the condensed consolidated statement of operations and comprehensive loss. The results of operations of this acquisition are included in the accompanying condensed consolidated statements of operations from the date of acquisition. Virtual Observer On April 1, 2020, the Company acquired all of the issued and outstanding shares of common stock of Virtual Observer, formerly Coordinated Systems, Inc., for cash consideration of approximately $32.2 million, subject to adjustment, pursuant to a stock purchase agreement by and among the Company and Robert H. Hutcheon, David R. Brower and Daniel J. McGrail, dated January 15, 2020. This acquisition, was accounted for as a business combination, is intended to expand the Company's portfolio to include a cloud-based Workforce Optimization ("WFO") offering as a complement to its ongoing strategic partnerships with leading WFO providers. The excess of the purchase price over identifiable intangible assets and net tangible assets in the amount of $22.6 million was allocated to goodwill, which is not deductible for tax purposes. The fair values assigned to assets acquired and liabilities assumed are based on management’s best estimates and assumptions as of the reporting date and are considered final. The following table presents the final allocation of the purchase price at the acquisition date (in thousands): Cash $ 168 Tangible assets acquired 200 Acquired technology 12,200 Customer relationships 500 Trade name and trademarks 100 Goodwill 22,646 Total assets acquired 35,814 Deferred tax liability (2,910) Liabilities assumed (682) Total $ 32,222 The acquired technology, customer relationships, and trade name and trademarks will be amortized on a straight-line basis over their estimated useful lives of five years, five years, and two years, respectively. The Company used the income approach to estimate the fair value of intangible assets acquired. In connection with this acquisition, the Company incurred total acquisition-related transaction costs of $0.9 million and $0.3 million in 2020 and 2019, respectively, that have been expensed as incurred and included in general and administrative expenses in the condensed consolidated statements of operations and comprehensive loss.

Subsequent event

Subsequent event	6 Months Ended
	Jun. 30, 2021
Subsequent Events [Abstract]
Subsequent event	Subsequent event On July 16, 2021, the Company entered into the Merger Agreement. The Merger Agreement provides for the merger of Merger Sub with and into the Company, with the Company continuing as the surviving corporation and as a wholly owned subsidiary of Zoom. Subject to the terms and conditions of the Merger Agreement, each issued and outstanding share of the Company’s common stock will be cancelled and automatically converted into the right to receive 0.5533 shares of class A common stock, par value $0.001 per share of Zoom (“Zoom Class A Common Stock”) (with cash being paid, without interest and less applicable withholding taxes, in lieu of any fractional shares of Zoom Class A Common Stock). The shares of Zoom Class A Common Stock to be issued in connection with the Merger will be listed on The Nasdaq Global Select Market (“Nasdaq”). The Merger is intended to qualify as a reorganization for U.S. federal income tax purposes. As a result of the Merger, the Company will cease to be a publicly traded company. The Merger Agreement contains customary representations, warranties and covenants. Under the terms of the Merger Agreement, the completion of the Merger is subject to certain customary closing conditions, including, among others: (i) the approval of the Company’s stockholders; (ii) the approval for listing on Nasdaq of the Zoom Class A Common Stock to be issued in the Merger; (iii) the effectiveness of a registration statement on Form S-4 filed by Zoom registering the Zoom Class A Common Stock to be issued in connection with the Merger; (iv) the accuracy of the parties’ respective representations and warranties in the Merger Agreement, subject to specified materiality qualifications; (v) compliance by the parties with their respective covenants in the Merger Agreement in all material respects; (vi) the receipt of various domestic and foreign regulatory approvals; (vii) the receipt by each party of opinions to the effect that the Merger will qualify as a reorganization for U.S. federal income tax purposes; and (viii) the absence of a material adverse effect with respect to the Company and its subsidiaries on or after the date of the Merger Agreement that is continuing as of immediately prior to the closing. The Mergers are anticipated to close in the first half of the 2022 calendar year, subject to stockholder approval, receipt of required regulatory approvals, and other customary closing conditions. The Company cannot predict with certainty, however, whether and when all of the required closing conditions will be satisfied or if the Merger will close. Each of the Company and Zoom may terminate the Merger Agreement under certain specified circumstances, including if (i) the Merger is not consummated on or before January 16, 2022, subject to two extensions of three months each in order to obtain required regulatory (including telecommunications-related) approvals and one additional extension of three months in order to obtain certain required telecommunications-related approvals, (ii ) the approval of the Company’s stockholders is not obtained, and (iii) the Company’s Board of Directors makes an adverse recommendation change with respect to the proposed transaction or terminates the Merger Agreement to enter into a superior acquisition proposal. In certain circumstances in connection with the termination of the Merger Agreement, including if the Company’s Board of Directors changes or withdraws its recommendation of the Merger to its stockholders or terminates the Merger Agreement to enter into an agreement with respect to a superior acquisition proposal, the Company will be required to pay Zoom a termination fee of $450 million in cash. The foregoing summary of the Merger Agreement and the transactions contemplated thereby does not purport to be complete and is subject to, and qualified in its entirety by, the full text of the Merger Agreement, which is filed as Exhibit 2.1 of the Company’s Current Report on Form 8-K filed on July 19, 2021 and incorporated by reference herein.

Description of Business and S_2

Description of Business and Summary of Significant Accounting Policies (Policies)	6 Months Ended
	Jun. 30, 2021
Accounting Policies [Abstract]
Basis of Presentation	Basis of Presentation The accompanying condensed consolidated financial statements have been prepared in accordance with generally accepted accounting principles in the United States (“GAAP”) and applicable rules and regulations of the Securities and Exchange Commission (“SEC”) regarding interim financial reporting. Certain information and note disclosures normally included in 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 consolidated financial statements and notes included in the Company’s Annual Report on Form 10-K for the year ended December 31, 2020. In the opinion of management, the condensed consolidated financial statements reflect all adjustments, which are normal and recurring in nature, necessary for fair financial statement presentation. All intercompany transactions and balances have been eliminated in consolidation.
Use of Estimates	Use of Estimates The preparation of condensed consolidated financial statements in accordance with GAAP requires management to make estimates and assumptions that affect the reported amounts of assets and liabilities and disclosure of contingent assets and liabilities at the date of the condensed consolidated financial statements and the reported amounts of revenue and expenses during the reporting period. The significant estimates made by management affect revenue and related reserves, as well as the fair value of liabilities assumed through business combinations. Management periodically evaluates such estimates and they are adjusted prospectively based upon such periodic evaluation. Actual results could differ from those estimates.
Recently Adopted Accounting Pronouncements and Recent Accounting Pronouncements Not Yet Effective	Recently Adopted Accounting Pronouncements In August 2020, the FASB issued ASU No. 2020-06, Debt-Debt with Conversion and Other Options (Subtopic 470-20) and Derivatives and Hedging-Contracts in Entity’s Own Equity (Subtopic 815-40): Accounting for Convertible Instruments and Contracts in an Entity’s Own Equity ("ASU 2020-06"), which simplifies the accounting for convertible instruments by removing the separation models for (1) convertible debt with a cash conversion feature and (2) convertible instruments with a beneficial conversion feature. The Company elected to early adopt ASU 2020-06 as of January 1, 2021 using a modified retrospective transition method. Applying the transition guidance, the Company was required to apply the guidance to all impacted financial instruments that were outstanding as of January 1, 2021 with the cumulative effect recognized as an adjustment to the opening balance of accumulated deficit. As a result of early adopting ASU 2020-06, the Company made certain adjustments to its accounting for the outstanding 0.125% convertible senior notes due 2023 (the "2023 convertible senior notes") and the outstanding 0.500% convertible senior notes due 2025 (the "2025 convertible senior notes", and, together with the 2023 convertible senior notes, the "convertible senior notes"). The adoption of ASU 2020-06 resulted in the re-combination of the liability and equity components of the convertible senior notes into a single liability instrument, which required the Company to record a $168.4 million decrease in additional paid in capital from the derecognition of the separated equity components of these notes, a $145.7 million increase in debt from the derecognition of the discount associated with the separated equity components of the convertible senior notes, and a $22.7 million cumulative effect decrease to the opening balance of its accumulated deficit as of January 1, 2021 upon transition. Interest expense recognized in future periods will be reduced as a result of accounting for the convertible senior notes as a single liability instrument. Since the Company had a net loss for the three and six months ended June 30, 2021, the convertible senior notes were determined to be anti-dilutive and therefore had no impact to basic or diluted net loss per share for the periods as a result of adopting ASU 2020-06. In December 2019, the FASB issued ASU No. 2019-12, Income Taxes (Topic 740): Simplifying the Accounting for Income Taxes (“ASU 2019-12”), which amends its guidance to simplify the accounting for income taxes by, among other things, removing exceptions to certain general principles in Topic 740, Income Taxes. The standard is effective for the Company beginning in the first quarter of 2021. The Company has adopted ASU 2019-12 and concluded that the impact on its condensed consolidated financial statements was immaterial. Recent Accounting Pronouncements Not Yet Effective The Company has reviewed or is in the process of evaluating all issued, but not yet effective, accounting pronouncements and does not believe the future adoption of any such accounting pronouncements will cause a material impact on its condensed consolidated financial position, operating results or cash flows.
Receivables	The Company receives payments from customers based upon billing cycles. Invoice payment terms are usually 30 days or less. Accounts receivable are recorded when the right to consideration becomes unconditional.
Deferred Contract Acquisition	Deferred contract acquisition costs are recorded when incurred and are amortized over an estimated customer benefit period of five years.
Revenue	The Company’s contract assets consist of unbilled amounts typically resulting from professional services revenue recognition when it exceeds the total amounts billed to the customer. The Company’s contract liabilities consist of advance payments and billings in excess of revenue recognized.

Revenue (Tables)

Revenue (Tables)	6 Months Ended
	Jun. 30, 2021
Revenue from Contract with Customer [Abstract]
Contract Balances	The following table provides information about accounts receivable, net, deferred contract acquisition costs, net, contract assets and contract liabilities from contracts with customers (in thousands): June 30, 2021 December 31, 2020 Accounts receivable, net $ 53,811 $ 48,731 Deferred contract acquisition costs, net: Current $ 26,791 $ 20,695 Non-current 69,689 51,934 Total deferred contract acquisition costs, net $ 96,480 $ 72,629 Contract assets and contract liabilities: Contract assets (included in prepaid expenses and other current assets) $ 1,654 $ 1,297 Contract liabilities (deferred revenue) 33,237 31,983 Contract liabilities (deferred revenue) (included in other long-term liabilities) 2,592 3,373 Net contract liabilities $ (34,175) $ (34,059)

Investments and Fair Value Me_2

Investments and Fair Value Measurements (Tables)	6 Months Ended
	Jun. 30, 2021
Fair Value Disclosures [Abstract]
Schedule of Marketable Investments	The Company’s marketable investments have been classified and accounted for as available-for-sale. The Company’s marketable investments as of June 30, 2021 and December 31, 2020 were as follows (in thousands): June 30, 2021 Short-Term Marketable Investments Cost Gross Unrealized Gains Gross Unrealized Losses Fair Value Certificates of deposit $ 1,788 $ 1 $ — $ 1,789 U.S. treasury 237,848 21 (4) 237,865 U.S. agency securities 76,909 12 (3) 76,918 Commercial paper 40,358 — — 40,358 Municipal bonds 25,236 2 (2) 25,236 Corporate bonds 8,821 1 (2) 8,820 Total $ 390,960 $ 37 $ (11) $ 390,986 June 30, 2021 Long-term Marketable Investments Cost Gross Unrealized Gains Gross Unrealized Losses Fair Value Certificates of deposit $ 509 $ 1 $ — $ 510 U.S. treasury 2,994 — — 2,994 U.S. agency securities 53,252 — (31) 53,221 Municipal bonds 14,858 3 (2) 14,859 Corporate bonds 1,174 — — 1,174 Total $ 72,787 $ 4 $ (33) $ 72,758 December 31, 2020 Short-Term Marketable Investments Cost Gross Unrealized Gains Gross Unrealized Losses Fair Value Certificates of deposit $ 3,479 $ 1 $ — $ 3,480 U.S. treasury 287,315 41 (4) 287,352 U.S. agency securities 67,227 12 (6) 67,233 Commercial paper 5,093 — — 5,093 Municipal bonds 2,684 1 (1) 2,684 Corporate bonds 17,323 6 — 17,329 Total $ 383,121 $ 61 $ (11) $ 383,171 December 31, 2020 Long-term Marketable Investments Cost Gross Unrealized Gains Gross Unrealized Losses Fair Value U.S. treasury $ 10,189 $ — $ — $ 10,189 U.S. agency securities 31,469 9 (1) 31,477 Municipal bonds 461 — — 461 Total $ 42,119 $ 9 $ (1) $ 42,127
Schedule of Gross Unrealized Losses and Fair Value of Marketable Investments	The following table presents the gross unrealized losses and the fair value for those marketable investments that were in an unrealized loss position for less than 12 months as of June 30, 2021 and December 31, 2020 (in thousands): June 30, 2021 December 31, 2020 Gross Unrealized Losses Fair Value Gross Unrealized Losses Fair Value U.S. treasury $ (4) $ 48,266 $ (4) $ 78,549 U.S. agency securities (34) 81,845 (7) 39,443 Municipal bonds (4) 17,263 (1) 1,201 Corporate bonds (2) 7,444 (1) 1,347 Total $ (44) $ 154,818 $ (13) $ 120,540
Schedule of Marketable Investments by Contractual Maturity	The amortized cost and fair values of the Company’s marketable investments by contractual maturity as of June 30, 2021 and December 31, 2020 were as follows (in thousands): June 30, 2021 December 31, 2020 Cost Fair Value Cost Fair Value Due within one year $ 390,960 $ 390,986 $ 383,121 $ 383,171 Due after one year 72,787 72,758 42,119 42,127 Total $ 463,747 $ 463,744 $ 425,240 $ 425,298
Schedule of Assets Carried at Fair Value	The following tables set forth the Company’s assets measured at fair value by level within the fair value hierarchy (in thousands): June 30, 2021 Level 1 Level 2 Level 3 Total Assets Cash equivalents Money market funds $ 53,799 $ — $ — $ 53,799 Municipal bonds — 14,644 — 14,644 Total cash equivalents $ 53,799 $ 14,644 $ — $ 68,443 Marketable investments (short and long term) Certificates of deposit $ — $ 2,299 $ — $ 2,299 U.S. treasury 240,859 — — 240,859 U.S. agency securities and government sponsored securities — 130,139 — 130,139 Commercial paper — 40,358 — 40,358 Municipal bonds — 40,095 — 40,095 Corporate bonds — 9,994 — 9,994 Total marketable investments $ 240,859 $ 222,885 $ — $ 463,744 Liabilities Contingent consideration $ — $ — $ 23,300 $ 23,300 December 31, 2020 Level 1 Level 2 Level 3 Total Assets Cash equivalents Money market funds $ 89,888 $ — $ — $ 89,888 U.S. treasury 39,997 — — 39,997 Total cash equivalents $ 129,885 $ — $ — $ 129,885 Marketable investments (short and long-term) Certificates of deposit $ — $ 3,480 $ — $ 3,480 U.S. treasury 297,540 — — 297,540 U.S. agency securities — 98,711 — 98,711 Commercial paper — 5,093 — 5,093 Municipal bonds — 3,145 — 3,145 Corporate bonds — 17,329 — 17,329 Total marketable investments $ 297,540 $ 127,758 $ — $ 425,298 Liabilities Contingent consideration $ — $ — $ 18,100 $ 18,100
Summary of the Changes for Contingent Consideration Liabilities	A reconciliation of the beginning and ending balance for contingent consideration consisted of the following (in thousands): Three Months Ended June 30, 2021 Six Months Ended June 30, 2021 Balance, beginning of period $ 20,600 $ 18,100 Change in fair value of contingent consideration 2,700 5,200 Balance, end of period $ 23,300 $ 23,300

Financial Statement Components

Financial Statement Components (Tables)	6 Months Ended
	Jun. 30, 2021
Financial Statement Components [Abstract]
Schedule of Cash and Cash Equivalents	Cash and cash equivalents consisted of the following (in thousands): June 30, 2021 December 31, 2020 Cash $ 106,756 $ 90,487 Money market funds 53,799 89,888 U.S. treasury — 39,997 Municipal bonds 14,644 — Total cash and cash equivalents $ 175,199 $ 220,372
Schedule of Accounts Receivable	Accounts receivable, net consisted of the following (in thousands): June 30, 2021 December 31, 2020 Trade accounts receivable $ 48,501 $ 42,366 Unbilled trade accounts receivable, net of advance client deposits 5,451 6,492 Allowance for doubtful accounts (141) (127) Accounts receivable, net $ 53,811 $ 48,731
Schedule of Prepaid Expenses and Other Current Assets	Prepaid expenses and other current assets consisted of the following (in thousands): June 30, 2021 December 31, 2020 Prepaid expenses $ 13,724 $ 9,816 Other current assets 6,732 5,036 Contract assets 1,654 1,297 Prepaid expenses and other current assets $ 22,110 $ 16,149
Schedule of Property and Equipment	Property and equipment, net consisted of the following (in thousands): June 30, 2021 December 31, 2020 Computer and network equipment $ 101,047 $ 89,763 Computer software 32,694 25,888 Internal-use software development costs 500 500 Furniture and fixtures 3,964 3,372 Leasehold improvements 5,531 2,335 Property and equipment 143,736 121,858 Accumulated depreciation and amortization (80,629) (70,645) Property and equipment, net $ 63,107 $ 51,213 Property and equipment capitalized under finance lease obligations consists primarily of computer and network equipment and was as follows (in thousands): June 30, 2021 December 31, 2020 Gross $ 44,009 $ 45,021 Less: accumulated depreciation and amortization (42,211) (41,908) Total $ 1,798 $ 3,113
Schedule of Accrued and Other Current Liabilities	Accrued and other current liabilities consisted of the following (in thousands): June 30, 2021 December 31, 2020 Accrued expenses $ 15,068 $ 15,217 Accrued compensation and benefits 35,656 29,233 Contingent consideration 23,300 — Accrued and other current liabilities $ 74,024 $ 44,450
Schedule of Long-term Liabilities	Other long-term liabilities consisted of the following (in thousands): June 30, 2021 December 31, 2020 Deferred revenue $ 2,592 $ 3,373 Deferred tax liabilities 3,511 4,438 Other long-term liabilities 7,010 5,554 Contingent consideration — 18,100 Other long-term liabilities $ 13,113 $ 31,465

Goodwill and Intangible Assets

Goodwill and Intangible Assets (Tables)	6 Months Ended
	Jun. 30, 2021
Goodwill and Intangible Assets Disclosure [Abstract]
Intangible Assets Activity	The following table summarizes the activity in the Company's intangible assets balance during the three and six months ended June 30, 2021 (in thousands): Three Months Ended June 30, 2021 Six Months Ended June 30, 2021 Beginning of the period $ 48,737 $ 51,684 Amortization (2,947) (5,894) End of the period $ 45,790 $ 45,790
Schedule of Intangible Assets	The components of intangible assets were as follows (in thousands): June 30, 2021 December 31, 2020 Gross Carrying Amount Accumulated Amortization Net Carrying Amount Weighted Average Remaining Amortization period (Years) Gross Carrying Amount Accumulated Amortization Net Carrying Amount Weighted Average Remaining Amortization period (Years) Developed technology $ 56,214 $ (12,291) $ 43,923 4.5 $ 56,214 $ (6,761) $ 49,453 4.9 Acquired workforce 470 (256) 214 1.4 470 (177) 293 1.9 Customer relationships 1,600 (261) 1,339 4.2 1,600 (101) 1,499 4.7 Trademarks 500 (186) 314 1.3 500 (61) 439 1.8 Total $ 58,784 $ (12,994) $ 45,790 4.4 $ 58,784 $ (7,100) $ 51,684 4.9
Schedule of Expected Future Amortization Expense of Intangible Assets	As of June 30, 2021, the expected future amortization expense for intangible assets was as follows (in thousands): Period Expected Future Amortization Expense Remaining 2021 $ 5,893 2022 11,704 2023 10,870 2024 7,527 2025 5,596 Thereafter 4,200 Total $ 45,790

Debt (Tables)

Debt (Tables)	6 Months Ended
	Jun. 30, 2021
Convertible Senior Notes, Due 2025
Debt Instrument [Line Items]
Schedule of Net Carrying Amount of Notes and Impact to Additional Paid-in Capital	The net carrying amount of the 2025 convertible senior notes as of June 30, 2021 (post-ASU 2020-06 adoption) and as of December 31, 2020 (pre-ASU 2020-06 adoption) was as follows (in thousands): June 30, 2021 December 31, 2020 Principal $ 747,500 $ 747,500 Unamortized debt discount — (141,792) Unamortized issuance costs (14,707) (13,192) Net carrying amount $ 732,793 $ 592,516 The net carrying amount of the equity component of the 2025 convertible senior notes as of June 30, 2021 (post-ASU 2020-06 adoption) and as of December 31, 2020 (pre-ASU 2020-06 adoption) was as follows (in thousands): June 30, 2021 December 31, 2020 Equity component $ — $ 158,321 Issuance costs — (3,958) Net carrying amount $ — $ 154,363
Schedule of Interest Expense Related to the Notes	Interest expense related to the 2025 convertible senior notes was as follows (in thousands): Three Months Ended Six Months Ended June 30, 2021 June 30, 2020 June 30, 2021 June 30, 2020 Contractual interest expense $ 1,121 $ 362 $ 2,055 $ 362 Amortization of debt discount — 2,528 — 2,528 Amortization of issuance costs 912 235 1,802 235 Total interest expense $ 2,033 $ 3,125 $ 3,857 $ 3,125
Schedule of Maturities of Debt	Maturity of the Company’s 2025 convertible senior notes as of June 30, 2021 was as follows (in thousands): Period Amount to Mature 2025 (Maturity date of June 1, 2025) $ 747,500 Total $ 747,500
Convertible Senior Notes, Due 2023
Debt Instrument [Line Items]
Schedule of Net Carrying Amount of Notes and Impact to Additional Paid-in Capital	The net carrying amount of the 2023 convertible senior notes as of June 30, 2021 (post-ASU 2020-06 adoption) and as of December 31, 2020 (pre-ASU 2020-06 adoption) was as follows (in thousands): June 30, 2021 December 31, 2020 Principal $ 41,278 $ 58,867 Unamortized debt discount — (7,367) Unamortized issuance costs (483) (700) Net carrying amount $ 40,795 $ 50,800 The net carrying amount of the equity component of the 2023 convertible senior notes as of June 30, 2021 (post-ASU 2020-06 adoption) and as of December 31, 2020 (pre-ASU 2020-06 adoption) was as follows (in thousands): June 30, 2021 December 31, 2020 Equity component $ — $ 14,505 Issuance costs — (455) Net carrying amount $ — $ 14,050
Schedule of Interest Expense Related to the Notes	Interest expense related to the 2023 convertible senior notes was as follows (in thousands): Three Months Ended Six Months Ended June 30, 2021 June 30, 2020 June 30, 2021 June 30, 2020 Contractual interest expense $ 6 $ 60 $ 23 $ 141 Amortization of debt discount — 2,272 — 5,304 Amortization of issuance costs 73 216 157 504 Total interest expense $ 79 $ 2,548 $ 180 $ 5,949
Schedule of Maturities of Debt	Maturity of the Company’s 2023 convertible senior notes as of June 30, 2021 was as follows (in thousands): Period Amount to Mature 2023 (Maturity date of May 1, 2023) $ 41,278 Total $ 41,278

Stockholders' Equity (Tables)

Stockholders' Equity (Tables)	6 Months Ended
	Jun. 30, 2021
Equity [Abstract]
Schedule of Common Stock Reserved for Future Issuance	Shares of common stock reserved for future issuance related to outstanding equity awards and employee equity incentive plans were as follows (in thousands): June 30, 2021 Stock options outstanding 2,129 Restricted stock units outstanding 2,273 Shares available for future grant under 2014 Plan 14,165 Shares available for future issuance under ESPP 3,129 Total shares of common stock reserved 21,696
Schedule of Stock Option Activity	A summary of the Company’s stock option activity during the six months ended June 30, 2021 is as follows (in thousands, except years and per share data): Number of Weighted Weighted Aggregate Outstanding as of December 31, 2020 2,255 $ 26.33 Options granted (weighted average grant date fair value of $81.48 per share) 130 180.76 Options exercised (246) 18.05 Options forfeited or expired (10) 82.62 Outstanding as of June 30, 2021 2,129 $ 36.47 5.3 $ 312,868
Schedule of RSU Activity	A summary of the Company’s restricted stock unit ("RSU"), activity during the six months ended June 30, 2021 is as follows (in thousands, except per share data): Number of Shares Weighted Average Grant Date Fair Value Per Share Outstanding as of December 31, 2020 2,267 $ 65.42 RSUs granted 691 179.79 RSUs vested and released (596) 58.11 RSUs forfeited (89) 83.94 Outstanding as of June 30, 2021 2,273 100.80
Schedule of Stock-based Compensation Expense	Stock-based compensation expense was as follows (in thousands): Three Months Ended Six Months Ended June 30, 2021 June 30, 2020 June 30, 2021 June 30, 2020 Cost of revenue $ 3,781 $ 2,499 $ 6,886 $ 4,488 Research and development 6,152 3,684 10,915 6,491 Sales and marketing 8,208 5,265 14,979 9,371 General and administrative 6,760 5,343 13,029 10,235 Total stock-based compensation $ 24,901 $ 16,791 $ 45,809 $ 30,585
Schedule of Unrecognized Compensation Expense	As of June 30, 2021, unrecognized stock-based compensation expense by award type and their expected weighted-average recognition periods are summarized in the following table (in thousands, except years). Stock Option RSU ESPP Unrecognized stock-based compensation expense $ 26,930 $ 217,556 $ 1,907 Weighted-average amortization period 2.7 years 3.1 years 0.4 years
Schedule of Valuation Assumptions, Stock Option	The weighted-average assumptions used to value stock options granted during the periods presented were as follows: Stock Options Three Months Ended Six Months Ended June 30, 2021 June 30, 2020 June 30, 2021 June 30, 2020 Expected term (years) 6.0 6.0 6.0 6.0 Volatility 47 % 48 % 47 % 47 % Risk-free interest rate 1.0 % 0.4 % 1.0 % 1.1 % Dividend yield (1) — — — — (1) The Company has not paid, and does not anticipate paying, cash dividends on its shares of common stock. Accordingly, the expected dividend yield is zero.

Net Loss Per Share (Tables)

Net Loss Per Share (Tables)	6 Months Ended
	Jun. 30, 2021
Earnings Per Share [Abstract]
Basic and Diluted Net Loss Per Share	The following table presents the calculation of basic and diluted net loss per share (in thousands, except per share data): Three Months Ended Six Months Ended June 30, 2021 June 30, 2020 June 30, 2021 June 30, 2020 Net loss $ (16,530) $ (16,052) $ (28,862) $ (23,489) Weighted-average shares used in computing basic and diluted net loss per share 67,292 63,282 67,008 62,494 Basic and diluted net loss per share $ (0.25) $ (0.25) $ (0.43) $ (0.38)
Schedule of Antidilutive Securities Excluded from Computation of Net Loss Per Share	The following securities were excluded from the calculation of diluted net loss per share because their effect would have been anti-dilutive (in thousands): Three Months Ended Six Months Ended June 30, 2021 June 30, 2020 June 30, 2021 June 30, 2020 Stock options 2,129 2,431 2,129 2,431 Restricted stock units 2,273 2,753 2,273 2,753 Convertible senior notes (1) 6,708 1,106 6,796 984 Total 11,110 6,290 11,198 6,168

Geographical Information (Table

Geographical Information (Tables)	6 Months Ended
	Jun. 30, 2021
Segment Reporting [Abstract]
Schedule of Revenues and Property and Equipment by Geographic Region	The following table summarizes revenues by geographic region based on client billing address (in thousands): Three Months Ended Six Months Ended June 30, 2021 June 30, 2020 June 30, 2021 June 30, 2020 United States $ 131,257 $ 91,784 $ 257,143 $ 179,215 International 12,525 8,008 24,521 15,665 Total revenue $ 143,782 $ 99,792 $ 281,664 $ 194,880 The following table summarizes total property and equipment, net in the respective locations (in thousands): June 30, 2021 December 31, 2020 United States $ 54,748 $ 43,339 International 8,359 7,874 Property and equipment, net $ 63,107 $ 51,213

Leases (Tables)

Leases (Tables)	6 Months Ended
	Jun. 30, 2021
Leases [Abstract]
Schedule of Lease Expenses	The components of lease expenses were as follows (in thousands): Three Months Ended Six Months Ended June 30, 2021 June 30, 2020 June 30, 2021 June 30, 2020 Operating lease cost $ 2,517 $ 1,515 $ 5,185 $ 3,031 Finance lease cost: Amortization of right-of-use assets $ 544 $ 982 $ 1,261 $ 2,120 Interest on finance lease liabilities 5 63 18 145 Total finance lease cost $ 549 $ 1,045 $ 1,279 $ 2,265 Supplemental cash flow information related to leases was as follows (in thousands): Three Months Ended Six Months Ended June 30, 2021 June 30, 2020 June 30, 2021 June 30, 2020 Cash paid for amounts included in the measurement of lease liabilities: Operating cash used in operating leases $ (1,370) $ (1,607) $ (3,408) $ (3,190) Financing cash used in finance leases (119) (966) (575) (2,195) Right of use assets obtained in exchange for lease obligations: Operating leases 4,090 364 42,429 4,256 Finance leases — — — — Weighted average remaining terms were as follows (in years): June 30, 2021 December 31, 2020 Weighted average remaining lease term Operating leases 7.9 2.6 Finance leases 0.2 0.5 Weighted average discount rates were as follows: June 30, 2021 December 31, 2020 Weighted average discount rate Operating leases 3.2 % 4.5 % Finance leases 12.3 % 7.9 %
Schedule of Balance Sheet Information Related to Leases	Supplemental balance sheet information related to leases was as follows (in thousands): June 30, 2021 December 31, 2020 Operating leases Operating lease right-of-use assets $ 46,966 $ 9,010 Operating lease liabilities $ 7,758 $ 3,912 Operating lease liabilities — less current portion 46,029 5,379 Total operating lease liabilities $ 53,787 $ 9,291 Finance leases Property and equipment, gross $ 44,009 $ 45,021 Less: accumulated depreciation and amortization (42,211) (41,908) Property and equipment, net $ 1,798 $ 3,113 Finance lease liabilities: Finance leases $ 36 $ 612 Finance lease liabilities — less current portion — — Total finance lease liabilities $ 36 $ 612
Schedule of Operating Lease Maturities	Maturities of lease liabilities were as follows (in thousands): Year Ending December 31, Operating Leases Finance Leases Remaining 2021 $ 3,807 $ 37 2022 10,312 — 2023 8,799 — 2024 6,016 — 2025 4,916 — Thereafter 27,360 Total future minimum lease payments 61,210 37 Less: imputed interest (7,423) (1) Total $ 53,787 $ 36
Schedule of Finance Lease Maturities	Maturities of lease liabilities were as follows (in thousands): Year Ending December 31, Operating Leases Finance Leases Remaining 2021 $ 3,807 $ 37 2022 10,312 — 2023 8,799 — 2024 6,016 — 2025 4,916 — Thereafter 27,360 Total future minimum lease payments 61,210 37 Less: imputed interest (7,423) (1) Total $ 53,787 $ 36

Acquisitions (Tables)

Acquisitions (Tables)	6 Months Ended
	Jun. 30, 2021
Business Combination and Asset Acquisition [Abstract]
Schedule of Recognized Identified Assets Acquired and Liabilities Assumed	The following table presents the preliminary allocation of the purchase price at the acquisition date (in thousands): Cash $ 1,394 Property and equipment acquired 124 Other assets acquired 2,238 Acquired technology 28,600 Customer relationships 1,100 Trade name and trademarks 400 Goodwill 130,976 Total assets acquired 164,832 Liabilities assumed (3,525) Deferred tax liability (4,616) Total consideration $ 156,691 Total consideration (net of cash acquired) $ 155,297 Cash $ 168 Tangible assets acquired 200 Acquired technology 12,200 Customer relationships 500 Trade name and trademarks 100 Goodwill 22,646 Total assets acquired 35,814 Deferred tax liability (2,910) Liabilities assumed (682) Total $ 32,222

Description of Business and S_3

Description of Business and Summary of Significant Accounting Policies (Details) - USD ($) $ in Thousands		Jun. 30, 2021	Mar. 31, 2021	Dec. 31, 2020	Jun. 30, 2020	Mar. 31, 2020	Dec. 31, 2019	May 31, 2018
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Adjustment to stockholders' equity		$ 162,706	$ 144,206	$ 279,164	$ 254,408	$ 206,466	$ 196,458
Cumulative Effect, Period of Adoption, Adjustment
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Adjustment to stockholders' equity	[1]			(145,669)
Cumulative Effect, Period of Adoption, Adjustment | ASU 2020-06
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Adjustment to stockholders' equity				145,700
Convertible Senior Notes, Due 2023 | Convertible debt
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Stated interest rate on debt (percent)								0.125%
Convertible Senior Notes, Due 2025 | Convertible debt
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Stated interest rate on debt (percent)					0.50%
Additional Paid-In Capital
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Adjustment to stockholders' equity		366,637	331,528	476,941	$ 432,877	368,260	351,870
Additional Paid-In Capital | Cumulative Effect, Period of Adoption, Adjustment
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Adjustment to stockholders' equity	[1]			(168,412)
Additional Paid-In Capital | Cumulative Effect, Period of Adoption, Adjustment | ASU 2020-06
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Adjustment to stockholders' equity				(168,400)
Accumulated Deficit
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Adjustment to stockholders' equity		$ (204,298)	$ (187,768)	(198,179)	$ (179,538)	$ (163,486)	$ (156,049)
Accumulated Deficit | Cumulative Effect, Period of Adoption, Adjustment
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Adjustment to stockholders' equity	[1]			22,743
Accumulated Deficit | Cumulative Effect, Period of Adoption, Adjustment | ASU 2020-06
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Adjustment to stockholders' equity				(22,700)
Revision of Prior Period, Error Correction, Adjustment | Unwind Of Partially Capped Calls On Convertible Debt | Additional Paid-In Capital
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Adjustment to stockholders' equity				2,300
Revision of Prior Period, Error Correction, Adjustment | Unwind Of Partially Capped Calls On Convertible Debt | Treasury Stock
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Adjustment to stockholders' equity				$ (2,300)
[1]	Effective January 1, 2021, the Company adopted ASU 2020-06. Accordingly, the Company recorded a net reduction to opening accumulated deficit of $22.7 million and a net reduction to opening additional paid-in capital of $168.4 million as of January 1, 2021 due to the cumulative impact of adopting this new standard. See Note 1 for more information.

Revenue - Contract Balances (De

Revenue - Contract Balances (Details) - USD ($) $ in Thousands	Jun. 30, 2021	Dec. 31, 2020
Revenue from Contract with Customer [Abstract]
Accounts receivable, net	$ 53,811	$ 48,731
Deferred contract acquisition costs, current	26,791	20,695
Deferred contract acquisition costs, non-current	69,689	51,934
Total deferred contract acquisition costs, net	96,480	72,629
Contract assets (included in prepaid expenses and other current assets)	1,654	1,297
Contract liabilities (deferred revenue)	33,237	31,983
Contract liabilities (deferred revenue) (included in other long-term liabilities)	2,592	3,373
Net contract liabilities	$ (34,175)	$ (34,059)

Revenue - Narrative (Details)

Revenue - Narrative (Details) $ in Millions	3 Months Ended	6 Months Ended
	Jun. 30, 2021USD ($)	Jun. 30, 2021USD ($)
Revenue, Initial Application Period Cumulative Effect Transition [Line Items]
Contract revenue recognized	$ 5	$ 25.3
Contract acquisition costs
Revenue, Initial Application Period Cumulative Effect Transition [Line Items]
Amortization period of capitalized contract cost	5 years	5 years

Revenue - Remaining Performance

Revenue - Remaining Performance Obligations (Details) $ in Millions	6 Months Ended
	Jun. 30, 2021USD ($)
Revenue from Contract with Customer [Abstract]
Performance obligation	$ 443
Performance obligation, description of timing	The Company expects to recognize revenue on approximately three-fourths of the remaining performance obligation over the next 24 months, with the balance recognized thereafter. The Company has elected the optional exemption, which allows for the exclusion of the amounts for remaining performance obligations that are part of contracts with an original expected duration of one year or less. Such remaining performance obligations represent unsatisfied or partially unsatisfied performance obligations pursuant to ASC 606
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items]
Performance obligation	$ 443
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2021-07-01
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items]
Remaining performance obligation expected to be recognized (percent)	75.00%
Performance obligation satisfaction period	24 months

Investments and Fair Value Me_3

Investments and Fair Value Measurements - Schedule of Marketable Investments (Details) - USD ($) $ in Thousands	Jun. 30, 2021	Dec. 31, 2020
Debt Securities, Available-for-sale [Line Items]
Cost	$ 463,747	$ 425,240
Fair Value	463,744	425,298
Short-Term Marketable Investments
Debt Securities, Available-for-sale [Line Items]
Cost	390,960	383,121
Gross Unrealized Gains	37	61
Gross Unrealized Losses	(11)	(11)
Fair Value	390,986	383,171
Long-term Marketable Investments
Debt Securities, Available-for-sale [Line Items]
Cost	72,787	42,119
Gross Unrealized Gains	4	9
Gross Unrealized Losses	(33)	(1)
Fair Value	72,758	42,127
Certificates of deposit
Debt Securities, Available-for-sale [Line Items]
Fair Value	2,299	3,480
Certificates of deposit | Short-Term Marketable Investments
Debt Securities, Available-for-sale [Line Items]
Cost	1,788	3,479
Gross Unrealized Gains	1	1
Gross Unrealized Losses	0	0
Fair Value	1,789	3,480
Certificates of deposit | Long-term Marketable Investments
Debt Securities, Available-for-sale [Line Items]
Cost	509
Gross Unrealized Gains	1
Gross Unrealized Losses	0
Fair Value	510
U.S. treasury
Debt Securities, Available-for-sale [Line Items]
Fair Value	240,859	297,540
U.S. treasury | Short-Term Marketable Investments
Debt Securities, Available-for-sale [Line Items]
Cost	237,848	287,315
Gross Unrealized Gains	21	41
Gross Unrealized Losses	(4)	(4)
Fair Value	237,865	287,352
U.S. treasury | Long-term Marketable Investments
Debt Securities, Available-for-sale [Line Items]
Cost	2,994	10,189
Gross Unrealized Gains	0	0
Gross Unrealized Losses	0	0
Fair Value	2,994	10,189
U.S. agency securities
Debt Securities, Available-for-sale [Line Items]
Fair Value	130,139	98,711
U.S. agency securities | Short-Term Marketable Investments
Debt Securities, Available-for-sale [Line Items]
Cost	76,909	67,227
Gross Unrealized Gains	12	12
Gross Unrealized Losses	(3)	(6)
Fair Value	76,918	67,233
U.S. agency securities | Long-term Marketable Investments
Debt Securities, Available-for-sale [Line Items]
Cost	53,252	31,469
Gross Unrealized Gains	0	9
Gross Unrealized Losses	(31)	(1)
Fair Value	53,221	31,477
Commercial paper
Debt Securities, Available-for-sale [Line Items]
Fair Value	40,358	5,093
Commercial paper | Short-Term Marketable Investments
Debt Securities, Available-for-sale [Line Items]
Cost	40,358	5,093
Gross Unrealized Gains	0	0
Gross Unrealized Losses	0	0
Fair Value	40,358	5,093
Municipal bonds
Debt Securities, Available-for-sale [Line Items]
Fair Value	40,095	3,145
Municipal bonds | Short-Term Marketable Investments
Debt Securities, Available-for-sale [Line Items]
Cost	25,236	2,684
Gross Unrealized Gains	2	1
Gross Unrealized Losses	(2)	(1)
Fair Value	25,236	2,684
Municipal bonds | Long-term Marketable Investments
Debt Securities, Available-for-sale [Line Items]
Cost	14,858	461
Gross Unrealized Gains	3	0
Gross Unrealized Losses	(2)	0
Fair Value	14,859	461
Corporate bonds
Debt Securities, Available-for-sale [Line Items]
Fair Value	9,994	17,329
Corporate bonds | Short-Term Marketable Investments
Debt Securities, Available-for-sale [Line Items]
Cost	8,821	17,323
Gross Unrealized Gains	1	6
Gross Unrealized Losses	(2)	0
Fair Value	8,820	$ 17,329
Corporate bonds | Long-term Marketable Investments
Debt Securities, Available-for-sale [Line Items]
Cost	1,174
Gross Unrealized Gains	0
Gross Unrealized Losses	0
Fair Value	$ 1,174

Investments and Fair Value Me_4

Investments and Fair Value Measurements - Schedule of Continuous Unrealized Loss Position (Details) - USD ($) $ in Thousands	Jun. 30, 2021	Dec. 31, 2020
Debt Securities, Available-for-sale [Line Items]
Gross Unrealized Losses	$ (44)	$ (13)
Fair Value	154,818	120,540
U.S. treasury
Debt Securities, Available-for-sale [Line Items]
Gross Unrealized Losses	(4)	(4)
Fair Value	48,266	78,549
U.S. agency securities
Debt Securities, Available-for-sale [Line Items]
Gross Unrealized Losses	(34)	(7)
Fair Value	81,845	39,443
Municipal bonds
Debt Securities, Available-for-sale [Line Items]
Gross Unrealized Losses	(4)	(1)
Fair Value	17,263	1,201
Corporate bonds
Debt Securities, Available-for-sale [Line Items]
Gross Unrealized Losses	(2)	(1)
Fair Value	$ 7,444	$ 1,347

Investments and Fair Value Me_5

Investments and Fair Value Measurements - Maturity Dates (Details) - USD ($) $ in Thousands	Jun. 30, 2021	Dec. 31, 2020
Cost
Due within one year	$ 390,960	$ 383,121
Due after one year	72,787	42,119
Cost	463,747	425,240
Fair Value
Due within one year	390,986	383,171
Due after one year	72,758	42,127
Total	$ 463,744	$ 425,298

Investments and Fair Value Me_6

Investments and Fair Value Measurements - Schedule of Assets Carried at Fair Value (Details) - USD ($) $ in Thousands	Jun. 30, 2021	Dec. 31, 2020
Assets
Cash equivalents	$ 68,443	$ 129,885
Marketable investments (short and long term)	463,744	425,298
Liabilities
Contingent consideration	23,300	18,100
Level 1
Assets
Cash equivalents	53,799	129,885
Marketable investments (short and long term)	240,859	297,540
Liabilities
Contingent consideration	0	0
Level 2
Assets
Cash equivalents	14,644	0
Marketable investments (short and long term)	222,885	127,758
Liabilities
Contingent consideration	0	0
Level 3
Assets
Cash equivalents	0	0
Marketable investments (short and long term)	0	0
Liabilities
Contingent consideration	23,300	18,100
Certificates of deposit
Assets
Marketable investments (short and long term)	2,299	3,480
Certificates of deposit | Level 1
Assets
Marketable investments (short and long term)	0	0
Certificates of deposit | Level 2
Assets
Marketable investments (short and long term)	2,299	3,480
Certificates of deposit | Level 3
Assets
Marketable investments (short and long term)	0	0
U.S. treasury
Assets
Marketable investments (short and long term)	240,859	297,540
U.S. treasury | Level 1
Assets
Marketable investments (short and long term)	240,859	297,540
U.S. treasury | Level 2
Assets
Marketable investments (short and long term)	0	0
U.S. treasury | Level 3
Assets
Marketable investments (short and long term)	0	0
U.S. agency securities
Assets
Marketable investments (short and long term)	130,139	98,711
U.S. agency securities | Level 1
Assets
Marketable investments (short and long term)	0	0
U.S. agency securities | Level 2
Assets
Marketable investments (short and long term)	130,139	98,711
U.S. agency securities | Level 3
Assets
Marketable investments (short and long term)	0	0
Commercial paper
Assets
Marketable investments (short and long term)	40,358	5,093
Commercial paper | Level 1
Assets
Marketable investments (short and long term)	0	0
Commercial paper | Level 2
Assets
Marketable investments (short and long term)	40,358	5,093
Commercial paper | Level 3
Assets
Marketable investments (short and long term)	0	0
Municipal bonds
Assets
Marketable investments (short and long term)	40,095	3,145
Municipal bonds | Level 1
Assets
Marketable investments (short and long term)	0	0
Municipal bonds | Level 2
Assets
Marketable investments (short and long term)	40,095	3,145
Municipal bonds | Level 3
Assets
Marketable investments (short and long term)	0	0
Corporate bonds
Assets
Marketable investments (short and long term)	9,994	17,329
Corporate bonds | Level 1
Assets
Marketable investments (short and long term)	0	0
Corporate bonds | Level 2
Assets
Marketable investments (short and long term)	9,994	17,329
Corporate bonds | Level 3
Assets
Marketable investments (short and long term)	0	0
Money market funds
Assets
Cash equivalents	53,799	89,888
Money market funds | Level 1
Assets
Cash equivalents	53,799	89,888
Money market funds | Level 2
Assets
Cash equivalents	0	0
Money market funds | Level 3
Assets
Cash equivalents	0	0
Municipal bonds
Assets
Cash equivalents	14,644
Municipal bonds | Level 1
Assets
Cash equivalents	0
Municipal bonds | Level 2
Assets
Cash equivalents	14,644
Municipal bonds | Level 3
Assets
Cash equivalents	$ 0
U.S. treasury
Assets
Cash equivalents		39,997
U.S. treasury | Level 1
Assets
Cash equivalents		39,997
U.S. treasury | Level 2
Assets
Cash equivalents		0
U.S. treasury | Level 3
Assets
Cash equivalents		$ 0

Investments and Fair Value Me_7

Investments and Fair Value Measurements - Narrative (Details) - USD ($)	3 Months Ended	6 Months Ended
	Jun. 30, 2021	Jun. 30, 2021	Jun. 30, 2020	Dec. 31, 2020	Nov. 18, 2020
Debt Instrument [Line Items]
Impairment loss on available-for-sale debt securities		$ 0
Contingent consideration	$ 23,300,000	23,300,000		$ 18,100,000
Change in fair of value of contingent consideration		5,200,000	$ 0
Inference Solutions
Debt Instrument [Line Items]
Contingent consideration	23,300,000	23,300,000			$ 18,100,000
Inference Solutions | Maximum
Debt Instrument [Line Items]
Contingent consideration	24,000,000	24,000,000		24,000,000
Level 2
Debt Instrument [Line Items]
Contingent consideration	0	0		0
Level 3
Debt Instrument [Line Items]
Contingent consideration	23,300,000	23,300,000		18,100,000
Level 3 | Inference Solutions
Debt Instrument [Line Items]
Change in fair of value of contingent consideration	2,700,000	5,200,000
Level 3 | Inference Solutions | Maximum
Debt Instrument [Line Items]
Contingent consideration	23,300,000	23,300,000
Nonrecurring
Debt Instrument [Line Items]
Assets measured at fair value on nonrecurring basis	0	0		0
Liabilities measured at fair value on nonrecurring basis	0	0		0
Convertible Senior Notes, Due 2023 | Level 2 | Convertible debt
Debt Instrument [Line Items]
Fair value of long-term debt	184,200,000	184,200,000		253,100,000
Convertible Senior Notes, Due 2025 | Level 2 | Convertible debt
Debt Instrument [Line Items]
Fair value of long-term debt	$ 1,108,200,000	$ 1,108,200,000		$ 1,098,500,000

Investments and Fair Value Me_8

Investments and Fair Value Measurements - Reconciliation of Contingent Consideration (Details) - Fair Value, Recurring - Liability - USD ($) $ in Thousands	3 Months Ended	6 Months Ended
	Jun. 30, 2021	Jun. 30, 2021
Summary of changes in contingent consideration liabilities
Balance, beginning of period	$ 20,600	$ 18,100
Change in fair value of contingent consideration	2,700	5,200
Balance, end of period	$ 23,300	$ 23,300

Financial Statement Component_2

Financial Statement Components - Schedule of Cash and Cash Equivalents (Details) - USD ($) $ in Thousands	Jun. 30, 2021	Dec. 31, 2020
Cash and Cash Equivalents [Line Items]
Cash and cash equivalents	$ 175,199	$ 220,372
Cash
Cash and Cash Equivalents [Line Items]
Cash and cash equivalents	106,756	90,487
Money market funds
Cash and Cash Equivalents [Line Items]
Cash and cash equivalents	53,799	89,888
U.S. treasury
Cash and Cash Equivalents [Line Items]
Cash and cash equivalents	0	39,997
Municipal bonds
Cash and Cash Equivalents [Line Items]
Cash and cash equivalents	$ 14,644	$ 0

Financial Statement Component_3

Financial Statement Components - Schedule of Accounts Receivable (Details) - USD ($) $ in Thousands	Jun. 30, 2021	Dec. 31, 2020
Accounts Receivable [Line Items]
Allowance for doubtful accounts	$ (141)	$ (127)
Accounts receivable, net	53,811	48,731
Trade accounts receivable
Accounts Receivable [Line Items]
Trade accounts receivable	48,501	42,366
Unbilled trade accounts receivable, net of advance client deposits
Accounts Receivable [Line Items]
Trade accounts receivable	$ 5,451	$ 6,492

Financial Statement Component_4

Financial Statement Components - Schedule of Prepaid Expenses and Other Current Assets (Details) - USD ($) $ in Thousands	Jun. 30, 2021	Dec. 31, 2020
Financial Statement Components [Abstract]
Prepaid expenses	$ 13,724	$ 9,816
Other current assets	6,732	5,036
Contract assets	1,654	1,297
Prepaid expenses and other current assets	$ 22,110	$ 16,149

Financial Statement Component_5

Financial Statement Components - Schedule of Property and Equipment (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2021	Jun. 30, 2020	Jun. 30, 2021	Jun. 30, 2020	Dec. 31, 2020
Property, Plant and Equipment [Line Items]
Property and equipment	$ 143,736		$ 143,736		$ 121,858
Accumulated depreciation and amortization	(80,629)		(80,629)		(70,645)
Property and equipment, net	63,107		63,107		51,213
Depreciation and amortization associated with property and equipment	6,700	$ 4,500	12,500	$ 8,400
Computer and network equipment
Property, Plant and Equipment [Line Items]
Property and equipment	101,047		101,047		89,763
Computer software
Property, Plant and Equipment [Line Items]
Property and equipment, gross	32,694		32,694		25,888
Internal-use software development costs
Property, Plant and Equipment [Line Items]
Property and equipment, gross	500		500		500
Furniture and fixtures
Property, Plant and Equipment [Line Items]
Property and equipment, gross	3,964		3,964		3,372
Leasehold improvements
Property, Plant and Equipment [Line Items]
Property and equipment, gross	$ 5,531		$ 5,531		$ 2,335

Financial Statement Component_6

Financial Statement Components - Schedule of Property and Equipment under Finance Lease Obligations (Details) - USD ($) $ in Thousands	Jun. 30, 2021	Dec. 31, 2020
Financial Statement Components [Abstract]
Gross	$ 44,009	$ 45,021
Less: accumulated depreciation and amortization	(42,211)	(41,908)
Property and equipment, net	$ 1,798	$ 3,113

Financial Statement Component_7

Financial Statement Components - Schedule of Accrued and Other Current Liabilities (Details) - USD ($) $ in Thousands	Jun. 30, 2021	Dec. 31, 2020
Financial Statement Components [Abstract]
Accrued expenses	$ 15,068	$ 15,217
Accrued compensation and benefits	35,656	29,233
Contingent consideration	23,300	0
Accrued and other current liabilities	$ 74,024	$ 44,450

Financial Statement Component_8

Financial Statement Components - Schedule of Long-term Liabilities (Details) - USD ($) $ in Thousands	Jun. 30, 2021	Dec. 31, 2020
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Deferred revenue	$ 2,592	$ 3,373
Deferred tax liabilities	3,511	4,438
Other long-term liabilities	7,010	5,554
Contingent consideration	0	18,100
Other long-term liabilities	$ 13,113	$ 31,465

Goodwill and Intangible Asset_2

Goodwill and Intangible Assets - Goodwill and Intangible Asset Activity (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2021	Jun. 30, 2020	Jun. 30, 2021	Jun. 30, 2020
Finite-lived Intangible Assets [Roll Forward]
Finite-Lived Intangible Assets, Net, Beginning Balance	$ 48,737		$ 51,684
Amortization of intangible assets	(2,947)	$ (1,700)	(5,894)	$ (2,800)
Finite-Lived Intangible Assets, Net, Ending Balance	$ 45,790		$ 45,790

Goodwill and Intangible Asset_3

Goodwill and Intangible Assets - Schedule of Intangible Assets (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended		12 Months Ended
	Jun. 30, 2021	Jun. 30, 2020	Jun. 30, 2021	Jun. 30, 2020	Dec. 31, 2020	Mar. 31, 2021
Acquired Finite-Lived Intangible Assets
Gross Carrying Amount	$ 58,784		$ 58,784		$ 58,784
Accumulated Amortization	(12,994)		(12,994)		(7,100)
Total	45,790		$ 45,790		$ 51,684	$ 48,737
Weighted Average Remaining Amortization period (Years)			4 years 4 months 24 days		4 years 10 months 24 days
Amortization of intangible assets	2,947	$ 1,700	$ 5,894	$ 2,800
Developed technology
Acquired Finite-Lived Intangible Assets
Gross Carrying Amount	56,214		56,214		$ 56,214
Accumulated Amortization	(12,291)		(12,291)		(6,761)
Total	43,923		$ 43,923		$ 49,453
Weighted Average Remaining Amortization period (Years)			4 years 6 months		4 years 10 months 24 days
Acquired workforce
Acquired Finite-Lived Intangible Assets
Gross Carrying Amount	470		$ 470		$ 470
Accumulated Amortization	(256)		(256)		(177)
Total	214		$ 214		$ 293
Weighted Average Remaining Amortization period (Years)			1 year 4 months 24 days		1 year 10 months 24 days
Customer relationships
Acquired Finite-Lived Intangible Assets
Gross Carrying Amount	1,600		$ 1,600		$ 1,600
Accumulated Amortization	(261)		(261)		(101)
Total	1,339		$ 1,339		$ 1,499
Weighted Average Remaining Amortization period (Years)			4 years 2 months 12 days		4 years 8 months 12 days
Trademarks
Acquired Finite-Lived Intangible Assets
Gross Carrying Amount	500		$ 500		$ 500
Accumulated Amortization	(186)		(186)		(61)
Total	$ 314		$ 314		$ 439
Weighted Average Remaining Amortization period (Years)			1 year 3 months 18 days		1 year 9 months 18 days

Goodwill and Intangible Asset_4

Goodwill and Intangible Assets - Future Amortization Expense (Details) - USD ($) $ in Thousands	Jun. 30, 2021	Mar. 31, 2021	Dec. 31, 2020
Goodwill and Intangible Assets Disclosure [Abstract]
Remaining 2021	$ 5,893
2022	11,704
2023	10,870
2024	7,527
2025	5,596
Thereafter	4,200
Total	$ 45,790	$ 48,737	$ 51,684

Debt - Convertible Senior Notes

Debt - Convertible Senior Notes and Capped Call (Details)	1 Months Ended		2 Months Ended	3 Months Ended		6 Months Ended		12 Months Ended	24 Months Ended
	May 31, 2020USD ($)shares	May 31, 2018USD ($)$ / shares	Jun. 30, 2020USD ($)$ / shares	Jun. 30, 2021USD ($)$ / sharesshares	Jun. 30, 2020USD ($)shares	Jun. 30, 2021USD ($)day$ / sharesRateshares	Jun. 30, 2020USD ($)shares	Dec. 31, 2020USD ($)shares	Jun. 30, 2021USD ($)dayconversion_election$ / sharesshares	May 21, 2020$ / shares
Debt Instrument [Line Items]
Purchase of capped calls related to the 2025 convertible senior notes					$ 90,448,000		$ 90,448,000
Cash consideration to repurchase note						$ 17,622,000	181,462,000
Loss on early extinguishment of debt				$ 0	$ 5,794,000	$ 0	$ 5,794,000
Common Stock
Debt Instrument [Line Items]
Equity component from partial repurchase of 2023 convertible senior notes (in shares) | shares				182,000	2,724,000	325,000	2,724,000
Treasury Stock
Debt Instrument [Line Items]
Partial unwind of capped calls related to the 2023 convertible senior notes (in shares) | shares						46,724		15,714
Convertible Senior Notes, Due 2023 | Common Stock
Debt Instrument [Line Items]
Equity component from partial repurchase of 2023 convertible senior notes (in shares) | shares				181,560		324,575
Convertible Senior Notes, Due 2023 | Treasury Stock
Debt Instrument [Line Items]
Partial unwind of capped calls related to the 2023 convertible senior notes (in shares) | shares				27,938		46,724
Convertible debt
Debt Instrument [Line Items]
Debt balance				$ 788,800,000		$ 788,800,000			$ 788,800,000
Convertible debt | Convertible Senior Notes, Due 2023
Debt Instrument [Line Items]
Stated interest rate on debt (percent)		0.125%
Proceeds from issuance of debt		$ 250,800,000
Multiple of principle amount						$ 1,000			$ 1,000
Conversion ratio on convertible debt | Rate						2449.78%
Conversion price on convertible debt (in USD per share) | $ / shares				$ 40.82		$ 40.82			$ 40.82
Sinking fund payment						$ 0
Equity component								$ 14,505,000
Effective interest rate on debt (percent)	5.32%			6.39%		6.39%			6.39%
Payment on debt issuance cost		8,000,000				$ 500,000
Debt issuance costs		$ 6,000,000		$ 483,000		483,000		700,000	$ 483,000
Convertible debt				40,800,000		40,800,000			40,800,000
Debt balance				$ 41,278,000		$ 41,278,000		58,867,000	$ 41,278,000
Amortization of debt issuance costs, Effective interest rate | Rate						0.76%
Cap price of the capped call transactions (in dollars per share) | $ / shares		$ 62.80
Number of shares covered in the Capped Call Transactions (shares) | shares				6,300,000		6,300,000			6,300,000
Cost of Capped Call Transactions recorded in additional paid in capital				$ 31,400,000		$ 31,400,000			$ 31,400,000
Debt instrument, repurchase amount	$ 181,000,000
Aggregate consideration to repurchase note	449,600,000
Cash consideration to repurchase note	181,000,000
Debt instrument, convertible, carrying amount of debt component	155,800,000
Debt instrument, convertible, carrying amount of equity component	293,800,000							14,050,000
Carrying value of debt subject to repurchase, net	150,400,000
Third party transaction costs	$ 500,000
Loss on early extinguishment of debt					$ 5,800,000	$ 1,200,000
Debt issuance costs, gross, within extinguishment of debt			$ 2,700,000		$ 2,700,000		$ 2,700,000
Number of conversion features triggered | conversion_election									1
Conversion price per share, requiring conversion of instrument (in USD per share) | $ / shares				$ 53.07		$ 53.07			$ 53.07
Debt instrument, conversion multiple of aggregate principal amount						$ 17,600,000
Conversion of aggregate principal amount, term 1						$ 1,200,000
Convertible debt | Convertible Senior Notes, Due 2023 | Common Stock
Debt Instrument [Line Items]
Equity component from partial repurchase of 2023 convertible senior notes (in shares) | shares	2,723,581
Debt instrument, conversion multiple of aggregate principal amount, shares | shares						324,575
Convertible debt | Convertible Senior Notes, Due 2023 | Fundamental change event
Debt Instrument [Line Items]
Debt redemption price as percentage of principal amount						100.00%
Convertible debt | Convertible Senior Notes, Due 2023 | On or after May 5, 2021
Debt Instrument [Line Items]
Number of trading days | day						20
Number of consecutive trading days | day						30
Threshold percentage of stock price trigger						130.00%
Debt redemption price as percentage of principal amount						100.00%
Number of trading days preceding notice of redemption | day						2
Convertible debt | Convertible Senior Notes, Due 2023 | Convertible, term one
Debt Instrument [Line Items]
Number of trading days | day									20
Number of consecutive trading days | day									30
Threshold percentage of stock price trigger									130.00%
Convertible debt | Convertible Senior Notes, Due 2025
Debt Instrument [Line Items]
Stated interest rate on debt (percent)			0.50%		0.50%		0.50%
Stated additional interest rate on debt (percent)			0.00500		0.00500		0.00500
Proceeds from issuance of debt			$ 728,800,000
Multiple of principle amount						$ 1,000
Conversion ratio on convertible debt | Rate						744.37%
Conversion price on convertible debt (in USD per share) | $ / shares				134.34		$ 134.34			$ 134.34
Premium on conversion price in relation to closing price (percentage)										30.00%
Closing price of common stock (in dollars per share) | $ / shares				183.39		183.39			183.39	$ 103.34
Share price of common stock with conversion premium (in dollars per share) | $ / shares				$ 174.64		$ 174.64			$ 174.64
Sinking fund payment						$ 0
Equity component								158,321,000
Effective interest rate on debt (percent)				5.76%		5.76%			5.76%
Payment on debt issuance cost			18,700,000			$ 14,700,000
Debt issuance costs			$ 14,700,000	$ 14,707,000	$ 14,700,000	14,707,000	$ 14,700,000	13,192,000	$ 14,707,000
Convertible debt				732,800,000		732,800,000			732,800,000
Debt balance				$ 747,500,000		$ 747,500,000		747,500,000	$ 747,500,000
Amortization of debt issuance costs, Effective interest rate | Rate						1.00%
Cap price of the capped call transactions (in dollars per share) | $ / shares			$ 206.68
Number of shares covered in the Capped Call Transactions (shares) | shares				5,600,000		5,600,000			5,600,000
Purchase of capped calls related to the 2025 convertible senior notes								90,500,000
Debt instrument, convertible, carrying amount of equity component								$ 154,363,000
Convertible debt | Convertible Senior Notes, Due 2025 | Fundamental change event
Debt Instrument [Line Items]
Debt redemption price as percentage of principal amount						100.00%
Convertible debt | Convertible Senior Notes, Due 2025 | on or after June 6, 2023
Debt Instrument [Line Items]
Number of trading days | day						20
Number of consecutive trading days | day						30
Threshold percentage of stock price trigger						130.00%
Debt redemption price as percentage of principal amount						100.00%
Number of trading days preceding notice of redemption | day						2
Convertible debt | Convertible Senior Notes, Due 2025 | Convertible, term one
Debt Instrument [Line Items]
Number of trading days | day						20
Number of consecutive trading days | day						30
Threshold percentage of stock price trigger						130.00%
Convertible debt | Convertible Senior Notes, Due 2025 | Convertible, term two
Debt Instrument [Line Items]
Number of trading days | day						5
Number of consecutive trading days | day						5
Threshold percentage of stock price trigger						98.00%
Private placement | Convertible debt | Convertible Senior Notes, Due 2023
Debt Instrument [Line Items]
Aggregate principal amount of debt		$ 258,800,000	$ 747,500,000		747,500,000		747,500,000
Option to purchase additional debt through private offering			$ 97,500,000		$ 97,500,000		$ 97,500,000

Debt - Schedule of Net Carrying

Debt - Schedule of Net Carrying Amount of the Liability Component of the Notes (Details) - Convertible debt - USD ($) $ in Thousands	Jun. 30, 2021	Dec. 31, 2020	Jun. 30, 2020	May 31, 2018
Debt Instrument [Line Items]
Principal	$ 788,800
Convertible Senior Notes, Due 2025
Debt Instrument [Line Items]
Principal	747,500	$ 747,500
Unamortized debt discount	0	(141,792)
Unamortized issuance costs	(14,707)	(13,192)	$ (14,700)
Total debt, net carrying value	732,793	592,516
Convertible Senior Notes, Due 2023
Debt Instrument [Line Items]
Principal	41,278	58,867
Unamortized debt discount	0	(7,367)
Unamortized issuance costs	(483)	(700)		$ (6,000)
Total debt, net carrying value	$ 40,795	$ 50,800

Debt - Schedule of Equity Compo

Debt - Schedule of Equity Component of Debt (Details) - Convertible debt - USD ($) $ in Thousands	Dec. 31, 2020	May 31, 2020
Convertible Senior Notes, Due 2025
Debt Instrument [Line Items]
Equity component	$ 158,321
Issuance costs	(3,958)
Net carrying amount	154,363
Convertible Senior Notes, Due 2023
Debt Instrument [Line Items]
Equity component	14,505
Issuance costs	(455)
Net carrying amount	$ 14,050	$ 293,800

Debt - Schedule of Interest Exp

Debt - Schedule of Interest Expense (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2021	Jun. 30, 2020	Jun. 30, 2021	Jun. 30, 2020
Debt Instrument [Line Items]
Interest Expense	$ 2,118	$ 5,734	$ 4,056	$ 9,218
Convertible Senior Notes, Due 2025 | Convertible debt
Debt Instrument [Line Items]
Contractual interest expense	1,121	362	2,055	362
Amortization of debt discount	0	2,528	0	2,528
Amortization of issuance costs	912	235	1,802	235
Interest Expense	2,033	3,125	3,857	3,125
Convertible Senior Notes, Due 2023 | Convertible debt
Debt Instrument [Line Items]
Contractual interest expense	6	60	23	141
Amortization of debt discount	0	2,272	0	5,304
Amortization of issuance costs	73	216	157	504
Interest Expense	$ 79	$ 2,548	$ 180	$ 5,949

Debt - Schedule of Maturities o

Debt - Schedule of Maturities of Debt (Details) - Convertible debt - USD ($) $ in Thousands	Jun. 30, 2021	Dec. 31, 2020
Debt Instrument [Line Items]
Total	$ 788,800
Convertible Senior Notes, Due 2025
Debt Instrument [Line Items]
2025 (Maturity date of June 1, 2025)	747,500
Total	747,500	$ 747,500
Convertible Senior Notes, Due 2023
Debt Instrument [Line Items]
2023 (Maturity date of May 1, 2023)	41,278
Total	$ 41,278	$ 58,867

Stockholders' Equity - Capital

Stockholders' Equity - Capital Structure (Details) - $ / shares	3 Months Ended		6 Months Ended		12 Months Ended
	Jun. 30, 2021	Jun. 30, 2020	Jun. 30, 2021	Jun. 30, 2020	Dec. 31, 2020
Stockholders' Equity Capital Structure [Line Items]
Common stock shares authorized (shares)	450,000,000		450,000,000
Common Stock par value (in dollars per share)	$ 0.001		$ 0.001
Common stock shares issued (shares)	67,683,848		67,683,848		66,496,060
Common stock shares outstanding (shares)	67,683,848		67,683,848		66,496,060
Preferred stock shares authorized (shares)	5,000,000		5,000,000
Preferred stock par value (in dollars per share)	$ 0.001		$ 0.001
Preferred stock shares issued (shares)	0		0		0
Preferred stock shares outstanding (shares)	0		0		0
Common Stock
Stockholders' Equity Capital Structure [Line Items]
Equity component from partial repurchase of 2023 convertible senior notes (in shares)	182,000	2,724,000	325,000	2,724,000
Common Stock | Convertible Senior Notes, Due 2023
Stockholders' Equity Capital Structure [Line Items]
Equity component from partial repurchase of 2023 convertible senior notes (in shares)	181,560		324,575
Treasury Stock
Stockholders' Equity Capital Structure [Line Items]
Partial unwind of capped calls related to the 2023 convertible senior notes (in shares)			46,724		15,714
Treasury Stock | Convertible Senior Notes, Due 2023
Stockholders' Equity Capital Structure [Line Items]
Partial unwind of capped calls related to the 2023 convertible senior notes (in shares)	27,938		46,724

Stockholders' Equity - Common S

Stockholders' Equity - Common Stock Reserved for Future Issuance (Details) shares in Thousands	Jun. 30, 2021shares
Class of Stock
Common stock reserved for future issuance (in shares)	21,696
Stock options
Class of Stock
Common stock reserved for future issuance (in shares)	2,129
Restricted stock units
Class of Stock
Common stock reserved for future issuance (in shares)	2,273
ESPP
Class of Stock
Common stock reserved for future issuance (in shares)	3,129
2014 Plan
Class of Stock
Common stock reserved for future issuance (in shares)	14,165

Stockholders' Equity - Stock Op

Stockholders' Equity - Stock Option Activity (Details) $ / shares in Units, shares in Thousands, $ in Thousands	6 Months Ended
	Jun. 30, 2021USD ($)$ / sharesshares
Options Outstanding, Weighted Average Exercise Price [Roll Forward]
Closing market price of common stock (in USD per share)	$ 183.39
Stock options
Options Outstanding [Roll Forward]
Outstanding, beginning balance (in shares) | shares	2,255
Options granted (in shares) | shares	130
Options exercised (in shares) | shares	(246)
Options forfeited or expired (in shares) | shares	(10)
Outstanding, ending balance (in shares) | shares	2,129
Options Outstanding, Weighted Average Exercise Price [Roll Forward]
Outstanding, beginning balance, weighted average exercise price (in USD per share)	$ 26.33
Options granted, weighted average exercise price (in USD per share)	180.76
Options exercised, weighted average exercise price (in USD per share)	18.05
Options forfeited or expired, weighted average exercise price (in USD per share)	82.62
Outstanding, ending balance, weighted average exercise price (in USD per share)	$ 36.47
Outstanding, ending balance, weighted average remaining contractual life (years)	5 years 3 months 18 days
Outstanding, ending balance, aggregate intrinsic value | $	$ 312,868
Weighted average grant date fair value, options granted (in USD per share)	$ 81.48

Stockholders' Equity - RSU Acti

Stockholders' Equity - RSU Activity (Details) - Restricted stock units shares in Thousands	6 Months Ended
	Jun. 30, 2021$ / sharesshares
Number of Shares
Outstanding, beginning balance (in shares) | shares	2,267
RSUs granted (in shares) | shares	691
RSUs vested and released (in shares) | shares	(596)
RSUs forfeited (in shares) | shares	(89)
Outstanding, ending balance (in shares) | shares	2,273
Weighted Average Grant Date Fair Value Per Share
Outstanding, beginning balance, weighted-average grant date fair value per share (in USD per share) | $ / shares	$ 65.42
RSUs granted, weighted average grant date fair value (in USD per share) | $ / shares	179.79
RSUs vested and released, weighted average grant date fair value (in USD per share) | $ / shares	58.11
RSUs forfeited, weighted average grant date fair value (in USD per share) | $ / shares	83.94
Outstanding, ending balance, weighted-average grant date fair value per share (in USD per share) | $ / shares	$ 100.80

Stockholders' Equity - Stock-ba

Stockholders' Equity - Stock-based Compensation (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2021	Jun. 30, 2020	Jun. 30, 2021	Jun. 30, 2020
Stock-based Compensation Expense
Stock-based compensation expense	$ 24,901	$ 16,791	$ 45,809	$ 30,585
Stock options
Stock-based Compensation Expense
Unrecognized stock-based compensation expense	26,930		$ 26,930
Weighted-average amortization period (years)			2 years 8 months 12 days
Restricted stock units
Stock-based Compensation Expense
Unrecognized stock-based compensation expense	217,556		$ 217,556
Weighted-average amortization period (years)			3 years 1 month 6 days
ESPP
Stock-based Compensation Expense
Unrecognized stock-based compensation expense	1,907		$ 1,907
Weighted-average amortization period (years)			4 months 24 days
Cost of revenue
Stock-based Compensation Expense
Stock-based compensation expense	3,781	2,499	$ 6,886	4,488
Research and development
Stock-based Compensation Expense
Stock-based compensation expense	6,152	3,684	10,915	6,491
Sales and marketing
Stock-based Compensation Expense
Stock-based compensation expense	8,208	5,265	14,979	9,371
General and administrative
Stock-based Compensation Expense
Stock-based compensation expense	$ 6,760	$ 5,343	$ 13,029	$ 10,235

Stockholders' Equity - Valuatio

Stockholders' Equity - Valuation Assumptions (Details) - Stock options	3 Months Ended		6 Months Ended
	Jun. 30, 2021	Jun. 30, 2020	Jun. 30, 2021	Jun. 30, 2020
Class of Stock
Expected term (years)	6 years	6 years	6 years	6 years
Volatility (percent)	47.00%	48.00%	47.00%	47.00%
Risk-free interest rate (percent)	1.00%	0.40%	1.00%	1.10%
Dividend yield (percent)	0.00%	0.00%	0.00%	0.00%

Net Loss Per Share - Basic and

Net Loss Per Share - Basic and Diluted Net Loss Per Share (Details) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2021	Jun. 30, 2020	Jun. 30, 2021	Jun. 30, 2020
Earnings Per Share [Abstract]
Net loss	$ (16,530)	$ (16,052)	$ (28,862)	$ (23,489)
Weighted-average shares used in computing basic loss per share (in shares)	67,292,000	63,282,000	67,008,000	62,494,000
Weighted-average shares used in computing diluted loss per share (in shares)	67,292,000	63,282,000	67,008,000	62,494,000
Basic loss per share (in USD per share)	$ (0.25)	$ (0.25)	$ (0.43)	$ (0.38)
Diluted loss per share (in usd per share)	$ (0.25)	$ (0.25)	$ (0.43)	$ (0.38)

Net Loss Per Share - Antidiluti

Net Loss Per Share - Antidilutive Securities Excluded from Computation of Diluted Net Loss Per Share (Details) - $ / shares shares in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2021	Jun. 30, 2020	Jun. 30, 2021	Jun. 30, 2020
Antidilutive Securities Excluded from Computation of Earnings Per Share
Anti-dilutive securities excluded from calculation of diluted net loss per share (shares)	11,110	6,290	11,198	6,168
Convertible Senior Notes, Due 2023 | Convertible debt
Antidilutive Securities Excluded from Computation of Earnings Per Share
Conversion price on convertible debt (in USD per share)	$ 40.82		$ 40.82
Stock options
Antidilutive Securities Excluded from Computation of Earnings Per Share
Anti-dilutive securities excluded from calculation of diluted net loss per share (shares)	2,129	2,431	2,129	2,431
Restricted stock units
Antidilutive Securities Excluded from Computation of Earnings Per Share
Anti-dilutive securities excluded from calculation of diluted net loss per share (shares)	2,273	2,753	2,273	2,753
Convertible senior notes
Antidilutive Securities Excluded from Computation of Earnings Per Share
Anti-dilutive securities excluded from calculation of diluted net loss per share (shares)	6,708	1,106	6,796	984

Income Taxes (Details)

Income Taxes (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2021	Jun. 30, 2020	Jun. 30, 2021	Jun. 30, 2020
Income Tax Disclosure [Abstract]
Benefit from income taxes	$ (135)	$ (2,876)	$ (652)	$ (2,807)

Commitments and Contingencies (

Commitments and Contingencies (Details) - USD ($) $ in Millions	1 Months Ended		6 Months Ended
	Jun. 30, 2021	Sep. 30, 2020	Jun. 30, 2021
Hosting and telecommunications agreement
Other Commitments [Line Items]
Total commitments under agreements	$ 11.8		$ 11.8
Purchase Commitment - Cloud Services Agreement
Other Commitments [Line Items]
Term of commitment (in years)		3 years
Expiring commercial commitment balance	7.5	$ 12.5	7.5
Commercial commitment to be paid remainder of 2021	5		5
Commercial commitment to be paid in year 2022	$ 2.5		2.5
Purchase Commitment - Additional Cloud Services Agreement
Other Commitments [Line Items]
Term of commitment (in years)	3 years
Expiring commercial commitment balance	$ 5		5
Commercial commitment to be paid remainder of 2021	1.1		1.1
Commercial commitment to be paid in year 2022	1.7		1.7
Commercial Commitment to be paid in year 2023	2.2		$ 2.2
Maximum | Hosting and telecommunications agreement
Other Commitments [Line Items]
Period for various agreements (in months)			60 months
Convertible debt
Other Commitments [Line Items]
Debt balance	$ 788.8		$ 788.8

Geographical Information - Sche

Geographical Information - Schedule of Revenue and Property and Equipment by Geographic Region (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2021	Jun. 30, 2020	Jun. 30, 2021	Jun. 30, 2020	Dec. 31, 2020
Revenues from External Customers and Long-Lived Assets
Revenue	$ 143,782	$ 99,792	$ 281,664	$ 194,880
Property and equipment, net	63,107		63,107		$ 51,213
United States
Revenues from External Customers and Long-Lived Assets
Revenue	131,257	91,784	257,143	179,215
Property and equipment, net	54,748		54,748		43,339
International
Revenues from External Customers and Long-Lived Assets
Revenue	12,525	$ 8,008	24,521	$ 15,665
Property and equipment, net	$ 8,359		$ 8,359		$ 7,874

Leases - Narrative (Details)

Leases - Narrative (Details) - USD ($) $ in Thousands	6 Months Ended
	Jun. 30, 2021	Feb. 01, 2021	Dec. 31, 2020
Lessee, Lease, Description [Line Items]
Operating lease termination notice, period (in days)	30 days
Operating lease liability	$ 53,787		$ 9,291
Amount of lease obligation, not yet commenced	$ 1,800
Operating lease not yet commenced, term of lease (in years)	3 years
Bishop Ranch Building Lease
Lessee, Lease, Description [Line Items]
Operating lease, term of contract (in years)		10 years
Operating lease liability		$ 46,400
Minimum
Lessee, Lease, Description [Line Items]
Operating lease, term of contract (in years)	1 year
Operating lease, extension term (in years)	3 years
Maximum
Lessee, Lease, Description [Line Items]
Operating lease, term of contract (in years)	10 years
Operating lease, extension term (in years)	5 years

Leases - Lease Cost and Supplem

Leases - Lease Cost and Supplemental Cash Flow (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2021	Jun. 30, 2020	Jun. 30, 2021	Jun. 30, 2020
Leases [Abstract]
Operating lease cost	$ 2,517	$ 1,515	$ 5,185	$ 3,031
Finance lease cost:
Amortization of right-of-use assets	544	982	1,261	2,120
Interest on finance lease liabilities	5	63	18	145
Total finance lease cost	549	1,045	1,279	2,265
Cash paid for amounts included in the measurement of lease liabilities:
Operating cash used in operating leases	(1,370)	(1,607)	(3,408)	(3,190)
Financing cash used in finance leases	(119)	(966)	(575)	(2,195)
Right-of-use assets obtained in exchange for operating leases	4,090	364	42,429	4,256
Right of use assets obtained in exchange for finance leases	$ 0	$ 0	$ 0	$ 0

Leases - Balance Sheet Disclosu

Leases - Balance Sheet Disclosures (Details) - USD ($) $ in Thousands	Jun. 30, 2021	Dec. 31, 2020
Leases [Abstract]
Operating lease right-of-use assets	$ 46,966	$ 9,010
Operating lease liabilities	7,758	3,912
Operating lease liabilities — less current portion	46,029	5,379
Total operating lease liabilities	53,787	9,291
Gross	44,009	45,021
Less: accumulated depreciation and amortization	(42,211)	(41,908)
Property and equipment, net	1,798	3,113
Finance lease liabilities	36	612
Finance lease liabilities — less current portion	0	0
Total finance lease liabilities	$ 36	$ 612
Finance Lease, Right-of-Use Asset, Balance Sheet Location [Extensible List]	Property and equipment, net	Property and equipment, net

Leases - Weighted Average Remai

Leases - Weighted Average Remaining Terms and Discount Rates (Details)	Jun. 30, 2021	Dec. 31, 2020
Leases [Abstract]
Weighted average remaining lease term, Operating leases (in years)	7 years 10 months 24 days	2 years 7 months 6 days
Weighted average remaining lease term, Finance leases (in years)	2 months 12 days	6 months
Weighted average discount rate, Operating leases (percent)	3.20%	4.50%
Weighted average discount rate, Finance leases (percent)	12.30%	7.90%

Leases - Lease Maturities (Deta

Leases - Lease Maturities (Details) - USD ($) $ in Thousands	Jun. 30, 2021	Dec. 31, 2020
Operating Leases
Remaining 2021	$ 3,807
2022	10,312
2023	8,799
2024	6,016
2025	4,916
Thereafter	27,360
Total future minimum lease payments	61,210
Less: imputed interest	(7,423)
Total	53,787	$ 9,291
Finance Leases
Remaining 2021	37
2022	0
2023	0
2024	0
2025	0
Thereafter
Total future minimum lease payments	37
Less: imputed interest	(1)
Total	$ 36	$ 612

Acquisitions - Inference Soluti

Acquisitions - Inference Solutions Narrative (Details) - USD ($) $ in Thousands	Nov. 18, 2020	Jun. 30, 2021	Jun. 30, 2021	Jun. 30, 2020	Dec. 31, 2020
Business Acquisition [Line Items]
Cash paid to acquire business			$ 0	$ 28,313
Contingent consideration		$ 23,300	23,300		$ 18,100
Goodwill		165,420	165,420		165,420
Inference Solutions
Business Acquisition [Line Items]
Consideration transferred	$ 156,700
Cash paid to acquire business	137,000
Contingent consideration	18,100	23,300	23,300
Contingent consideration, range of outcomes, low		0	0
Contingent consideration, range of outcomes, high		24,000	24,000
Goodwill	$ 130,976
Business combination, acquisition related costs		0	300		2,900
Inference Solutions | Acquired technology
Business Acquisition [Line Items]
Acquired finite-lived intangible assets, weighted average useful life (Years)	6 years
Inference Solutions | Customer relationships
Business Acquisition [Line Items]
Acquired finite-lived intangible assets, weighted average useful life (Years)	5 years
Inference Solutions | Trade name and trademarks
Business Acquisition [Line Items]
Acquired finite-lived intangible assets, weighted average useful life (Years)	2 years
Inference Solutions | Maximum
Business Acquisition [Line Items]
Contingent consideration		$ 24,000	$ 24,000		$ 24,000

Acquisitions - Inference Solu_2

Acquisitions - Inference Solutions Table (Details) - USD ($) $ in Thousands	Jun. 30, 2021	Dec. 31, 2020	Nov. 18, 2020
Business Acquisition [Line Items]
Goodwill	$ 165,420	$ 165,420
Inference Solutions
Business Acquisition [Line Items]
Cash			$ 1,394
Property and equipment acquired			124
Other assets acquired			2,238
Goodwill			130,976
Total assets acquired			164,832
Liabilities assumed			(3,525)
Deferred tax liability			(4,616)
Total consideration			156,691
Total consideration (net of cash acquired)			155,297
Inference Solutions | Acquired technology
Business Acquisition [Line Items]
Finite-lived intangibles acquired			28,600
Inference Solutions | Customer relationships
Business Acquisition [Line Items]
Finite-lived intangibles acquired			1,100
Inference Solutions | Trade name and trademarks
Business Acquisition [Line Items]
Finite-lived intangibles acquired			$ 400

Acquisitions - Virtual Observer

Acquisitions - Virtual Observer Narrative (Details) - USD ($) $ in Thousands	Apr. 01, 2020	Jun. 30, 2021	Jun. 30, 2020	Dec. 31, 2020	Dec. 31, 2019
Business Acquisition [Line Items]
Cash paid to acquire business		$ 0	$ 28,313
Goodwill		$ 165,420		$ 165,420
Virtual Observer, formerly known as Coordinated Systems, Inc.
Business Acquisition [Line Items]
Cash paid to acquire business	$ 32,200
Goodwill	$ 22,646
Business combination, acquisition related costs				$ 900	$ 300
Virtual Observer, formerly known as Coordinated Systems, Inc. | Acquired technology
Business Acquisition [Line Items]
Acquired finite-lived intangible assets, weighted average useful life (Years)	5 years
Virtual Observer, formerly known as Coordinated Systems, Inc. | Customer relationships
Business Acquisition [Line Items]
Acquired finite-lived intangible assets, weighted average useful life (Years)	5 years
Virtual Observer, formerly known as Coordinated Systems, Inc. | Trade name and trademarks
Business Acquisition [Line Items]
Acquired finite-lived intangible assets, weighted average useful life (Years)	2 years

Acquisitions - Virtual Observ_2

Acquisitions - Virtual Observer Table (Details) - USD ($) $ in Thousands	Jun. 30, 2021	Dec. 31, 2020	Apr. 01, 2020
Business Acquisition [Line Items]
Goodwill	$ 165,420	$ 165,420
Virtual Observer, formerly known as Coordinated Systems, Inc.
Business Acquisition [Line Items]
Cash			$ 168
Tangible assets acquired			200
Goodwill			22,646
Total assets acquired			35,814
Deferred tax liability			(2,910)
Liabilities assumed			(682)
Total consideration			32,222
Virtual Observer, formerly known as Coordinated Systems, Inc. | Acquired technology
Business Acquisition [Line Items]
Finite-lived intangibles acquired			12,200
Virtual Observer, formerly known as Coordinated Systems, Inc. | Customer relationships
Business Acquisition [Line Items]
Finite-lived intangibles acquired			500
Virtual Observer, formerly known as Coordinated Systems, Inc. | Trade name and trademarks
Business Acquisition [Line Items]
Finite-lived intangibles acquired			$ 100

Subsequent event (Details)

Subsequent event (Details)	Jul. 16, 2021USD ($)extension	Jun. 30, 2022$ / shares	Jun. 30, 2021$ / shares
Subsequent Event [Line Items]
Common Stock par value (in dollars per share)			$ 0.001
Subsequent Event | Five9, Inc.
Subsequent Event [Line Items]
Termination fee potentially required to be paid to Zoom | $	$ 450,000,000
Number of extensions to receive approval | extension	2
Extension period (months)	3 months
Number of additional extensions to receive approval | extension	1
Subsequent Event | Five9, Inc. | Zoom | Forecast
Subsequent Event [Line Items]
Consideration transferred, equity interests issued and issuable, entity shares issued per share (in shares)		$ 0.5533
Common Stock par value (in dollars per share)		$ 0.001