Okta (OKTA) 10-Q 29 Aug 19 2020 Q2 Quarterly report Financial data

Cover Page

Cover Page	6 Months Ended
	Jul. 31, 2019shares
Entity Information [Line Items]
Document Type	10-Q
Document Quarterly Report	true
Document Period End Date	Jul. 31, 2019
Document Transition Report	false
Entity File Number	001-38044
Entity Registrant Name	Okta, Inc.
Entity Incorporation, State or Country Code	DE
Entity Address, Address Line One	100 First Street, Suite 600
Entity Tax Identification Number	26-4175727
Entity Address, City or Town	San Francisco
Entity Address, State or Province	CA
Entity Address, Postal Zip Code	94105
City Area Code	888
Local Phone Number	722-7871
Title of 12(b) Security	Class A common stock, par value $0.0001 per share
Trading Symbol	OKTA
Security Exchange Name	NASDAQ
Entity Current Reporting Status	Yes
Entity Interactive Data Current	Yes
Entity Filer Category	Large Accelerated Filer
Smaller Reporting Company	false
Emerging Growth Company	false
Entity Shell Company	false
Amendment Flag	false
Entity Central Index Key	0001660134
Current Fiscal Year End Date	--01-31
Document Fiscal Year Focus	2020
Document Period Focus	Q2
Class A Common Stock
Entity Information [Line Items]
Entity Common Stock, Shares Outstanding	106,594,796
Class B Common Stock
Entity Information [Line Items]
Entity Common Stock, Shares Outstanding	10,153,338

Condensed Consolidated Balance

Condensed Consolidated Balance Sheets - USD ($) $ in Thousands	Jul. 31, 2019	Jan. 31, 2019	[1]
Current assets:
Cash and cash equivalents	$ 206,753	$ 298,394
Short-term investments	350,712	265,374
Accounts receivable, net of allowances of $1,331 and $2,098	87,851	91,926
Deferred commissions	27,062	24,185
Prepaid expenses and other current assets	24,642	28,237
Total current assets	697,020	708,116
Property and equipment, net	51,858	52,921
Operating lease right-of-use assets	116,706	121,389
Deferred commissions, noncurrent	59,560	54,812
Intangible assets, net	34,712	13,897
Goodwill	47,964	18,089
Other assets	18,990	15,089
Total assets	1,026,810	984,313
Current liabilities:
Accounts payable	3,492	2,431
Accrued expenses and other current liabilities	31,843	33,653
Accrued compensation	21,869	19,770
Convertible senior notes, net	279,741	271,628
Deferred revenue	283,724	245,622
Total current liabilities	620,669	573,104
Operating lease liabilities, noncurrent	143,706	147,046
Deferred revenue, noncurrent	7,469	8,768
Other liabilities, noncurrent	4,241	3,018
Total liabilities	776,085	731,936
Commitments and contingencies (Note 11)
Stockholders’ equity:
Preferred stock, par value $0.0001 per share; 100,000 shares authorized, no shares issued and outstanding as of July 31, 2019 and January 31, 2019.	0	0
Additional paid-in capital	839,523	744,896
Accumulated other comprehensive loss	(1,653)	(319)
Accumulated deficit	(587,157)	(492,211)
Total stockholders’ equity	250,725	252,377
Total liabilities and stockholders’ equity	1,026,810	984,313
Class A Common Stock
Stockholders’ equity:
Common stock	11	10
Class B Common Stock
Stockholders’ equity:
Common stock	$ 1	$ 1
[1]	Adjusted for adoption of ASC 842, Leases. See Note 2.

Condensed Consolidated Balanc_2

Condensed Consolidated Balance Sheets (Parenthetical) - USD ($) $ in Thousands	Jul. 31, 2019	Jan. 31, 2019
Statement of Financial Position [Abstract]
Allowance for accounts receivable	$ 1,331	$ 2,098
Preferred stock, par value (in dollars per share)	$ 0.0001	$ 0.0001
Preferred stock, shares authorized (in shares)	100,000,000	100,000,000
Preferred stock, shares issued (in shares)	0	0
Preferred stock, shares outstanding (in shares)	0	0
Class A Common Stock
Common stock par value (in dollars per share)	$ 0.0001	$ 0.0001
Common stock, shares authorized (in shares)	1,000,000,000	1,000,000,000
Common stock, shares issued (in shares)	106,595,000	101,093,000
Common stock, shares outstanding (in shares)	106,595,000	101,093,000
Class B Common Stock
Common stock par value (in dollars per share)	$ 0.0001	$ 0.0001
Common stock, shares authorized (in shares)	120,000,000	120,000,000
Common stock, shares issued (in shares)	10,153,000	11,059,000
Common stock, shares outstanding (in shares)	10,153,000	11,059,000

Condensed Consolidated Statemen

Condensed Consolidated Statements of Operations - USD ($) shares in Thousands, $ in Thousands	3 Months Ended		6 Months Ended
	Jul. 31, 2019	Jul. 31, 2018	Jul. 31, 2019	Jul. 31, 2018
Revenue:
Total revenue	$ 140,480	$ 94,586	$ 265,703	$ 178,207
Cost of revenue:
Total cost of revenue	38,780	28,228	73,875	52,335
Gross profit	101,700	66,358	191,828	125,872
Operating expenses:
Research and development	40,045	24,829	74,077	44,758
Sales and marketing	78,385	59,004	160,497	108,497
General and administrative	26,887	20,955	52,653	36,025
Total operating expenses	145,317	104,788	287,227	189,280
Operating loss	(43,617)	(38,430)	(95,399)	(63,408)
Interest expense	(4,304)	(4,058)	(8,545)	(6,775)
Other income, net	3,464	2,296	6,364	3,798
Loss before benefit from income taxes	(44,457)	(40,192)	(97,580)	(66,385)
Benefit from income taxes	(1,477)	(985)	(2,634)	(1,216)
Net loss	$ (42,980)	$ (39,207)	$ (94,946)	$ (65,169)	[1]
Net loss per share, basic and diluted (in dollars per share)	$ (0.37)	$ (0.37)	$ (0.83)	$ (0.62)
Weighted-average shares used to compute net loss per share, basic and diluted (in shares)	115,033	106,702	114,042	105,475
Subscription
Revenue:
Total revenue	$ 132,494	$ 87,854	$ 249,657	$ 164,695
Cost of revenue:
Total cost of revenue	27,917	19,211	52,457	35,543
Professional services and other
Revenue:
Total revenue	7,986	6,732	16,046	13,512
Cost of revenue:
Total cost of revenue	$ 10,863	$ 9,017	$ 21,418	$ 16,792
[1]	Adjusted for adoption of ASC 842, Leases. See Note 2.

Condensed Consolidated Statem_2

Condensed Consolidated Statements of Comprehensive Loss - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jul. 31, 2019	Jul. 31, 2018	Jul. 31, 2019	Jul. 31, 2018
Statement of Comprehensive Income [Abstract]
Net loss	$ (42,980)	$ (39,207)	$ (94,946)	$ (65,169)	[1]
Other comprehensive income (loss):
Net change in unrealized losses on available-for-sale securities	194	77	389	(48)
Foreign currency translation adjustments	(1,390)	(379)	(1,723)	(823)
Other comprehensive loss	(1,196)	(302)	(1,334)	(871)
Comprehensive loss	$ (44,176)	$ (39,509)	$ (96,280)	$ (66,040)
[1]	Adjusted for adoption of ASC 842, Leases. See Note 2.

Condensed Consolidated Statem_3

Condensed Consolidated Statements of Stockholders' Equity - USD ($) $ in Thousands	Total		Common stock and additional paid-in capital	Accumulated deficit	Accumulated other comprehensive loss
Beginning balance at Jan. 31, 2018			$ 565,663	$ (366,714)	$ 391
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Issuance of common stock upon exercise of stock options and other activity, net			29,154
Issuance of common stock for settlement of RSUs			0
Stock-based compensation			32,660
Equity component of convertible senior notes, net of issuance costs			77,631
Issuance of warrants related to convertible notes			52,440
Purchase of convertible senior notes hedges			(80,040)
Net loss	$ (65,169)	[1]		(65,169)
Other comprehensive loss					(871)
Ending balance at Jul. 31, 2018	245,145		677,508	(431,883)	(480)
Beginning balance at Apr. 30, 2018			642,471	(392,676)	(178)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Issuance of common stock upon exercise of stock options and other activity, net			16,740
Issuance of common stock for settlement of RSUs			0
Stock-based compensation			18,308
Equity component of convertible senior notes, net of issuance costs			(11)
Issuance of warrants related to convertible notes			0
Purchase of convertible senior notes hedges			0
Net loss	(39,207)			(39,207)
Other comprehensive loss					(302)
Ending balance at Jul. 31, 2018	245,145		677,508	(431,883)	(480)
Beginning balance at Jan. 31, 2019	252,377	[2]	744,907	(492,211)	(319)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Issuance of common stock upon exercise of stock options and other activity, net			37,481
Issuance of common stock for settlement of RSUs			2,809
Stock-based compensation			54,338
Equity component of convertible senior notes, net of issuance costs			0
Issuance of warrants related to convertible notes			0
Purchase of convertible senior notes hedges			0
Net loss	(94,946)			(94,946)
Other comprehensive loss					(1,334)
Ending balance at Jul. 31, 2019	250,725		839,535	(587,157)	(1,653)
Beginning balance at Apr. 30, 2019			784,078	(544,177)	(457)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Issuance of common stock upon exercise of stock options and other activity, net			23,965
Issuance of common stock for settlement of RSUs			0
Stock-based compensation			31,492
Equity component of convertible senior notes, net of issuance costs			0
Issuance of warrants related to convertible notes			0
Purchase of convertible senior notes hedges			0
Net loss	(42,980)			(42,980)
Other comprehensive loss					(1,196)
Ending balance at Jul. 31, 2019	$ 250,725		$ 839,535	$ (587,157)	$ (1,653)
[1]	Adjusted for adoption of ASC 842, Leases. See Note 2.
[2]	Adjusted for adoption of ASC 842, Leases. See Note 2.

Condensed Consolidated Statem_4

Condensed Consolidated Statements of Cash Flows - USD ($) $ in Thousands	6 Months Ended
	Jul. 31, 2019	Jul. 31, 2018	[1]
Cash flows from operating activities:
Net loss	$ (94,946)	$ (65,169)
Adjustments to reconcile net loss to net cash provided by (used in) operating activities:
Stock-based compensation	53,959	32,357
Depreciation, amortization and accretion	7,916	3,699
Amortization of debt discount and issuance costs	8,113	6,413
Amortization of deferred commissions	13,192	9,613
Deferred income taxes	(3,057)	(1,575)
Non-cash charitable contributions	652	1,008
Other	84	18
Changes in operating assets and liabilities:
Accounts receivable	4,459	(7,240)
Deferred commissions	(21,372)	(14,240)
Prepaid expenses and other assets	1,534	622
Operating lease right-of-use assets	6,189	7,540
Accounts payable	1,368	767
Accrued compensation	4,717	498
Accrued expenses and other liabilities	1,304	2,061
Operating lease liabilities	(159)	(4,554)
Deferred revenue	36,175	26,811
Net cash provided by (used in) operating activities	20,128	(1,371)
Cash flows from investing activities:
Capitalization of internal-use software costs	(1,330)	(1,725)
Purchases of property and equipment	(9,917)	(9,790)
Purchases of securities available for sale and other	(237,693)	(320,018)
Proceeds from maturities of securities available for sale	136,344	79,500
Proceeds from sales of securities available for sale and other	17,329	0
Purchases of intangible assets	(8,500)	0
Payments for business acquisition, net of cash acquired	(44,223)	(15,638)
Net cash used in investing activities	(147,990)	(267,671)
Cash flows from financing activities:
Proceeds from issuance of convertible senior notes, net of issuance costs	0	334,980
Purchase of convertible senior notes hedge	0	(80,040)
Proceeds from issuance of warrants related to convertible notes	0	52,440
Proceeds from stock option exercises, net of repurchases	27,453	21,055
Proceeds from shares issued in connection with employee stock purchase plan	9,005	6,654
Other, net	(126)	(206)
Net cash provided by financing activities	36,332	334,883
Effects of changes in foreign currency exchange rates on cash, cash equivalents and restricted cash	(1,187)	(632)
Net increase (decrease) in cash, cash equivalents and restricted cash	(92,717)	65,209
Cash, cash equivalents and restricted cash at beginning of period	311,215	136,233
Cash, cash equivalents and restricted cash at end of period	218,498	201,442
Supplementary cash flow disclosure:
Interest	431	0
Income taxes	654	0
Vesting of early exercised common stock options	370	459
Common stock issued as charitable contribution	652	1,008
Operating lease right-of-use assets exchanged for lease obligations	1,665	125,526
Property and equipment acquired through tenant improvement allowance	0	22,237
Property and equipment and other accrued but not yet paid	602	605
Bonus settled through the issuance of common stock	2,809	0
Reconciliation of cash, cash equivalents and restricted cash within the condensed consolidated balance sheets to the amounts shown in the condensed consolidated statements of cash flows above:
Total cash, cash equivalents and restricted cash	$ 311,215	$ 136,233
[1]	Adjusted for adoption of ASC 842, Leases. See Note 2.

Overview and Basis of Presentat

Overview and Basis of Presentation	6 Months Ended
	Jul. 31, 2019
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Overview and Basis of Presentation	Overview and Basis of Presentation Description of Business Okta, Inc. (the Company) is the leading independent identity management platform for the enterprise. The Okta Identity Cloud enables the Company’s customers to securely connect people to technology, anywhere, anytime and from any device. The Company was incorporated in January 2009 as Saasure Inc., a California corporation, and was later reincorporated in April 2010 under the name Okta, Inc. as a Delaware corporation. The Company is headquartered in San Francisco, California. Basis of Presentation and Principles of Consolidation The accompanying unaudited condensed consolidated financial statements, which include the accounts of the Company and its wholly owned subsidiaries, have been prepared in conformity with U.S. generally accepted accounting principles (GAAP). All intercompany balances and transactions have been eliminated in consolidation. The condensed consolidated balance sheet as of January 31, 2019 , included herein, was derived from the audited financial statements as of that date. The unaudited condensed consolidated financial statements reflect all normal recurring adjustments necessary to present fairly the results of operations for the interim periods presented, but are not necessarily indicative of the results of operations to be anticipated for the full fiscal year ending January 31, 2020 or any future period. The Company’s fiscal year ends on January 31. References to fiscal 2020 , for example, refer to the fiscal year ending January 31, 2020 . The condensed consolidated financial statements should be read in conjunction with the audited consolidated financial statements and notes included in the Company’s Form 10-K filed with the Securities and Exchange Commission (SEC) on March 14, 2019. Effective February 1, 2018, the Company adopted the requirements of Accounting Standards Update (ASU) No. 2016-02, Leases (ASC 842) as discussed in Note 2. All amounts and disclosures set forth in this Form 10-Q have been updated to comply with this standard, as indicated by references to "as adjusted" in these condensed consolidated financial statements and related notes. Certain reclassifications of prior period amounts have been made in our condensed consolidated financial statements to conform to the current period presentation. We reclassified $14.8 million of certain accrued accounts payable to accrued expenses as of January 31, 2019. These reclassifications had no impact on net loss, stockholders’ equity or cash flows as previously reported. Convertible Senior Notes In February 2018, the Company issued $345.0 million aggregate principal amount of 0.25% convertible senior notes due February 15, 2023 (2023 Notes) in a private offering, including the initial purchasers’ exercise in full of their option to purchase additional notes. The Company received aggregate proceeds of $345.0 million , before deducting costs of issuance of $10.0 million . See Note 9 for additional details. Use of Estimates The preparation of condensed consolidated financial statements in conformity with GAAP requires management to make estimates, judgments and assumptions that affect the reported amounts of assets and liabilities, 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 Company bases its estimates on historical experience and on other assumptions that its management believes are reasonable under the circumstances. Actual results could vary from those estimates. The Company’s most significant estimates include the stand alone selling price (SSP) for each distinct performance obligation included in customer contracts with multiple performance obligations, the determination of the period of benefit for deferred commissions, the determination of the effective interest rate of the liability components of the 2023 Notes, the determination of the incremental borrowing rate used for operating lease liabilities, the valuation of deferred income tax assets, contingencies and the valuation of acquired intangible assets.

Accounting Standards and Signif

Accounting Standards and Significant Accounting Policies	6 Months Ended
	Jul. 31, 2019
Accounting Policies [Abstract]
Accounting Standards and Significant Accounting Policies	Accounting Standards and Significant Accounting Policies Recently Adopted Accounting Pronouncements In February 2016, the Financial Accounting Standards Board (FASB) issued ASU No. 2016-02, Leases (ASC 842) , which requires lessees to record a right-of-use asset and a corresponding lease liability on their balance sheet for most leases. The Company adopted the requirements of ASC 842 as of February 1, 2019, using the modified retrospective method for leases that existed as of February 1, 2017, or were entered into thereafter. The modified retrospective method provides a method for recording existing leases at adoption and in comparative periods that approximates the results of a full retrospective approach. In order to simplify an entity’s transition, ASC 842 provides a package of three practical expedients, which must be elected together and applied consistently to all of an entity’s leases. The Company elected to utilize the package of practical expedients and, therefore, did not reassess: • whether contractual arrangements that expired prior to or existed as of February 1, 2017, are or contain leases, • the classification of leases that expired prior to or existed as of February 1, 2017, and • initial direct costs for leases that existed as of February 1, 2017. As of the later of February 1, 2017 or each lease’s respective commencement date, the Company recorded lease liabilities equal to the present value of the remaining minimum lease payments and right-of-use assets equal to the corresponding lease liability adjusted for (i) any prepaid or accrued lease payments, (ii) the remaining balance of any lease incentives received, (iii) unamortized initial direct costs and (iv) any impairments. The Company adjusted its condensed consolidated balance sheet from amounts previously reported due to the adoption of ASC 842. Select condensed consolidated balance sheet line items, which reflect the adoption of ASC 842, are as follows (in thousands): As of January 31, 2019 As Reported Adoption of ASC 842 As Adjusted (unaudited) Assets Current assets: Prepaid expenses and other current assets $ 29,451 $ (1,214 ) $ 28,237 Total current assets 709,330 (1,214 ) 708,116 Operating lease right-of-use assets — 121,389 121,389 Other noncurrent assets 15,286 (197 ) 15,089 Total assets $ 864,335 $ 119,978 $ 984,313 Liabilities and stockholders’ equity Current liabilities: Accrued expenses and other liabilities $ 24,740 $ 8,913 $ 33,653 Total current liabilities 564,191 8,913 573,104 Other noncurrent liabilities 38,999 (35,981 ) 3,018 Operating lease liabilities, noncurrent — 147,046 147,046 Total liabilities 611,958 119,978 731,936 Total liabilities and stockholders’ equity $ 864,335 $ 119,978 $ 984,313 The Company’s condensed consolidated statement of cash flows reflects the adoption of ASC 842. The adoption of ASC 842 did not have an impact on cash provided by or used in operating, investing, or financing activities or on the Company’s condensed consolidated statements of operations. Significant Accounting Policies The Company’s significant accounting policies are discussed in “Note 2. Summary of Significant Accounting Policies” in Item 8. Financial Statements and Supplementary Data of its Form 10-K for the fiscal year ended January 31, 2019. Except for the accounting policies for operating leases that were updated below as a result of adopting ASC 842, there have been no significant changes to these policies for the six months ended July 31, 2019 . Operating Leases and Incremental Borrowing Rate The Company leases office space under operating leases with expiration dates through 2028. The Company determines whether an arrangement constitutes a lease and records lease liabilities and right-of-use assets on its consolidated balance sheets at lease commencement. Lease liabilities are measured based on the present value of the total lease payments not yet paid discounted based on the more readily determinable of the rate implicit in the lease or the Company’s incremental borrowing rate, which is the estimated rate the Company would be required to pay for a collateralized borrowing equal to the total lease payments over the term of the lease. The estimation of the incremental borrowing rate is based on an analysis of publicly traded debt securities of companies with similar credit and financial profiles. Right-of-use assets are measured based on the corresponding lease liability adjusted for (i) payments made to the lessor at or before the commencement date, (ii) initial direct costs incurred and (iii) tenant incentives under the lease. Recognition of rent expense begins when the lessor makes the underlying asset available to the Company. The Company does not assume renewals or early terminations of its leases unless it is reasonably certain to exercise these options at commencement and does not allocate consideration between lease and non-lease components. For short-term leases, the Company records rent expense in its condensed consolidated statements of operations on a straight-line basis over the lease term and records variable lease payments as incurred. Recently Issued Accounting Pronouncements Not Yet Adopted In June 2016, the FASB issued ASU 2016-13, Financial Instruments - Credit Losses: Measurement of Credit Losses on Financial Instruments, which changes the impairment model for most financial assets. The new model uses a forward-looking expected loss method, which will generally result in earlier recognition of allowances for losses. This guidance is effective for the Company on February 1, 2020 with early adoption permitted. The Company is currently evaluating the impact of the adoption of this standard on its condensed consolidated financial statements. In August 2018, the FASB issued ASU 2018-15, Customer’s Accounting for Implementation Costs Incurred in a Cloud Computing Arrangement That Is a Service Contract (ASU 2018-15), which requires a customer in a cloud computing arrangement that is a service contract to follow the internal-use software guidance in Accounting Standards Codification 350-40 to determine which implementation costs to defer and recognize as an asset. This guidance is effective for the Company on February 1, 2020 with early adoption permitted. The Company is currently evaluating the impact of the adoption of this standard on its condensed consolidated financial statements.

Business Combinations

Business Combinations	6 Months Ended
	Jul. 31, 2019
Business Combinations [Abstract]
Business Combinations	Business Combinations On July 13, 2018, the Company acquired all issued and outstanding capital stock of ScaleFT, Inc. (ScaleFT), a “zero trust” security company which provides access solutions for the modern workforce. The acquisition date cash consideration transferred for ScaleFT was $15.6 million , net of $0.6 million in cash acquired. The Company recorded $4.6 million for developed technology intangible assets with an estimated useful life of three years and $11.8 million of goodwill which is primarily attributed to the assembled workforce as well as the integration of ScaleFT’s technology and the Company’s technology. The Company incurred $1.1 million of acquisition-related costs, which were recorded as general and administrative expense in the quarter ended July 31, 2018. On March 18, 2019, the Company acquired all issued and outstanding capital stock of Azuqua, Inc. (Azuqua), a company which provides a no-code, cloud-based integration platform that automates workflows between applications and services. The acquisition date cash consideration transferred for Azuqua was $44.2 million , net of $1.1 million in cash acquired. The Company recorded $15.7 million for developed technology intangible assets with an estimated useful life of five years and preliminarily recorded $29.9 million of goodwill which is primarily attributed to the assembled workforce as well as the integration of Azuqua’s technology and the Company’s technology. The Company incurred $3.0 million of acquisition-related costs, which were recorded as general and administrative expense in the quarter ended April 30, 2019. The Company also incurred total deferred compensation arrangements in connection with these acquisitions of $10.8 million , of which $2.1 million was recognized as compensation during the six months ended July 31, 2019 . The remaining deferred compensation balance of $7.1 million will be recognized over a future weighted-average period of 1.9 years subject to continued service with the Company. These acquisitions did not have a material impact on the Company’s condensed consolidated financial statements; therefore, historical and proforma disclosures have not been presented.

Cash Equivalents and Short-Term

Cash Equivalents and Short-Term Investments	6 Months Ended
	Jul. 31, 2019
Investments, Debt and Equity Securities [Abstract]
Cash Equivalents and Short-Term Investments	Cash Equivalents and Short-Term Investments The amortized cost, unrealized gain (loss) and estimated fair value of the Company’s cash equivalents and short-term investments as of July 31, 2019 and January 31, 2019 were as follows (in thousands): As of July 31, 2019 Amortized Cost Unrealized Gain Unrealized Loss Estimated Fair Value (unaudited) Cash equivalents: Money market funds $ 116,155 $ — $ — $ 116,155 Corporate debt securities 4,999 — (1 ) 4,998 Total cash equivalents 121,154 — (1 ) 121,153 Short-term investments: U.S. treasury securities 204,210 189 (22 ) 204,377 Corporate debt securities 146,135 203 (3 ) 146,335 Total short-term investments 350,345 392 (25 ) 350,712 Total $ 471,499 $ 392 $ (26 ) $ 471,865 As of January 31, 2019 Amortized Cost Unrealized Gain Unrealized Loss Estimated Fair Value Cash equivalents: Money market funds $ 247,426 $ — $ — $ 247,426 Corporate debt securities 3,409 — (1 ) 3,408 Total cash equivalents 250,835 — (1 ) 250,834 Short-term investments: U.S. treasury securities 195,913 37 (53 ) 195,897 Corporate debt securities 69,483 13 (19 ) 69,477 Total short-term investments 265,396 50 (72 ) 265,374 Total $ 516,231 $ 50 $ (73 ) $ 516,208 All short-term investments were designated as available-for-sale securities as of July 31, 2019 and January 31, 2019 . The Company’s short-term investments as of July 31, 2019 and January 31, 2019 all mature within one year, as follows (in thousands): As of July 31, 2019 As of January 31, 2019 Amortized Cost Estimated Fair Value Amortized Cost Estimated Fair Value (unaudited) Due within one year $ 350,345 $ 350,712 $ 265,396 $ 265,374 The Company had 7 and 34 short-term investments in unrealized loss positions as of July 31, 2019 and January 31, 2019 , respectively. There were no material gross unrealized gains or losses from available-for-sale securities and no material realized gains or losses from available-for-sale securities that were reclassified out of accumulated other comprehensive income for the three and six months ended July 31, 2019 or 2018 . For available-for-sale debt securities that have unrealized losses, the Company evaluates whether (i) the Company has the intention to sell any of these investments and (ii) it is not more likely than not that the Company will be required to sell any of these available-for-sale debt securities before recovery of the entire amortized cost basis. Based on this evaluation, the Company determined that there were no other-than-temporary impairments associated with short-term investments as of July 31, 2019 and January 31, 2019

Fair Value Measurements

Fair Value Measurements	6 Months Ended
	Jul. 31, 2019
Fair Value Disclosures [Abstract]
Fair Value Measurements	Fair Value Measurements The Company measures its financial assets at fair value each reporting period using a fair value hierarchy that prioritizes the use of observable inputs and minimizes the use of unobservable inputs when measuring fair value. A financial instrument’s classification within the fair value hierarchy is based upon the lowest level of input that is significant to the fair value measurement. Three levels of inputs may be used to measure as follows: Level 1-Valuations based on observable inputs that reflect quoted prices for identical assets or liabilities in active markets. Level 2-Valuations based on inputs that are directly or indirectly observable in the marketplace. Level 3-Valuations based on unobservable inputs that are supported by little or no market activity. Assets and Liabilities Measured at Fair Value on a Recurring Basis The following table presents information about the Company’s financial assets and liabilities that are measured at fair value on a recurring basis using the above input categories (in thousands): As of July 31, 2019 Level 1 Level 2 Level 3 Total (unaudited) Assets: Cash equivalents: Money market funds $ 116,155 $ — $ — $ 116,155 Corporate debt securities — 4,998 — 4,998 Total cash equivalents 116,155 4,998 — 121,153 Short-term investments: U.S. treasury securities — 204,377 — 204,377 Corporate debt securities — 146,335 — 146,335 Total short-term investments — 350,712 — 350,712 Total cash equivalents and short-term investments $ 116,155 $ 355,710 $ — $ 471,865 As of January 31, 2019 Level 1 Level 2 Level 3 Total Assets: Cash equivalents: Money market funds $ 247,426 $ — $ — $ 247,426 Corporate debt securities — 3,408 — 3,408 Total cash equivalents 247,426 3,408 — 250,834 Short-term investments: U.S. treasury securities — 195,897 — 195,897 Corporate debt securities — 69,477 — 69,477 Total short-term investments — 265,374 — 265,374 Total cash equivalents and short-term investments $ 247,426 $ 268,782 $ — $ 516,208 The carrying amounts of certain financial instruments, including cash held in banks, accounts receivable and accounts payable approximate fair value due to their short-term maturities and are excluded from the fair value table above. Fair Value Measurements of Other Financial Instruments The following table presents the carrying amounts and estimated fair values of our financial instruments that are not recorded at fair value on the condensed consolidated balance sheets (in thousands): As of July 31, 2019 Net Carrying Amount Before Unamortized Debt Issuance Costs Estimated Fair Value (unaudited) Convertible senior notes $ 285,696 $ 958,925 The difference between the principal amount of the 2023 Notes, $345.0 million , and the net carrying amount before unamortized debt issuance costs represents the unamortized debt discount (See Note 9 for additional details). The estimated fair value of the 2023 Notes, which are Level 2 financial instruments, was determined based on the quoted bid price of the convertible senior notes in an over-the-counter market on the last trading day of the reporting period. As of July 31, 2019 , the difference between the net carrying amount of the 2023 Notes and estimated fair value represents the equity conversion value premium the market assigned to the 2023 Notes. Based on the closing price of our common stock of $130.83 on July 31, 2019 , the if-converted value of the 2023 Notes exceeded the principal amount of $345.0 million .

Deferred Commissions

Deferred Commissions	6 Months Ended
	Jul. 31, 2019
Revenue from Contract with Customer [Abstract]
Deferred Commissions	Deferred Commissions Sales commissions capitalized as contract costs totaled $11.6 million and $8.5 million in the three months ended July 31, 2019 and 2018 , respectively, and $21.4 million and $14.2 million in the six months ended July 31, 2019 and 2018 , respectively. Amortization of contract costs was $6.9 million and $5.0 million for the three months ended July 31, 2019 and 2018 , respectively, and $13.2 million and $9.6 million for the six months ended July 31, 2019 and 2018 , respectively. There was no impairment loss in relation to the costs capitalized. Deferred Revenue Deferred revenue, which is a contract liability, consists primarily of payments received in advance of revenue recognition under the Company’s contracts with customers and is recognized as the revenue recognition criteria are met. Subscription revenue recognized during the three months ended July 31, 2019 and 2018 that was included in the deferred revenue balances at the beginning of the respective periods was $113.1 million and $73.1 million , respectively , and $174.9 million and $114.3 million for the six months ended July 31, 2019 and 2018 , respectively. Professional services and other revenue recognized in the three and six months ended July 31, 2019 and 2018 from deferred revenue balances at the beginning of the respective periods was not material. Transaction Price Allocated to the Remaining Performance Obligations Transaction price allocated to the remaining performance obligations represents contracted revenue that has not yet been recognized, which includes deferred revenue for subscription contracts that have been invoiced and will be recognized as revenue in future periods. As of July 31, 2019 , total remaining noncancelable performance obligations under the Company’s subscription contracts with customers was approximately $913.6 million . Of this amount, the Company expects to recognize revenue of approximately $461.1 million , or 51% , over the next 12 months, with the balance to be recognized as revenue thereafter. Revenue from remaining performance obligations for professional services and other contracts as of July 31, 2019 was not material. Unbilled Receivables The Company receives payments from customers based on billing schedules as established in its contracts. Unbilled receivables and contract assets represent amounts for which the Company has recognized revenue in excess of billings pursuant to its revenue recognition policy. As of July 31, 2019 and January 31, 2019 , contract assets and unbilled receivables were $1.0 million and $1.5 million

Goodwill and Intangible Assets,

Goodwill and Intangible Assets, net	6 Months Ended
	Jul. 31, 2019
Goodwill and Intangible Assets Disclosure [Abstract]
Goodwill and Intangible Assets, net	Goodwill and Intangible Assets, net Goodwill As of July 31, 2019 and January 31, 2019 , goodwill was $48.0 million and $18.1 million , respectively. During the six months ended July 31, 2019 , the Company recorded $29.9 million of goodwill in connection with the Azuqua acquisition that was completed in March 2019. See Note 3 for further details. No goodwill impairments were recorded during the three and six months ended July 31, 2019 and 2018 . Intangible Assets, net Intangible assets consisted of the following (in thousands): As of July 31, 2019 Gross Accumulated Amortization Net (unaudited) Capitalized internal-use software costs $ 21,494 $ (12,342 ) $ 9,152 Purchased developed technology 28,800 (3,381 ) 25,419 Software licenses 1,023 (882 ) 141 $ 51,317 $ (16,605 ) $ 34,712 As of January 31, 2019 Gross Accumulated Amortization Net Capitalized internal-use software costs $ 19,838 $ (9,969 ) $ 9,869 Purchased developed technology 4,600 (833 ) 3,767 Software licenses 1,023 (763 ) 260 $ 25,461 $ (11,565 ) $ 13,896 The Company capitalized $1.2 million and $0.8 million of internal-use software costs in the three months ended July 31, 2019 and 2018 , respectively, and $1.7 million and $2.0 million of internal-use software costs in the six months ended July 31, 2019 and 2018 , respectively. Stock-based compensation expense included in the total amounts capitalized were immaterial. During the three months ended July 31, 2019 , in connection with an asset acquisition, the Company recorded $8.5 million of purchased developed technology with an estimated useful life of five years. During the six months ended July 31, 2019 , the Company recorded $24.2 million of purchased developed technology, of which $15.7 million related to the Azuqua acquisition (see Note 3 for further details). Intangible amortization expense was $3.0 million and $1.2 million for the three months ended July 31, 2019 and 2018 , respectively, and $5.1 million and $2.4 million for the six months ended July 31, 2019 and 2018 , respectively.

Deferred Revenue and Performanc

Deferred Revenue and Performance Obligations	6 Months Ended
	Jul. 31, 2019
Revenue from Contract with Customer [Abstract]
Deferred Revenue and Performance Obligations	Deferred Commissions Sales commissions capitalized as contract costs totaled $11.6 million and $8.5 million in the three months ended July 31, 2019 and 2018 , respectively, and $21.4 million and $14.2 million in the six months ended July 31, 2019 and 2018 , respectively. Amortization of contract costs was $6.9 million and $5.0 million for the three months ended July 31, 2019 and 2018 , respectively, and $13.2 million and $9.6 million for the six months ended July 31, 2019 and 2018 , respectively. There was no impairment loss in relation to the costs capitalized. Deferred Revenue Deferred revenue, which is a contract liability, consists primarily of payments received in advance of revenue recognition under the Company’s contracts with customers and is recognized as the revenue recognition criteria are met. Subscription revenue recognized during the three months ended July 31, 2019 and 2018 that was included in the deferred revenue balances at the beginning of the respective periods was $113.1 million and $73.1 million , respectively , and $174.9 million and $114.3 million for the six months ended July 31, 2019 and 2018 , respectively. Professional services and other revenue recognized in the three and six months ended July 31, 2019 and 2018 from deferred revenue balances at the beginning of the respective periods was not material. Transaction Price Allocated to the Remaining Performance Obligations Transaction price allocated to the remaining performance obligations represents contracted revenue that has not yet been recognized, which includes deferred revenue for subscription contracts that have been invoiced and will be recognized as revenue in future periods. As of July 31, 2019 , total remaining noncancelable performance obligations under the Company’s subscription contracts with customers was approximately $913.6 million . Of this amount, the Company expects to recognize revenue of approximately $461.1 million , or 51% , over the next 12 months, with the balance to be recognized as revenue thereafter. Revenue from remaining performance obligations for professional services and other contracts as of July 31, 2019 was not material. Unbilled Receivables The Company receives payments from customers based on billing schedules as established in its contracts. Unbilled receivables and contract assets represent amounts for which the Company has recognized revenue in excess of billings pursuant to its revenue recognition policy. As of July 31, 2019 and January 31, 2019 , contract assets and unbilled receivables were $1.0 million and $1.5 million

Convertible Senior Notes, Net

Convertible Senior Notes, Net	6 Months Ended
	Jul. 31, 2019
Debt Disclosure [Abstract]
Convertible Senior Notes, Net	Convertible Senior Notes, Net Convertible Senior Notes The 2023 Notes are senior, unsecured obligations of the Company, and bear interest at a fixed rate of 0.25% per year. Interest is payable in cash semi-annually in arrears on February 15 and August 15 of each year, beginning on August 15, 2018. The 2023 Notes mature on February 15, 2023 unless earlier repurchased or converted. The Company may not redeem the 2023 Notes prior to maturity. The total net proceeds from the 2023 Notes, after deducting initial purchasers’ discounts and debt issuance costs, was approximately $335.0 million . The terms of the 2023 Notes are governed by an Indenture by and between the Company and Wilmington Trust, National Association, as Trustee (the Indenture). Upon conversion, the 2023 Notes may be settled in cash, shares of Class A common stock or a combination of cash and shares of Class A common stock, at the Company’s election. It is the Company’s current intent to settle the principal amount of the 2023 Notes with cash. The 2023 Notes are convertible at an initial conversion rate of 20.6795 shares of Class A common stock per $1,000 principal amount of 2023 Notes, which is equal to an initial conversion price of approximately $48.36 per share of Class A common stock, subject to adjustment under certain circumstances in accordance with the terms of the Indenture. Prior to the close of business on the business day immediately preceding October 15, 2022, holders of the 2023 Notes may convert all or a portion of their 2023 Notes only in multiples of $1,000 principal amount, under the following circumstances: • during any fiscal quarter commencing after the fiscal quarter ending on April 30, 2018 (and only during such fiscal quarter), if the last reported sale price of Class A common stock for at least 20 trading days (whether or not consecutive) during the period of 30 consecutive trading days ending on, and including, the last trading day of the immediately preceding fiscal quarter is greater than or equal to 130% of the conversion price of the 2023 Notes on each applicable trading day; • during the five business day period after any five consecutive trading day period in which the trading price per $1,000 principal amount of the 2023 Notes for each trading day of that five consecutive trading day period was less than 98% of the product of the last reported sale price of Class A common stock and the conversion rate on such trading day; or • upon the occurrence of specified corporate events, as described in the Indenture. On or after October 15, 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 Notes regardless of the foregoing circumstances. For at least twenty trading days during the period of thirty consecutive trading days ended July 31, 2019 , the last reported sale price of the Company’s common stock was equal to or exceeded 130% of the conversion price of the 2023 Notes on each applicable trading day. As a result, the 2023 Notes are convertible at the option of the holders during the fiscal quarter ending October 31, 2019 and were classified as current liabilities on the condensed consolidated balance sheet as of July 31, 2019 . During the three months ended July 31, 2019 , the Company received a request to convert an immaterial amount of 2023 Notes. Holders of the 2023 Notes who convert their 2023 Notes in connection with certain corporate events that constitute a make-whole fundamental change (as defined in the Indenture) are, under certain circumstances, entitled to an increase in the conversion rate. Additionally, in the event of a corporate event that constitutes a fundamental change (as defined in the Indenture), holders of the 2023 Notes may require the Company to repurchase all or a portion of their 2023 Notes at a price equal to 100% of the principal amount of the 2023 Notes being repurchased, plus any accrued and unpaid interest. In accounting for the issuance of the 2023 Notes, the Company separated the 2023 Notes into liability and equity components. The carrying amounts of the liability components were calculated by measuring the fair value of similar liabilities that do not have associated convertible features. The carrying amount of the equity components representing the conversion option were determined by deducting the fair value of the liability component from the par value of the 2023 Notes. The Company bifurcated the conversion option of the 2023 Notes from the debt instrument, classified the conversion option in equity and will accrete the resulting debt discount as interest expense over the contractual term of the 2023 Notes using the effective interest rate method. The equity component is not remeasured as long as the Notes continue to meet the conditions for equity classification. The effective interest rate of the liability component of the 2023 Notes is 5.68% . This interest rate was based on the interest rates of similar liabilities held by other companies with similar credit risk ratings at the time of issuance that did not have associated convertible features. The following table sets forth total interest expense recognized related to the 2023 Notes (in thousands): Three Months Ended July 31, Six Months Ended July 31, 2019 2018 2019 2018 (unaudited) Contractual interest expense $ 215 $ 216 $ 431 $ 362 Amortization of debt issuance costs 329 288 648 478 Amortization of debt discount 3,759 3,554 7,465 5,935 Total $ 4,303 $ 4,058 $ 8,544 $ 6,775 Total issuance costs of $10.0 million related to the 2023 Notes were allocated between liability and equity in the same proportion as the allocation of the total proceeds to the liability and equity components. Issuance costs attributable to the liability component are being amortized to interest expense over the respective term of the 2023 Notes using the effective interest rate method. The issuance costs attributable to the equity component were netted against the respective equity component in Additional paid-in capital. The Company recorded liability issuance costs of $7.7 million and equity issuance costs of $2.3 million . The 2023 Notes, net consisted of the following (in thousands): As of July 31, 2019 (unaudited) Liability component: Principal $ 345,000 Less: unamortized debt issuance costs and debt discount (65,259 ) Net carrying amount $ 279,741 At Issuance Equity component: 2023 Notes $ 79,962 Less: issuance costs (2,320 ) Carrying amount of the equity component (1) $ 77,642 (1) Included in the condensed consolidated balance sheets within Additional paid-in capital. Note Hedges In connection with the pricing of the 2023 Notes, the Company entered into convertible note hedge transactions with respect to its Class A common stock (the Note Hedges). The Note Hedges are purchased call options that give the Company the option to purchase, subject to anti-dilution adjustments substantially identical to those in the 2023 Notes, approximately 7.1 million shares of its Class A common stock for $48.36 per share (subject to adjustment), corresponding to the approximate initial conversion price of the 2023 Notes, exercisable upon conversion of the 2023 Notes. The Note Hedges will expire in 2023, if not exercised earlier. The Note Hedges are intended to offset potential dilution to the Company’s Class A common stock and/or offset the potential cash payments that the Company could be required to make in excess of the principal amount upon any conversion of the 2023 Notes under certain circumstances. The Note Hedges are separate transactions and are not part of the terms of the 2023 Notes. The Company paid an aggregate amount of $80.0 million for the Note Hedges. The amount paid for the Note Hedges was recorded as a reduction to Additional paid-in capital in the condensed consolidated balance sheets. Warrants In connection with the issuance of the 2023 Notes, the Company also entered into separate warrant transactions pursuant to which it sold net-share-settled (or, at the Company’s election subject to certain conditions, cash-settled) warrants (the Warrants) to acquire, subject to anti-dilution adjustments, up to approximately 7.1 million shares over 80 scheduled trading days beginning in May 2023 of the Company’s Class A common stock at an initial exercise price of $68.06 per share (subject to adjustment). If the Warrants are not exercised on their exercise dates, they will expire. If the market value per share of the Company’s Class A common stock exceeds the applicable exercise price of the Warrants, the Warrants could have a dilutive effect on the Company’s Class A common stock unless, subject to the terms of the Warrants, the Company elects to cash settle the Warrants. The Warrants are separate transactions and are not part of the terms of the 2023 Notes or the Note Hedges. The Company received aggregate proceeds of $52.4 million from the sale of the Warrants in connection with the 2023 Notes. The proceeds from the sale of the Warrants was recorded as an increase to Additional paid-in capital in the condensed consolidated balance sheets.

Leases

Leases	6 Months Ended
	Jul. 31, 2019
Leases [Abstract]
Leases	Leases The Company has entered into various non-cancelable office space operating leases with original lease periods expiring between 2020 and 2028. These do not contain material variable rent payments, residual value guarantees, covenants or other restrictions. The Company has various sublease agreements with third parties. The subleases have remaining lease terms of between one and five years. Sublease income, which is recorded as a reduction of rental expense, was $0.7 million and $1.4 million for the three and six months ended July 31, 2019 . Operating lease costs for the three and six months ended July 31, 2019 and 2018 , are as follows (in thousands): Three Months Ended July 31, Six Months Ended July 31, 2019 2018 2019 2018 (unaudited) Operating lease cost (1) $ 5,620 $ 5,807 $ 11,083 $ 9,241 (1) Amounts are presented gross of sublease income and include short-term leases, which are immaterial. The weighted-average remaining term of the Company’s operating leases was 8.4 and 8.9 years and the weighted-average discount rate used to measure the present value of the operating lease liabilities was 5.9% for each period as of July 31, 2019 and January 31, 2019 , respectively. Maturities of the Company’s operating lease liabilities, which do not include short-term leases, as of July 31, 2019 are as follows (in thousands): Operating Leases (unaudited) 2020 $ 12,157 2021 24,504 2022 24,189 2023 23,765 2024 24,252 Thereafter 95,733 Total lease payments 204,600 Less imputed interest (45,310 ) Total operating lease liabilities $ 159,290 Cash payments included in the measurement of the Company’s operating lease liabilities were $ 2.4 million and $ 3.1 million for the three months ended July 31, 2019 and 2018 , respectively, and $4.8 million and $6.1 million for the six months ended July 31, 2019 and 2018 , respectively. As of July 31, 2019 , the Company has $ 35.6 million of undiscounted future payments under an operating lease that has not yet commenced, which is excluded from the table above. This operating lease will commence in fiscal 2021 and has a lease term of 8.7 years.

Commitments and Contingencies

Commitments and Contingencies	6 Months Ended
	Jul. 31, 2019
Commitments and Contingencies Disclosure [Abstract]
Commitments and Contingencies	Commitments and Contingencies Letters of Credit In conjunction with the execution of leases, letters of credit in the aggregate amount of $11.7 million and $12.7 million were issued and outstanding as of July 31, 2019 and January 31, 2019 , respectively. No draws have been made under such letters of credit. Legal Matters From time to time in the normal course of business, the Company may be subject to various legal matters such as threatened or pending claims or proceedings. There were no such material matters as of July 31, 2019 .

Employee Incentive Plans

Employee Incentive Plans	6 Months Ended
	Jul. 31, 2019
Share-based Payment Arrangement [Abstract]
Employee Incentive Plans	Employee Incentive Plans The Company’s equity incentive plans provide for granting stock options, restricted stock units (RSUs) and restricted stock awards to employees, consultants, officers and directors. In addition, the Company offers an Employee Stock Purchase Plan (ESPP) to eligible employees. Stock-based compensation expense was recorded in the following cost and expense categories in the Company’s condensed consolidated statements of operations (in thousands): Three Months Ended July 31, Six Months Ended July 31, 2019 2018 2019 2018 (unaudited) Cost of revenue Subscription $ 3,111 $ 1,901 $ 5,533 $ 3,430 Professional services and other 1,873 1,083 3,392 1,972 Research and development 9,082 5,272 15,428 9,485 Sales and marketing 9,236 5,471 16,022 9,624 General and administrative 7,972 4,495 13,584 7,846 Total $ 31,274 $ 18,222 $ 53,959 $ 32,357 Stock-based compensation expense recorded to research and development in the condensed consolidated statements of operations excludes amounts that were capitalized related to internal-use software for the three and six months ended July 31, 2019 and 2018 . See Note 7 for further details. Equity Incentive Plans The Company has two equity incentive plans: the 2009 Stock Plan (2009 Plan) and the 2017 Equity Incentive Plan (2017 Plan). All shares that remain available for future grants are under the 2017 Plan. As of July 31, 2019 , options to purchase 13,442,997 shares of Class B common stock and 1,144,327 shares of Class A common stock remain outstanding. Shares of common stock reserved for future issuance are as follows: As of July 31, 2019 (unaudited) Stock options and unvested RSUs outstanding 19,988,414 Available for future stock option and RSU grants 16,501,443 Available for ESPP 3,778,949 40,268,806 Stock Options A summary of the Company’s stock option activity and related information is as follows: Number of Options Weighted- Average Exercise Price Weighted- Average Remaining Contractual Term (Years) Aggregate Intrinsic Value (in thousands) Outstanding as of January 31, 2019 17,803,794 $ 9.16 7.1 $ 1,304,446 Granted 412,360 82.16 Exercised (3,376,704 ) 8.13 Canceled (252,126 ) 11.67 Outstanding as of July 31, 2019 (unaudited) 14,587,324 $ 11.42 6.6 $ 1,741,854 As of July 31, 2019 Vested and exercisable (unaudited) 9,195,820 $ 7.87 6.1 $ 1,130,712 As of July 31, 2019 , there was a total of $39.4 million of unrecognized stock-based compensation expense, which is expected to be recognized over a weighted-average period of 1.8 years. Restricted Stock Units A summary of the Company’s RSU activity and related information is as follows: Number of Weighted- Outstanding as of January 31, 2019 4,835,536 $ 44.49 Granted 1,895,182 115.86 Vested (1,016,224 ) 43.60 Forfeited (313,404 ) 45.44 Outstanding as of July 31, 2019 (unaudited) 5,401,090 $ 69.65 As of July 31, 2019 , there was $353.1 million of unrecognized stock-based compensation expense related to unvested RSUs, which is expected to be recognized over a weighted-average period of 3.0 years based on vesting under the award service conditions. Employee Stock Purchase Plan Except for the initial offering period which began April 7, 2017 and ended on June 20, 2018, the ESPP provides for 12-month offering periods beginning June 21 and December 21 of each year, and each offering period consists of up to two six-month purchase periods. The Company estimated the fair value of ESPP purchase rights using a Black-Scholes option pricing model with the following assumptions: Three Months Ended July 31, Six Months Ended July 31, 2019 2018 2019 2018 (unaudited) Expected volatility 43% - 59% 39% - 40% 43% - 59% 39% - 40% Expected term (in years) 0.5 - 1.0 0.5 - 1.0 0.5 - 1.0 0.5 - 1.0 Risk-free interest rate 2.05% - 1.95% 2.12% - 2.34% 2.05% - 1.95% 2.12% - 2.34% Expected dividend yield — — — — During the three and six months ended July 31, 2019 , the Company’s employees purchased 197,703 shares of its Class A common stock under the ESPP. The shares were purchased at a weighted-average purchase price of $45.55 per share, with total proceeds of $9.0 million. As of July 31, 2019 , there was $8.3 million of unrecognized stock-based compensation expense related to the ESPP that is expected to be recognized over an average vesting period of 0.9 years.

Income Taxes

Income Taxes	6 Months Ended
	Jul. 31, 2019
Income Tax Disclosure [Abstract]
Income Taxes	Income Taxes For the three and six months ended July 31, 2019 , the Company recorded a tax benefit of $1.5 million and $2.6 million , respectively, on pretax losses of $44.5 million and $97.6 million , respectively. The effective tax rate for the three and six months ended July 31, 2019 was 3.3% and 2.7% , respectively. The effective tax rate differs from the statutory rate primarily as a result of not recognizing deferred tax assets for U.S. losses due to a full valuation allowance against U.S. deferred tax assets, release of the valuation allowance in the United States in connection with the Azuqua acquisition and excess tax benefits from stock-based compensation in the United Kingdom. These tax benefits were partially offset by income tax expense in profitable foreign jurisdictions and U.S. state taxes. For the three and six months ended July 31, 2018 , the Company recorded a tax benefit of $1.0 million and $1.2 million , respectively, on pretax losses of $40.2 million and $66.4 million , respectively. The effective tax rate for the three and six months ended July 31, 2018 was 2.5% and 1.8% , respectively. The effective tax rate differs from the statutory rate primarily as a result of not recognizing a deferred tax asset for U.S. losses due to having a full valuation allowance against U.S. deferred tax assets, release of the valuation allowance in the United States in connection with the ScaleFT acquisition and excess tax benefits from stock-based compensation in the United Kingdom. These tax benefits were partially offset by income tax expense in profitable foreign jurisdictions and U.S. state taxes.

Net Loss Per Share

Net Loss Per Share	6 Months Ended
	Jul. 31, 2019
Earnings Per Share [Abstract]
Net Loss Per Share	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 July 31, Six Months Ended July 31, 2019 2018 2019 2018 Class A Class B Class A Class B Class A Class B Class A Class B (unaudited) Numerator: Net loss $ (39,250 ) $ (3,730 ) $ (33,862 ) $ (5,345 ) $ (86,516 ) $ (8,430 ) $ (53,242 ) $ (11,927 ) Denominator: Weighted-average shares outstanding - basic and diluted 105,049 9,984 92,156 14,546 103,917 10,125 86,172 19,303 Net loss per share, basic and diluted $ (0.37 ) $ (0.37 ) $ (0.37 ) $ (0.37 ) $ (0.83 ) $ (0.83 ) $ (0.62 ) $ (0.62 ) As the Company was in a loss position for all periods presented, basic net loss per share is the same as diluted net loss per share as the inclusion of all potential common shares outstanding would have been anti-dilutive. Potentially dilutive securities that were not included in the diluted per share calculations because they would be anti-dilutive were as follows (in thousands): As of July 31, 2019 2018 (unaudited) Unvested restricted common stock issued and outstanding — 400 Stock options issued and outstanding 14,587 20,898 Unvested RSUs issued and outstanding 5,401 4,891 Unvested restricted stock awards issued and outstanding 177 388 Shares related to convertible senior notes 7,134 7,134 Shares subject to warrants related to the issuance of convertible senior notes 7,134 — Shares committed under the ESPP 215 360 Unvested shares subject to repurchase 14 96 34,662 34,167 The Company expects to settle the principal amount of the 2023 Notes in cash, and therefore, the Company uses the treasury stock method for calculating any potential dilutive effect of the conversion option on diluted net income per share, if applicable. The conversion option of the 2023 Notes and exercise rights of the Warrants will have a dilutive impact on net income per share of common stock when the average market price per share of the Company’s Class A common stock for a given period exceeds the conversion price of the 2023 Notes of $48.36 per share and exercise price of the Warrants of $68.06 per share, respectively. During the three months ended July 31, 2019 , the weighted average price per share of the Company’s Class A common stock exceeded the conversion price of the 2023 Notes and exercise price of the Warrants; however, since the Company is in a net loss position there was no dilutive effect during any period presented.

Accounting Standards and Sign_2

Accounting Standards and Significant Accounting Policies (Policies)	6 Months Ended
	Jul. 31, 2019
Accounting Policies [Abstract]
Basis of Presentation	The accompanying unaudited condensed consolidated financial statements, which include the accounts of the Company and its wholly owned subsidiaries, have been prepared in conformity with U.S. generally accepted accounting principles (GAAP).
Principles of Consolidation	All intercompany balances and transactions have been eliminated in consolidation. The condensed consolidated balance sheet as of January 31, 2019 , included herein, was derived from the audited financial statements as of that date. The unaudited condensed consolidated financial statements reflect all normal recurring adjustments necessary to present fairly the results of operations for the interim periods presented, but are not necessarily indicative of the results of operations to be anticipated for the full fiscal year ending January 31, 2020
Fiscal Period	The Company’s fiscal year ends on January 31. References to fiscal 2020 , for example, refer to the fiscal year ending January 31, 2020
Reclassifications	Certain reclassifications of prior period amounts have been made in our condensed consolidated financial statements to conform to the current period presentation.
Use of Estimates	The preparation of condensed consolidated financial statements in conformity with GAAP requires management to make estimates, judgments and assumptions that affect the reported amounts of assets and liabilities, 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 Company bases its estimates on historical experience and on other assumptions that its management believes are reasonable under the circumstances. Actual results could vary from those estimates. The Company’s most significant estimates include the stand alone selling price (SSP) for each distinct performance obligation included in customer contracts with multiple performance obligations, the determination of the period of benefit for deferred commissions, the determination of the effective interest rate of the liability components of the 2023 Notes, the determination of the incremental borrowing rate used for operating lease liabilities, the valuation of deferred income tax assets, contingencies and the valuation of acquired intangible assets.
Operating Leases and Incremental Borrowing Rate	The Company leases office space under operating leases with expiration dates through 2028. The Company determines whether an arrangement constitutes a lease and records lease liabilities and right-of-use assets on its consolidated balance sheets at lease commencement. Lease liabilities are measured based on the present value of the total lease payments not yet paid discounted based on the more readily determinable of the rate implicit in the lease or the Company’s incremental borrowing rate, which is the estimated rate the Company would be required to pay for a collateralized borrowing equal to the total lease payments over the term of the lease. The estimation of the incremental borrowing rate is based on an analysis of publicly traded debt securities of companies with similar credit and financial profiles. Right-of-use assets are measured based on the corresponding lease liability adjusted for (i) payments made to the lessor at or before the commencement date, (ii) initial direct costs incurred and (iii) tenant incentives under the lease. Recognition of rent expense begins when the lessor makes the underlying asset available to the Company. The Company does not assume renewals or early terminations of its leases unless it is reasonably certain to exercise these options at commencement and does not allocate consideration between lease and non-lease components. For short-term leases, the Company records rent expense in its condensed consolidated statements of operations on a straight-line basis over the lease term and records variable lease payments as incurred.
Recently Adopted Accounting Pronouncements and Recently Issued Accounting Pronouncements Not Yet Adopted	In February 2016, the Financial Accounting Standards Board (FASB) issued ASU No. 2016-02, Leases (ASC 842) , which requires lessees to record a right-of-use asset and a corresponding lease liability on their balance sheet for most leases. The Company adopted the requirements of ASC 842 as of February 1, 2019, using the modified retrospective method for leases that existed as of February 1, 2017, or were entered into thereafter. The modified retrospective method provides a method for recording existing leases at adoption and in comparative periods that approximates the results of a full retrospective approach. In order to simplify an entity’s transition, ASC 842 provides a package of three practical expedients, which must be elected together and applied consistently to all of an entity’s leases. The Company elected to utilize the package of practical expedients and, therefore, did not reassess: • whether contractual arrangements that expired prior to or existed as of February 1, 2017, are or contain leases, • the classification of leases that expired prior to or existed as of February 1, 2017, and • initial direct costs for leases that existed as of February 1, 2017. As of the later of February 1, 2017 or each lease’s respective commencement date, the Company recorded lease liabilities equal to the present value of the remaining minimum lease payments and right-of-use assets equal to the corresponding lease liability adjusted for (i) any prepaid or accrued lease payments, (ii) the remaining balance of any lease incentives received, (iii) unamortized initial direct costs and (iv) any impairments. In June 2016, the FASB issued ASU 2016-13, Financial Instruments - Credit Losses: Measurement of Credit Losses on Financial Instruments, which changes the impairment model for most financial assets. The new model uses a forward-looking expected loss method, which will generally result in earlier recognition of allowances for losses. This guidance is effective for the Company on February 1, 2020 with early adoption permitted. The Company is currently evaluating the impact of the adoption of this standard on its condensed consolidated financial statements. In August 2018, the FASB issued ASU 2018-15, Customer’s Accounting for Implementation Costs Incurred in a Cloud Computing Arrangement That Is a Service Contract (ASU 2018-15), which requires a customer in a cloud computing arrangement that is a service contract to follow the internal-use software guidance in Accounting Standards Codification 350-40 to determine which implementation costs to defer and recognize as an asset. This guidance is effective for the Company on February 1, 2020 with early adoption permitted. The Company is currently evaluating the impact of the adoption of this standard on its condensed consolidated financial statements.

Accounting Standards and Sign_3

Accounting Standards and Significant Accounting Policies (Tables)	6 Months Ended
	Jul. 31, 2019
Accounting Policies [Abstract]
Schedule of Impact of New Accounting Pronouncements	Select condensed consolidated balance sheet line items, which reflect the adoption of ASC 842, are as follows (in thousands): As of January 31, 2019 As Reported Adoption of ASC 842 As Adjusted (unaudited) Assets Current assets: Prepaid expenses and other current assets $ 29,451 $ (1,214 ) $ 28,237 Total current assets 709,330 (1,214 ) 708,116 Operating lease right-of-use assets — 121,389 121,389 Other noncurrent assets 15,286 (197 ) 15,089 Total assets $ 864,335 $ 119,978 $ 984,313 Liabilities and stockholders’ equity Current liabilities: Accrued expenses and other liabilities $ 24,740 $ 8,913 $ 33,653 Total current liabilities 564,191 8,913 573,104 Other noncurrent liabilities 38,999 (35,981 ) 3,018 Operating lease liabilities, noncurrent — 147,046 147,046 Total liabilities 611,958 119,978 731,936 Total liabilities and stockholders’ equity $ 864,335 $ 119,978 $ 984,313

Cash Equivalents and Short-Te_2

Cash Equivalents and Short-Term Investments (Tables)	6 Months Ended
	Jul. 31, 2019
Investments, Debt and Equity Securities [Abstract]
Schedule of Amortized Costs, Unrealized Gains and Losses and Estimated Fair Value of Cash Equivalents and Short-term Investments	The amortized cost, unrealized gain (loss) and estimated fair value of the Company’s cash equivalents and short-term investments as of July 31, 2019 and January 31, 2019 were as follows (in thousands): As of July 31, 2019 Amortized Cost Unrealized Gain Unrealized Loss Estimated Fair Value (unaudited) Cash equivalents: Money market funds $ 116,155 $ — $ — $ 116,155 Corporate debt securities 4,999 — (1 ) 4,998 Total cash equivalents 121,154 — (1 ) 121,153 Short-term investments: U.S. treasury securities 204,210 189 (22 ) 204,377 Corporate debt securities 146,135 203 (3 ) 146,335 Total short-term investments 350,345 392 (25 ) 350,712 Total $ 471,499 $ 392 $ (26 ) $ 471,865 As of January 31, 2019 Amortized Cost Unrealized Gain Unrealized Loss Estimated Fair Value Cash equivalents: Money market funds $ 247,426 $ — $ — $ 247,426 Corporate debt securities 3,409 — (1 ) 3,408 Total cash equivalents 250,835 — (1 ) 250,834 Short-term investments: U.S. treasury securities 195,913 37 (53 ) 195,897 Corporate debt securities 69,483 13 (19 ) 69,477 Total short-term investments 265,396 50 (72 ) 265,374 Total $ 516,231 $ 50 $ (73 ) $ 516,208
Schedule of Contractual Maturities of Short-term Investments	The Company’s short-term investments as of July 31, 2019 and January 31, 2019 all mature within one year, as follows (in thousands): As of July 31, 2019 As of January 31, 2019 Amortized Cost Estimated Fair Value Amortized Cost Estimated Fair Value (unaudited) Due within one year $ 350,345 $ 350,712 $ 265,396 $ 265,374

Fair Value Measurements (Tables

Fair Value Measurements (Tables)	6 Months Ended
	Jul. 31, 2019
Fair Value Disclosures [Abstract]
Schedule of Financial Assets and Liabilities Measured at Fair Value on a Recurring Basis	The following table presents information about the Company’s financial assets and liabilities that are measured at fair value on a recurring basis using the above input categories (in thousands): As of July 31, 2019 Level 1 Level 2 Level 3 Total (unaudited) Assets: Cash equivalents: Money market funds $ 116,155 $ — $ — $ 116,155 Corporate debt securities — 4,998 — 4,998 Total cash equivalents 116,155 4,998 — 121,153 Short-term investments: U.S. treasury securities — 204,377 — 204,377 Corporate debt securities — 146,335 — 146,335 Total short-term investments — 350,712 — 350,712 Total cash equivalents and short-term investments $ 116,155 $ 355,710 $ — $ 471,865 As of January 31, 2019 Level 1 Level 2 Level 3 Total Assets: Cash equivalents: Money market funds $ 247,426 $ — $ — $ 247,426 Corporate debt securities — 3,408 — 3,408 Total cash equivalents 247,426 3,408 — 250,834 Short-term investments: U.S. treasury securities — 195,897 — 195,897 Corporate debt securities — 69,477 — 69,477 Total short-term investments — 265,374 — 265,374 Total cash equivalents and short-term investments $ 247,426 $ 268,782 $ — $ 516,208
Schedule of Carrying Amounts and Estimated Fair Values of Convertible Note	The following table presents the carrying amounts and estimated fair values of our financial instruments that are not recorded at fair value on the condensed consolidated balance sheets (in thousands): As of July 31, 2019 Net Carrying Amount Before Unamortized Debt Issuance Costs Estimated Fair Value (unaudited) Convertible senior notes $ 285,696 $ 958,925

Goodwill and Intangible Asset_2

Goodwill and Intangible Assets, net (Tables)	6 Months Ended
	Jul. 31, 2019
Goodwill and Intangible Assets Disclosure [Abstract]
Schedule of Intangible Assets, net	Intangible assets consisted of the following (in thousands): As of July 31, 2019 Gross Accumulated Amortization Net (unaudited) Capitalized internal-use software costs $ 21,494 $ (12,342 ) $ 9,152 Purchased developed technology 28,800 (3,381 ) 25,419 Software licenses 1,023 (882 ) 141 $ 51,317 $ (16,605 ) $ 34,712 As of January 31, 2019 Gross Accumulated Amortization Net Capitalized internal-use software costs $ 19,838 $ (9,969 ) $ 9,869 Purchased developed technology 4,600 (833 ) 3,767 Software licenses 1,023 (763 ) 260 $ 25,461 $ (11,565 ) $ 13,896

Convertible Senior Notes, Net (

Convertible Senior Notes, Net (Tables)	6 Months Ended
	Jul. 31, 2019
Debt Disclosure [Abstract]
Schedule of Interest Expense	The following table sets forth total interest expense recognized related to the 2023 Notes (in thousands): Three Months Ended July 31, Six Months Ended July 31, 2019 2018 2019 2018 (unaudited) Contractual interest expense $ 215 $ 216 $ 431 $ 362 Amortization of debt issuance costs 329 288 648 478 Amortization of debt discount 3,759 3,554 7,465 5,935 Total $ 4,303 $ 4,058 $ 8,544 $ 6,775
Schedule of Liability and Equity Component of 2023 Notes	The 2023 Notes, net consisted of the following (in thousands): As of July 31, 2019 (unaudited) Liability component: Principal $ 345,000 Less: unamortized debt issuance costs and debt discount (65,259 ) Net carrying amount $ 279,741 At Issuance Equity component: 2023 Notes $ 79,962 Less: issuance costs (2,320 ) Carrying amount of the equity component (1) $ 77,642 (1) Included in the condensed consolidated balance sheets within Additional paid-in capital.

Leases (Tables)

Leases (Tables)	6 Months Ended
	Jul. 31, 2019
Leases [Abstract]
Schedule of Operating Lease Costs	Operating lease costs for the three and six months ended July 31, 2019 and 2018 , are as follows (in thousands): Three Months Ended July 31, Six Months Ended July 31, 2019 2018 2019 2018 (unaudited) Operating lease cost (1) $ 5,620 $ 5,807 $ 11,083 $ 9,241 (1) Amounts are presented gross of sublease income and include short-term leases, which are immaterial.
Schedule of Maturities of Operating Leases	Maturities of the Company’s operating lease liabilities, which do not include short-term leases, as of July 31, 2019 are as follows (in thousands): Operating Leases (unaudited) 2020 $ 12,157 2021 24,504 2022 24,189 2023 23,765 2024 24,252 Thereafter 95,733 Total lease payments 204,600 Less imputed interest (45,310 ) Total operating lease liabilities $ 159,290

Employee Incentive Plans (Table

Employee Incentive Plans (Tables)	6 Months Ended
	Jul. 31, 2019
Share-based Payment Arrangement [Abstract]
Schedule of Stock-based Compensation Expense by Statement of Operations Location	Stock-based compensation expense was recorded in the following cost and expense categories in the Company’s condensed consolidated statements of operations (in thousands): Three Months Ended July 31, Six Months Ended July 31, 2019 2018 2019 2018 (unaudited) Cost of revenue Subscription $ 3,111 $ 1,901 $ 5,533 $ 3,430 Professional services and other 1,873 1,083 3,392 1,972 Research and development 9,082 5,272 15,428 9,485 Sales and marketing 9,236 5,471 16,022 9,624 General and administrative 7,972 4,495 13,584 7,846 Total $ 31,274 $ 18,222 $ 53,959 $ 32,357
Schedule of Shares of Common Stock Reserved for Future Issuance	Shares of common stock reserved for future issuance are as follows: As of July 31, 2019 (unaudited) Stock options and unvested RSUs outstanding 19,988,414 Available for future stock option and RSU grants 16,501,443 Available for ESPP 3,778,949 40,268,806
Schedule of Stock Option Activity	A summary of the Company’s stock option activity and related information is as follows: Number of Options Weighted- Average Exercise Price Weighted- Average Remaining Contractual Term (Years) Aggregate Intrinsic Value (in thousands) Outstanding as of January 31, 2019 17,803,794 $ 9.16 7.1 $ 1,304,446 Granted 412,360 82.16 Exercised (3,376,704 ) 8.13 Canceled (252,126 ) 11.67 Outstanding as of July 31, 2019 (unaudited) 14,587,324 $ 11.42 6.6 $ 1,741,854 As of July 31, 2019 Vested and exercisable (unaudited) 9,195,820 $ 7.87 6.1 $ 1,130,712
Schedule of Nonvested Restricted Stock Units Activity	A summary of the Company’s RSU activity and related information is as follows: Number of Weighted- Outstanding as of January 31, 2019 4,835,536 $ 44.49 Granted 1,895,182 115.86 Vested (1,016,224 ) 43.60 Forfeited (313,404 ) 45.44 Outstanding as of July 31, 2019 (unaudited) 5,401,090 $ 69.65

Net Loss Per Share (Tables)

Net Loss Per Share (Tables)	6 Months Ended
	Jul. 31, 2019
Earnings Per Share [Abstract]
Schedule of 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 July 31, Six Months Ended July 31, 2019 2018 2019 2018 Class A Class B Class A Class B Class A Class B Class A Class B (unaudited) Numerator: Net loss $ (39,250 ) $ (3,730 ) $ (33,862 ) $ (5,345 ) $ (86,516 ) $ (8,430 ) $ (53,242 ) $ (11,927 ) Denominator: Weighted-average shares outstanding - basic and diluted 105,049 9,984 92,156 14,546 103,917 10,125 86,172 19,303 Net loss per share, basic and diluted $ (0.37 ) $ (0.37 ) $ (0.37 ) $ (0.37 ) $ (0.83 ) $ (0.83 ) $ (0.62 ) $ (0.62 )
Schedule of Potentially Dilutive Securities Excluded from Diluted Per Share Calculation	Potentially dilutive securities that were not included in the diluted per share calculations because they would be anti-dilutive were as follows (in thousands): As of July 31, 2019 2018 (unaudited) Unvested restricted common stock issued and outstanding — 400 Stock options issued and outstanding 14,587 20,898 Unvested RSUs issued and outstanding 5,401 4,891 Unvested restricted stock awards issued and outstanding 177 388 Shares related to convertible senior notes 7,134 7,134 Shares subject to warrants related to the issuance of convertible senior notes 7,134 — Shares committed under the ESPP 215 360 Unvested shares subject to repurchase 14 96 34,662 34,167

Overview and Basis of Present_2

Overview and Basis of Presentation - Narrative (Details) - USD ($)	1 Months Ended
	Feb. 28, 2018	Jul. 31, 2019	Jan. 31, 2019
Class of Stock [Line Items]
Increase in accrued expenses		$ 31,843,000	$ 33,653,000	[1]
Accounts payable		$ 3,492,000	2,431,000	[1]
Convertible Senior Notes Due 2023 | Senior Notes
Class of Stock [Line Items]
Aggregate principal amount	$ 345,000,000
Fixed interest rate	0.25%
Gross proceeds from issuance of debt	$ 345,000,000
Issuance costs	$ 10,000,000
Accounting Standards Update 2016-02
Class of Stock [Line Items]
Increase in accrued expenses			$ 14,800,000
[1]	Adjusted for adoption of ASC 842, Leases. See Note 2.

Accounting Standards and Sign_4

Accounting Standards and Significant Accounting Policies - Schedule of Impact of New Accounting Pronouncements (Details) - USD ($) $ in Thousands	Jul. 31, 2019	Jan. 31, 2019
Current assets:
Prepaid expenses and other current assets	$ 24,642	$ 28,237	[1]
Total current assets	697,020	708,116	[1]
Operating lease right-of-use assets	116,706	121,389	[1]
Other noncurrent assets	18,990	15,089	[1]
Total assets	1,026,810	984,313	[1]
Current liabilities:
Accrued expenses and other current liabilities	31,843	33,653	[1]
Total current liabilities	620,669	573,104	[1]
Other noncurrent liabilities	4,241	3,018	[1]
Operating lease liabilities, noncurrent	143,706	147,046	[1]
Total liabilities	776,085	731,936	[1]
Total liabilities and stockholders’ equity	$ 1,026,810	984,313	[1]
Accounting Standards Update 2016-02
Current liabilities:
Accrued expenses and other current liabilities		14,800
As Reported
Current assets:
Prepaid expenses and other current assets		29,451
Total current assets		709,330
Operating lease right-of-use assets		0
Other noncurrent assets		15,286
Total assets		864,335
Current liabilities:
Accrued expenses and other current liabilities		24,740
Total current liabilities		564,191
Other noncurrent liabilities		38,999
Operating lease liabilities, noncurrent		0
Total liabilities		611,958
Total liabilities and stockholders’ equity		864,335
Adoption of ASC 842 | Accounting Standards Update 2016-02
Current assets:
Prepaid expenses and other current assets		(1,214)
Total current assets		(1,214)
Operating lease right-of-use assets		121,389
Other noncurrent assets		(197)
Total assets		119,978
Current liabilities:
Accrued expenses and other current liabilities		8,913
Total current liabilities		8,913
Other noncurrent liabilities		(35,981)
Operating lease liabilities, noncurrent		147,046
Total liabilities		119,978
Total liabilities and stockholders’ equity		$ 119,978
[1]	Adjusted for adoption of ASC 842, Leases. See Note 2.

Business Combinations - Narrati

Business Combinations - Narrative (Details) - USD ($) $ in Thousands	Mar. 18, 2019	Jul. 13, 2018	Apr. 30, 2019	Jul. 31, 2018	Jul. 31, 2019	Jul. 31, 2018	[1]	Jan. 31, 2019	[2]
Business Acquisition [Line Items]
Payments for business acquisition, net of cash acquired					$ 44,223	$ 15,638
Purchased developed technology					24,200
Goodwill					47,964			$ 18,089
ScaleFT, Inc.
Business Acquisition [Line Items]
Payments for business acquisition, net of cash acquired		$ 15,600
Cash acquired from acquisition		600
Goodwill		11,800
Acquisition related costs				$ 1,100
ScaleFT, Inc. | Purchased developed technology
Business Acquisition [Line Items]
Purchased developed technology		$ 4,600
Useful life of acquired intangible assets		3 years
Azuqua, Inc.
Business Acquisition [Line Items]
Payments for business acquisition, net of cash acquired	$ 44,200
Cash acquired from acquisition	1,100
Purchased developed technology					15,700
Goodwill	29,900
Acquisition related costs			$ 3,000
Azuqua, Inc. | Purchased developed technology
Business Acquisition [Line Items]
Purchased developed technology	$ 15,700
Useful life of acquired intangible assets	5 years
ScaleFT, Inc And Azuqua, Inc.
Business Acquisition [Line Items]
Deferred compensation liability					10,800
Compensation Expense					2,100
Remaining balance of noncurrent deferred compensation liability					$ 7,100
Period of recognition of deferred compensation					1 year 10 months 24 days
[1]	Adjusted for adoption of ASC 842, Leases. See Note 2.
[2]	Adjusted for adoption of ASC 842, Leases. See Note 2.

Cash Equivalents and Short-Te_3

Cash Equivalents and Short-Term Investments - Schedule of Amortized Costs, Unrealized Gains and Losses and Estimated Fair Value of Cash Equivalents and Short-term Investments (Details) - USD ($) $ in Thousands	Jul. 31, 2019	Jan. 31, 2019
Cash Equivalents and Short-term Investments [Abstract]
Amortized Cost	$ 471,499	$ 516,231
Unrealized Gain	392	50
Unrealized Loss	(26)	(73)
Estimated Fair Value	471,865	516,208
U.S. treasury securities
Cash Equivalents and Short-term Investments [Abstract]
Amortized Cost	204,210	195,913
Unrealized Gain	189	37
Unrealized Loss	(22)	(53)
Estimated Fair Value	204,377	195,897
Corporate debt securities
Cash Equivalents and Short-term Investments [Abstract]
Amortized Cost	146,135	69,483
Unrealized Gain	203	13
Unrealized Loss	(3)	(19)
Estimated Fair Value	146,335	69,477
Cash Equivalents
Cash Equivalents and Short-term Investments [Abstract]
Amortized Cost	121,154	250,835
Unrealized Gain	0	0
Unrealized Loss	(1)	(1)
Estimated Fair Value	121,153	250,834
Cash Equivalents | Money market funds
Cash Equivalents and Short-term Investments [Abstract]
Amortized Cost	116,155	247,426
Unrealized Gain	0	0
Unrealized Loss	0	0
Estimated Fair Value	116,155	247,426
Cash Equivalents | Corporate debt securities
Cash Equivalents and Short-term Investments [Abstract]
Amortized Cost	4,999	3,409
Unrealized Gain	0	0
Unrealized Loss	(1)	(1)
Estimated Fair Value	4,998	3,408
Short-term Investments [Member]
Cash Equivalents and Short-term Investments [Abstract]
Amortized Cost	350,345	265,396
Unrealized Gain	392	50
Unrealized Loss	(25)	(72)
Estimated Fair Value	$ 350,712	$ 265,374

Cash Equivalents and Short-Te_4

Cash Equivalents and Short-Term Investments - Schedule of Contractual Maturities of Short-term Investments (Details) - USD ($) $ in Thousands	Jul. 31, 2019	Jan. 31, 2019
Amortized Cost
Amortized cost, due within one year	$ 350,345	$ 265,396
Estimated Fair Value
Estimated fair value, due within one year	$ 350,712	$ 265,374

Cash Equivalents and Short-Te_5

Cash Equivalents and Short-Term Investments - Narrative (Details)	3 Months Ended	6 Months Ended	12 Months Ended
	Jul. 31, 2018USD ($)	Jul. 31, 2019USD ($)investment	Jan. 31, 2019USD ($)investment
Investments, Debt and Equity Securities [Abstract]
Number of short-term investments in unrealized loss positions | investment		7	34
Gross unrealized gains or losses from available-for-sale securities	$ 0	$ 0
Realized gains or losses reclassified out of accumulated other comprehensive income	$ 0	0
Other-than-temporary impairment short term investment		$ 0	$ 0

Fair Value Measurements - Sched

Fair Value Measurements - Schedule of Financial Assets and Liabilities Measured at Fair Value on a Recurring Basis (Details) - Fair Value, Measurements, Recurring - USD ($) $ in Thousands	Jul. 31, 2019	Jan. 31, 2019
Assets:
Cash equivalents, fair value	$ 121,153	$ 250,834
Short term investments, fair value	350,712	265,374
Total cash equivalents and short-term investments	471,865	516,208
U.S. treasury securities
Assets:
Short term investments, fair value	204,377	195,897
Corporate debt securities
Assets:
Short term investments, fair value	146,335	69,477
Money market funds
Assets:
Cash equivalents, fair value	116,155	247,426
Corporate debt securities
Assets:
Cash equivalents, fair value	4,998	3,408
Level 1
Assets:
Cash equivalents, fair value	116,155	247,426
Short term investments, fair value	0	0
Total cash equivalents and short-term investments	116,155	247,426
Level 1 | U.S. treasury securities
Assets:
Short term investments, fair value	0	0
Level 1 | Corporate debt securities
Assets:
Short term investments, fair value	0	0
Level 1 | Money market funds
Assets:
Cash equivalents, fair value	116,155	247,426
Level 1 | Corporate debt securities
Assets:
Cash equivalents, fair value	0	0
Level 2
Assets:
Cash equivalents, fair value	4,998	3,408
Short term investments, fair value	350,712	265,374
Total cash equivalents and short-term investments	355,710	268,782
Level 2 | U.S. treasury securities
Assets:
Short term investments, fair value	204,377	195,897
Level 2 | Corporate debt securities
Assets:
Short term investments, fair value	146,335	69,477
Level 2 | Money market funds
Assets:
Cash equivalents, fair value	0	0
Level 2 | Corporate debt securities
Assets:
Cash equivalents, fair value	4,998	3,408
Level 3
Assets:
Cash equivalents, fair value	0	0
Short term investments, fair value	0	0
Total cash equivalents and short-term investments	0	0
Level 3 | U.S. treasury securities
Assets:
Short term investments, fair value	0	0
Level 3 | Corporate debt securities
Assets:
Short term investments, fair value	0	0
Level 3 | Money market funds
Assets:
Cash equivalents, fair value	0	0
Level 3 | Corporate debt securities
Assets:
Cash equivalents, fair value	$ 0	$ 0

Fair Value Measurements - Sch_2

Fair Value Measurements - Schedule of Carrying Amounts and Estimated Fair Values of Convertible Note (Details) - Senior Notes - Convertible Senior Notes Due 2023 $ in Thousands	Jul. 31, 2019USD ($)
Net Carrying Amount Before Unamortized Debt Issuance Costs
Debt Instrument [Line Items]
Convertible senior notes	$ 285,696
Estimated Fair Value
Debt Instrument [Line Items]
Convertible senior notes	$ 958,925

Fair Value Measurements - Narra

Fair Value Measurements - Narrative (Details) $ / shares in Units, $ in Thousands	Jul. 31, 2019USD ($)$ / shares
Debt Instrument [Line Items]
Closing price of common stock (in dollars per share) | $ / shares	$ 130.83
Convertible Senior Notes Due 2023 | Senior Notes
Debt Instrument [Line Items]
Aggregate principal amount | $	$ 345,000

Deferred Commissions (Details)

Deferred Commissions (Details) - USD ($)	3 Months Ended		6 Months Ended
	Jul. 31, 2019	Jul. 31, 2018	Jul. 31, 2019	Jul. 31, 2018
Revenue from Contract with Customer [Abstract]
Sales commissions capitalized as contract costs	$ 11,600,000	$ 8,500,000	$ 21,400,000	$ 14,200,000
Amortization of contract costs	6,900,000	5,000,000	$ 13,200,000	$ 9,600,000
Impairment loss related to costs capitalized	$ 0	$ 0

Goodwill and Intangible Asset_3

Goodwill and Intangible Assets, net - Narrative (Details) - USD ($)	3 Months Ended		6 Months Ended
	Jul. 31, 2019	Jul. 31, 2018	Jul. 31, 2019	Jul. 31, 2018	Mar. 18, 2019	Jan. 31, 2019	[1]
Finite-Lived Intangible Assets [Line Items]
Goodwill	$ 47,964,000		$ 47,964,000			$ 18,089,000
Goodwill impairments	0	$ 0	0	$ 0
Capitalized internal-use software	1,200,000	800,000	1,700,000	2,000,000
Share-based Payment Arrangement	8,500,000
Purchased developed technology	24,200,000		24,200,000
Intangible amortization expense	3,000,000	$ 1,200,000	5,100,000	$ 2,400,000
Azuqua, Inc.
Finite-Lived Intangible Assets [Line Items]
Goodwill					$ 29,900,000
Goodwill acquired in connection with acquisition			29,900,000
Purchased developed technology	$ 15,700,000		$ 15,700,000
Azuqua, Inc. | Purchased developed technology
Finite-Lived Intangible Assets [Line Items]
Purchased developed technology					$ 15,700,000
[1]	Adjusted for adoption of ASC 842, Leases. See Note 2.

Goodwill and Intangible Asset_4

Goodwill and Intangible Assets, net - Schedule of Intangible Assets (Details) - USD ($) $ in Thousands	Jul. 31, 2019	Jan. 31, 2019
Finite-Lived Intangible Assets [Line Items]
Gross	$ 51,317	$ 25,461
Accumulated Amortization	(16,605)	(11,565)
Net	34,712	13,896
Capitalized internal-use software costs
Finite-Lived Intangible Assets [Line Items]
Gross	21,494	19,838
Accumulated Amortization	(12,342)	(9,969)
Net	9,152	9,869
Purchased developed technology
Finite-Lived Intangible Assets [Line Items]
Gross	28,800	4,600
Accumulated Amortization	(3,381)	(833)
Net	25,419	3,767
Software licenses
Finite-Lived Intangible Assets [Line Items]
Gross	1,023	1,023
Accumulated Amortization	(882)	(763)
Net	$ 141	$ 260

Deferred Revenue and Performa_2

Deferred Revenue and Performance Obligations - Narrative (Details) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jul. 31, 2019	Jul. 31, 2018	Jul. 31, 2019	Jul. 31, 2018	Jan. 31, 2019
Revenue from Contract with Customer [Abstract]
Revenue recognized that was included in the contract liability balance	$ 113.1	$ 73.1	$ 174.9	$ 114.3
Unbilled receivables	$ 1		$ 1		$ 1.5

Deferred Revenue and Performa_3

Deferred Revenue and Performance Obligations - Performance Obligations (Details) $ in Millions	Jul. 31, 2019USD ($)
Revenue from Contract with Customer [Abstract]
Revenue from remaining performance obligations	$ 913.6
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2019-05-01
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items]
Performance obligations expected to be satisfied, expected timing	12 months
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2019-08-01
Revenue from Contract with Customer [Abstract]
Revenue from remaining performance obligations	$ 461.1
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items]
Remaining performance obligation, percentage	51.00%

Convertible Senior Notes, Net -

Convertible Senior Notes, Net - Convertible Senior Notes (Details) - Senior Notes - Convertible Senior Notes Due 2023 $ / shares in Units, $ in Thousands	1 Months Ended		6 Months Ended
	Apr. 30, 2019day	Feb. 28, 2018USD ($)day$ / shares	Jul. 31, 2019USD ($)
Debt Instrument [Line Items]
Fixed interest rate		0.25%
Net proceeds from notes		$ 335,000
Initial conversion rate of common stock		0.0206795
Conversion price (in dollars per share) | $ / shares		$ 48.36
Limitation on sale of common stock (in days) | day		20
Limitation on sale of common stock due to sale price threshold (in days) | day	20	30
Threshold percentage of stock price trigger		130.00%	130.00%
Percentage of closing sale price in excess of convertible notes		98.00%
Redemption price percentage		100.00%
Effective interest rate		5.68%
Issuance costs		$ 10,000
Issuance costs attributable to liability component			$ 7,700
Period After Consecutive Trading Days		5 days
Additional Paid-in Capital
Debt Instrument [Line Items]
Issuance costs attributable to equity component			$ 2,320

Convertible Senior Notes, Net_2

Convertible Senior Notes, Net - Schedule of Interest Expense (Details) - Senior Notes - Convertible Senior Notes Due 2023 - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jul. 31, 2019	Jul. 31, 2018	Jul. 31, 2019	Jul. 31, 2018
Debt Instrument [Line Items]
Contractual interest expense	$ 215	$ 216	$ 431	$ 362
Amortization of debt issuance costs	329	288	648	478
Amortization of debt discount	3,759	3,554	7,465	5,935
Total	$ 4,303	$ 4,058	$ 8,544	$ 6,775

Convertible Senior Notes, Net_3

Convertible Senior Notes, Net - Schedule of Liability and Equity Component of 2023 Notes (Details) - Senior Notes - Convertible Senior Notes Due 2023 $ in Thousands	Jul. 31, 2019USD ($)
Liability component:
Principal	$ 345,000
Less: unamortized debt issuance costs and debt discount	(65,259)
Net carrying amount	279,741
Additional Paid-in Capital
Equity component:
2023 Notes	79,962
Less: issuance costs	(2,320)
Carrying amount of the equity component	$ 77,642

Convertible Senior Notes, Net_4

Convertible Senior Notes, Net - Note Hedges and Warrants (Details) - USD ($) $ / shares in Units, $ in Thousands, shares in Millions	1 Months Ended	6 Months Ended
	Feb. 28, 2018	Jul. 31, 2019	Jul. 31, 2018	[1]
Debt Instrument [Line Items]
Aggregate amount paid for cost of Note Hedge	$ 80,000
Number of warrants issued, subject to anti-dilution adjustments (in shares)	7.1
Per share value, shares issuable under warrants granted (in dollars per share)	$ 68.06
Proceeds from issuance of warrants related to convertible notes	$ 52,400	$ 0	$ 52,440
Senior Notes | Convertible Senior Notes Due 2023
Debt Instrument [Line Items]
Shares issuable under warrants granted (in shares)	7.1
Conversion price (in dollars per share)	$ 48.36
[1]	Adjusted for adoption of ASC 842, Leases. See Note 2.

Leases - Narrative (Details)

Leases - Narrative (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jul. 31, 2019	Jul. 31, 2018	Jul. 31, 2019	Jul. 31, 2018	Jan. 31, 2019
Other Commitments [Line Items]
Finance Lease, Liability, Undiscounted Excess Amount	$ 45,310		$ 45,310
Sublease minimum remaining lease term	1 year
Sublease maximum remaining lease term			5 years
Sublease income	$ 700		$ 1,400
Weighted average remaining lease term	8 years 4 months 24 days		8 years 4 months 24 days		8 years 10 months 24 days
Weighted average discount rate	5.90%		5.90%
Cash payments included in the measurement of operating lease liabilities	$ 2,400	$ 3,100	$ 4,800	$ 6,100
Undiscounted future payments under operating leases that have not yet commenced	$ 35,600		$ 35,600
Operating lease terms for leases that have not yet commenced	8 years 8 months 12 days		8 years 8 months 12 days

Leases - Schedule of Operating

Leases - Schedule of Operating Lease Costs (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jul. 31, 2019	Jul. 31, 2018	Jul. 31, 2019	Jul. 31, 2018
Lease cost:
Operating lease cost	$ 5,620	$ 5,807	$ 11,083	$ 9,241

Leases - Schedule of Maturities

Leases - Schedule of Maturities of Operating Leases (Details) $ in Thousands	Jul. 31, 2019USD ($)
Lessee, Operating Lease, Liability, Payment, Due [Abstract]
2020	$ 12,157
2021	24,504
2022	24,189
2023	23,765
2024	24,252
Thereafter	95,733
Total lease payments	204,600
Less imputed interest	(45,310)
Total operating lease liabilities	$ 159,290

Commitments and Contingencies -

Commitments and Contingencies - Narrative (Details) - Letter of Credit - USD ($)	Jul. 31, 2019	Jan. 31, 2019
Other Commitments [Line Items]
Letters of credit issued and outstanding		$ 12,700,000
Draws on line of credit	$ 0

Employee Incentive Plans - Sche

Employee Incentive Plans - Schedule of Stock-based Compensation Expense by Statement of Operations Location (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jul. 31, 2019	Jul. 31, 2018	Jul. 31, 2019	Jul. 31, 2018
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Stock-based compensation expense	$ 31,274	$ 18,222	$ 53,959	$ 32,357
Subscription
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Stock-based compensation expense	3,111	1,901	5,533	3,430
Professional services and other
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Stock-based compensation expense	1,873	1,083	3,392	1,972
Research and development
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Stock-based compensation expense	9,082	5,272	15,428	9,485
Sales and marketing
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Stock-based compensation expense	9,236	5,471	16,022	9,624
General and administrative
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Stock-based compensation expense	$ 7,972	$ 4,495	$ 13,584	$ 7,846

Employee Incentive Plans - Narr

Employee Incentive Plans - Narrative (Details) $ / shares in Units, $ in Millions	3 Months Ended	6 Months Ended
	Jul. 31, 2019USD ($)$ / sharesshares	Jul. 31, 2019USD ($)incentive_plan$ / sharesshares	Jan. 31, 2019shares
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Number of equity incentive plans | incentive_plan		2
Options to purchase common stock outstanding (in shares)	14,587,324	14,587,324	17,803,794
Unrecognized stock-based compensation expense related to stock options | $	$ 39.4	$ 39.4
Stock Issued During Period, Value, Employee Stock Purchase Plan | $		9
Unrecognized stock-based compensation expenses related to unvested RSUs | $	$ 353.1	$ 353.1
Number of options, granted (in shares)		412,360
Restricted stock units
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Granted during period (in shares)		1,895,182
Vested during period (in shares)		1,016,224
Stock options
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Weighted average stock-based compensation recognition period		1 year 9 months 18 days
ESPP
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Weighted average stock-based compensation recognition period		10 months 24 days
Employee purchase of Class A common stock under the ESPP	434,640	197,703
Share-based Compensation Arrangement by Share-based Payment Award, Per Share Weighted Average Price of Shares Purchased | $ / shares	$ 45.55	$ 45.55
Unrecognized compensation costs related to unvested restricted stock units | $	$ 8.3	$ 8.3
Restricted stock units | Stock options
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Weighted average stock-based compensation recognition period		3 years
2017 Equity Incentive Plan | Class B Common Stock
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Options to purchase common stock outstanding (in shares)	13,442,997	13,442,997
2017 Equity Incentive Plan | Class A Common Stock
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Options to purchase common stock outstanding (in shares)	1,144,327	1,144,327

Employee Incentive Plans - Sc_2

Employee Incentive Plans - Schedule of Common Stock Reserved for Future Issuance (Details)	Jul. 31, 2019shares
Class of Stock [Line Items]
Common stock reserved for future issuance and options and unvested RSUs outstanding (in shares)	40,268,806
Stock Options And Restricted Stock Units
Class of Stock [Line Items]
Stock options and unvested RSUs outstanding (in shares)	19,988,414
Common stock, reserved for future issuance (in shares)	16,501,443
ESPP
Class of Stock [Line Items]
Common stock, reserved for future issuance (in shares)	3,778,949

Employee Incentive Plans - Sc_3

Employee Incentive Plans - Schedule of Stock Option Activity (Details) - USD ($) $ / shares in Units, $ in Thousands	6 Months Ended	12 Months Ended
	Jul. 31, 2019	Jan. 31, 2019
Number of Options
Number of options, outstanding beginning of period (in shares)	17,803,794
Number of options, granted (in shares)	412,360
Number of options, exercised (in shares)	(3,376,704)
Number of options, canceled (in shares)	(252,126)
Number of options, outstanding end of period (in shares)	14,587,324	17,803,794
Vested and exercisable, number of options (in shares)	9,195,820
Weighted- Average Exercise Price
Options outstanding, weighted average exercise price beginning of period (in dollars per share)	$ 9.16
Options granted, weighted average exercise price (in dollars per share)	82.16
Options exercised, weighted average exercise price (in dollars per share)	8.13
Options canceled, weighted average exercise price (in dollars per share)	11.67
Options outstanding, weighted average exercise price end of period (in dollars per share)	11.42	$ 9.16
Vested and exercisable, weighted average exercise price (in dollars per share)	$ 7.87
Additional Disclosures
Options outstanding, weighted average remaining contractual term	6 years 7 months 6 days	7 years 1 month 6 days
Options outstanding, aggregate intrinsic value	$ 1,741,854	$ 1,304,446
Vested and exercisable, weighted average remaining contractual term	6 years 1 month 6 days
Vested and exercisable, aggregate intrinsic value	$ 1,130,712

Employee Incentive Plans - Sc_4

Employee Incentive Plans - Schedule of Restricted Stock Unit Activity (Details) - Restricted stock units	6 Months Ended
	Jul. 31, 2019$ / sharesshares
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Nonvested, Number of Shares [Roll Forward]
Beginning balance (in shares) | shares	4,835,536
Granted during period (in shares) | shares	1,895,182
Vested during period (in shares) | shares	(1,016,224)
Forfeited during period (in shares) | shares	(313,404)
Ending balance (in shares) | shares	5,401,090
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Nonvested, Weighted Average Grant Date Fair Value [Abstract]
Beginning balance (in dollars per share) | $ / shares	$ 44.49
Granted during period (in dollars per share) | $ / shares	115.86
Vested during period (in dollars per share) | $ / shares	43.60
Forfeited during period (in dollars per share) | $ / shares	45.44
Ending balance (in dollars per share) | $ / shares	$ 69.65

Employee Incentive Plans - Sc_5

Employee Incentive Plans - Schedule of Black-Scholes Option Pricing Model Estimated Fair Value Assumptions (Details) - shares	3 Months Ended		6 Months Ended
	Jul. 31, 2019	Jul. 31, 2018	Jul. 31, 2019	Jul. 31, 2018
ESPP
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Expected volatility	43.00%	39.00%	43.00%	39.00%
Share-based Compensation Arrangement by Share-based Payment Award, Fair Value Assumptions, Expected Volatility Rate, Maximum	59.00%	40.00%	59.00%	40.00%
Expected term (in years)	0 years	0 years
Risk-free interest rate	2.05%	2.12%	2.05%	2.12%
Share-based Compensation Arrangement by Share-based Payment Award, Fair Value Assumptions, Risk Free Interest Rate, Maximum	1.95%	2.34%	1.95%	2.34%
Employee purchase of Class A common stock under the ESPP	434,640		197,703
Stock options
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Expected term (in years)	0 years
Minimum | ESPP
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Expected term (in years)	6 months	6 months	6 months	6 months
Maximum | ESPP
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Expected term (in years)	1 year	1 year	1 year	1 year

Income Taxes - Narrative (Detai

Income Taxes - Narrative (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jul. 31, 2019	Jul. 31, 2018	Jul. 31, 2019	Jul. 31, 2018
Income Tax Disclosure [Abstract]
Tax benefit	$ 1,477	$ 985	$ 2,634	$ 1,216
Pretax losses	$ 44,457	$ 40,192	$ 97,580	$ 66,385
Effective income tax rate	3.30%	2.50%	2.70%	1.80%

Net Loss Per Share - Schedule o

Net Loss Per Share - Schedule of Basic and Diluted Net Loss Per Share (Details) - USD ($) $ / shares in Units, shares in Thousands, $ in Thousands	3 Months Ended		6 Months Ended
	Jul. 31, 2019	Jul. 31, 2018	Jul. 31, 2019	Jul. 31, 2018
Numerator:
Net loss	$ (42,980)	$ (39,207)	$ (94,946)	$ (65,169)	[1]
Denominator:
Weighted-average shares outstanding - basic and diluted (in shares)	115,033	106,702	114,042	105,475
Net loss per share, basic and diluted (in dollars per share)	$ (0.37)	$ (0.37)	$ (0.83)	$ (0.62)
Class A Common Stock
Numerator:
Net loss	$ (39,250)	$ (33,862)
Denominator:
Weighted-average shares outstanding - basic and diluted (in shares)	105,049	92,156	103,917	86,172
Net loss per share, basic and diluted (in dollars per share)	$ (0.37)	$ (0.37)	$ (0.83)	$ (0.62)
Class B Common Stock
Numerator:
Net loss	$ (3,730)	$ (5,345)
Denominator:
Weighted-average shares outstanding - basic and diluted (in shares)	9,984	14,546	10,125	19,303
Net loss per share, basic and diluted (in dollars per share)	$ (0.37)	$ (0.37)	$ (0.83)	$ (0.62)
Common Stock | Class A Common Stock
Numerator:
Net loss			$ (86,516)	$ (53,242)
Common Stock | Class B Common Stock
Numerator:
Net loss			$ (8,430)	$ (11,927)
[1]	Adjusted for adoption of ASC 842, Leases. See Note 2.

Net Loss Per Share - Schedule_2

Net Loss Per Share - Schedule of Potentially Dilutive Securities Excluded from Computation of Diluted Per Share (Details) - shares shares in Thousands	6 Months Ended
	Jul. 31, 2019	Jul. 31, 2018
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Antidilutive securities excluded from computation of earnings per share (in shares)	34,662	34,167
Unvested restricted common stock issued and outstanding
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Antidilutive securities excluded from computation of earnings per share (in shares)	0	400
Stock options issued and outstanding
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Antidilutive securities excluded from computation of earnings per share (in shares)	14,587	20,898
Unvested RSUs issued and outstanding
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Antidilutive securities excluded from computation of earnings per share (in shares)	5,401	4,891
Unvested restricted stock awards issued and outstanding
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Antidilutive securities excluded from computation of earnings per share (in shares)	177	388
Shares related to convertible senior notes
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Antidilutive securities excluded from computation of earnings per share (in shares)	7,134	7,134
Shares subject to warrants related to the issuance of convertible senior notes
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Antidilutive securities excluded from computation of earnings per share (in shares)	7,134	0
Shares committed under the ESPP
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Antidilutive securities excluded from computation of earnings per share (in shares)	215	360
Unvested shares subject to repurchase
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Antidilutive securities excluded from computation of earnings per share (in shares)	14	96

Net Loss Per Share - Narrative

Net Loss Per Share - Narrative (Details)	Feb. 28, 2018$ / shares
Debt Instrument [Line Items]
Per share value, shares issuable under warrants granted (in dollars per share)	$ 68.06
Convertible Senior Notes Due 2023 | Senior Notes
Debt Instrument [Line Items]
Conversion price (in dollars per share)	$ 48.36

Uncategorized Items - okta-7312

Label	Element	Value
Restricted Cash and Cash Equivalents, Current	us-gaap_RestrictedCashAndCashEquivalentsAtCarryingValue	$ 307,000
Restricted Cash and Cash Equivalents, Current	us-gaap_RestrictedCashAndCashEquivalentsAtCarryingValue	0	[1]
Restricted Cash and Cash Equivalents, Noncurrent	us-gaap_RestrictedCashAndCashEquivalentsNoncurrent	11,438,000
Restricted Cash and Cash Equivalents, Noncurrent	us-gaap_RestrictedCashAndCashEquivalentsNoncurrent	$ 8,560,000	[1]
[1]	Adjusted for adoption of ASC 842, Leases. See Note 2.