Document and Entity Information - shares	9 Months Ended
Document and Entity Information - shares	Oct. 31, 2017	Nov. 30, 2017
Entity Information [Line Items]
Document Type	10-Q
Document Period End Date	Oct. 31, 2017
Amendment Flag	false
Entity Registrant Name	Okta, Inc.
Entity Central Index Key	0001660134
Current Fiscal Year End Date	--01-31
Entity Filer Category	Non-accelerated Filer
Document Fiscal Year Focus	2018
Document Period Focus	Q3
Class A Common Stock
Entity Information [Line Items]
Entity Common Stock, Shares Outstanding		40,488,329
Class B Common Stock
Entity Information [Line Items]
Entity Common Stock, Shares Outstanding		61,435,859

Condensed Consolidated Balance Sheets - USD ($) $ in Thousands	Oct. 31, 2017	Jan. 31, 2017
Current assets:
Cash and cash equivalents	$ 137,575	$ 23,282
Short-term investments	86,043	14,390
Accounts receivable, net of allowances of $976 and $1,306	46,882	34,544
Deferred commissions	14,134	13,549
Prepaid expenses and other current assets	10,038	7,025
Total current assets	294,672	92,790
Property and equipment, net	13,122	11,026
Deferred commissions, noncurrent	9,163	10,050
Intangible assets, net	11,455	9,155
Goodwill	6,282	2,630
Other assets	2,463	4,984
Total assets	337,157	130,635
Current liabilities:
Accounts payable	12,875	9,387
Accrued expenses and other current liabilities	4,955	8,363
Accrued compensation	14,671	9,866
Deferred revenue	138,460	108,012
Total current liabilities	170,961	135,628
Deferred revenue, noncurrent	3,188	5,711
Other liabilities, noncurrent	6,553	4,947
Total liabilities	180,702	146,286
Commitments and contingencies (Note 8)
Redeemable convertible preferred stock	0	227,954
Stockholders’ equity (deficit):
Preferred stock	0	0
Additional paid-in capital	534,304	44,469
Accumulated other comprehensive loss	(69)	(167)
Accumulated deficit	(377,790)	(287,909)
Total stockholders’ equity (deficit)	156,455	(243,605)
Total liabilities, redeemable convertible preferred stock and stockholders’ equity (deficit)	337,157	130,635
Class A Common Stock
Stockholders’ equity (deficit):
Common stock	2	0
Class B Common Stock
Stockholders’ equity (deficit):
Common stock	$ 8	$ 2

Condensed Consolidated Balance Sheets (Parenthetical) - USD ($) $ in Thousands	Oct. 31, 2017	Jan. 31, 2017
Statement of Financial Position [Abstract]
Allowance for accounts receivable	$ 976	$ 1,306

Condensed Consolidated Statements of Operations - USD ($) shares in Thousands, $ in Thousands	3 Months Ended		9 Months Ended
	Oct. 31, 2017	Oct. 31, 2016	Oct. 31, 2017	Oct. 31, 2016
Revenue
Subscription	$ 62,705	$ 38,123	$ 167,142	$ 99,125
Professional services and other	5,533	4,160	15,098	12,381
Total revenue	68,238	42,283	182,240	111,506
Cost of revenue
Subscription	13,553	8,597	37,401	24,523
Professional services and other	7,570	5,506	20,867	15,739
Total cost of revenue	21,123	14,103	58,268	40,262
Gross profit	47,115	28,180	123,972	71,244
Operating expenses
Research and development	19,190	9,706	51,472	28,127
Sales and marketing	49,606	32,442	126,383	87,264
General and administrative	13,546	7,922	37,133	21,009
Total operating expenses	82,342	50,070	214,988	136,400
Operating loss	(35,227)	(21,890)	(91,016)	(65,156)
Other income, net	509	50	872	138
Loss before income taxes	(34,718)	(21,840)	(90,144)	(65,018)
Provision (benefit) for income taxes	(940)	91	(463)	267
Net loss	$ (33,778)	$ (21,931)	$ (89,681)	$ (65,285)
Net loss per share attributable to common stockholders, basic and diluted (in dollars per share)	$ (0.35)	$ (1.14)	$ (1.17)	$ (3.46)
Weighted-average shares used to compute net loss per share attributable to common stockholders, basic and diluted (in shares)	95,474	19,174	76,950	18,850

Condensed Consolidated Statements of Comprehensive Loss - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Oct. 31, 2017	Oct. 31, 2016	Oct. 31, 2017	Oct. 31, 2016
Statement of Comprehensive Income [Abstract]
Net loss	$ (33,778)	$ (21,931)	$ (89,681)	$ (65,285)
Net change in unrealized gains (losses) on available-for-sale securities	(58)	(20)	(70)	14
Foreign currency translation adjustments	(81)	(89)	168	(144)
Other comprehensive income (loss)	(139)	(109)	98	(130)
Comprehensive loss	$ (33,917)	$ (22,040)	$ (89,583)	$ (65,415)

Condensed Consolidated Statements of Cash Flows - USD ($) $ in Thousands	9 Months Ended
	Oct. 31, 2017	Oct. 31, 2016
Cash flows from operating activities:
Net loss	$ (89,681)	$ (65,285)
Adjustments to reconcile net loss to net cash used in operating activities:
Depreciation, amortization and accretion	5,111	3,177
Stock-based compensation	35,292	11,869
Amortization of deferred commissions	12,798	9,926
Deferred income taxes	(960)	0
Non-cash charitable contributions	708	129
Other	997	173
Changes in operating assets and liabilities:
Accounts receivable	(12,742)	(3,606)
Deferred commissions	(12,495)	(11,207)
Prepaid expenses and other current and noncurrent assets	(2,989)	(2,312)
Accounts payable	6,255	2,453
Accrued compensation	5,931	(1,268)
Accrued expenses and other current and noncurrent liabilities	(1,545)	259
Deferred revenue	27,925	20,293
Net cash used in operating activities	(25,395)	(35,399)
Cash flows from investing activities:
Capitalization of internal-use software costs	(4,072)	(3,992)
Purchases of property and equipment and other	(5,570)	(4,647)
Purchases of securities available for sale	(95,344)	0
Proceeds from sales of securities available for sale	1,538	6,207
Proceeds from maturities and redemption of securities available for sale	21,985	5,000
Net cash provided by (used in) investing activities	(81,463)	2,568
Cash flows from financing activities:
Proceeds from initial public offering, net of underwriters' discounts and commissions	199,948	0
Payments of deferred offering costs	(4,038)	(990)
Proceeds from stock option exercises, net of repurchases, and other	25,800	1,665
Principal payments on financing arrangements	(343)	(213)
Net cash provided by financing activities	221,367	462
Effects of changes in foreign currency exchange rates on cash and cash equivalents	53	(144)
Net increase (decrease) in cash, cash equivalents and restricted cash	114,562	(32,513)
Cash, cash equivalents and restricted cash at beginning of period	23,282	58,081
Cash, cash equivalents and restricted cash at end of period	137,844	25,568
Non-cash investing and financing activities:
Vesting of early exercised common stock options	986	997
Issuance of common stock in connection with warrant exercises	272	0
Common stock issued as charitable contribution	708	129
Deferred offering costs, accrued but not yet paid	0	438
Property and equipment and other, accrued but not yet paid	710	990
Issuance of common stock in connection with business combination	2,160	0
Conversion of redeemable convertible preferred stock to common stock	228,362	0
Cash paid for taxes	668	90
Reconciliation of cash, cash equivalents and restricted cash within the condensed consolidated balance sheets to the amounts shown in the statements of cash flows above:
Total cash, cash equivalents and restricted cash	$ 23,282	$ 58,081

Overview and Basis of Presentation	9 Months Ended
Overview and Basis of Presentation	Oct. 31, 2017
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) pioneered identity in the cloud. The Okta Identity Cloud enables customers to secure their users and connect them to technology, anywhere, anytime and from any device. The Company was originally incorporated in January 2009 as SaaSure Inc., a California corporation, and, in April 2010, the Company reincorporated in Delaware as Okta, Inc. The Company is headquartered in San Francisco, California. Initial Public Offering In April 2017, the Company completed an initial public offering (IPO), in which the Company issued and sold 12,650,000 shares of its newly authorized Class A common stock, which included 1,650,000 shares sold pursuant to the exercise by the underwriters’ option to purchase additional shares at a public offering price of $17.00 per share. The Company received aggregate proceeds of $200.0 million from the IPO, net of underwriters’ discounts and commissions, before deducting offering costs of approximately $5.6 million. Immediately prior to the completion of the IPO, all shares of common stock then outstanding were reclassified as Class B common stock, and all shares of redeemable convertible preferred stock then outstanding were converted into 59,491,640 shares of common stock on a one-to-one basis and then reclassified into Class B common stock. See Note 9 for additional details. As of October 31, 2017, 39,290,132 shares of the Company’s Class A common stock and 62,081,326 shares of Class B common stock were outstanding. The Class A common stock outstanding includes the shares issued in the IPO and shares converted from Class B common stock. 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) and applicable rules and regulations of the Securities and Exchange Commission (SEC) regarding interim financial reporting. All intercompany balances and transactions have been eliminated in consolidation. Certain reclassifications of prior period amounts have been made in our condensed consolidated balance sheets and condensed consolidated statements of of cash flows to conform to the current period presentation. The condensed consolidated balance sheet as of January 31, 2017, 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 balance sheet, statements of operations, statements of comprehensive loss and the statements of cash flows for the interim periods, but are not necessarily indicative of the results of operations to be anticipated for the full fiscal year ending January 31, 2018 or any future period. The Company’s fiscal year ends on January 31. References to fiscal 2018, for example, refer to the fiscal year ending January 31, 2018. The condensed consolidated financial statements should be read in conjunction with the audited consolidated financial statements and notes included in the Company’s final prospectus filed with the SEC pursuant to Rule 424(b) under the Securities Act of 1933, as amended, on April 7, 2017 (the Prospectus).

Summary of Significant Accounting Policies

9 Months Ended

Oct. 31, 2017

Accounting Policies [Abstract]

Summary of Significant Accounting Policies

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 and judgments involve revenue recognition with respect to the determination of the relative selling prices for the Company’s services, determination of the fair value of the Company’s common stock prior to the completion of the IPO, valuation of the Company’s stock-based awards, valuation of deferred income tax assets and contingencies.

Significant Accounting Policies

The Company’s significant accounting policies are discussed in “Index to Consolidated Financial Statements-Note 2. Summary of Significant Accounting Policies” in the Prospectus. There have been no significant changes to these policies for the nine months ended October 31, 2017, except as noted below:

Stock-Based Compensation

All stock-based compensation to employees, including the purchase rights issued under the Company's 2017 Employee Stock Purchase Plan (ESPP), is based on the fair value of the awards on the date of grant. Prior to the IPO, the fair value of the Company’s common stock was determined by the estimated fair value of the Company’s common stock at the time of grant. After the IPO, the fair value is determined using the market closing price of its Class A common stock on the date of grant. The Company uses the Black-Scholes option pricing model to measure the fair value of its stock options granted to employees and non-employees and the purchase rights issued under the ESPP to employees. The unvested options issued to non-employees are remeasured to fair value at the end of each reporting period. This cost is recognized as an expense following the straight-line attribution method, over the requisite service period, for stock options, restricted stock units (RSUs) and restricted stock, and over the offering period, for the purchase rights issued under the ESPP. Prior to adoption of ASU 2016-09, the stock-based compensation was recorded net of estimated forfeitures.

In March 2016, the Financial Accounting Standards Board (FASB) issued Accounting Standards Update (ASU) No. 2016-09, “Compensation—Stock Compensation (Topic 718): Improvements to Employee Share-Based Payment Accounting.” This new guidance was intended to simplify several areas of accounting for stock-based compensation arrangements, including the accounting for income taxes, the classification of excess tax benefits on the statement of cash flows and the accounting for forfeitures. This guidance is effective for fiscal years, and interim periods within those years, beginning after December 15, 2016. The Company adopted this guidance in the three months ended April 30, 2017. The new guidance allows entities to account for forfeitures as they occur. The Company elected to account for forfeitures as they occur and adopted this provision on a modified retrospective basis. An adjustment of $0.2 million representing cumulative prior years’ impact was recognized as an adjustment to decrease retained earnings in the period of adoption. The adoption of the amendments related to the accounting for income taxes and classification of excess tax benefits on the statement of cash flows were adopted prospectively. See Note 11 for further details of the effects of adoption of the new accounting standard on income taxes. Adoption of all other changes in the new guidance did not have a significant impact on the Company's consolidated financial statements.

Net Loss per Share

The Company computes basic and diluted net loss per share attributable to common stockholders in conformity with the two-class method required for participating securities. Under the two-class method, basic net loss per share attributable to common stockholders is calculated by dividing the net loss attributable to common stockholders by the weighted-average number of shares of common stock outstanding during the period, less shares subject to repurchase, without consideration for potentially dilutive securities as they do not share in losses. The diluted net loss per share attributable to common stockholders is computed giving effect to all potential dilutive common stock equivalents outstanding for the period. For purposes of this calculation, options to purchase common stock, unvested RSUs, purchase rights issued under the ESPP, shares subject to repurchase from early exercised options, and common stock and restricted stock issued in connection with certain business combinations are considered common stock equivalents but have been excluded from the calculation of diluted net loss per share attributable to common stockholders as the effect is antidilutive.

Since the Company's IPO, Class A and Class B common stock are the only outstanding equity of the Company. The rights of the holders of Class A and Class B common stock are identical, except with respect to voting and conversion. Each share of Class A common stock is entitled to one vote per share and each share of Class B common stock is entitled to 10 votes per share. Shares of Class B common stock may be converted into Class A common stock at any time at the option of the stockholder on a one-for-one basis, and are automatically converted into Class A common stock upon sale or transfer, subject to certain limited exceptions. Shares of Class A common stock are not convertible.

New Accounting Pronouncements

In May 2014, the FASB issued ASU No. 2014-09, Revenue from Contracts with Customers (Topic 606) (ASU 2014-09) and has modified the standard thereafter. The standard replaces existing revenue recognition rules with a comprehensive revenue measurement and recognition standard and expanded disclosure requirements. ASU 2014-09, as amended, becomes effective for the Company on February 1, 2018. The standard permits the use of either the retrospective or modified retrospective transition method. Under the retrospective transition method, the standard applies to contracts in all reporting periods presented. Under the modified retrospective transition method, the standard applies only to contracts still open as of February 1, 2018, recognizing in beginning retained earnings an adjustment for the cumulative effect of the change and providing additional disclosures comparing results to previous standards. The Company is currently evaluating the retrospective transition method.

The Company believes that the new standard will impact the following policies and disclosures:


•	removal of the current limitation on contingent revenue will result in revenue being recognized earlier for certain contracts;


•	revenue for all professional services, including fixed fee, will be recognized based on a proportional performance basis;


•	required disclosures including information about the transaction price allocated to remaining performance obligations and related timing of revenue recognition; and


•	accounting for deferred commissions including costs that qualify for deferral and the amortization period.

The requirement to defer incremental contract acquisition costs and recognize them over the contract period or expected customer life will affect the Company’s determination of the related period of benefit for amortization purposes and have a material impact on accounting for sales commissions for the periods presented. The Company has assigned internal resources, engaged a third-party service provider and is currently evaluating the impacts of systems implementations. The Company will continue to evaluate and analyze all other aspects of Topic 606 that may impact it.

In January 2016, the FASB issued ASU No. 2016-01 (Subtopic 825-10), Financial Instruments Overall: Recognition and Measurement of Financial Assets and Financial Liabilities (ASU 2016-01), which primarily affects the accounting for equity investments, financial liabilities under the fair value option and the presentation and disclosure requirements for financial instruments. In addition, the FASB clarified guidance related to the valuation allowance assessment when recognizing deferred tax assets resulting from unrealized losses on available-for-sale debt securities. The accounting for other financial instruments, such as loans, investments in debt securities and financial liabilities is largely unchanged. ASU 2016-01 is effective for fiscal years, beginning after December 15, 2018 and interim periods in fiscal years beginning after December 15, 2019. Early adoption is permitted. The Company is currently evaluating the impact of the adoption on its consolidated financial statements.

In February 2016, the FASB issued ASU No. 2016-02 (Topic 842), Leases (ASU 2016-02), which supersedes the guidance in topic ASC 840, Leases. The new standard requires lessees to apply a dual approach, classifying leases as either finance or operating leases based on the principle of whether or not the lease is effectively a financed purchase by the lessee. A lessee is also required to record a right-of-use asset and a lease liability for all leases with a term of greater than 12 months regardless of their classification. Leases with a term of 12 months or less will be accounted for similar to existing guidance for operating leases today. Under the standard, disclosures are required to meet the objective of enabling users of financial statements to assess the amount, timing, and uncertainty of cash flows arising from leases. The Company will be required to recognize and measure leases existing at, or entered into after, the beginning of the earliest comparative period presented using a modified retrospective approach, with certain practical expedients available. ASU 2016-02 is effective for fiscal years beginning after December 15, 2018 and interim periods within subsequent fiscal years. Early adoption is permitted. The Company is currently evaluating both the timing and the impact of the adoption of this standard on its consolidated financial statements.

In January 2017, the FASB issued ASU No. 2017-01, Business Combinations (Topic 805) Clarifying the Definition of a Business (ASU 2017-04), which amends the guidance of FASB Accounting Standards Codification Topic 805, “Business Combinations,” adding guidance to assist entities with evaluating whether transactions should be accounted for as acquisitions or disposals of assets or businesses. The definition of a business affects many areas of accounting including acquisitions, disposals, goodwill, and consolidation. This guidance is effective for annual and interim periods beginning after December 15, 2017, and early adoption is permitted under certain circumstances. The adoption of this standard is not expected to have a material impact on the Company’s consolidated financial statements.

In January 2017, the FASB issued ASU No. 2017-04, Simplifying the Test for Goodwill Impairment (ASU 2017-04), which removes the second step of the goodwill impairment test that requires a hypothetical purchase price allocation. A goodwill impairment will now be the amount by which a reporting unit’s carrying value exceeds its fair value, not to exceed the carrying amount of goodwill. This guidance is effective for interim and annual reporting periods beginning after December 15, 2019 and will be applied prospectively. Early adoption is permitted for annual or any interim impairment tests with a measurement date on or after January 1, 2017. The adoption of this standard is not expected to have a material impact on the Company’s consolidated financial statements.

In May 2017, the FASB issued ASU No. 2017-09, Compensation—Stock Compensation (Topic 718) Scope of Modification Accounting (ASU 2017-09), which clarifies which changes to the terms or conditions of a share-based payment award are subject to the guidance on modification accounting. Entities would apply the modification accounting guidance unless the value, vesting requirements and classification of a share-based payment award are the same immediately before and after a change to the terms or conditions of the award. This guidance is effective for annual and interim periods beginning after December 15, 2017, and would be applied prospectively to awards modified on or after the effective date. Early adoption is permitted. The adoption of this standard is not expected to have a material impact on the Company’s consolidated financial statements.

Business Combinations	9 Months Ended
Business Combinations	Oct. 31, 2017
Business Combinations [Abstract]
Business Combinations	Business Combinations On February 17, 2017, the Company acquired the rights to hire certain employees and a non-exclusive intellectual property license from Stormpath, Inc. (Stormpath), a privately-held technology company which had built a user management and authentication service for software development teams. The transaction has been accounted for as a business combination and is expected to enhance the Company’s product offerings and service by leveraging the talents of the engineering teams. The total consideration of $3.7 million, consisting of 200,000 shares of common stock valued at $2.2 million issued to Stormpath and replacement awards of $1.5 million issued to the hired employees, was recognized as goodwill. See Note 10 for further details on replacement awards issued in this transaction. Goodwill is not deductible for tax purposes. Pro forma results of operations for the transaction have not been presented as they were not material to the condensed consolidated statements of operations. In addition, the Company issued an incremental 800,000 shares of restricted common stock valued at $8.6 million to Stormpath in connection with the transaction. These shares of restricted common stock will vest ratably on the first and second anniversaries of the transaction date upon achieving the respective performance conditions, including the continued employment of certain employees with Okta and the wind down of the Stormpath, Inc. entity. The aggregate fair value, as determined on the date of the transaction, of the shares of restricted common stock will be recognized as post-combination stock-based compensation in the statement of operations over two years based on an accelerated attribution method. See Note 10 for further details.

Cash Equivalents and Short-Term Investments

9 Months Ended

Oct. 31, 2017

Investments, Debt and Equity Securities [Abstract]

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 October 31, 2017 and January 31, 2017 were as follows (in thousands):



	As of October 31, 2017
	(unaudited)
	Amortized Cost		Unrealized Gain		Unrealized Loss			Estimated Fair Value
Cash equivalents:
Money market funds	$	115,939	$	—	$	—		$	115,939
Total cash equivalents	$	115,939	$	—	$	—		$	115,939
Investments:
Commercial paper	16,973		—		—			16,973
U.S. treasury securities	46,570		—		(57		)	46,513
Corporate debt securities	22,570		—		(13		)	22,557
Total short-term investments	86,113		—		(70		)	86,043
Total	$	202,052	$	—	$	(70	)	$	201,982



	As of January 31, 2017
	Amortized Cost		Unrealized Gain		Unrealized Loss			Estimated Fair Value
Cash equivalents:
Money market funds	$	10,565	$	—	$	—		$	10,565
Total cash equivalents	$	10,565	$	—	$	—		$	10,565
Investments:
Asset-backed securities	1,538		—		—			1,538
Corporate debt securities	12,842		13		(3		)	12,852
Total short-term investments	14,380		13		(3		)	14,390
Total	$	24,945	$	13	$	(3	)	$	24,955

All short-term investments were designated as available-for-sale securities as of October 31, 2017 and January 31, 2017.

The Company had 17 and five short-term investments in unrealized loss positions as of October 31, 2017 and January 31, 2017, respectively. There were no material gross unrealized gains or losses from available-for-sale securities and no realized gains or losses from available-for-sale securities that were reclassified out of accumulated other comprehensive income for the three and nine months ended October 31, 2017 or 2016.

For available-for-sale debt securities that have unrealized losses, the Company evaluates whether (i) it has the intention to sell any of these investments and (ii) whether it is not more likely than not that it 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 October 31, 2017 and January 31, 2017.

The following tables present the contractual maturities of the Company’s short-term investments as of October 31, 2017 and January 31, 2017 (in thousands):



	As of October 31, 2017
	(unaudited)
	Amortized Cost		Estimated Fair Value
Due within one year	$	73,602	$	73,553
Due between one to five years	12,511		12,490
	$	86,113	$	86,043



	As of January 31, 2017
	Amortized Cost		Estimated Fair Value
Due within one year	$	12,842	$	12,852
Due between one to five years	1,538		1,538
	$	14,380	$	14,390

Fair Value Measurements

9 Months Ended

Oct. 31, 2017

Fair Value Disclosures [Abstract]

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.

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 October 31, 2017
	(unaudited)
	Level 1		Level 2		Level 3		Total
Assets:
Cash equivalents:
Money market funds	$	115,939	$	—	$	—	$	115,939
Total cash equivalents	$	115,939	$	—	$	—	$	115,939
Short-term investments:
Commercial paper	$	—	$	16,973	$	—	$	16,973
U.S. treasury securities	—		46,513		—		46,513
Corporate debt securities	—		22,557		—		22,557
Total short-term investments	—		86,043		—		86,043
Total cash equivalents and short-term investments	$	115,939	$	86,043	$	—	$	201,982



	As of January 31, 2017
	Level 1		Level 2		Level 3		Total
Assets:
Cash equivalents:
Money market funds	$	10,565	$	—	$	—	$	10,565
Total cash equivalents	$	10,565	$	—	$	—	$	10,565
Short-term investments:
Asset-backed securities	$	—	$	1,538	$	—	$	1,538
Corporate debt securities	—		12,852		—		12,852
Total short-term investments	—		14,390		—		14,390
Total cash equivalents and short-term investments	$	10,565	$	14,390	$	—	$	24,955
Liabilities:
Series B redeemable convertible preferred stock warrant	$	—	$	—	$	304	$	304

Level 3 instruments consist solely of the Company’s Series B redeemable convertible preferred stock warrant liability. During the three months ended April 30, 2017, the Series B redeemable convertible preferred stock warrant liability that was outstanding as of January 31, 2017 was exercised. The corresponding warrant liability was remeasured to fair value and reclassified to additional paid-in capital. The expense resulting from remeasurement was recognized in other income, net in the condensed consolidated statements of operations.

The change in the fair value of the Series B redeemable convertible preferred stock warrant liability was as follows (in thousands):



Balance at January 31, 2017	$	304
Increase in fair value of warrant through exercise date	103
Reclassification of remaining warrant liability to additional paid-in capital	(407		)
Balance at October 31, 2017	$	—

The Company had no transfers between levels of the fair value hierarchy of its assets measured at fair value.

The carrying amounts of certain financial instruments, including cash held in banks, accounts receivable, accounts payable and the financing arrangements (see Note 7) approximate fair value due to their short-term maturities and are excluded from the fair value table above.

- Definition

The entire disclosure for the fair value of financial instruments (as defined), including financial assets and financial liabilities (collectively, as defined), and the measurements of those instruments as well as disclosures related to the fair value of non-financial assets and liabilities. Such disclosures about the financial instruments, assets, and liabilities would include: (1) the fair value of the required items together with their carrying amounts (as appropriate); (2) for items for which it is not practicable to estimate fair value, disclosure would include: (a) information pertinent to estimating fair value (including, carrying amount, effective interest rate, and maturity, and (b) the reasons why it is not practicable to estimate fair value; (3) significant concentrations of credit risk including: (a) information about the activity, region, or economic characteristics identifying a concentration, (b) the maximum amount of loss the entity is exposed to based on the gross fair value of the related item, (c) policy for requiring collateral or other security and information as to accessing such collateral or security, and (d) the nature and brief description of such collateral or security; (4) quantitative information about market risks and how such risks are managed; (5) for items measured on both a recurring and nonrecurring basis information regarding the inputs used to develop the fair value measurement; and (6) for items presented in the financial statement for which fair value measurement is elected: (a) information necessary to understand the reasons for the election, (b) discussion of the effect of fair value changes on earnings, (c) a description of [similar groups] items for which the election is made and the relation thereof to the balance sheet, the aggregate carrying value of items included in the balance sheet that are not eligible for the election; (7) all other required (as defined) and desired information.

+ References + Details

Goodwill and Intangible Assets, net

9 Months Ended

Oct. 31, 2017

Goodwill and Intangible Assets Disclosure [Abstract]

Goodwill and Intangible Assets, net

Goodwill

During the three months ended April 30, 2017, the Company recorded $3.7 million of goodwill related to its transaction with Stormpath (see Note 3). As of October 31, 2017 and January 31, 2017, goodwill was $6.3 million and $2.6 million, respectively. No goodwill impairments were recorded during the three and nine months ended October 31, 2017 and 2016, respectively.

Intangible Assets, net

Intangible assets consisted of the following (in thousands):



	As of October 31, 2017
	(unaudited)
	Gross		Accumulated Amortization			Net
Capitalized internal-use software costs	$	15,344	$	(4,446	)	$	10,898
Software licenses	1,023		(466		)	557
Purchased developed technology	570		(570		)	—
	$	16,937	$	(5,482	)	$	11,455



	As of January 31, 2017
	Gross		Accumulated Amortization			Net
Capitalized internal-use software costs	$	10,859	$	(2,487	)	$	8,372
Software licenses	1,093		(314		)	779
Purchased developed technology	570		(566		)	4
	$	12,522	$	(3,367	)	$	9,155

The Company capitalized $1.7 million and $1.9 million of internal-use software costs in the three months ended October 31, 2017 and 2016, respectively, and $5.0 million and $4.4 million in the nine months ended October 31, 2017 and 2016, respectively. Included in the total amounts capitalized are stock-based compensation expense of $0.3 million and $0.2 million in the three months ended October 31, 2017 and 2016, respectively, and $0.9 million and $0.4 million in the nine months ended October 31, 2017 and 2016, respectively. The Company reversed $0.5 million of previously capitalized costs in the three months ended October 31, 2017 as they were not realizable. The charge was recognized in research and development in the condensed consolidated statements of operations.

Amortization expense was $0.8 million and $0.5 million for the three months ended October 31, 2017 and 2016, respectively, and $2.1 million and $1.3 million for the nine months ended October 31, 2017 and 2016, respectively.

- Definition

The entire disclosure for the aggregate amount of goodwill and a description of intangible assets, which may include (a) for amortizable intangible assets (also referred to as finite-lived intangible assets), the carrying amount, the amount of any significant residual value, and the weighted-average amortization period, (b) for intangible assets not subject to amortization (also referred to as indefinite-lived intangible assets), the carrying amount, and (c) the amount of research and development assets acquired and written off in the period, including the line item in the income statement in which the amounts written off are aggregated, if not readily apparent from the income statement. Also discloses (a) for amortizable intangibles assets in total and by major class, the gross carrying amount and accumulated amortization, the total amortization expense for the period, and the estimated aggregate amortization expense for each of the five succeeding fiscal years, (b) for intangible assets not subject to amortization the carrying amount in total and by major class, and (c) for goodwill, in total and for each reportable segment, the changes in the carrying amount of goodwill during the period (including the aggregate amount of goodwill acquired, the aggregate amount of impairment losses recognized, and the amount of goodwill included in the gain (loss) on disposal of a reporting unit). If any part of goodwill has not been allocated to a reportable segment, discloses the unallocated amount and the reasons for not allocating. For each impairment loss recognized related to an intangible asset (excluding goodwill), discloses: (a) a description of the impaired intangible asset and the facts and circumstances leading to the impairment, (b) the amount of the impairment loss and the method for determining fair value, (c) the caption in the income statement or the statement of activities in which the impairment loss is aggregated, and (d) the segment in which the impaired intangible asset is reported. For each goodwill impairment loss recognized, discloses: (a) a description of the facts and circumstances leading to the impairment, (b) the amount of the impairment loss and the method of determining the fair value of the associated reporting unit, and (c) if a recognized impairment loss is an estimate not finalized and the reasons why the estimate is not final. May also disclose the nature and amount of any significant adjustments made to a previous estimate of an impairment loss.

+ References + Details

Debt and Financing Arrangements	9 Months Ended
Debt and Financing Arrangements	Oct. 31, 2017
Debt Disclosure [Abstract]
Debt and Financing Arrangements	Debt and Financing Arrangements Loan and Security Agreement On March 10, 2014, the Company entered into a line of credit and term loan agreement with Silicon Valley Bank (SVB) in the amounts of $5.0 million and $10.0 million, respectively. On June 17, 2015, the Company expanded its line of credit from $5.0 million to $20.0 million and extended the term by one year to mature on March 10, 2017. The term loan facility expired during the year ended January 31, 2015 and no amounts were drawn. On November 21, 2016, the Company amended the agreement to extend the maturity date to November 21, 2018 and increase the borrowing capacity of the line of credit (Revolving Line) to $40.0 million. The available amount, not to exceed $40.0 million, is based on certain revenue metrics and is reduced by letters of credit totaling $4.4 million as of October 31, 2017 established in connection with facility lease agreements. As of October 31, 2017, $35.6 million was available under the Revolving Line. Proceeds from loans made under the Revolving Line may be borrowed, repaid and reborrowed until November 21, 2018. Repayment of any outstanding proceeds are payable on November 21, 2018, but may be prepaid without penalty. Borrowings under the Revolving Line bear interest at an annual rate based on the one-year Prime rate plus a spread of 0.75%. Interest is payable quarterly. The Company is required to pay a quarterly facility fee to SVB of 0.15% per annum on the average undrawn portion available under the facility plus balances of outstanding letters of credits. Additionally, the Company is required to pay an upfront, one-time, commitment fee of $0.1 million and annual anniversary fees of $0.1 million on the amendment’s first and second anniversary dates. As of October 31, 2017 and January 31, 2017, no amounts had been drawn under the Revolving Line and the Company was in compliance with all covenants pursuant to the loan and security agreement. As part of the initial loan agreement, upon closing, the Company granted SVB a warrant to purchase 187,500 shares of common stock at $1.40 per share, with a potential to acquire up to an additional 112,500 shares of common stock at the same price, which right would be triggered upon future amounts drawn under the loan agreement. No additional amounts were drawn under the credit facility and as such, the conditional warrant to acquire up to an additional 112,500 shares was not issued. The fair value of the common stock warrant at the time of issuance was recorded as debt issuance costs. Upon exercise of the warrant in March 2017, 168,750 shares were issued and 18,750 shares were withheld by the Company in lieu of cash exercise. Financing Arrangements In May 2015, the Company purchased software and related maintenance and support from a third party under a financing arrangement with a gross value of $0.9 million at an implicit interest rate of 5.0%. The financed obligation will be due in April 2018, and as of October 31, 2017 and January 31, 2017, $0.1 million and $0.4 million, respectively, was outstanding under this obligation. In January 2017, the Company acquired additional software licenses from a third party under a separate financing arrangement with a gross value of $0.4 million at an implicit interest rate of 4.5%. The financed obligation will be due in January 2019 and as of October 31, 2017 and January 31, 2017, $0.3 million and $0.4 million respectively, was outstanding under this obligation.

Commitments and Contingencies

9 Months Ended

Oct. 31, 2017

Commitments and Contingencies Disclosure [Abstract]

Commitments and Contingencies

In July 2017, the Company entered into a non-cancellable contractual agreement with a third-party provider of datacenter hosting facilities for a period of three years. Future annual commitments under this agreement are $10.0 million.

Leases

The Company leases office space under noncancelable operating leases for its San Francisco, California headquarters, as well as its offices in San Jose, California; Bellevue, Washington; London, England; Sydney, Australia; and Toronto, Canada. These office leases expire on various dates through August 2026.

Certain facility lease agreements contain rent holidays, allowances and rent escalation provisions. For these leases, the Company recognizes the related rental expense on a straight-line basis over the lease period of the facility and records the difference between amounts charged to operations and amounts paid as deferred rent. These rent holidays, allowances and rent escalations are considered in determining the straight-line expense to be recorded over the lease term. Deferred rent was $5.0 million and $4.8 million as of October 31, 2017 and January 31, 2017, respectively, and the current and noncurrent portions are included in accrued expenses and other current liabilities and other liabilities, noncurrent, respectively, in the condensed consolidated balance sheets. Rent expense was $3.0 million and $1.9 million for the three months ended October 31, 2017 and 2016, respectively, and $7.6 million and $5.5 million for the nine months ended October 31, 2017 and 2016, respectively.

In August 2017, the Company executed an amendment to its San Jose lease to add space and extend the lease term through August 2024. The incremental commitment for the additional space is $6.3 million with a tenant improvement allowance of up to $0.8 million. Rental payments will commence in August 2018.

In conjunction with the execution of the leases, letters of credit in the aggregate amount of $4.4 million and $5.4 million were issued and outstanding as of October 31, 2017 and January 31, 2017, respectively. No draws have been made under such letters of credit.

As of October 31, 2017, the future minimum lease payments by fiscal year under the financing arrangements and various operating leases are as follows (in thousands):



	Financing Arrangements			Operating Leases		Purchase Obligations		Total
Remainder of 2018	$	212		$	2,968	$	2,595	$	5,775
2019	212			12,343		10,401		22,956
2020	—			9,441		10,301		19,742
2021	—			6,088		4,167		10,255
2022	—			5,749		—		5,749
Thereafter	—			13,896		—		13,896
Total minimum lease payments	$	424		$	50,485	$	27,464	$	78,373
Less: amount representing interest	(29		)	—		—		(29		)
Present value of minimum lease payments	$	395		$	50,485	$	27,464	$	78,344

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 October 31, 2017.

Stockholders' Equity (Deficit)	9 Months Ended
Stockholders' Equity (Deficit)	Oct. 31, 2017
Equity [Abstract]
Stockholders' Equity (Deficit)	Stockholders’ Equity (Deficit) Redeemable Convertible Preferred Stock Immediately prior to the completion of the IPO, all shares of redeemable convertible preferred stock then outstanding were converted into 59,491,640 shares of common stock on a one-to-one basis and then immediately reclassified into Class B common stock. As of October 31, 2017, there were no shares of redeemable convertible preferred stock issued and outstanding. Common Stock Immediately prior to the completion of the IPO, all shares of common stock then outstanding were reclassified into Class B common stock. Shares offered and sold in the IPO consisted of the newly authorized shares of Class A common stock. As of October 31, 2017, the Company had authorized 1,000,000,000 shares of Class A common stock and had authorized 120,000,000 shares of Class B common stock, each with par value $0.0001 per share. As of January 31, 2017, the Company had authorized 120,000,000 shares of common stock with par value $0.0001 per share. As of October 31, 2017, 39,290,132 shares of Class A common stock and 62,081,326 shares of Class B common stock were issued and outstanding. Holders of Class A and Class B common stock are entitled to one vote per share and 10 votes per share, respectively, and the shares of Class A common stock and Class B common stock are identical, except for voting and conversion rights. Awards Issued as Charitable Contributions During the three and nine months ended October 31, 2017, the Company granted 24,287 shares of Class A common stock as charitable contributions and recognized $0.7 million as general and administrative expense in the condensed consolidated statement of operations. During the three and nine months ended October 31, 2016, the Company granted 13,935 shares of Class B common stock as a charitable contribution and recognized $0.1 million as general and administrative expense in the condensed consolidated statement of operations.

Employee Incentive Plans

9 Months Ended

Oct. 31, 2017

Disclosure of Compensation Related Costs, Share-based Payments [Abstract]

Employee Incentive Plans

The Company’s equity incentive plans provide for granting stock options, RSUs and restricted stock awards to employees, consultants, officers and directors. In addition, the Company offers an ESPP to eligible employees.

Stock-based compensation expense by award type was as follows (in thousands):



	Three Months Ended October 31,				Nine Months Ended October 31,
	2017		2016		2017		2016
Stock options	$	6,162	$	4,836	$	18,313	$	11,869
RSUs	3,587		—		5,088		—
ESPP	2,146		—		4,946		—
Restricted stock awards	880		—		2,400		—
Restricted common stock	1,633		—		4,545		—
Total	$	14,408	$	4,836	$	35,292	$	11,869

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 October 31,				Nine Months Ended October 31,
	2017		2016		2017		2016
Cost of revenue
Subscription	$	1,421	$	578	$	3,163	$	1,417
Professional services and other	979		304		2,186		890
Research and development	5,174		808		12,913		2,162
Sales and marketing	3,894		1,619		9,290		4,385
General and administrative	2,940		1,527		7,740		3,015
Total	$	14,408	$	4,836	$	35,292	$	11,869

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 nine months ended October 31, 2017 and 2016. See Note 6 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). Upon the completion of the Company’s IPO in April 2017, the Company ceased granting equity under the 2009 Plan, and all shares that remained available for future issuance under the 2009 Plan at that time were transferred to the 2017 Plan. As of October 31, 2017, 27,052,658 options to purchase Class B common stock granted under the 2009 Plan remain outstanding and 65,000 options to purchase Class A common stock granted under the 2017 Plan remain outstanding.

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, 2017	32,866,862		$	6.01	8.2	$	145,570
Granted	2,661,568		11.48
Exercised	(7,205,213	)	3.58
Canceled	(1,205,559	)	7.67
Outstanding as of October 31, 2017	27,117,658		$	7.12	7.9	$	591,162
As of October 31, 2017
Vested and exercisable	10,699,293		$	4.86	6.9	$	257,446

The weighted-average grant-date fair value of options granted was $12.27 and $4.19 for the three months ended October 31, 2017 and 2016, respectively, and $5.37 and $3.93 for the nine months ended October 31, 2017 and 2016, respectively. The aggregate fair value of stock options vested was $5.9 million, and $3.9 million for the three months ended October 31, 2017 and 2016, respectively, and $18.9 million and $9.5 million for the nine months ended October 31, 2017 and 2016, respectively. The intrinsic value of the options exercised, which represents the difference between the fair market value of the Company’s common stock on the date of exercise and the exercise price of each option, was $139.4 million and $2.6 million for the three months ended October 31, 2017 and 2016, respectively, and $158.7 million and $4.5 million for the nine months ended October 31, 2017 and 2016, respectively.

As of October 31, 2017, there was a total of $60.6 million of unrecognized stock-based compensation expense, which is expected to be recognized over a weighted-average period of 2.8 years.

The Company used the Black-Scholes option pricing model to estimate the fair value of stock options granted with the following assumptions:



	Three Months Ended October 31,		Nine Months Ended October 31,
	2017	2016	2017	2016

	(unaudited)
Expected volatility	41.4%	40.9%-41.6%	40.4%-41.4%	40.9%-44.3%
Expected term (in years)	6.3	5.8-6.1	6.3-6.4	5.8-6.4
Risk-free interest rate	1.87%	1.22%-1.42%	1.87%-2.21%	1.13%-1.54%
Expected dividend yield	—	—	—	—

Options Subject to Early Exercise

Prior to the IPO, at the discretion of the board of directors, certain options were exercisable immediately at the date of grant but subject to a repurchase right, under which the Company may buy back any unvested shares at their original exercise price in the event of an employee’s termination prior to full vesting. The consideration received for an exercise of an unvested option is considered to be a deposit of the exercise price and the related dollar amount is recorded as a liability. The liabilities are reclassified into equity as the awards vest. As of October 31, 2017 and January 31, 2017, the Company had $1.4 million and $2.2 million, respectively, recorded in accrued expenses and other current liabilities related to early exercises of options to acquire 248,083 and 467,180 shares of Class B common stock, respectively.

Restricted Stock Units

A summary of the Company’s RSU activity and related information is as follows:



	Number of RSUs		Weighted- Average Grant Date Fair Value Per Share
Outstanding as of January 31, 2017	—		$	—
Granted	2,567,667		24.08
Vested	—		—
Forfeited	(61,451	)	23.68
Outstanding as of October 31, 2017	2,506,216		$	24.08

The Company granted 347,740 and 2,567,667 RSUs with an aggregate fair value of $10.2 million and $61.8 million in the three and nine months ended October 31, 2017, respectively, of which all are unvested and outstanding as of October 31, 2017. As of October 31, 2017, there was $55.1 million of unrecognized stock-based compensation expense related to unvested RSUs, which is expected to be recognized over a weighted-average period of 3.6 years based on vesting under the award service conditions.

Equity Awards Issued in Connection with Business Combinations

In connection with the Stormpath transaction, the Company issued 800,000 shares of restricted common stock to Stormpath with an aggregate fair value of $8.6 million to be recognized as post combination stock-based compensation. The restricted common stock will vest ratably on the first and second anniversaries of the transaction date upon achievement of the respective performance conditions, including the continued employment of certain employees with the Company and the wind down of the Stormpath, Inc. entity. The stock-based compensation expense related to the restricted common stock has a requisite service period of two years and will be recognized using an accelerated attribution method due to the existence of performance conditions.

As of October 31, 2017, there was $4.1 million of unrecognized compensation expense related to restricted common stock which is expected to be recognized over the remaining weighted average life of 1.0 years. These shares of restricted common stock were separately authorized by the Company’s board of directors, and did not reduce the number of shares available for future issuance under the 2009 Plan or the 2017 Plan.

The Company separately entered into retention arrangements with certain employees of Stormpath and issued 598,500 restricted stock awards under the 2009 Plan with an aggregate fair value of $6.6 million with performance conditions, including continued employment of certain employees with the Company and the wind down of the Stormpath, Inc. entity. The restricted stock awards will vest ratably over two or three years from the transaction date. Additionally, the Company granted 518,900 service-based stock options under the 2009 Plan to certain Stormpath employees with an aggregate fair value of $2.5 million to vest ratably over the requisite four-year service period.

The restricted stock awards and stock options offered directly to Stormpath employees for employment with the Company are deemed replacement awards and a portion of such awards are considered compensation for pre-combination service. Of the $9.1 million total aggregate fair value of the awards, $1.5 million is related to pre-combination service and is recognized as goodwill and a reduction to the post-combination compensation expense. The post-combination expenses for the restricted stock awards and stock options are $5.5 million and $2.1 million, respectively. The expense related to the restricted stock awards will be recognized over two or three years based on an accelerated attribution method. The expense for the stock options will be recognized ratably over the requisite service period.

As of October 31, 2017, there was $3.1 million of unrecognized compensation expense related to unvested restricted stock awards, which is expected to be recognized over the remaining weighted average life of 1.5 years.

As of October 31, 2017, there was $1.8 million of unrecognized compensation cost related to unvested stock options, which is expected to be recognized over the remaining weighted average life of 2.4 years. The related stock options expense and activity are included within the Stock Options section above.

All of these shares are outstanding as of October 31, 2017.

Employee Stock Purchase Plan

In February 2017, the Company’s board of directors adopted, and in March 2017, the Company’s stockholders approved the 2017 Employee Stock Purchase Plan, or the ESPP, which became effective prior to the completion of the IPO. The ESPP initially reserves and authorizes the issuance of up to a total of 3,000,000 shares of Class A common stock to participating employees. Except for the initial offering period, the ESPP provides for 12-month offering periods beginning June 21 and December 21 of each year, and each offering period will consist of two six-month purchase periods. The initial offering period began April 7, 2017 and will end on June 20, 2018.

On each purchase date, eligible employees will purchase the shares at a price per share equal to 85% of the lesser of (1) the fair market value of our stock on the offering date or (2) the fair market value of our stock on the purchase date.

As of October 31, 2017, there was $6.0 million of unrecognized stock-based compensation expense related to the ESPP that is expected to be recognized over the remaining term of the initial offering period.

The Company estimated the fair value of ESPP purchase rights using a Black-Scholes option pricing model with the following assumptions:



		Nine Months Ended October 31,
		2017

	(unaudited)
Expected volatility		31.8%-37.4%
Expected term (in years)		0.5-1.2
Risk-free interest rate		0.95%-1.22%
Expected dividend yield		—

Income Taxes	9 Months Ended
Income Taxes	Oct. 31, 2017
Income Tax Disclosure [Abstract]
Income Taxes	Income Taxes For the three and nine months ended October 31, 2017, the Company recorded a tax benefit of $0.9 million and $0.5 million on a pretax loss of $34.7 million and $90.1 million, respectively. The effective tax rate for the three and nine months ended October 31, 2017 was 2.7% and 0.5%, respectively. The effective tax rates differ from the statutory rates primarily as a result of tax benefits from stock-based compensation in the United Kingdom and providing no benefit on pretax losses incurred in the United States, as the Company has determined that the benefit of the losses is not more likely than not to be realized. For the three and nine months ended October 31, 2016, the Company recorded a tax provision of $0.1 million and $0.3 million on a pretax loss of $21.8 million and $65.0 million, respectively. The effective tax rate for the three and nine months ended October 31, 2016 was (0.4)%. The effective tax rates differ from the statutory rates primarily as a result of providing no benefit on pretax losses incurred in the United States, as the Company has determined that the benefit of the losses is not more likely than not to be realized. The Company adopted ASU 2016-09, Compensation - Stock Compensation (Topic 718), effective February 1, 2017. Upon adoption, the Company recorded a retrospective increase of $0.3 million in gross U.S. deferred tax assets for previously unrecognized excess tax benefits that existed as of January 31, 2017, and a corresponding increase of $0.3 million in valuation allowance against these deferred tax assets, as the Company’s U.S. deferred tax assets are subject to a full valuation allowance. As such, the net impact to the Company’s retained earnings was zero. The adopted guidance requires all of the tax effects related to share-based payments to be recorded through the income statement. The Company’s effective tax rate reflected $1.2 million of tax benefit from stock-based compensation as a result of exercised options in the current period. The Company’s income tax rate may fluctuate based upon its stock price and the amount of stock options exercised and equity awards vested in a particular quarter.

Net Loss Per Share

9 Months Ended

Oct. 31, 2017

Earnings Per Share [Abstract]

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 October 31,
	2017						2016
	Class A			Class B			Class A		Class B

	(unaudited)
Numerator:
Net loss	$	(8,858	)	$	(24,919	)	$	—	$	(21,931	)
Denominator:
Weighted-average shares outstanding - basic and diluted	25,039			70,435			—		19,174
Net loss per share attributable to common stockholders - basic and diluted:	$	(0.35	)	$	(0.35	)	$	—	$	(1.14	)



	Nine Months Ended October 31,
	2017						2016
	Class A			Class B			Class A		Class B

	(unaudited)
Numerator:
Net loss	$	(16,908	)	$	(72,773	)	$	—	$	(65,285	)
Denominator:
Weighted-average shares outstanding - basic and diluted	14,508			62,442			—		18,850
Net loss per share attributable to common stockholders - basic and diluted:	$	(1.17	)	$	(1.17	)	$	—	$	(3.46	)

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 October 31,
	2017	2016

Conversion of convertible preferred stock	—	59,465
Conversion of common stock warrant	—	188
Conversion of convertible preferred stock warrant	—	29
Restricted common stock issued and outstanding	800	—
Issued and outstanding stock options	27,118	32,160
Unvested RSUs issued and outstanding	2,506	—
Unvested restricted stock awards issued and outstanding	599	—
Shares committed under the ESPP	1,082	—
Unvested shares subject to repurchase	248	540
	32,353	92,382

Related Party Transactions	9 Months Ended
Related Party Transactions	Oct. 31, 2017
Related Party Transactions [Abstract]
Related Party Transactions	Related Party Transactions Certain members of the board of directors serve as directors of and/or are executive officers of and, in some cases, are investors in, companies that are customers or vendors of the Company. Certain of the Company’s executive officers also serve as directors of or serve in an advisory capacity to companies that are customers or vendors of the Company. Related party transactions were not material as of and for the three and nine months ended October 31, 2017 and 2016.

Subsequent Events	9 Months Ended
Subsequent Events	Oct. 31, 2017
Subsequent Events [Abstract]
Subsequent Events	Subsequent Events On December 2, 2017, the Company entered into an office lease (Lease) to lease approximately 207,066 rentable square feet in an office building in San Francisco, California (Premises) expected to become the Company’s new corporate headquarters. The Premises will be delivered in phases during the total term of the Lease. One floor, or approximately 19,060 square feet, of the Premises is scheduled to be delivered on or about February 1, 2018, as phase one, and nine floors, or approximately 188,006 square feet, of the Premises are scheduled to be delivered on or about June 1, 2018, as phase two. The lease payments associated with phases one and two will be approximately $170.6 million, and annual lease payments are approximately $1.3 million and $8.7 million for the first and second year, respectively (net of 11 and eight months of rent abatement in the first year related to phase one and phase two, respectively, and five months of rent abatement in the second year related to phase two). The Lease has a 10 year term, which is expected to expire in October 2028. The Company is entitled to two five-year options to extend the Lease, subject to certain requirements. In addition, the landlord will provide a tenant improvement allowance of up to $20.7 million for leasehold improvements in phases one and two, as the phases are delivered, beginning in February 2018. Subject to certain terms and conditions, the Lease requires the Company to lease two and a half additional floors, or approximately 47,939 square feet, of the Premises, beginning in February 2020, as phase three. The lease payments associated with phase three will be approximately $35.6 million, and annual lease payments for the first year are approximately $2.2 million (net of five months of rent abatement). In addition, the landlord will provide a tenant improvement allowance of up to $4.0 million for leasehold improvements in phase three. The Company has obtained a standby letter of credit (Letter of Credit) in the amount of $8.0 million, which may be drawn down by the landlord to be applied for certain purposes upon the Company’s breach of any provisions under the Lease. Subject to certain terms and conditions, the Lease requires the Company to increase the amount of the Letter of Credit by $1.9 million in connection with phase three. Restricted cash of $8.0 million has been pledged for the Letter of Credit.

Summary of Significant Accounting Policies (Policies)

9 Months Ended

Oct. 31, 2017

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) and applicable rules and regulations of the Securities and Exchange Commission (SEC) regarding interim financial reporting. All intercompany balances and transactions have been eliminated in consolidation. Certain reclassifications of prior period amounts have been made in our condensed consolidated balance sheets and condensed consolidated statements of of cash flows to conform to the current period presentation.

The condensed consolidated balance sheet as of January 31, 2017, 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 balance sheet, statements of operations, statements of comprehensive loss and the statements of cash flows for the interim periods, but are not necessarily indicative of the results of operations to be anticipated for the full fiscal year ending January 31, 2018 or any future period.

The Company’s fiscal year ends on January 31. References to fiscal 2018, for example, refer to the fiscal year ending January 31, 2018.

Principles of Consolidation

The condensed consolidated financial statements should be read in conjunction with the audited consolidated financial statements and notes included in the Company’s final prospectus filed with the SEC pursuant to Rule 424(b) under the Securities Act of 1933, as amended, on April 7, 2017 (the Prospectus).

Use of Estimates

Stock-Based Compensation

Net Loss per Share

New Accounting Pronouncements

The Company believes that the new standard will impact the following policies and disclosures:


•	removal of the current limitation on contingent revenue will result in revenue being recognized earlier for certain contracts;


•	revenue for all professional services, including fixed fee, will be recognized based on a proportional performance basis;


•	required disclosures including information about the transaction price allocated to remaining performance obligations and related timing of revenue recognition; and


•	accounting for deferred commissions including costs that qualify for deferral and the amortization period.

Cash Equivalents and Short-Term Investments (Tables)

9 Months Ended

Oct. 31, 2017

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



	As of October 31, 2017
	(unaudited)
	Amortized Cost		Unrealized Gain		Unrealized Loss			Estimated Fair Value
Cash equivalents:
Money market funds	$	115,939	$	—	$	—		$	115,939
Total cash equivalents	$	115,939	$	—	$	—		$	115,939
Investments:
Commercial paper	16,973		—		—			16,973
U.S. treasury securities	46,570		—		(57		)	46,513
Corporate debt securities	22,570		—		(13		)	22,557
Total short-term investments	86,113		—		(70		)	86,043
Total	$	202,052	$	—	$	(70	)	$	201,982



	As of January 31, 2017
	Amortized Cost		Unrealized Gain		Unrealized Loss			Estimated Fair Value
Cash equivalents:
Money market funds	$	10,565	$	—	$	—		$	10,565
Total cash equivalents	$	10,565	$	—	$	—		$	10,565
Investments:
Asset-backed securities	1,538		—		—			1,538
Corporate debt securities	12,842		13		(3		)	12,852
Total short-term investments	14,380		13		(3		)	14,390
Total	$	24,945	$	13	$	(3	)	$	24,955

Schedule of Contractual Maturities of Short-term Investments

The following tables present the contractual maturities of the Company’s short-term investments as of October 31, 2017 and January 31, 2017 (in thousands):



	As of October 31, 2017
	(unaudited)
	Amortized Cost		Estimated Fair Value
Due within one year	$	73,602	$	73,553
Due between one to five years	12,511		12,490
	$	86,113	$	86,043



	As of January 31, 2017
	Amortized Cost		Estimated Fair Value
Due within one year	$	12,842	$	12,852
Due between one to five years	1,538		1,538
	$	14,380	$	14,390

Fair Value Measurements (Tables)

9 Months Ended

Oct. 31, 2017

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 October 31, 2017
	(unaudited)
	Level 1		Level 2		Level 3		Total
Assets:
Cash equivalents:
Money market funds	$	115,939	$	—	$	—	$	115,939
Total cash equivalents	$	115,939	$	—	$	—	$	115,939
Short-term investments:
Commercial paper	$	—	$	16,973	$	—	$	16,973
U.S. treasury securities	—		46,513		—		46,513
Corporate debt securities	—		22,557		—		22,557
Total short-term investments	—		86,043		—		86,043
Total cash equivalents and short-term investments	$	115,939	$	86,043	$	—	$	201,982



	As of January 31, 2017
	Level 1		Level 2		Level 3		Total
Assets:
Cash equivalents:
Money market funds	$	10,565	$	—	$	—	$	10,565
Total cash equivalents	$	10,565	$	—	$	—	$	10,565
Short-term investments:
Asset-backed securities	$	—	$	1,538	$	—	$	1,538
Corporate debt securities	—		12,852		—		12,852
Total short-term investments	—		14,390		—		14,390
Total cash equivalents and short-term investments	$	10,565	$	14,390	$	—	$	24,955
Liabilities:
Series B redeemable convertible preferred stock warrant	$	—	$	—	$	304	$	304

Schedule of Changes in Series B Redeemable Convertible Preferred Stock Warrant Fair Value

The change in the fair value of the Series B redeemable convertible preferred stock warrant liability was as follows (in thousands):



Balance at January 31, 2017	$	304
Increase in fair value of warrant through exercise date	103
Reclassification of remaining warrant liability to additional paid-in capital	(407		)
Balance at October 31, 2017	$	—

Goodwill and Intangible Assets, net (Tables)

9 Months Ended

Oct. 31, 2017

Goodwill and Intangible Assets Disclosure [Abstract]

Schedule of Intangible Assets, net

Intangible assets consisted of the following (in thousands):



	As of October 31, 2017
	(unaudited)
	Gross		Accumulated Amortization			Net
Capitalized internal-use software costs	$	15,344	$	(4,446	)	$	10,898
Software licenses	1,023		(466		)	557
Purchased developed technology	570		(570		)	—
	$	16,937	$	(5,482	)	$	11,455



	As of January 31, 2017
	Gross		Accumulated Amortization			Net
Capitalized internal-use software costs	$	10,859	$	(2,487	)	$	8,372
Software licenses	1,093		(314		)	779
Purchased developed technology	570		(566		)	4
	$	12,522	$	(3,367	)	$	9,155

Commitments and Contingencies (Tables)

9 Months Ended

Oct. 31, 2017

Commitments and Contingencies Disclosure [Abstract]

Schedule of Purchase Obligations Fiscal Maturity Schedule

As of October 31, 2017, the future minimum lease payments by fiscal year under the financing arrangements and various operating leases are as follows (in thousands):



	Financing Arrangements			Operating Leases		Purchase Obligations		Total
Remainder of 2018	$	212		$	2,968	$	2,595	$	5,775
2019	212			12,343		10,401		22,956
2020	—			9,441		10,301		19,742
2021	—			6,088		4,167		10,255
2022	—			5,749		—		5,749
Thereafter	—			13,896		—		13,896
Total minimum lease payments	$	424		$	50,485	$	27,464	$	78,373
Less: amount representing interest	(29		)	—		—		(29		)
Present value of minimum lease payments	$	395		$	50,485	$	27,464	$	78,344

Schedule of Future Minimum Lease Payments for Capital Leases

As of October 31, 2017, the future minimum lease payments by fiscal year under the financing arrangements and various operating leases are as follows (in thousands):



	Financing Arrangements			Operating Leases		Purchase Obligations		Total
Remainder of 2018	$	212		$	2,968	$	2,595	$	5,775
2019	212			12,343		10,401		22,956
2020	—			9,441		10,301		19,742
2021	—			6,088		4,167		10,255
2022	—			5,749		—		5,749
Thereafter	—			13,896		—		13,896
Total minimum lease payments	$	424		$	50,485	$	27,464	$	78,373
Less: amount representing interest	(29		)	—		—		(29		)
Present value of minimum lease payments	$	395		$	50,485	$	27,464	$	78,344

Schedule of Future Minimum Rental Payments for Operating Leases

As of October 31, 2017, the future minimum lease payments by fiscal year under the financing arrangements and various operating leases are as follows (in thousands):



	Financing Arrangements			Operating Leases		Purchase Obligations		Total
Remainder of 2018	$	212		$	2,968	$	2,595	$	5,775
2019	212			12,343		10,401		22,956
2020	—			9,441		10,301		19,742
2021	—			6,088		4,167		10,255
2022	—			5,749		—		5,749
Thereafter	—			13,896		—		13,896
Total minimum lease payments	$	424		$	50,485	$	27,464	$	78,373
Less: amount representing interest	(29		)	—		—		(29		)
Present value of minimum lease payments	$	395		$	50,485	$	27,464	$	78,344

Employee Incentive Plans (Tables)

9 Months Ended

Oct. 31, 2017

Disclosure of Compensation Related Costs, Share-based Payments [Abstract]

Schedule of Stock-based Compensation Expense by Award Type

Stock-based compensation expense by award type was as follows (in thousands):



	Three Months Ended October 31,				Nine Months Ended October 31,
	2017		2016		2017		2016
Stock options	$	6,162	$	4,836	$	18,313	$	11,869
RSUs	3,587		—		5,088		—
ESPP	2,146		—		4,946		—
Restricted stock awards	880		—		2,400		—
Restricted common stock	1,633		—		4,545		—
Total	$	14,408	$	4,836	$	35,292	$	11,869

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 October 31,				Nine Months Ended October 31,
	2017		2016		2017		2016
Cost of revenue
Subscription	$	1,421	$	578	$	3,163	$	1,417
Professional services and other	979		304		2,186		890
Research and development	5,174		808		12,913		2,162
Sales and marketing	3,894		1,619		9,290		4,385
General and administrative	2,940		1,527		7,740		3,015
Total	$	14,408	$	4,836	$	35,292	$	11,869

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, 2017	32,866,862		$	6.01	8.2	$	145,570
Granted	2,661,568		11.48
Exercised	(7,205,213	)	3.58
Canceled	(1,205,559	)	7.67
Outstanding as of October 31, 2017	27,117,658		$	7.12	7.9	$	591,162
As of October 31, 2017
Vested and exercisable	10,699,293		$	4.86	6.9	$	257,446

Schedule of Black-Scholes Option Pricing Model Estimated Fair Value Assumptions

The Company used the Black-Scholes option pricing model to estimate the fair value of stock options granted with the following assumptions:



	Three Months Ended October 31,		Nine Months Ended October 31,
	2017	2016	2017	2016

	(unaudited)
Expected volatility	41.4%	40.9%-41.6%	40.4%-41.4%	40.9%-44.3%
Expected term (in years)	6.3	5.8-6.1	6.3-6.4	5.8-6.4
Risk-free interest rate	1.87%	1.22%-1.42%	1.87%-2.21%	1.13%-1.54%
Expected dividend yield	—	—	—	—

Schedule of Nonvested Restricted Stock Units Activity [Table Text Block]

A summary of the Company’s RSU activity and related information is as follows:



	Number of RSUs		Weighted- Average Grant Date Fair Value Per Share
Outstanding as of January 31, 2017	—		$	—
Granted	2,567,667		24.08
Vested	—		—
Forfeited	(61,451	)	23.68
Outstanding as of October 31, 2017	2,506,216		$	24.08

Schedule of ESPP Black-Scholes Option Pricing Model Estimated Fair Value Assumptions

The Company estimated the fair value of ESPP purchase rights using a Black-Scholes option pricing model with the following assumptions:



		Nine Months Ended October 31,
		2017

	(unaudited)
Expected volatility		31.8%-37.4%
Expected term (in years)		0.5-1.2
Risk-free interest rate		0.95%-1.22%
Expected dividend yield		—

Net Loss Per Share (Tables)

9 Months Ended

Oct. 31, 2017

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 October 31,
	2017						2016
	Class A			Class B			Class A		Class B

	(unaudited)
Numerator:
Net loss	$	(8,858	)	$	(24,919	)	$	—	$	(21,931	)
Denominator:
Weighted-average shares outstanding - basic and diluted	25,039			70,435			—		19,174
Net loss per share attributable to common stockholders - basic and diluted:	$	(0.35	)	$	(0.35	)	$	—	$	(1.14	)



	Nine Months Ended October 31,
	2017						2016
	Class A			Class B			Class A		Class B

	(unaudited)
Numerator:
Net loss	$	(16,908	)	$	(72,773	)	$	—	$	(65,285	)
Denominator:
Weighted-average shares outstanding - basic and diluted	14,508			62,442			—		18,850
Net loss per share attributable to common stockholders - basic and diluted:	$	(1.17	)	$	(1.17	)	$	—	$	(3.46	)

Schedule of Potentially Dilutive Securities Excluded from Computation of Diluted Per Share

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 October 31,
	2017	2016

Conversion of convertible preferred stock	—	59,465
Conversion of common stock warrant	—	188
Conversion of convertible preferred stock warrant	—	29
Restricted common stock issued and outstanding	800	—
Issued and outstanding stock options	27,118	32,160
Unvested RSUs issued and outstanding	2,506	—
Unvested restricted stock awards issued and outstanding	599	—
Shares committed under the ESPP	1,082	—
Unvested shares subject to repurchase	248	540
	32,353	92,382

Overview and Basis of Presentation - Narrative (Details) - USD ($) $ / shares in Units, $ in Thousands			9 Months Ended
	Apr. 07, 2017	Apr. 06, 2017	Oct. 31, 2017	Oct. 31, 2016
Class of Stock [Line Items]
Initial public offering costs			$ 4,038	$ 990
Class A Common Stock
Class of Stock [Line Items]
Price per share in initial public offering (in dollars per share)	$ 17.00
Common stock outstanding (in shares)			39,290,132
Redeemable Convertible Preferred Stock
Class of Stock [Line Items]
Redeemable convertible preferred stock converted to common class B stock (in shares)		59,491,640
Class B Common Stock
Class of Stock [Line Items]
Common class B stock after conversion of redeemable convertible stock (in shares)		59,491,640
Common stock outstanding (in shares)			62,081,326
Initial Public Offering
Class of Stock [Line Items]
Proceeds from initial public offering, net of underwriters' discounts and commissions	$ 200,000
Initial public offering costs	$ 5,600
Initial Public Offering \| Class A Common Stock
Class of Stock [Line Items]
Shares issued in initial public offering (in shares)	12,650,000
Underwriters' Option to Purchase Additional Shares \| Class A Common Stock
Class of Stock [Line Items]
Shares issued in initial public offering (in shares)	1,650,000

Summary of Significant Accounting Policies - Narrative (Details) $ in Millions	9 Months Ended
	Oct. 31, 2017 vote	Feb. 01, 2017 USD ($)
Retained Earnings \| Accounting Standards Update 2016-09 - Forfeiture Rate Component
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Cumulative impact adjustment \| $		$ 0.2
Class A Common Stock
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Number of votes per share	1
Class B Common Stock
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Number of votes per share	10

Business Combinations - Narrative (Details) - Stormpath Inc. $ in Millions	Feb. 17, 2017 USD ($) shares
Business Acquisition [Line Items]
Total purchase price	$ 3.7
Shares included in total consideration (in shares) \| shares	200,000
Restricted common stock
Business Acquisition [Line Items]
Incremental shares issued (in shares) \| shares	800,000
Incremental shares issued	$ 8.6
Stock-based compensation vesting period	2 years
Stormpath Investors
Business Acquisition [Line Items]
Total purchase price	$ 2.2
Stormpath Workforce
Business Acquisition [Line Items]
Total purchase price	1.5
Incremental shares issued	$ 9.1

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	Oct. 31, 2017	Jan. 31, 2017
Cash equivalents:
Cash equivalents, amortized cost	$ 115,939	$ 10,565
Cash equivalents, estimated fair value	115,939	10,565
Investments:
Investments, amortized cost	86,113	14,380
Investments, estimated fair value	86,043	14,390
Total short-term investments, amortized cost	86,113	14,380
Total short-term investments, unrealized gain	0	13
Total short-term investments, unrealized loss	(70)	(3)
Total short-term investments, estimated fair value	86,043	14,390
Amortized cost	202,052	24,945
Estimated fair value	201,982	24,955
Commercial paper
Investments:
Investments, amortized cost	16,973
Investments, unrealized gain	0
Investments, unrealized loss	0
Investments, estimated fair value	16,973
U.S. treasury securities
Investments:
Investments, amortized cost	46,570
Investments, unrealized gain	0
Investments, unrealized loss	(57)
Investments, estimated fair value	46,513
Corporate debt securities
Investments:
Investments, amortized cost	22,570	12,842
Investments, unrealized gain	0	13
Investments, unrealized loss	(13)	(3)
Investments, estimated fair value	22,557	12,852
Asset-backed securities
Investments:
Investments, amortized cost		1,538
Investments, unrealized gain		0
Investments, unrealized loss		0
Investments, estimated fair value		$ 1,538
Money market funds
Cash equivalents:
Cash equivalents, amortized cost	115,939
Cash equivalents, estimated fair value	$ 115,939

Cash Equivalents and Short-Term Investments - Narrative (Details)	3 Months Ended		9 Months Ended		12 Months Ended
	Oct. 31, 2017 USD ($) investment	Oct. 31, 2016 USD ($)	Oct. 31, 2017 USD ($) investment	Oct. 31, 2016 USD ($)	Jan. 31, 2017 USD ($) investment
Investments, Debt and Equity Securities [Abstract]
Number of short-term investments in unrealized loss positions \| investment	17		17		5
Gross unrealized gains or lesses from available-for-sale securities	$ 0	$ 0	$ 0	$ 0
Realized gains or losses reclassified out of accumulated other comprehensive income	$ 0	$ 0	0	$ 0
Other-than-temporary impairment short term investment			$ 0		$ 0

Cash Equivalents and Short-Term Investments - Schedule of Contractual Maturities of Short-term Investments (Details) - USD ($) $ in Thousands	Oct. 31, 2017	Jan. 31, 2017
Amortized Cost
Amortized cost, due within one year	$ 73,602	$ 12,842
Amortized cost, due between one to five years	12,511	1,538
Investments, amortized cost	86,113	14,380
Estimated Fair Value
Estimated fair value, due within one year	73,553	12,852
Estimated fair value, due between one to five years	12,490	1,538
Estimated fair value total	$ 86,043	$ 14,390

Fair Value Measurements - Schedule of Financial Assets and Liabilities Measured at Fair Value on a Recurring Basis (Details) - USD ($) $ in Thousands	Oct. 31, 2017	Jan. 31, 2017
Assets:
Fair value, cash equivalents	$ 115,939	$ 10,565
Money market funds
Assets:
Fair value, cash equivalents	115,939
Fair Value, Measurements, Recurring
Assets:
Fair value, cash equivalents	115,939	10,565
Short term investments, fair value	86,043	14,390
Total cash equivalents and short-term investments	201,982	24,955
Liabilities:
Series B redeemable convertible preferred stock warrant		304
Fair Value, Measurements, Recurring \| Level 1
Assets:
Fair value, cash equivalents	115,939	10,565
Short term investments, fair value	0	0
Total cash equivalents and short-term investments	115,939	10,565
Liabilities:
Series B redeemable convertible preferred stock warrant		0
Fair Value, Measurements, Recurring \| Level 2
Assets:
Fair value, cash equivalents	0	0
Short term investments, fair value	86,043	14,390
Total cash equivalents and short-term investments	86,043	14,390
Liabilities:
Series B redeemable convertible preferred stock warrant		0
Fair Value, Measurements, Recurring \| Level 3
Assets:
Fair value, cash equivalents	0	0
Short term investments, fair value	0	0
Total cash equivalents and short-term investments	0	0
Liabilities:
Series B redeemable convertible preferred stock warrant		304
Fair Value, Measurements, Recurring \| Commercial paper
Assets:
Short term investments, fair value	16,973
Fair Value, Measurements, Recurring \| Commercial paper \| Level 1
Assets:
Short term investments, fair value	0
Fair Value, Measurements, Recurring \| Commercial paper \| Level 2
Assets:
Short term investments, fair value	16,973
Fair Value, Measurements, Recurring \| Commercial paper \| Level 3
Assets:
Short term investments, fair value	0
Fair Value, Measurements, Recurring \| U.S. treasury securities
Assets:
Short term investments, fair value	46,513
Fair Value, Measurements, Recurring \| U.S. treasury securities \| Level 1
Assets:
Short term investments, fair value	0
Fair Value, Measurements, Recurring \| U.S. treasury securities \| Level 2
Assets:
Short term investments, fair value	46,513
Fair Value, Measurements, Recurring \| U.S. treasury securities \| Level 3
Assets:
Short term investments, fair value	0
Fair Value, Measurements, Recurring \| Corporate debt securities
Assets:
Short term investments, fair value	22,557	12,852
Fair Value, Measurements, Recurring \| Corporate debt securities \| Level 1
Assets:
Short term investments, fair value	0	0
Fair Value, Measurements, Recurring \| Corporate debt securities \| Level 2
Assets:
Short term investments, fair value	22,557	12,852
Fair Value, Measurements, Recurring \| Corporate debt securities \| Level 3
Assets:
Short term investments, fair value	0	0
Fair Value, Measurements, Recurring \| Asset-backed securities
Assets:
Short term investments, fair value		1,538
Fair Value, Measurements, Recurring \| Asset-backed securities \| Level 1
Assets:
Short term investments, fair value		0
Fair Value, Measurements, Recurring \| Asset-backed securities \| Level 2
Assets:
Short term investments, fair value		1,538
Fair Value, Measurements, Recurring \| Asset-backed securities \| Level 3
Assets:
Short term investments, fair value		0
Fair Value, Measurements, Recurring \| Money market funds
Assets:
Fair value, cash equivalents	115,939	10,565
Fair Value, Measurements, Recurring \| Money market funds \| Level 1
Assets:
Fair value, cash equivalents	115,939	10,565
Fair Value, Measurements, Recurring \| Money market funds \| Level 2
Assets:
Fair value, cash equivalents	0	0
Fair Value, Measurements, Recurring \| Money market funds \| Level 3
Assets:
Fair value, cash equivalents	$ 0	$ 0

Fair Value Measurements - Schedule of Changes in Series B Redeemable Convertible Preferred Stock Warrant Fair Value (Details) - Redeemable Convertible Preferred Stock Warrant $ in Thousands	9 Months Ended
	Oct. 31, 2017 USD ($)
Fair Value, Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Balance as of beginning of period	$ 304
Increase in fair value of warrant through exercise date	103
Reclassification of remaining warrant liability to additional paid-in capital	(407)
Balance as of end of period	$ 0

Goodwill and Intangible Assets, net - Narrative (Details) - USD ($)	3 Months Ended			9 Months Ended
	Oct. 31, 2017	Apr. 30, 2017	Oct. 31, 2016	Oct. 31, 2017	Oct. 31, 2016	Jan. 31, 2017
Goodwill [Line Items]
Goodwill	$ 6,282,000			$ 6,282,000		$ 2,630,000
Goodwill impairments	0		$ 0	0	$ 0
Capitalized internal-use software	1,700,000		1,900,000	5,000,000	4,400,000
Amortization expense	800,000		500,000	2,100,000	1,300,000
Stormpath Inc.
Goodwill [Line Items]
Goodwill, acquired during period		$ 3,700,000
Capitalized internal-use software costs
Goodwill [Line Items]
Stock-based compensation included in capitalized software costs	300,000		$ 200,000	$ 900,000	$ 400,000
Research and development expense
Goodwill [Line Items]
Reversal of previously capitalized costs	$ 500,000

Goodwill and Intangible Assets, net - Schedule of Intangible Assets (Details) - USD ($) $ in Thousands	Oct. 31, 2017	Jan. 31, 2017
Finite-Lived Intangible Assets [Line Items]
Gross	$ 16,937	$ 12,522
Accumulated Amortization	(5,482)	(3,367)
Net	11,455	9,155
Capitalized internal-use software costs
Finite-Lived Intangible Assets [Line Items]
Gross	15,344	10,859
Accumulated Amortization	(4,446)	(2,487)
Net	10,898	8,372
Software licenses
Finite-Lived Intangible Assets [Line Items]
Gross	1,023	1,093
Accumulated Amortization	(466)	(314)
Net	557	779
Purchased developed technology
Finite-Lived Intangible Assets [Line Items]
Gross	570	570
Accumulated Amortization	(570)	(566)
Net	$ 0	$ 4

Debt and Financing Arrangements - Narrative (Details) - USD ($)		1 Months Ended	9 Months Ended
	Jun. 17, 2015	Mar. 31, 2017	Oct. 31, 2017	Nov. 21, 2018	Nov. 21, 2017	Jan. 31, 2017	Nov. 21, 2016	May 31, 2015	Mar. 10, 2014
Debt Instrument [Line Items]
Letters of credit issued and outstanding			$ 4,400,000			$ 5,400,000
Loan and Security Agreement
Debt Instrument [Line Items]
Letters of credit issued and outstanding			4,400,000.0
Shares issuable under warrants granted (in shares)									187,500
Per share value, shares issuable under warrants granted (in dollars per share)									$ 1.4
Additional shares issuable under warrants granted (in shares)									112,500
Warrants exercised during period, shares issued (in shares)		168,750
Warrants exercised, shares withheld in lieu of cash (in shares)		18,750
Loan and Security Agreement \| Term Loan
Debt Instrument [Line Items]
Loan face amount									$ 10,000,000.0
Loan and Security Agreement \| Revolving Credit Facility \| Line of Credit
Debt Instrument [Line Items]
Line of credit maximum borrowing capacity	$ 20,000,000.0						$ 40,000,000.0		5,000,000.0
Line of credit maturity extension	1 year
Available borrowing capacity			$ 35,600,000
Unused line of credit percentage fee			0.15%
Line of credit commitment fee							$ 100,000
Draws on line of credit			$ 0			0			$ 0
Loan and Security Agreement \| Revolving Credit Facility \| Line of Credit \| Prime Rate
Debt Instrument [Line Items]
Line of credit interest rate			0.75%
Financing Agreement 2015 \| Capital Lease
Debt Instrument [Line Items]
Loan face amount								$ 900,000.0
Financing agreement, implicit interest rate								5.00%
Financing agreement outstanding			$ 100,000			400,000
Financing Agreement 2017 \| Capital Lease
Debt Instrument [Line Items]
Loan face amount						$ 400,000.0
Financing agreement, implicit interest rate						4.50%
Financing agreement outstanding			$ 300,000			$ 400,000
Scenario, Forecast \| Loan and Security Agreement \| Revolving Credit Facility \| Line of Credit
Debt Instrument [Line Items]
Line of credit commitment fee				$ 100,000	$ 100,000

Commitments and Contingencies - Narrative (Details) - USD ($)	1 Months Ended		3 Months Ended		9 Months Ended
	Aug. 31, 2017	Jul. 31, 2017	Oct. 31, 2017	Oct. 31, 2016	Oct. 31, 2017	Oct. 31, 2016	Jan. 31, 2017
Other Commitments [Line Items]
Deferred rent			$ 5,000,000		$ 5,000,000		$ 4,800,000
Rent expense			3,000,000	$ 1,900,000	7,600,000	$ 5,500,000
Letters of credit issued and outstanding			4,400,000		4,400,000		$ 5,400,000
Letter of Credit
Other Commitments [Line Items]
Draws on line of credit			$ 0		$ 0
Data Center Operations
Other Commitments [Line Items]
Non-cancellable contractual agreement period		3 years
Future annual commitments		$ 10,000,000
San Jose Office Space, Amendment
Other Commitments [Line Items]
Incremental commitment	$ 6,300,000
Leasehold Improvements \| San Jose Office Space, Amendment
Other Commitments [Line Items]
Incremental commitment	$ 800,000

Commitments and Contingencies - Summary of Future Commitment Maturity Schedules (Details) $ in Thousands	Oct. 31, 2017 USD ($)
Financing Arrangements
Remainder of 2018	$ 212
2019	212
2020	0
2021	0
2022	0
Thereafter	0
Total minimum lease payments	424
Less: amount representing interest	(29)
Present value of minimum lease payments	395
Operating Leases
Remainder of 2018	2,968
2019	12,343
2020	9,441
2021	6,088
2022	5,749
Thereafter	13,896
Total minimum lease payments	50,485
Purchase Obligations
Remainder of 2018	2,595
2019	10,401
2020	10,301
2021	4,167
2022	0
Thereafter	0
Total minimum lease payments	27,464
Total
Remainder of 2018	5,775
2019	22,956
2020	19,742
2021	10,255
2022	5,749
Thereafter	13,896
Total minimum lease payments	78,373
Present value of minimum lease payments	$ 78,344

Stockholders' Equity (Deficit) - Narrative (Details) $ / shares in Units, $ in Thousands		3 Months Ended		9 Months Ended
	Apr. 06, 2017 shares	Oct. 31, 2017 USD ($) $ / shares shares	Oct. 31, 2016 USD ($) shares	Oct. 31, 2017 USD ($) vote $ / shares shares	Oct. 31, 2016 USD ($) shares	Jan. 31, 2017 $ / shares shares
Class of Stock [Line Items]
Shares authorized, (in shares)						120,000,000
Common stock par value (in dollars per share) \| $ / shares						$ 0.0001
General and administrative expenses recognized \| $		$ 13,546	$ 7,922	$ 37,133	$ 21,009
Redeemable Convertible Preferred Stock
Class of Stock [Line Items]
Redeemable convertible preferred stock converted to common class B stock (in shares)	59,491,640
Redeemable preferred stock outstanding (in shares)		0		0
Class A Common Stock
Class of Stock [Line Items]
Shares authorized, (in shares)		1,000,000,000		1,000,000,000
Common stock par value (in dollars per share) \| $ / shares		$ 0.0001		$ 0.0001
Common stock outstanding (in shares)		39,290,132		39,290,132
Number of votes per share \| vote				1
Class B Common Stock
Class of Stock [Line Items]
Common class B stock after conversion of redeemable convertible stock (in shares)	59,491,640
Shares authorized, (in shares)		120,000,000		120,000,000
Common stock par value (in dollars per share) \| $ / shares		$ 0.0001		$ 0.0001
Common stock outstanding (in shares)		62,081,326		62,081,326
Number of votes per share \| vote				10
Contribution of Nonmonetary Assets to Charitable Organization \| Class A Common Stock
Class of Stock [Line Items]
Shares issued as charitable contributions (in shares)		24,287		24,287
General and administrative expenses recognized \| $		$ 700		$ 700
Contribution of Nonmonetary Assets to Charitable Organization \| Class B Common Stock
Class of Stock [Line Items]
Shares issued as charitable contributions (in shares)			13,935		13,935
General and administrative expenses recognized \| $			$ 100		$ 100

Employee Incentive Plans - Schedule of Stock-based Compensation Expense by Award Type (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Oct. 31, 2017	Oct. 31, 2016	Oct. 31, 2017	Oct. 31, 2016
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Stock-based compensation expense	$ 14,408	$ 4,836	$ 35,292	$ 11,869
Stock options
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Stock-based compensation expense	6,162	4,836	18,313	11,869
RSUs
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Stock-based compensation expense	3,587	0	5,088	0
ESPP
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Stock-based compensation expense	2,146	0	4,946	0
Restricted stock awards
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Stock-based compensation expense	880	0	2,400	0
Restricted common stock
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Stock-based compensation expense	$ 1,633	$ 0	$ 4,545	$ 0

Employee Incentive Plans - Schedule of Stock-based Compensation Expense by Statement of Operations Location (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Oct. 31, 2017	Oct. 31, 2016	Oct. 31, 2017	Oct. 31, 2016
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Stock-based compensation expense	$ 14,408	$ 4,836	$ 35,292	$ 11,869
Subscription
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Stock-based compensation expense	1,421	578	3,163	1,417
Professional services and other
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Stock-based compensation expense	979	304	2,186	890
Research and development
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Stock-based compensation expense	5,174	808	12,913	2,162
Sales and marketing
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Stock-based compensation expense	3,894	1,619	9,290	4,385
General and administrative
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Stock-based compensation expense	$ 2,940	$ 1,527	$ 7,740	$ 3,015

Employee Incentive Plans - Narrative (Details) $ / shares in Units, $ in Millions		1 Months Ended	3 Months Ended		9 Months Ended		12 Months Ended
	Feb. 17, 2017 USD ($) shares	Mar. 31, 2017 offering_period shares	Oct. 31, 2017 USD ($) $ / shares shares	Oct. 31, 2016 USD ($) $ / shares	Oct. 31, 2017 USD ($) equity_incentive_plan $ / shares shares	Oct. 31, 2016 USD ($) $ / shares	Jan. 31, 2017 USD ($) shares
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Number of equity incentive plans \| equity_incentive_plan					2
Options to purchase common stock outstanding (in shares) \| shares							32,866,862
Weighted average grant date fair value of options granted (in dollars per share) \| $ / shares			$ 12.27	$ 4.19	$ 5.37	$ 3.93
Grant date fair value of vested stock options			$ 5.9	$ 3.9	$ 18.9	$ 9.5
Intrinsic value of options exercised			139.4	$ 2.6	158.7	$ 4.5
Unrecognized stock-based compensation expense			$ 60.6		$ 60.6
Number of options, granted (in shares) \| shares					2,661,568
Class B Common Stock
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Shares subject to early exercise, liability recorded in accrued expenses and other current liabilities					$ 1.4		$ 2.2
Number of options subject to early exercise (in shares) \| shares			248,083		248,083		467,180
Restricted stock units
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Weighted average stock-based compensation recognition period					3 years 7 months 6 days
Granted during period (in shares) \| shares			347,740		2,567,667
Shares issued fair value			$ 10.2		$ 61.8
Unrecognized compensation costs related to unvested restricted stock units			55.1		$ 55.1
Stock options
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Weighted average stock-based compensation recognition period					2 years 9 months 18 days
ESPP
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Unrecognized compensation costs related to unvested restricted stock units			6.0		$ 6.0
Shares authorized (in shares) \| shares		3,000,000
ESPP offering period		12 months
Number of offering periods \| offering_period		2
Employee share purchase price percentage					85.00%
Stormpath Inc.
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Pre-combination service consideration	$ 3.7
Stormpath Inc. \| Restricted common stock
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Granted during period (in shares) \| shares	800,000
Shares issued fair value	$ 8.6
Stock-based compensation vesting period	2 years
Stormpath Inc. \| Restricted stock awards
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Weighted average stock-based compensation recognition period					1 year
Unrecognized compensation costs related to unvested restricted stock units			4.1		$ 4.1
Stormpath Inc. \| Stormpath Workforce
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Shares issued fair value	$ 9.1
Pre-combination service consideration	$ 1.5
Stormpath Inc. \| Stormpath Workforce \| Restricted stock awards
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Weighted average stock-based compensation recognition period					1 year 6 months
Granted during period (in shares) \| shares	598,500
Shares issued fair value	$ 6.6
Unrecognized compensation costs related to unvested restricted stock units	5.5		3.1		$ 3.1
Stormpath Inc. \| Stormpath Workforce \| Stock options
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Unrecognized stock-based compensation expense	2.1		$ 1.8		$ 1.8
Weighted average stock-based compensation recognition period					2 years 4 months 24 days
Shares issued fair value	$ 2.5
Stock-based compensation vesting period	4 years
Number of options, granted (in shares) \| shares	518,900
Minimum \| Stormpath Inc. \| Stormpath Workforce \| Restricted stock awards
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Stock-based compensation vesting period	2 years
Maximum \| Stormpath Inc. \| Stormpath Workforce \| Restricted stock awards
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Stock-based compensation vesting period	3 years
2009 Stock Plan
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Options to purchase common stock outstanding (in shares) \| shares			27,117,658		27,117,658
2009 Stock Plan \| Class B Common Stock
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Options to purchase common stock outstanding (in shares) \| shares			27,052,658		27,052,658
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) \| shares			65,000		65,000

Employee Incentive Plans - Schedule of Stock Option Activity (Details) - USD ($) $ / shares in Units, $ in Thousands	9 Months Ended	12 Months Ended
	Oct. 31, 2017	Jan. 31, 2017
Number of Options
Number of options, outstanding beginning of period (in shares)	32,866,862
Number of options, granted (in shares)	2,661,568
Number of options, exercised (in shares)	(7,205,213)
Number of options, canceled (in shares)	(1,205,559)
Number of options, outstanding end of period (in shares)		32,866,862
Vested and exercisable, number of options (in shares)	10,699,293
Weighted- Average Exercise Price
Options outstanding, weighted average exercise price beginning of period (in dollars per share)	$ 6.01
Options granted, weighted average exercise price (in dollars per share)	11.48
Options exercised, weighted average exercise price (in dollars per share)	3.58
Options canceled, weighted average exercise price (in dollars per share)	7.67
Options outstanding, weighted average exercise price end of period (in dollars per share)	7.12	$ 6.01
Vested and exercisable, weighted average exercise price (in dollars per share)	$ 4.86
Additional Disclosures
Options outstanding, weighted average remaining contractual term	7 years 10 months 21 days	8 years 2 months 16 days
Options outstanding, aggregate intrinsic value	$ 591,162	$ 145,570
Vested and exercisable, weighted average remaining contractual term	6 years 11 months 9 days
Vested and exercisable, aggregate intrinsic value	$ 257,446

Employee Incentive Plans - Schedule of Black-Scholes Option Pricing Model Estimated Fair Value Assumptions (Details)	3 Months Ended		9 Months Ended
	Oct. 31, 2017	Oct. 31, 2016	Oct. 31, 2017	Oct. 31, 2016
Stock options
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Expected volatility rate	41.40%
Expected volatility, minimum		40.90%	40.40%	40.90%
Expected volatility, maximum		41.60%	41.40%	44.30%
Expected term (in years)	6 years 3 months 18 days
Risk-free interest rate	1.87%
Risk-free interest rate, minimum		1.22%	1.87%	1.13%
Risk-free interest rate, maximum		1.42%	2.21%	1.54%
Expected dividend yield	0.00%	0.00%	0.00%	0.00%
Stock options \| Minimum
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Expected term (in years)		5 years 9 months 18 days	6 years 3 months 18 days	5 years 9 months 18 days
Stock options \| Maximum
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Expected term (in years)		6 years 1 month 6 days	6 years 4 months 24 days	6 years 4 months 24 days
ESPP
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Expected volatility, minimum			31.80%
Expected volatility, maximum			37.40%
Risk-free interest rate, minimum			0.95%
Risk-free interest rate, maximum			1.22%
Expected dividend yield			0.00%
ESPP \| Minimum
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Expected term (in years)			6 months
ESPP \| Maximum
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Expected term (in years)			1 year 2 months 12 days

Employee Incentive Plans - Schedule of Restricted Stock Unit Activity (Details) - Restricted stock units - $ / shares	3 Months Ended	9 Months Ended
	Oct. 31, 2017	Oct. 31, 2017
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Nonvested, Number of Shares [Roll Forward]
Outstanding as of January 31, 2017 (in shares)		0
Granted during period (in shares)	347,740	2,567,667
Vested during period (in shares)		0
Forfeited during period (in shares)		(61,451)
Outstanding as of October 31, 2017 (in shares)	2,506,216	2,506,216
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Nonvested, Weighted Average Grant Date Fair Value [Abstract]
Outstanding as of January 31, 2017 (in usd per share)		$ 0.00
Granted during period (in usd per share)		24.08
Vested during period (in usd per share)		0.00
Forfeited during period (in usd per share)		23.68
Outstanding as of October 31, 2017 (in usd per share)	$ 24.08	$ 24.08

Income Taxes - Narrative (Details) - USD ($)	3 Months Ended		9 Months Ended
Income Taxes - Narrative (Details) - USD ($)	Oct. 31, 2017	Oct. 31, 2016	Oct. 31, 2017	Oct. 31, 2016	Feb. 01, 2017
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Tax provision (benefit)	$ (940,000)	$ 91,000	$ (463,000)	$ 267,000
Loss before income taxes	$ 34,718,000	$ 21,840,000	$ 90,144,000	$ 65,018,000
Effective income tax rate	2.70%	(0.40%)	0.50%	(0.40%)
Tax benefit from stock-based compensation			$ 1,200,000
Accounting Standards Update 2016-09
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Increase of deferred tax assets					$ 300,000
Increase of deferred tax asset valuation allowance					300,000
Retained Earnings \| Accounting Standards Update 2016-09
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Cumulative impact adjustment					$ 0

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		9 Months Ended
	Oct. 31, 2017	Oct. 31, 2016	Oct. 31, 2017	Oct. 31, 2016
Numerator:
Net loss	$ (33,778)	$ (21,931)	$ (89,681)	$ (65,285)
Denominator:
Weighted-average shares outstanding - basic and diluted (in shares)	95,474	19,174	76,950	18,850
Net loss per share attributable to common stockholders - basic and diluted (in dollars per share)	$ (0.35)	$ (1.14)	$ (1.17)	$ (3.46)
Class A Common Stock
Numerator:
Net loss	$ (8,858)	$ 0	$ (16,908)	$ 0
Denominator:
Weighted-average shares outstanding - basic and diluted (in shares)	25,039	0	14,508	0
Net loss per share attributable to common stockholders - basic and diluted (in dollars per share)	$ (0.35)	$ 0.00	$ (1.17)	$ 0.00
Class B Common Stock
Numerator:
Net loss	$ (24,919)	$ (21,931)	$ (72,773)	$ (65,285)
Denominator:
Weighted-average shares outstanding - basic and diluted (in shares)	70,435	19,174	62,442	18,850
Net loss per share attributable to common stockholders - basic and diluted (in dollars per share)	$ (0.35)	$ (1.14)	$ (1.17)	$ (3.46)

Net Loss Per Share - Schedule of Potentially Dilutive Securities Excluded from Computation of Diluted Per Share (Details) - shares shares in Thousands	9 Months Ended
	Oct. 31, 2017	Oct. 31, 2016
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Antidilutive securities excluded from computation of earnings per share (in shares)	32,353	92,382
Conversion of convertible preferred stock
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Antidilutive securities excluded from computation of earnings per share (in shares)	0	59,465
Conversion of common stock warrant
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Antidilutive securities excluded from computation of earnings per share (in shares)	0	188
Conversion of convertible preferred stock warrant
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Antidilutive securities excluded from computation of earnings per share (in shares)	0	29
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)	800	0
Issued and outstanding stock options
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Antidilutive securities excluded from computation of earnings per share (in shares)	27,118	32,160
RSUs
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Antidilutive securities excluded from computation of earnings per share (in shares)	2,506	0
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)	599	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)	1,082	0
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)	248	540

Subsequent Events - Narrative (Details)	Dec. 02, 2017 USD ($) ft² renewal_option	Dec. 01, 2017	Oct. 31, 2017 USD ($)	Jan. 31, 2017 USD ($)
Subsequent Event [Line Items]
Letters of credit issued and outstanding			$ 4,400,000	$ 5,400,000
Subsequent Event
Subsequent Event [Line Items]
Office lease, rentable square feet \| ft²	207,066
Letters of credit issued and outstanding	$ 8,000,000
Phase One \| Subsequent Event
Subsequent Event [Line Items]
Office lease, rentable square feet \| ft²	19,060
Office lease, number of floors	1
Rent abatement (in months)	11 months
Phase Two \| Subsequent Event
Subsequent Event [Line Items]
Office lease, rentable square feet \| ft²	188,006
Office lease, number of floors	9
Phases One and Two \| Subsequent Event
Subsequent Event [Line Items]
Total lease payments	$ 170,600,000
Annual lease payments for the first year	1,300,000
Annual lease payments for the second year	$ 8,700,000
Lease term	10 years
Number of renewal extensions \| renewal_option	2
Renewal term	5 years
Phases One and Two \| Leasehold Improvements \| Subsequent Event
Subsequent Event [Line Items]
Tenant improvement allowance	$ 20,700,000
Phase Two, Year One \| Subsequent Event
Subsequent Event [Line Items]
Rent abatement (in months)	8 months
Phase Two, Year Two \| Subsequent Event
Subsequent Event [Line Items]
Rent abatement (in months)	5 months
Phase Three \| Subsequent Event
Subsequent Event [Line Items]
Office lease, rentable square feet \| ft²	47,939
Office lease, number of floors		2.5
Total lease payments	$ 35,600,000
Annual lease payments for the first year	$ 2,200,000
Rent abatement (in months)	5 months
Phase Three \| Leasehold Improvements \| Subsequent Event
Subsequent Event [Line Items]
Tenant improvement allowance	$ 4,000,000
Line of Credit \| Subsequent Event
Subsequent Event [Line Items]
Line of credit maximum borrowing capacity	8,000,000.0
Line of Credit \| Phase Three \| Subsequent Event
Subsequent Event [Line Items]
Required increase to the letter of credit	$ 1,900,000

Label	Element	Value
Restricted Cash and Cash Equivalents, Noncurrent	us-gaap_RestrictedCashAndCashEquivalentsNoncurrent	$ 4,395,000
Restricted Cash and Cash Equivalents, Noncurrent	us-gaap_RestrictedCashAndCashEquivalentsNoncurrent	269,000
Restricted Cash and Cash Equivalents, Current	us-gaap_RestrictedCashAndCashEquivalentsAtCarryingValue	1,039,000
Restricted Cash and Cash Equivalents, Current	us-gaap_RestrictedCashAndCashEquivalentsAtCarryingValue	$ 0