PURE STORAGE, INC., 10-Q filed on 9/4/2018
Quarterly Report
v3.10.0.1
Document and Entity Information - shares
6 Months Ended
Jul. 31, 2018
Aug. 24, 2018
Document Type 10-Q  
Amendment Flag false  
Document Period End Date Jul. 31, 2018  
Document Fiscal Year Focus 2019  
Document Fiscal Period Focus Q2  
Trading Symbol PSTG  
Entity Registrant Name Pure Storage, Inc.  
Entity Central Index Key 0001474432  
Current Fiscal Year End Date --01-31  
Entity Filer Category Large Accelerated Filer  
Class A    
Entity Common Stock, Shares Outstanding (in shares)   205,282,020
Class B    
Entity Common Stock, Shares Outstanding (in shares)   30,892,432
v3.10.0.1
Condensed Consolidated Balance Sheets - USD ($)
$ in Thousands
Jul. 31, 2018
Jan. 31, 2018
[1]
Current assets:    
Cash and cash equivalents $ 370,457 $ 244,057
Marketable securities 736,205 353,289
Accounts receivable, net of allowance of $1,062 and $957 as of January 31, 2018 and July 31, 2018 242,409 243,001
Inventory 41,673 34,497
Deferred commissions, current 23,521 21,088
Prepaid expenses and other current assets 36,071 47,552
Total current assets 1,450,336 943,484
Property and equipment, net 101,718 89,142
Intangible assets, net 4,305 5,057
Deferred income taxes, non-current 1,534 1,060
Restricted cash 15,778 14,763
Deferred commissions, non-current 67,948 66,225
Other assets, non-current 4,610 4,264
Total assets 1,646,229 1,123,995
Current liabilities:    
Accounts payable 68,058 84,420
Accrued compensation and benefits 51,654 59,898
Accrued expenses and other liabilities 27,049 26,829
Deferred revenue, current 213,100 191,229
Liability related to early exercised stock options 0 320
Total current liabilities 359,861 362,696
Convertible senior notes, net 436,687 0
Deferred revenue, non-current 200,147 182,873
Other liabilities, non-current 5,140 4,025
Total liabilities 1,001,835 549,594
Commitments and contingencies (Note 6)
Stockholders’ equity:    
Preferred stock, par value of $0.0001 per share— 20,000 shares authorized as of January 31, 2018 and July 31, 2018; no shares issued and outstanding as of January 31, 2018 and July 31, 2018 0 0
Class A and Class B common stock, par value of $0.0001 per share— 2,250,000 (Class A 2,000,000, Class B 250,000) shares authorized as of January 31, 2018 and July 31, 2018; 220,979 (Class A 129,502, Class B 91,477) and 235,412 (Class A 204,052, Class B 31,360) shares issued and outstanding as of January 31, 2018 and July 31, 2018 24 22
Additional paid-in capital 1,675,210 1,479,883
Accumulated other comprehensive loss (2,826) (1,917)
Accumulated deficit (1,028,014) (903,587)
Total stockholders’ equity 644,394 574,401
Total liabilities and stockholders’ equity $ 1,646,229 $ 1,123,995
[1] *Prior period information has been adjusted to reflect the adoption impact of Accounting Standards Codification 606, Revenue from Contracts with Customers (ASC 606), which we adopted on February 1, 2018.
v3.10.0.1
Condensed Consolidated Balance Sheets (Parenthetical) - USD ($)
$ in Thousands
Jul. 31, 2018
Jan. 31, 2018
[1]
Accounts receivable, allowance $ 957 $ 1,062
Preferred stock, par value (in dollars per share) $ 0.0001 $ 0.0001
Preferred stock, shares authorized (in shares) 20,000,000 20,000,000
Preferred stock, shares issued (in shares) 0 0
Preferred stock, shares outstanding (in shares) 0 0
Common stock, par value per share (in dollars per share) $ 0.0001 $ 0.0001
Common stock, shares authorized (in shares) 2,250,000,000 2,250,000,000
Common stock, shares issued (in shares) 235,412,000 220,979,000
Common stock, shares outstanding (in shares) 235,412,000 220,979,000
Class A    
Common stock, par value per share (in dollars per share) $ 0.0001 $ 0.0001
Common stock, shares authorized (in shares) 2,000,000,000 2,000,000,000
Common stock, shares issued (in shares) 204,051,868 129,502,000
Common stock, shares outstanding (in shares) 204,051,868 129,502,000
Class B    
Common stock, par value per share (in dollars per share) $ 0.0001 $ 0.0001
Common stock, shares authorized (in shares) 250,000,000 250,000,000
Common stock, shares issued (in shares) 31,359,938 91,477,000
Common stock, shares outstanding (in shares) 31,359,938 91,477,000
[1] *Prior period information has been adjusted to reflect the adoption impact of Accounting Standards Codification 606, Revenue from Contracts with Customers (ASC 606), which we adopted on February 1, 2018.
v3.10.0.1
Condensed Consolidated Statements of Operations - USD ($)
shares in Thousands, $ in Thousands
3 Months Ended 6 Months Ended
Jul. 31, 2018
Jul. 31, 2017
[1]
Jul. 31, 2018
Jul. 31, 2017
Revenue:        
Product $ 241,137 $ 179,669 $ 436,586 $ 322,519
Support subscription 67,747 45,001 128,243 84,796
Total revenue 308,884 224,670 564,829 407,315
Cost of revenue:        
Product 78,262 57,252 144,682 103,897
Support subscription 24,457 19,199 47,667 36,102
Total cost of revenue 102,719 76,451 192,349 139,999
Gross profit 206,165 148,219 372,480 267,316
Operating expenses:        
Research and development 84,031 69,361 162,523 134,789
Sales and marketing 143,749 117,552 266,116 209,315
General and administrative 33,591 22,162 60,921 42,258
Total operating expenses 261,371 209,075 489,560 386,362
Loss from operations (55,206) (60,856) (117,080) (119,046)
Other income (expense), net (4,032) 3,266 (5,031) 5,261
Loss before provision for income taxes (59,238) (57,590) (122,111) (113,785)
Provision for income taxes 885 821 2,316 1,785
Net loss $ (60,123) $ (58,411) [2] $ (124,427) $ (115,570) [3]
Net loss per share attributable to common stockholders, basic and diluted (in dollars per share) $ (0.26) $ (0.28) $ (0.55) $ (0.56)
Weighted-average shares used in computing net loss per share attributable to common stockholders, basic and diluted (in shares) 229,359 209,193 226,609 207,515
[1] * Prior period information has been adjusted to reflect the adoption impact of ASC 606, which we adopted on February 1, 2018.
[2] * Prior period information has been adjusted to reflect the adoption impact of ASC 606, which we adopted on February 1, 2018.
[3] * Prior period information has been adjusted to reflect the adoption impact of ASC 606 and ASU 2016-18, which we adopted on February 1, 2018
v3.10.0.1
Condensed Consolidated Statements of Comprehensive Loss - USD ($)
$ in Thousands
3 Months Ended 6 Months Ended
Jul. 31, 2018
Jul. 31, 2017
[2]
Jul. 31, 2018
Jul. 31, 2017
Statement of Comprehensive Income [Abstract]        
Net loss $ (60,123) $ (58,411) [1] $ (124,427) $ (115,570) [3]
Other comprehensive income (loss):        
Change in unrealized net gain (loss) on available-for-sale securities (193) 165 (909) 282
Comprehensive loss $ (60,316) $ (58,246) $ (125,336) $ (115,288)
[1] * Prior period information has been adjusted to reflect the adoption impact of ASC 606, which we adopted on February 1, 2018.
[2] * Prior period information has been adjusted to reflect the adoption impact of ASC 606, which we adopted on February 1, 2018.
[3] * Prior period information has been adjusted to reflect the adoption impact of ASC 606 and ASU 2016-18, which we adopted on February 1, 2018
v3.10.0.1
Condensed Consolidated Statements of Cash Flows - USD ($)
$ in Thousands
6 Months Ended
Jul. 31, 2018
Jul. 31, 2017
[1]
CASH FLOWS FROM OPERATING ACTIVITIES    
Net loss $ (124,427) $ (115,570)
Adjustments to reconcile net loss to net cash provided by (used in) operating activities:    
Depreciation and amortization 33,590 30,000
Amortization of debt discount and debt issuance costs 7,889 0
Stock-based compensation expense 97,609 69,057
Other 82 797
Changes in operating assets and liabilities:    
Accounts receivable, net 707 25
Inventory (8,900) (10,487)
Deferred commissions (4,155) (9,587)
Prepaid expenses and other assets 11,134 (186)
Accounts payable (18,135) 201
Accrued compensation and other liabilities (7,458) (2,993)
Deferred revenue 39,144 24,251
Net cash provided by (used in) operating activities 27,080 (14,492)
CASH FLOWS FROM INVESTING ACTIVITIES    
Purchases of property and equipment (42,733) (30,100)
Purchases of marketable securities (494,507) (95,358)
Sales of marketable securities 13,585 33,529
Maturities of marketable securities 97,793 73,681
Net cash used in investing activities (425,862) (18,248)
CASH FLOWS FROM FINANCING ACTIVITIES    
Net proceeds from exercise of stock options 29,067 6,793
Proceeds from issuance of common stock under employee stock purchase plan 19,698 14,166
Proceeds from issuance of convertible senior notes, net of issuance costs 562,062 0
Payment for purchase of capped calls (64,630) 0
Repurchase of common stock (20,000) 0
Net cash provided by financing activities 526,197 20,959
Net increase (decrease) in cash, cash equivalents and restricted cash 127,415 (11,781)
Cash, cash equivalents and restricted cash, beginning of period 258,820 196,409
Cash, cash equivalents and restricted cash, end of period 386,235 184,628
CASH, CASH EQUIVALENTS AND RESTRICTED CASH AT END OF PERIOD:    
Cash and cash equivalents 370,457 171,894
Restricted cash 15,778 12,734
Cash, cash equivalents and restricted cash, end of period 386,235 184,628
SUPPLEMENTAL DISCLOSURES OF CASH FLOW INFORMATION    
Cash paid for income taxes 3,023 1,661
SUPPLEMENTAL DISCLOSURES OF NON-CASH INVESTING AND FINANCING INFORMATION    
Property and equipment purchased but not yet paid 11,949 6,578
Vesting of early exercised stock options $ 320 $ 546
[1] * Prior period information has been adjusted to reflect the adoption impact of ASC 606 and ASU 2016-18, which we adopted on February 1, 2018
v3.10.0.1
Business Overview
6 Months Ended
Jul. 31, 2018
Organization, Consolidation and Presentation of Financial Statements [Abstract]  
Business Overview
Business Overview
Organization and Description of Business
Pure Storage, Inc. (the Company, we, us, or other similar pronouns) was originally incorporated in the state of Delaware in October 2009 under the name OS76, Inc. In January 2010, we changed our name to Pure Storage, Inc. We are headquartered in Mountain View, California and have wholly owned subsidiaries throughout the world.
We empower innovators to build a better world with data. Our data platform replaces storage systems designed for mechanical disk with all-flash systems optimized end-to-end for solid-state memory. Our Pure1 cloud-based support and management platform simplifies storage administration, while real-time scanning enables us to find and fix issues before they have an impact. Our business model replaces the traditional forklift upgrade cycle with Evergreen Storage subscriptions to hardware and software innovation, support and maintenance.
v3.10.0.1
Basis of Presentation and Summary of Significant Accounting Policies
6 Months Ended
Jul. 31, 2018
Accounting Policies [Abstract]  
Basis of Presentation and Summary of Significant Accounting Policies
Basis of Presentation and Summary of Significant Accounting Policies
Principles of Consolidation
The condensed consolidated financial statements include the accounts of the Company and our wholly owned subsidiaries. All intercompany balances and transactions have been eliminated in consolidation.
Unaudited Interim Consolidated Financial Information
The accompanying unaudited condensed consolidated financial statements have been prepared in accordance with generally accepted accounting principles in the United States (U.S. GAAP) and applicable rules and regulations of the Securities and Exchange Commission (the SEC) regarding interim financial reporting. Certain information and note disclosures normally included in the financial statements prepared in accordance with U.S. GAAP have been condensed or omitted pursuant to such rules and regulations. Therefore, these condensed consolidated financial statements should be read in conjunction with the consolidated financial statements and notes included in our Annual Report on Form 10-K for the year ended January 31, 2018.
In the opinion of management, the accompanying unaudited condensed consolidated financial statements reflect all normal recurring adjustments necessary to present fairly the financial position, results of operations, comprehensive loss and cash flows for the interim periods, but are not necessarily indicative of the results of operations to be anticipated for the full fiscal year 2019 or any future period. Certain prior period amounts have been adjusted as a result of adoption of new accounting pronouncements. Refer to "Recently Adopted Accounting Pronouncements" below for further information.
Use of Estimates
The preparation of financial statements in conformity with U.S. GAAP requires management to make estimates and assumptions that affect the amounts reported and disclosed in the financial statements and accompanying notes. Actual results could differ from these estimates. Such estimates include, but are not limited to, the determination of standalone selling price for revenue arrangements with multiple performance obligations, useful lives of intangible assets, property and equipment and deferred sales commissions, stock-based compensation, provision for income taxes including related reserves, and contingent liabilities. Management bases its estimates on historical experience and on various other assumptions which management believes to be reasonable, the results of which form the basis for making judgments about the carrying values of assets and liabilities.
Restricted Cash
Restricted cash is comprised of cash collateral related to our leases and for a vendor corporate credit card program. As of January 31, 2018 and July 31, 2018, we had restricted cash of $14.8 million and $15.8 million on the condensed consolidated balance sheets.
Marketable Securities
We classify our marketable securities as available-for-sale at the time of purchase and reevaluate such classification at each balance sheet date. We may sell these securities at any time for use in current operations even if they have not yet reached maturity. As a result, we classify our securities, including those with maturities beyond twelve months, as current assets in the accompanying condensed consolidated balance sheets. We carry these securities at fair value and record unrealized gains and losses, in accumulated other comprehensive loss, which is reflected as a component of stockholders’ equity. We evaluate our securities to assess whether those with unrealized loss positions are other than temporarily impaired. We consider impairments to be other than temporary if they are related to deterioration in credit risk or if it is likely we will sell the securities before the recovery of their cost basis. Realized gains and losses from the sale of marketable securities and declines in value deemed to be other than temporary are determined on the specific identification method. To date, there have been no declines in value deemed to be other than temporary in any of our securities. Realized gains and losses are reported in other income (expense), net in the condensed consolidated statements of operations.
Deferred Commissions
Deferred commissions consist of incremental costs paid to our sales force to obtain customer contracts. Deferred commissions related to product revenues are recognized upon transfer of control to customers and deferred commissions related to support subscription revenue are amortized over an expected useful life of six years. We determine the expected useful life based on an estimated benefit period by evaluating our technology development life cycle, expected customer relationship period, and other factors. We classify deferred commissions as current and non-current on our condensed consolidated balance sheets based on the timing of when we expect to recognize the expense. Amortization of deferred commissions is included in sales and marketing expense in the condensed consolidated statements of operations.
Changes in total deferred commissions during the periods presented are as follows (in thousands):
 
Three Months Ended July 31, 2018
 
Six Months Ended July 31, 2018
 
 
 
 
Beginning balance (1)
$
86,044

 
$
87,313

Additions
24,582

 
40,003

Recognition of deferred commissions
(19,157
)
 
(35,847
)
Ending balance as of July 31, 2018
$
91,469

 
$
91,469


____________________ 
(1) Balance as of January 31, 2018 was adjusted to reflect the adoption of ASC 606.

Of the $91.5 million total deferred commissions balance as of July 31, 2018, we expect to recognize approximately 26% as commission expense over the next 12 months and the remainder thereafter.
There was no impairment loss in relation to capitalized commissions for the three and six months ended July 31, 2017 and 2018.
Deferred Revenue
Deferred revenue primarily consists of amounts that have been invoiced but that have not yet been recognized as revenue and performance obligations pertaining to support subscription services. The current portion of deferred revenue represents the amounts that are expected to be recognized as revenue within one year of the condensed consolidated balance sheet dates.
Changes in total deferred revenue during the periods presented are as follows (in thousands):
 
Three Months Ended July 31, 2018
 
Six Months Ended July 31, 2018
Beginning balance (1)
$
388,614

 
$
374,102

Additions
92,511

 
167,782

Recognition of deferred revenue
(67,878
)
 
(128,637
)
Ending balance as of July 31, 2018
$
413,247

 
$
413,247

____________________ 
(1) Balance as of January 31, 2018 was adjusted to reflect the adoption of ASC 606.

During the three and six months ended July 31, 2017, we recognized $44.1 million and $75.1 million in revenue pertaining to deferred revenue as of the beginning of each period. During the three and six months ended July 31, 2018, we recognized $60.9 million and $106.2 million in revenue pertaining to deferred revenue as of the beginning of each period.
Of the $413.2 million remaining performance obligations as of July 31, 2018, we expect to recognize approximately 52% as revenue over the next 12 months and the remainder thereafter.
Substantially all of our contracted but not invoiced performance obligations are subject to cancellation and, therefore, are not considered in our remaining performance obligations.
Revenue Recognition
We derive revenue from two sources: (1) product revenue which includes hardware and embedded software and (2) support subscription revenue which includes customer support, hardware maintenance, and software upgrades on a when-and-if-available basis.
Our product revenue is derived from the sale of storage hardware and operating system software that is integrated into the hardware. We typically recognize product revenue upon transfer of control to our customers. Products are typically shipped directly by us to customers, and our channel partners do not stock our inventory.
Our support subscription revenue is derived from the sale of support subscription, which includes the right to receive unspecified software upgrades and enhancements on a when-and-if-available basis, bug fixes, parts replacement services related to the hardware, as well as access to our cloud-based management and support platform. Revenue related to support subscription is recognized ratably over the contractual term, which generally ranges from one to six years and represents our performance obligations period. The vast majority of our products are sold with support subscription agreements, which typically commence upon transfer of control of the corresponding products to our customers. Costs to service the support subscription are expensed as incurred. In addition, our Evergreen Storage program provides our customers who continually maintain active support subscription agreements for three years with an included controller refresh with each additional three year support subscription renewal. In accordance with revenue recognition guidance, the controller refresh represents an additional performance obligation and the allocated revenue is recognized in the period in which these controllers are shipped.
We recognize revenue upon the transfer of promised goods or services to customers in an amount that reflects the consideration we expect to be entitled in exchange for those goods or services. This is achieved through applying the following five-step approach:
Identification of the contract, or contracts, with a customer
Identification of the performance obligations in the contract
Determination of the transaction price
Allocation of the transaction price to the performance obligations in the contract
Recognition of revenue when, or as, we satisfy a performance obligation
When applying this five-step approach, we apply judgment in determining the customer's ability and intention to pay, which is based on a variety of factors including the customer's historical payment experience and/or published credit and financial information pertaining to the customer. To the extent a customer contract includes multiple promised goods or services, we determine whether promised goods or services are capable of being distinct in the context of the contract to be accounted for as a combined performance obligation. We allocate transaction price to each performance obligation for contracts that contain multiple performance obligations based on a relative standalone selling price, taking into account available information such as market conditions and internally approved pricing guidelines related to performance obligations.
Recently Adopted Accounting Pronouncements
In May 2014, the Financial Accounting Standards Board (FASB), issued Accounting Standards Update (ASU) No. 2014-09, Revenue from Contracts with Customers (ASU 2014-09 or ASC 606), requiring an entity to recognize revenue when it transfers promised goods or services to customers in an amount that reflects the consideration to which the entity expects to be entitled to in exchange for those goods or services. ASC 606 supersedes nearly all existing revenue recognition guidance under U.S. GAAP upon its effective date. The standard permits two methods of adoptions: retrospectively to each prior reporting period presented (full retrospective method), or retrospectively with the cumulative effect of applying the standard recognized at the date of application (cumulative catch-up transition method).
We adopted the standard using the full retrospective method beginning February 1, 2018, for the year ending January 31, 2019, and our historical financial information for the years ended January 31, 2017 and 2018 has been adjusted to conform to the new standard.
The most significant impact of the standard related to the removal of limitation on contingent revenue, resulting in an increase in product revenue and a decrease in support subscription revenue. In addition, the adoption of ASC 606 also resulted in differences in the timing of recognition of sales commissions. While the adoption of the standard changes certain line items within the net cash flow from operating activities, it had no impact to the net cash provided by or used in operating, investing, or financing activities on our condensed consolidated statements of cash flows.
The following line items on our condensed consolidated balance sheet as of January 31, 2018 have been adjusted to reflect the adoption of ASC 606 (in thousands):
 
As of January 31, 2018
 
As Previously Reported
 
Adjustment
 
As Adjusted
Assets
 
 
 
 
 
Deferred commissions, current
$
22,437

 
$
(1,349
)
 
$
21,088

Deferred commissions, non-current
20,288

 
45,937

 
66,225

Total deferred commissions
$
42,725

 
$
44,588

 
$
87,313

Liabilities
 
 
 
 
 
Deferred revenue, current
$
209,377

 
$
(18,148
)
 
$
191,229

Deferred revenue, non-current
196,632

 
(13,759
)
 
182,873

Total deferred revenue
$
406,009

 
$
(31,907
)
 
$
374,102

Stockholders' equity
 
 
 
 
 
Accumulated deficit
$
(980,082
)
 
$
76,495

 
$
(903,587
)

The following line items on our unaudited condensed consolidated statement of operations for the three and six months ended July 31, 2017 have been adjusted to reflect the adoption of ASC 606 (in thousands, except per share data):
 
Three Months Ended July 31, 2017
 
Six Months Ended July 31, 2017
 
As Previously Reported
 
Adjustment
 
As Adjusted
 
As Previously Reported
 
Adjustment
 
As Adjusted
Revenue:
 
 
 
 
 
 
 
 
 
 
 
Product
$
175,013

 
$
4,656

 
$
179,669

 
$
313,438

 
$
9,081

 
$
322,519

Support subscription
49,448

 
(4,447
)
 
45,001

 
93,654

 
(8,858
)
 
84,796

Total revenue
$
224,461

 
$
209

 
$
224,670

 
$
407,092

 
$
223

 
$
407,315

 
 
 
 
 
 
 
 
 
 
 
 
Gross profit
$
148,010

 
$
209

 
$
148,219

 
$
267,093

 
$
223

 
$
267,316

Sales and marketing
$
120,633

 
$
(3,081
)
 
$
117,552

 
$
217,597

 
$
(8,282
)
 
$
209,315

Total operating expenses
$
212,156

 
$
(3,081
)
 
$
209,075

 
$
394,644

 
$
(8,282
)
 
$
386,362

Loss from operations
$
(64,146
)
 
$
3,290

 
$
(60,856
)
 
$
(127,551
)
 
$
8,505

 
$
(119,046
)
Loss before provision for income taxes
$
(60,880
)
 
$
3,290

 
$
(57,590
)
 
$
(122,290
)
 
$
8,505

 
$
(113,785
)
Net loss
$
(61,701
)
 
$
3,290

 
$
(58,411
)
 
$
(124,075
)
 
$
8,505

 
$
(115,570
)
Net loss per share attributable to common stockholders, basic and diluted
$
(0.29
)
 
$
0.01

 
$
(0.28
)
 
$
(0.60
)
 
$
0.04

 
$
(0.56
)

Unaudited revenue by geographic location based on bill-to location, which reflects the adoption impact of ASC 606, are as follows (in thousands):
 
Three Months Ended July 31, 2017
 
Six Months Ended July 31, 2017
 
As Previously Reported
 
Adjustment
 
As Adjusted
 
As Previously Reported
 
Adjustment
 
As Adjusted
Revenue:
 
 
 
 
 
 
 
 
 
 
 
United States
$
165,466

 
$
154

 
$
165,620

 
$
311,960

 
$
165

 
$
312,125

Rest of the world
58,995

 
55

 
59,050

 
95,132

 
58

 
95,190

Total revenue
$
224,461

 
$
209

 
$
224,670

 
$
407,092

 
$
223

 
$
407,315



In November 2016, the FASB issued ASU No. 2016-18, Statement of Cash Flows (Topic 230): Restricted Cash (ASU 2016-18), which requires that a statement of cash flows explain the change during the period in the total of cash, cash equivalents, and restricted cash. We adopted ASU 2016-18 effective February 1, 2018 on a retrospective basis. Upon adoption, restricted cash is included with cash and cash equivalents when reconciling the beginning-of-period and end-of-period total amounts shown on the statement of cash flows. The adoption of this standard increased our previously reported net cash flow from investing activities for the periods in which there were changes in restricted cash but did not impact our net cash flow from operating activities or financing activities presented on our consolidated statements of cash flows.
The following line items in our unaudited condensed consolidated statement of cash flows for the six months ended July 31, 2017 have been adjusted to reflect the adoption of ASU 2016-18 and ASC 606 (in thousands):
 
Six Months Ended July 31, 2017
 
As Previously Reported
 
Adjustment
 
As Adjusted
Net loss (1)
$
(124,075
)
 
$
8,505

 
$
(115,570
)
Adjustments to reconcile net loss to net cash provided by (used in) operating activities:
 
 
 
 
 
Deferred commissions (1)
$
(4,607
)
 
$
(4,980
)
 
$
(9,587
)
Accrued compensation and other liabilities (1)
$
310

 
$
(3,303
)
 
$
(2,993
)
Deferred revenue (1)
$
24,473

 
$
(222
)
 
$
24,251

Cash used in operating activities
$
(14,492
)
 
$

 
$
(14,492
)
Cash, cash equivalents and restricted cash, beginning of period (2)
$
183,675

 
$
12,734

 
$
196,409

Cash, cash equivalents and restricted cash, end of period (2)
$
171,894

 
$
12,734

 
$
184,628

_____________________________________________________
(1) Adjustment pertaining to the adoption of ASC 606.
(2) Adjustment pertaining to the adoption of ASU 2016-18.
In June 2018, the FASB issued ASU No. 2018-07, Compensation - Stock Compensation (Topic 718) (ASU 2018-07). ASU 2018-07 aligns the accounting for share-based awards to employees and non-employees to follow the same model. The new standard is effective for fiscal years beginning after December 15, 2018 using a modified retrospective transition approach. Early adoption is permitted. We adopted this standard for the three and six months ended July 31, 2018 and the adoption of this standard did not materially impact our consolidated financial statements.
Recent Accounting Pronouncements Not Yet Adopted
In February 2016, the FASB issued ASU No. 2016-02, Leases (Topic 842) (ASU 2016-02). ASU 2016-02 requires lessees to recognize all leases with terms in excess of one year on their balance sheet as a right-of-use asset and a lease liability at the commencement date. The new standard also simplifies the accounting for sale and leaseback transactions. ASU 2016-02 requires the use of the modified retrospective method for leases existing at, or entered into after, the beginning of the earliest comparative period presented in the financial statements. In July 2018, the FASB issued ASU No. 2018-10, Leases (Topic 842), Codification Improvements to Topic 842, Leases (ASU 2018-10) and ASU No. 2018-11, Leases (Topic 842), Targeted Improvements (ASU 2018-11). ASU 2018-11 provides a new transition method in which an entity can initially apply the new lease standards at the adoption date and recognize a cumulative-effect adjustment to the opening balance of retained earnings in the period of adoption. These standards will be effective for us beginning on February 1, 2019 and early adoption is permitted. We expect to apply the new transition method prescribed by ASU 2018-11 at the adoption date. We are currently evaluating the impact of these standards on our consolidated financial statements.
In June 2016, the FASB issued ASU No. 2016-13, Financial Instruments-Credit Losses (Topic 326): Measurement of Credit Losses on Financial Instruments (ASU 2016-13). ASU 2016-13 amends guidance on reporting credit losses for assets held at amortized cost basis and available-for-sale debt securities to require that credit losses on available-for-sale debt securities be presented as an allowance rather than as a write-down. The measurement of credit losses for newly recognized financial assets and subsequent changes in the allowance for credit losses are recorded in the statements of operations. The amendments in this update will be effective for us beginning on February 1, 2020 with early adoption permitted on or after February 1, 2019. We are currently evaluating the impact of this standard on our consolidated financial statements.
In February 2018, the FASB issued ASU No. 2018-02, Income Statement - Reporting Comprehensive Income (Topic 220) - Reclassification of Certain Tax Effects from Accumulated Other Comprehensive Income. This standard allows a reclassification from accumulated other comprehensive income to retained earnings for stranded tax effects resulting from the Tax Cuts and Jobs Act of 2017 (the Tax Act) and requires certain disclosures about stranded tax effects. This standard will be effective for us beginning February 1, 2019 and should be applied either in the period of adoption or retrospectively. Early adoption is permitted. We do not expect this standard to have any impact on our consolidated financial statements.
v3.10.0.1
Financial Instruments
6 Months Ended
Jul. 31, 2018
Investments, Debt and Equity Securities [Abstract]  
Financial Instruments
Financial Instruments  
Fair Value Measurements
We measure our cash equivalents, marketable securities, and restricted cash at fair value on a recurring basis. We define fair value as the exchange price that would be received from sale of an asset or paid to transfer a liability in the principal or most advantageous market for the asset or liability in an orderly transaction between market participants on the measurement date. We measure our financial assets and liabilities at fair value at each reporting period using a fair value hierarchy which requires us to maximize the use of observable inputs and minimize 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 fair value:

Level 1 - Observable inputs are unadjusted quoted prices in active markets for identical assets or liabilities;

Level 2 - Observable inputs are quoted prices for similar assets and liabilities in active markets or inputs other than quoted prices that are observable for the assets or liabilities, either directly or indirectly through market corroboration, for substantially the full term of the financial instruments; and

Level 3 - Unobservable inputs that are supported by little or no market activity and that are significant to the fair value of the assets or liabilities. These inputs are based on our own assumptions used to measure assets and liabilities at fair value and require significant management judgment or estimation.
We classify our cash equivalents, marketable securities and restricted cash within Level 1 or Level 2 because they are valued using either quoted market prices or inputs other than quoted prices which are directly or indirectly observable in the market, including readily-available pricing sources for the identical underlying security which may not be actively traded. Our fixed income available-for-sale securities consist of high quality, investment grade securities from diverse issuers. The valuation techniques used to measure the fair value of our marketable securities were derived from non-binding market consensus prices that are corroborated by observable market data or quoted market prices for similar instruments.
In addition to our cash equivalents, marketable securities, and restricted cash, we measure the fair value of our convertible senior notes (the Notes) on a quarterly basis for disclosure purposes. We consider the fair value of the Notes at July 31, 2018 to be a Level 2 measurement due to limited trading activity of the Notes. Refer to Note 5 for further information.
Cash Equivalents, Marketable Securities and Restricted Cash
The following tables summarize our cash equivalents, marketable securities and restricted cash by significant investment categories as of January 31, 2018 and July 31, 2018 (in thousands):
 
 
As of January 31, 2018
 
Amortized
Cost
 
Gross Unrealized
Gains
 
Gross Unrealized
Losses
 
Fair
Value
 
Cash Equivalents
 
Marketable Securities
 
Restricted Cash
Level 1
 

 
 

 
 

 
 

 
 

 
 
 
 

Money market accounts
$

 
$

 
$

 
$
32,057

 
$
17,294

 
$

 
$
14,763

Level 2
 
 
 
 
 
 
 
 
 
 
 
 
 
U.S. government treasury notes
131,643

 

 
(651
)
 
130,992

 
10,172

 
120,820

 

U.S. government agencies
47,229

 

 
(333
)
 
46,896

 

 
46,896

 

Corporate debt securities
186,506

 
116

 
(1,049
)
 
185,573

 

 
185,573

 

Total
$
365,378

 
$
116

 
$
(2,033
)
 
$
395,518

 
$
27,466

 
$
353,289

 
$
14,763


 
As of July 31, 2018
 
Amortized
Cost
 
Gross Unrealized
Gains
 
Gross Unrealized
Losses
 
Fair
Value
 
Cash Equivalents
 
Marketable
Securities
 
Restricted Cash
Level 1
 
 
 
 
 
 
 
 
 
 
 
 
 
Money market accounts
$

 
$

 
$

 
$
29,047

 
$
13,269

 
$

 
$
15,778

Level 2
 
 
 
 
 
 
 
 
 
 
 
 
 
U.S. government treasury notes
326,328

 

 
(839
)
 
325,489

 
58,320

 
267,169

 

U.S. government agencies
76,443

 

 
(374
)
 
76,069

 
1,194

 
74,875

 

Corporate debt securities
383,340

 
104

 
(1,713
)
 
381,731

 

 
381,731

 

Foreign government bonds
5,151

 
1

 
(3
)
 
5,149

 

 
5,149

 

Asset-backed securities
7,283

 

 
(2
)
 
7,281

 

 
7,281

 

Total
$
798,545

 
$
105

 
$
(2,931
)
 
$
824,766

 
$
72,783

 
$
736,205

 
$
15,778


 
The amortized cost and estimated fair value of our marketable securities are shown below by contractual maturity (in thousands):
 
 
As of July 31, 2018
 
Amortized Cost
 
Fair Value
Due within one year
$
373,160

 
$
372,316

Due in one to five years
365,867

 
363,889

Total
$
739,027

 
$
736,205


 
The gross unrealized losses on our marketable securities as of July 31, 2018 were temporary in nature. The following table presents gross unrealized losses and fair values for those investments that were in a continuous unrealized loss as of July 31, 2018, aggregated by investment category (in thousands):
 
 
Less than 12 months
 
Greater than 12 months
 
Total
 
Fair
Value
 
Unrealized
Loss
 
Fair
Value
 
Unrealized
Loss
 
Fair
Value
 
Unrealized
Loss
U.S. government treasury notes
$
271,578

 
$
(483
)
 
$
48,941

 
$
(356
)
 
$
320,519

 
$
(839
)
U.S. government agencies
55,695

 
(227
)
 
20,374

 
(147
)
 
76,069

 
(374
)
Corporate debt securities
271,946

 
(1,454
)
 
30,654

 
(259
)
 
302,600

 
(1,713
)
Foreign government bonds
2,944

 
(3
)
 

 

 
2,944

 
(3
)
Asset-backed securities
5,016

 
(2
)
 

 

 
5,016

 
(2
)
Total
$
607,179

 
$
(2,169
)
 
$
99,969

 
$
(762
)
 
$
707,148

 
$
(2,931
)

 
Realized gains or losses on sale of marketable securities were not significant for all periods presented.
v3.10.0.1
Balance Sheet Components
6 Months Ended
Jul. 31, 2018
Balance Sheet Components Disclosure [Abstract]  
Balance Sheet Components
Balance Sheet Components
Inventory
Inventory consists of the following (in thousands):
 
As of
January 31, 2018
 
As of
July 31, 2018
Raw materials
$
1,181

 
$
2,828

Finished goods
33,316

 
38,845

Inventory
$
34,497

 
$
41,673


Property and Equipment, Net
Property and equipment, net, consists of the following (in thousands):
 
 
As of
January 31, 2018
 
As of
July 31, 2018
Test equipment
$
142,311

 
$
156,040

Computer equipment and software
72,329

 
92,863

Furniture and fixtures
5,363

 
5,482

Leasehold improvements
15,032

 
23,763

Total property and equipment
235,035

 
278,148

Less: accumulated depreciation and amortization
(145,893
)
 
(176,430
)
Property and equipment, net
$
89,142

 
$
101,718


 
Depreciation and amortization expense was $14.8 million and $16.8 million for the three months ended July 31, 2017 and 2018, and $29.2 million and $32.8 million for the six months ended July 31, 2017 and 2018.
Intangible Assets, Net
Intangible assets, net, consist of the following (in thousands):
 
 
As of
January 31, 2018
 
As of
July 31, 2018
Technology patents
$
10,125

 
$
10,125

Accumulated amortization
(5,068
)
 
(5,820
)
Intangible assets, net
$
5,057

 
$
4,305


 
Intangible assets amortization expense was $0.4 million for the three months ended July 31, 2017 and 2018, and $0.8 million for the six months ended July 31, 2017 and 2018. The weighted-average remaining useful life of technology patents is 2.9 years. Due to the defensive nature of these patents, the amortization expense is included in general and administrative expenses in the condensed consolidated statements of operations.
As of July 31, 2018, future expected amortization expense for intangible assets is as follows (in thousands):
 
Fiscal Years Ending January 31,
Estimated 
Future
Amortization
Expense
Remainder of 2019
$
752

2020
1,504

2021
1,504

2022
545

Total
$
4,305


Accrued Expenses and Other Liabilities
Accrued expenses and other liabilities consist of the following (in thousands):
 
 
As of
January 31, 2018
 
As of
July 31, 2018
Taxes payable
$
4,052

 
$
3,801

Accrued marketing
5,928

 
5,017

Accrued travel and entertainment expenses
4,386

 
2,556

Other accrued liabilities
12,463

 
15,675

Total accrued expenses and other liabilities
$
26,829

 
$
27,049

v3.10.0.1
Convertible Senior Notes
6 Months Ended
Jul. 31, 2018
Debt Disclosure [Abstract]  
Convertible Senior Notes
Convertible Senior Notes

In April 2018, we issued $575.0 million in principal amount of 0.125% convertible senior notes due 2023, in a private placement to qualified institutional buyers pursuant to Rule 144A under the Securities Act and received proceeds of $562.1 million, after deducting the underwriters’ discounts and commissions. The Notes are governed by an indenture (the Indenture) between us, as the issuer, and U.S. Bank National Association, as trustee. The Notes are our senior unsecured obligations. The Indenture does not contain any financial covenants or restrictions on the payments of dividends, the incurrence of indebtedness, or the issuance or repurchase of securities by us or any of our subsidiaries. The Notes mature on April 15, 2023 unless repurchased or redeemed by us or converted in accordance with their terms prior to the maturity date. Interest is payable semi-annually in arrears on April 15 and October 15 of each year, beginning on October 15, 2018.

The Notes are convertible for up to 21,884,155 shares of our common stock at an initial conversion rate of approximately 38.0594 shares of Class A common stock per $1,000 principal amount, which is equal to an initial conversion price of approximately $26.27 per share of Class A common stock, subject to adjustment. Holders of the Notes may surrender their Notes for conversion at their option at any time prior to the close of business on the business day immediately preceding October 15, 2022, only under the following circumstances:

during any fiscal quarter commencing after the fiscal quarter ending on July 31, 2018 (and only during such fiscal quarter), if the last reported sale price of our Class A common stock for at least 20 trading days (whether or not consecutive) during a period of 30 consecutive trading days ending on, and including, the last trading day of the immediately preceding fiscal quarter is greater than or equal to 130% of the conversion price for the Notes on each applicable trading day;

during the five business day period after any five consecutive trading day period (the measurement period), in which the trading price per $1,000 principal amount of Notes for each trading day of the measurement period was less than 98% of the product of the last reported sale price of our Class A common stock and the conversion rate for the Notes on each such trading day;

if we call any or all of the Notes for redemption, at any time prior to the close of business on the second scheduled trading day immediately preceding the redemption date; or

upon the occurrence of specified corporate events.

On or after October 15, 2022 until the close of business on the second scheduled trading day immediately preceding the maturity date, holders may convert all or any portion of their Notes at any time regardless of the foregoing circumstances. Upon conversion, holders will receive cash, shares of our Class A common stock, or a combination of cash and shares of our Class A common stock, at our election. We intend to settle the principal of the Notes in cash.

The conversion price will be subject to adjustment in some events. Following certain corporate events that occur prior to the maturity date or following our issuance of a notice of redemption, we will increase the conversion rate for a holder who elects to convert its Notes in connection with such corporate event or during the related redemption period in certain circumstances. Additionally, upon the occurrence of a corporate event that constitutes a “fundamental change” per the Indenture, holders of the Notes may require us to repurchase for cash all or a portion of the Notes at a purchase price equal to 100% of the principal amount of the Notes plus accrued and unpaid contingent interest.

We may not redeem the Notes prior to April 20, 2021. We may redeem for cash all or any portion of the Notes, at our option, on or after April 20, 2021 if the last reported sale price of our Class A common stock has been at least 130% of the conversion price then in effect for at least 20 trading days (whether or not consecutive) during any 30 consecutive trading day period (including the last trading day of such period) ending not more than two trading days immediately preceding the date on which we provide notice of redemption at a redemption price equal to 100% of the principal amount of the Notes to be redeemed, plus accrued and unpaid interest to, but excluding, the redemption date. No sinking fund is provided for the Notes.

In accounting for the issuance of the Notes, we separated the Notes into liability and equity components. The carrying amount of the liability component was determined by measuring the fair value of a similar liability that does not have an associated convertible feature. The carrying amount of the equity component representing the conversion option was calculated by deducting the fair value of the liability component from the principal amount of the Notes as a whole. The difference between the principal amount of the Notes and the liability component (the debt discount) is amortized to interest expense in the condensed consolidated statements of operations using the effective interest method over the term of the Notes. The equity component of the Notes is included in additional paid-in capital in the condensed consolidated balance sheets and is not remeasured as long as it continues to meet the conditions for equity classification.

In accounting for the transaction costs related to the issuance of the Notes, we allocated the total amount incurred to the liability and equity components using the same proportions as the initial carrying value of the Notes. Transaction costs attributable to the liability component were netted with the principal amount of the Notes in the condensed consolidated balance sheets and are being amortized to interest expense in the condensed consolidated statements of operations using the effective interest method over the term of the Notes. Transaction costs attributable to the equity component were netted with the equity component of the Notes in additional paid-in capital in the condensed consolidated balance sheets. Upon the issuance of the Notes, we recorded total debt issuance costs of $12.9 million, of which approximately $9.8 million was allocated to the Notes and approximately $3.1 million was allocated to additional paid-in capital.

The Notes consisted of the following (in thousands):
 
As of
July 31, 2018
Liability:
 
Principal
$
575,000

Less: debt discount, net of amortization
(128,976
)
Less: debt issuance costs, net of amortization
(9,337
)
Net carrying amount of the Notes
$
436,687

 
 
Stockholders' equity:
 
Allocated value of the conversion feature
$
136,333

Less: debt issuance costs
(3,068
)
Additional paid-in capital
$
133,265



The total estimated fair value of the Notes as of July 31, 2018 was approximately $607.2 million. The fair value was determined based on the closing trading price per $100 of the Notes as of the last day of trading for the period. The fair value of the Notes is primarily affected by the trading price of our common stock and market interest rates. Based on the closing price of our Class A common stock of $21.66 on July 31, 2018, the if-converted value of the Notes of $474.0 million was less than its principal amount.     

The following table sets forth total interest expense recognized related to the Notes for the three and six months ended July 31, 2018 (in thousands):
 
Three Months Ended July 31, 2018
 
Six Months Ended July 31, 2018
Amortization of debt discount
$
6,000

 
$
7,357

Amortization of debt issuance costs
434

 
532

Total amortization of debt discount and debt issuance costs
6,434

 
7,889

Contractual interest expense
181

 
224

Total interest expense related to the Notes
$
6,615

 
$
8,113

 
 
 
 
Effective interest rate of the liability component
5.6
%
 
5.6
%


In connection with the offering of the Notes, we paid $64.6 million to enter into capped call transactions with certain of the underwriters and their affiliates (the Capped Calls), whereby we have the option to purchase a total of 21,884,155 shares of our Class A common stock upon any conversion of Notes and/or offset any cash payments we are required to make in excess of the principal amount of the Notes, as the case may be, with such reduction or offset subject to a cap initially equal to $39.66 per share (which represents a premium of 100% over the last reported sales price of our Class A common stock on April 4, 2018), subject to certain adjustments (the Cap Price). The cost of the Capped Calls was accounted for as a reduction to additional paid-in capital on the condensed consolidated balance sheet. The Capped Calls are intended to reduce or offset potential dilution of our common stock upon any conversion of the Notes, subject to a cap based on the Cap Price.

Impact on Earnings Per Share
The Notes will not impact our diluted earnings per share until the average market price of our Class A common stock exceeds the conversion price of $26.27 per share, as we intend to settle the principal amount of the Notes in cash upon conversion. We are required under the treasury stock method to compute the potentially dilutive shares of common stock related to the Notes for periods we report net income. However, upon conversion, there will be no economic dilution from the Notes until the average market price of our Class A common stock exceeds the Cap Price of $39.66 per share, as exercise of the Capped Calls offsets any dilution from the Notes from the conversion price up to the Cap Price. Capped Calls are excluded from the calculation of diluted earnings per share, as they would be anti-dilutive under the treasury stock method.
v3.10.0.1
Commitments and Contingencies
6 Months Ended
Jul. 31, 2018
Commitments and Contingencies Disclosure [Abstract]  
Commitments and Contingencies
Commitments and Contingencies

Operating Leases
 
As of January 31, 2018 and July 31, 2018, the aggregate future minimum payments under non-cancelable operating leases were approximately $113.0 million and $153.7 million.
Letters of Credit
In connection with the lease amendment executed in March 2018, we issued a letter of credit of $1.5 million. As of January 31, 2018 and July 31, 2018, we had outstanding letters of credit in the aggregate amount of $9.6 million and $10.8 million, in connection with our facility leases. The letters of credit are collateralized by restricted cash and mature on various dates through August 2029.
Legal Matters
From time to time, we have become involved in claims and other legal matters arising in the normal course of business. We investigate these claims as they arise. Although claims are inherently unpredictable, we currently are not aware of any matters that we expect to have a material adverse effect on our business, financial position, results of operations or cash flows. Accordingly, we have not recorded any loss contingency on our condensed consolidated balance sheet as of July 31, 2018.
Indemnification
Our arrangements generally include certain provisions for indemnifying customers against liabilities if our products or services infringe a third party’s intellectual property rights. Other guarantees or indemnification arrangements include guarantees of product and service performance and standby letters of credit for lease facilities. It is not possible to determine the maximum potential amount under these indemnification obligations due to the limited history of prior indemnification claims and the unique facts and circumstances involved in each particular agreement. To date, we have not incurred any material costs as a result of such obligations and have not accrued any liabilities related to such obligations in the condensed consolidated financial statements. In addition, we indemnify our officers, directors and certain key employees while they are serving in good faith in their respective capacities. To date, there have been no claims under any indemnification provisions.
v3.10.0.1
Stockholders' Equity
6 Months Ended
Jul. 31, 2018
Equity [Abstract]  
Stockholders' Equity
Stockholders’ Equity
Preferred Stock
We have 20,000,000 authorized shares of undesignated preferred stock, the rights, preferences and privileges of which may be designated from time to time by our board of directors. As of July 31, 2018, there were no shares of preferred stock issued or outstanding.
Class A and Class B Common Stock
We have two classes of authorized common stock, Class A common stock and Class B common stock. As of July 31, 2018, we had 2,000,000,000 shares of Class A common stock authorized with a par value of $0.0001 per share and 250,000,000 shares of Class B common stock authorized with a par value of $0.0001 per share. As of July 31, 2018204,051,868 shares of Class A common stock were issued and outstanding and 31,359,938 shares of Class B common stock were issued and outstanding.
Repurchase of Common Stock
Concurrent with the issuance of the Notes (see Note 5), we repurchased and retired 1,008,573 shares, or $20.0 million, of our Class A common stock at $19.83 per share, which was equal to the closing price per share of our Class A common stock on April 4, 2018, the date of the pricing of the offering of the Notes. The repurchased shares were recorded as a reduction of additional paid-in capital on the condensed consolidated balance sheet.
v3.10.0.1
Equity Incentive Plans
6 Months Ended
Jul. 31, 2018
Disclosure of Compensation Related Costs, Share-based Payments [Abstract]  
Equity Incentive Plans
Equity Incentive Plans
Equity Incentive Plans
We maintain two equity incentive plans: the 2009 Equity Incentive Plan (the 2009 Plan) and the 2015 Equity Incentive Plan (the 2015 Plan). In August 2015, our board of directors adopted, and in September 2015 our stockholders approved, the 2015 Plan, which became effective in connection with our initial public offering (IPO) and serves as the successor to the 2009 Plan. The 2015 Plan provides for grants of incentive stock options, non-statutory stock options, stock appreciation rights, restricted stock awards, restricted stock unit awards, performance stock awards, performance cash awards, and other forms of stock awards to our employees, directors and consultants.
The exercise price of stock options will generally not be less than 100% of the fair market value of our common stock on the date of grant, as determined by our board of directors. Our equity awards generally vest over a two to four year period and expire no later than ten years from the date of grant.  
2015 Employee Stock Purchase Plan
In August 2015, our board of directors adopted, and our stockholders approved, the 2015 Employee Stock Purchase Plan (2015 ESPP), which became effective in connection with our IPO.
The 2015 ESPP allows eligible employees to purchase shares of our Class A common stock at a discount through payroll deductions of up to 30% of their eligible compensation, subject to a cap of 3,000 shares on any purchase date or $25,000 in any calendar year (as determined under applicable tax rules). The 2015 ESPP provides for 24 month offering periods beginning March 16th and September 16th of each year, and each offering period consists of four six-month purchase periods, subject to a reset provision. If the closing stock price on the offering date of a new offering falls below the closing stock price on the offering date of an ongoing offering, the ongoing offering would terminate immediately following the purchase of ESPP shares on the purchase date immediately preceding the new offering and participants in the terminated ongoing offering would automatically be enrolled in the new offering (ESPP reset), resulting in a modification. On each purchase date, eligible employees will purchase our Class A common stock at a price per share equal to 85% of the lesser of the fair market value of our Class A common stock on (1) the first trading day of the applicable offering period or (2) the purchase date. There was an ESPP reset in the three months ended April 30, 2017 that resulted in a total modification charge of $9.0 million, which is recognized over the new offering period ending March 15, 2019.
We recognized stock-based compensation expense related to our 2015 ESPP of $3.8 million and $7.9 million during the three months ended July 31, 2017 and 2018 and $7.9 million and $14.6 million during the six months ended July 31, 2017 and 2018. As of July 31, 2018, there was $23.9 million of unrecognized stock-based compensation expense related to our 2015 ESPP, which is expected to be recognized over a weighted-average period of approximately 0.9 years.
Stock Options
A summary of stock option activity under our equity incentive plans and related information is as follows:
 
 
Options Outstanding
 
Number of
Shares
 
Weighted-
Average
Exercise Price
 
Weighted-
Average
Remaining
Contractual Life (In Years)
 
Aggregate
Intrinsic
Value (in thousands)
Balance as of January 31, 2018
46,359,949

 
$
7.75

 
6.3
 
$
574,224

Options exercised
(5,884,173
)
 
4.94

 
 
 
 

Options forfeited/canceled
(1,191,720
)
 
9.36

 
 
 
 

Balance as of July 31, 2018
39,284,056

 
$
8.12

 
5.9
 
$
531,664

Vested and exercisable as of July 31, 2018
26,675,832

 
$
6.00

 
5.4
 
$
417,651


 
 
The aggregate intrinsic value of options vested and exercisable as of July 31, 2018 is calculated based on the difference between the exercise price and the closing price of $21.66 of our Class A common stock on July 31, 2018.
As of July 31, 2018, total unrecognized employee compensation cost related to outstanding options was $49.6 million, which is expected to be recognized over a weighted-average period of approximately 2.1 years.

Restricted Stock Units
A summary of the restricted stock unit activity under our 2015 Plan and related information is as follows:
 
Number of Restricted Stock Units Outstanding
 
Weighted-
Average
Grant Date
Fair Value
 
Aggregate
Intrinsic
Value (in thousands)
Unvested balance as of January 31, 2018
17,682,646

 
$
12.60

 
$
356,117

Granted
7,751,921

 
20.79

 


Vested
(4,117,282
)
 
12.50

 


Forfeited
(858,561
)
 
14.18

 


Converted
(1,142,838
)
 
11.86

 
 
Unvested balance as of July 31, 2018
19,315,886

 
$
15.87

 
$
418,359



As of July 31, 2018, total unrecognized employee compensation cost related to unvested restricted stock units was $273.3 million, which is expected to be recognized over a weighted-average period of approximately 3.0 years.

In March 2017, we granted 750,000 performance stock units (net of 77,000 canceled units), at a target percentage of 100%, with both performance and service vesting conditions payable in common shares, from 0% to 150% of the target number granted, contingent upon the degree to which the performance condition is met. In March 2018, a total of 780,000 shares was earned based on the performance condition achieved and these shares are subject to service conditions through the vesting periods. Stock-based compensation expense for these performance stock units, recognized on an accelerated attribution method, was $1.2 million and $0.5 million for the three months ended July 31, 2017 and 2018, and $1.6 million and $1.5 million for the six months ended July 31, 2017 and 2018.

In August 2017, we granted 464,744 performance stock units, at a target percentage of 100%, with both performance and service vesting conditions payable in common shares, from 0% to 150% of the target number granted, contingent upon the degree to which the performance condition is met. The performance condition for these performance stock units was set in March 2018 and accordingly, established the grant date for these awards from an accounting perspective and for determining the grant date fair value.

Restricted Stock

In March 2018, we converted certain restricted stock units and performance stock units that were previously granted into 1,375,210 shares of restricted stock for corporate tax benefit purposes. Of the 1,375,210 shares of restricted stock, 697,116 shares are performance restricted stock and 678,094 shares are subject to service vesting conditions only. The conversion did not change the fair value or vesting conditions and therefore no modification accounting was required.

During the three and six months ended July 31, 2018, we issued 21,047 shares and 1,954,908 shares of performance restricted stock, at the maximum performance percentage of 180%, with performance vesting conditions payable in common shares, contingent upon the degree to which the performance condition is met. The shares may be earned from 0% to 180%. Actual shares earned may be lower than the aggregate maximum number dependent on the degree to which the performance condition is met, and cannot be higher than the aggregate maximum number. Any portion of shares that are not earned will be canceled.

All unvested restricted shares are subject to repurchase. Stock-based compensation expense for performance restricted stock is recognized on an accelerated attribution method. In the three and six months ended July 31, 2018, we recognized $6.7 million and $10.2 million in stock-based compensation expense relating to restricted stock. As of July 31, 2018, total unrecognized employee compensation cost related to unvested restricted stock was $31.7 million, which is expected to be recognized over a weighted-average period of approximately 2.6 years.
Stock-Based Compensation Expense
The following table summarizes the components of stock-based compensation expense recognized in the condensed consolidated statements of operations (in thousands):
 
 
Three Months Ended July 31,
 
Six Months Ended July 31,
 
2017
 
2018
 
2017
 
2018
Cost of revenue—product
$
358

 
$
720

 
$
755

 
$
1,328

Cost of revenue—support subscription
2,245

 
2,929

 
4,019

 
5,613

Research and development
17,971

 
22,232

 
33,559

 
43,322

Sales and marketing
11,439

 
17,269

 
22,065

 
31,209

General and administrative
4,825

 
10,504

 
8,659

 
16,137

Total stock-based compensation expense
$
36,838

 
$
53,654

 
$
69,057

 
$
97,609



The tax benefit related to stock-based compensation expense for all periods presented was not material.
v3.10.0.1
Net Loss per Share Attributable to Common Stockholders
6 Months Ended
Jul. 31, 2018
Earnings Per Share [Abstract]  
Net Loss per Share Attributable to Common Stockholders
Net Loss per Share Attributable to Common Stockholders
Basic and diluted net loss per share attributable to common stockholders is presented in conformity with the two-class method required for participating securities.
Basic net loss per share attributable to common stockholders is computed by dividing the net loss by the weighted-average number of shares of common stock outstanding during the period, less shares subject to repurchase. Diluted net loss per share attributable to common stockholders is computed by giving effect to all potentially dilutive common stock equivalents including our outstanding stock options, common stock related to unvested early exercised stock options, common stock related to unvested restricted stock units and restricted stock awards, convertible senior notes to the extent dilutive, and common stock issuable pursuant to the ESPP.    For purposes of calculating basic and diluted net loss per share attributable to common shareholders, these potentially dilutive common stock equivalents have been excluded from the calculation of diluted net loss per share attributable to common stockholders as their effect is anti-dilutive.
The rights, including the liquidation and dividend rights, of the holders of our Class A and Class B common stock are identical, except with respect to voting. As the liquidation and dividend rights are identical, the undistributed earnings are allocated on a proportionate basis and the resulting net loss per share attributed to common stockholders will, therefore, be the same for both Class A and Class B common stock on an individual or combined basis.
The following table sets forth the computation of basic and diluted net loss per share attributable to common stockholders (in thousands, except per share data):
 
 
Three Months Ended July 31,
 
Six Months Ended July 31,
 
2017
 
2018
 
2017
 
2018
 
(As Adjusted*)
 
 
 
(As Adjusted*)
 
 
Net loss
$
(58,411
)
 
$
(60,123
)
 
$
(115,570
)
 
$
(124,427
)
Weighted-average shares used in computing net loss per share attributable to common stockholders, basic and diluted
209,193

 
229,359

 
207,515

 
226,609

Net loss per share attributable to common stockholders, basic and diluted
$
(0.28
)
 
$
(0.26
)
 
$
(0.56
)
 
$
(0.55
)


* Prior period information has been adjusted to reflect the adoption impact of ASC 606, which we adopted on February 1, 2018.

The following weighted-average outstanding shares of common stock equivalents were excluded from the computation of diluted net loss per share attributable to common stockholders for the periods presented because including them would have been anti-dilutive (in thousands):
 
 
Three Months Ended July 31,
 
Six Months Ended July 31,
 
2017
 
2018
 
2017
 
2018
Stock options to purchase common stock
53,878

 
40,920

 
54,864

 
42,923

Restricted stock units
15,710

 
19,957

 
13,759

 
19,486

Restricted stock and early exercised stock options
279

 
3,327

 
333

 
2,585

Employee stock purchase plan
898

 
1,154

 
898

 
1,127

Total
70,765

 
65,358

 
69,854

 
66,121

v3.10.0.1
Income Taxes
6 Months Ended
Jul. 31, 2018
Income Tax Disclosure [Abstract]  
Income Taxes
Income Taxes
Our provision for income taxes was primarily due to taxes on international operations and state income taxes. The difference between the provision for income taxes that would be derived by applying the statutory rate to our loss before income taxes and the provision for income taxes recorded was primarily attributable to changes in our valuation allowance, non-deductible stock-based compensation expense and the tax rate differential between the U.S. and foreign countries.
As of July 31, 2018, there were no material changes to either the nature or the amounts of the uncertain tax positions previously determined for the year ended January 31, 2018.
The Tax Act was signed into law on December 22, 2017. The new legislation decreases the U.S. corporate federal income tax rate from 35% to 21% effective January 1, 2018.
The Tax Act also includes a number of other provisions including the elimination of loss carrybacks and limitations on the use of future losses, limitations on the deductibility of executive compensation, limitation or modification on the deductibility of certain business expenses, the transition of U.S. international taxation from a worldwide tax system to a territorial system, and the introduction of a base erosion and anti-abuse tax. Under the Tax Act, the Global Intangible Low-Taxed Income (GILTI) provision taxes foreign income in excess of a deemed return on tangible assets of foreign corporations. Under U.S. GAAP, companies are allowed to make an accounting policy election to either (i) account for GILTI as a component of tax expense in the period in which a company is subject to the rules -- the period cost method, or (ii) account for GILTI in a company’s measurement of deferred taxes -- the deferred method. Because of the complexity of the new tax rules, we have not yet made an accounting policy election and are continuing to assess the impact of the Tax Act during the one-year measurement period from the Tax Act enactment date as allowed by Staff Accounting Bulletin No. 118 (SAB 118) issued in connection with the Tax Act. We expect to complete the accounting for the tax effects of the Tax Act in calendar year 2018.
v3.10.0.1
Segment Information
6 Months Ended
Jul. 31, 2018
Segment Reporting [Abstract]  
Segment Information
Segment Information
Our chief operating decision maker is a group comprised of our Chief Executive Officer, our Chief Financial Officer, and our President. This group reviews financial information presented on a consolidated basis for purposes of allocating resources and evaluating financial performance. We have one business activity and there are no segment managers who are held accountable for operations or operating results. Accordingly, we have a single reportable segment.
Disaggregation of Revenue
The following table depicts the disaggregation of revenue by geographic area based on the billing address of our customers and is consistent with how we evaluate our financial performance (in thousands):
 
 
Three Months Ended July 31,
 
Six Months Ended July 31,
 
2017
 
2018
 
2017
 
2018
 
(As Adjusted*)
 
 
 
(As Adjusted*)
 
 
United States
$
165,620

 
$
229,760

 
$
312,125

 
$
414,678

Rest of the world
59,050

 
79,124

 
95,190

 
150,151

Total revenue
$
224,670

 
$
308,884

 
$
407,315

 
$
564,829


* Prior period information has been adjusted to reflect the adoption impact of ASC 606, which we adopted on February 1, 2018.

Long-Lived Assets by Geographic Area
Long-lived assets by geographic area are summarized as follows (in thousands):
 
 
As of
January 31, 2018
 
As of
July 31, 2018
United States
$
85,430

 
$
97,250

Rest of the world
3,712

 
4,468

Total long-lived assets
$
89,142

 
$
101,718

v3.10.0.1
Subsequent Event
6 Months Ended
Jul. 31, 2018
Subsequent Events [Abstract]  
Subsequent Event
Subsequent Event
In August 2018, we acquired StorReduce, Inc., a cloud-first software-defined storage solution, for $25 million in cash, subject to adjustments. We are currently in the process of completing the purchase price allocation for this acquisition, which will be included in our condensed consolidated financial statements for the quarter ending October 31, 2018.
v3.10.0.1
Basis of Presentation and Summary of Significant Accounting Policies (Policies)
6 Months Ended
Jul. 31, 2018
Accounting Policies [Abstract]  
Principles of Consolidation
Principles of Consolidation
The condensed consolidated financial statements include the accounts of the Company and our wholly owned subsidiaries. All intercompany balances and transactions have been eliminated in consolidation.
Unaudited Interim Consolidated Financial Information
Unaudited Interim Consolidated Financial Information
The accompanying unaudited condensed consolidated financial statements have been prepared in accordance with generally accepted accounting principles in the United States (U.S. GAAP) and applicable rules and regulations of the Securities and Exchange Commission (the SEC) regarding interim financial reporting. Certain information and note disclosures normally included in the financial statements prepared in accordance with U.S. GAAP have been condensed or omitted pursuant to such rules and regulations. Therefore, these condensed consolidated financial statements should be read in conjunction with the consolidated financial statements and notes included in our Annual Report on Form 10-K for the year ended January 31, 2018.
In the opinion of management, the accompanying unaudited condensed consolidated financial statements reflect all normal recurring adjustments necessary to present fairly the financial position, results of operations, comprehensive loss and cash flows for the interim periods, but are not necessarily indicative of the results of operations to be anticipated for the full fiscal year 2019 or any future period. Certain prior period amounts have been adjusted as a result of adoption of new accounting pronouncements. Refer to "Recently Adopted Accounting Pronouncements" below for further information.
Use of Estimates
Use of Estimates
The preparation of financial statements in conformity with U.S. GAAP requires management to make estimates and assumptions that affect the amounts reported and disclosed in the financial statements and accompanying notes. Actual results could differ from these estimates. Such estimates include, but are not limited to, the determination of standalone selling price for revenue arrangements with multiple performance obligations, useful lives of intangible assets, property and equipment and deferred sales commissions, stock-based compensation, provision for income taxes including related reserves, and contingent liabilities. Management bases its estimates on historical experience and on various other assumptions which management believes to be reasonable, the results of which form the basis for making judgments about the carrying values of assets and liabilities.
Restricted Cash
Restricted Cash
Restricted cash is comprised of cash collateral related to our leases and for a vendor corporate credit card program.
Marketable Securities
Marketable Securities
We classify our marketable securities as available-for-sale at the time of purchase and reevaluate such classification at each balance sheet date. We may sell these securities at any time for use in current operations even if they have not yet reached maturity. As a result, we classify our securities, including those with maturities beyond twelve months, as current assets in the accompanying condensed consolidated balance sheets. We carry these securities at fair value and record unrealized gains and losses, in accumulated other comprehensive loss, which is reflected as a component of stockholders’ equity. We evaluate our securities to assess whether those with unrealized loss positions are other than temporarily impaired. We consider impairments to be other than temporary if they are related to deterioration in credit risk or if it is likely we will sell the securities before the recovery of their cost basis. Realized gains and losses from the sale of marketable securities and declines in value deemed to be other than temporary are determined on the specific identification method. To date, there have been no declines in value deemed to be other than temporary in any of our securities. Realized gains and losses are reported in other income (expense), net in the condensed consolidated statements of operations.
Deferred Commissions
Deferred Commissions
Deferred commissions consist of incremental costs paid to our sales force to obtain customer contracts. Deferred commissions related to product revenues are recognized upon transfer of control to customers and deferred commissions related to support subscription revenue are amortized over an expected useful life of six years. We determine the expected useful life based on an estimated benefit period by evaluating our technology development life cycle, expected customer relationship period, and other factors. We classify deferred commissions as current and non-current on our condensed consolidated balance sheets based on the timing of when we expect to recognize the expense. Amortization of deferred commissions is included in sales and marketing expense in the condensed consolidated statements of operations.
Deferred Revenue
Deferred Revenue
Deferred revenue primarily consists of amounts that have been invoiced but that have not yet been recognized as revenue and performance obligations pertaining to support subscription services. The current portion of deferred revenue represents the amounts that are expected to be recognized as revenue within one year of the condensed consolidated balance sheet dates.
Revenue Recognition
Revenue Recognition
We derive revenue from two sources: (1) product revenue which includes hardware and embedded software and (2) support subscription revenue which includes customer support, hardware maintenance, and software upgrades on a when-and-if-available basis.
Our product revenue is derived from the sale of storage hardware and operating system software that is integrated into the hardware. We typically recognize product revenue upon transfer of control to our customers. Products are typically shipped directly by us to customers, and our channel partners do not stock our inventory.
Our support subscription revenue is derived from the sale of support subscription, which includes the right to receive unspecified software upgrades and enhancements on a when-and-if-available basis, bug fixes, parts replacement services related to the hardware, as well as access to our cloud-based management and support platform. Revenue related to support subscription is recognized ratably over the contractual term, which generally ranges from one to six years and represents our performance obligations period. The vast majority of our products are sold with support subscription agreements, which typically commence upon transfer of control of the corresponding products to our customers. Costs to service the support subscription are expensed as incurred. In addition, our Evergreen Storage program provides our customers who continually maintain active support subscription agreements for three years with an included controller refresh with each additional three year support subscription renewal. In accordance with revenue recognition guidance, the controller refresh represents an additional performance obligation and the allocated revenue is recognized in the period in which these controllers are shipped.
We recognize revenue upon the transfer of promised goods or services to customers in an amount that reflects the consideration we expect to be entitled in exchange for those goods or services. This is achieved through applying the following five-step approach:
Identification of the contract, or contracts, with a customer
Identification of the performance obligations in the contract
Determination of the transaction price
Allocation of the transaction price to the performance obligations in the contract
Recognition of revenue when, or as, we satisfy a performance obligation
When applying this five-step approach, we apply judgment in determining the customer's ability and intention to pay, which is based on a variety of factors including the customer's historical payment experience and/or published credit and financial information pertaining to the customer. To the extent a customer contract includes multiple promised goods or services, we determine whether promised goods or services are capable of being distinct in the context of the contract to be accounted for as a combined performance obligation. We allocate transaction price to each performance obligation for contracts that contain multiple performance obligations based on a relative standalone selling price, taking into account available information such as market conditions and internally approved pricing guidelines related to performance obligations.
Recently Adopted Accounting Pronouncements and Recent Accounting Pronouncements Not Yet Adopted
Recently Adopted Accounting Pronouncements
In May 2014, the Financial Accounting Standards Board (FASB), issued Accounting Standards Update (ASU) No. 2014-09, Revenue from Contracts with Customers (ASU 2014-09 or ASC 606), requiring an entity to recognize revenue when it transfers promised goods or services to customers in an amount that reflects the consideration to which the entity expects to be entitled to in exchange for those goods or services. ASC 606 supersedes nearly all existing revenue recognition guidance under U.S. GAAP upon its effective date. The standard permits two methods of adoptions: retrospectively to each prior reporting period presented (full retrospective method), or retrospectively with the cumulative effect of applying the standard recognized at the date of application (cumulative catch-up transition method).
We adopted the standard using the full retrospective method beginning February 1, 2018, for the year ending January 31, 2019, and our historical financial information for the years ended January 31, 2017 and 2018 has been adjusted to conform to the new standard.
The most significant impact of the standard related to the removal of limitation on contingent revenue, resulting in an increase in product revenue and a decrease in support subscription revenue. In addition, the adoption of ASC 606 also resulted in differences in the timing of recognition of sales commissions. While the adoption of the standard changes certain line items within the net cash flow from operating activities, it had no impact to the net cash provided by or used in operating, investing, or financing activities on our condensed consolidated statements of cash flows.
The following line items on our condensed consolidated balance sheet as of January 31, 2018 have been adjusted to reflect the adoption of ASC 606 (in thousands):
 
As of January 31, 2018
 
As Previously Reported
 
Adjustment
 
As Adjusted
Assets
 
 
 
 
 
Deferred commissions, current
$
22,437

 
$
(1,349
)
 
$
21,088

Deferred commissions, non-current
20,288

 
45,937

 
66,225

Total deferred commissions
$
42,725

 
$
44,588

 
$
87,313

Liabilities
 
 
 
 
 
Deferred revenue, current
$
209,377

 
$
(18,148
)
 
$
191,229

Deferred revenue, non-current
196,632

 
(13,759
)
 
182,873

Total deferred revenue
$
406,009

 
$
(31,907
)
 
$
374,102

Stockholders' equity
 
 
 
 
 
Accumulated deficit
$
(980,082
)
 
$
76,495

 
$
(903,587
)

The following line items on our unaudited condensed consolidated statement of operations for the three and six months ended July 31, 2017 have been adjusted to reflect the adoption of ASC 606 (in thousands, except per share data):
 
Three Months Ended July 31, 2017
 
Six Months Ended July 31, 2017
 
As Previously Reported
 
Adjustment
 
As Adjusted
 
As Previously Reported
 
Adjustment
 
As Adjusted
Revenue:
 
 
 
 
 
 
 
 
 
 
 
Product
$
175,013

 
$
4,656

 
$
179,669

 
$
313,438

 
$
9,081

 
$
322,519

Support subscription
49,448

 
(4,447
)
 
45,001

 
93,654

 
(8,858
)
 
84,796

Total revenue
$
224,461

 
$
209

 
$
224,670

 
$
407,092

 
$
223

 
$
407,315

 
 
 
 
 
 
 
 
 
 
 
 
Gross profit
$
148,010

 
$
209

 
$
148,219

 
$
267,093

 
$
223

 
$
267,316

Sales and marketing
$
120,633

 
$
(3,081
)
 
$
117,552

 
$
217,597

 
$
(8,282
)
 
$
209,315

Total operating expenses
$
212,156

 
$
(3,081
)
 
$
209,075

 
$
394,644

 
$
(8,282
)
 
$
386,362

Loss from operations
$
(64,146
)
 
$
3,290

 
$
(60,856
)
 
$
(127,551
)
 
$
8,505

 
$
(119,046
)
Loss before provision for income taxes
$
(60,880
)
 
$
3,290

 
$
(57,590
)
 
$
(122,290
)
 
$
8,505

 
$
(113,785
)
Net loss
$
(61,701
)
 
$
3,290

 
$
(58,411
)
 
$
(124,075
)
 
$
8,505

 
$
(115,570
)
Net loss per share attributable to common stockholders, basic and diluted
$
(0.29
)
 
$
0.01

 
$
(0.28
)
 
$
(0.60
)
 
$
0.04

 
$
(0.56
)

Unaudited revenue by geographic location based on bill-to location, which reflects the adoption impact of ASC 606, are as follows (in thousands):
 
Three Months Ended July 31, 2017
 
Six Months Ended July 31, 2017
 
As Previously Reported
 
Adjustment
 
As Adjusted
 
As Previously Reported
 
Adjustment
 
As Adjusted
Revenue:
 
 
 
 
 
 
 
 
 
 
 
United States
$
165,466

 
$
154

 
$
165,620

 
$
311,960

 
$
165

 
$
312,125

Rest of the world
58,995

 
55

 
59,050

 
95,132

 
58

 
95,190

Total revenue
$
224,461

 
$
209

 
$
224,670

 
$
407,092

 
$
223

 
$
407,315



In November 2016, the FASB issued ASU No. 2016-18, Statement of Cash Flows (Topic 230): Restricted Cash (ASU 2016-18), which requires that a statement of cash flows explain the change during the period in the total of cash, cash equivalents, and restricted cash. We adopted ASU 2016-18 effective February 1, 2018 on a retrospective basis. Upon adoption, restricted cash is included with cash and cash equivalents when reconciling the beginning-of-period and end-of-period total amounts shown on the statement of cash flows. The adoption of this standard increased our previously reported net cash flow from investing activities for the periods in which there were changes in restricted cash but did not impact our net cash flow from operating activities or financing activities presented on our consolidated statements of cash flows.
The following line items in our unaudited condensed consolidated statement of cash flows for the six months ended July 31, 2017 have been adjusted to reflect the adoption of ASU 2016-18 and ASC 606 (in thousands):
 
Six Months Ended July 31, 2017
 
As Previously Reported
 
Adjustment
 
As Adjusted
Net loss (1)
$
(124,075
)
 
$
8,505

 
$
(115,570
)
Adjustments to reconcile net loss to net cash provided by (used in) operating activities:
 
 
 
 
 
Deferred commissions (1)
$
(4,607
)
 
$
(4,980
)
 
$
(9,587
)
Accrued compensation and other liabilities (1)
$
310

 
$
(3,303
)
 
$
(2,993
)
Deferred revenue (1)
$
24,473

 
$
(222
)
 
$
24,251

Cash used in operating activities
$
(14,492
)
 
$

 
$
(14,492
)
Cash, cash equivalents and restricted cash, beginning of period (2)
$
183,675

 
$
12,734

 
$
196,409

Cash, cash equivalents and restricted cash, end of period (2)
$
171,894

 
$
12,734

 
$
184,628

_____________________________________________________
(1) Adjustment pertaining to the adoption of ASC 606.
(2) Adjustment pertaining to the adoption of ASU 2016-18.
In June 2018, the FASB issued ASU No. 2018-07, Compensation - Stock Compensation (Topic 718) (ASU 2018-07). ASU 2018-07 aligns the accounting for share-based awards to employees and non-employees to follow the same model. The new standard is effective for fiscal years beginning after December 15, 2018 using a modified retrospective transition approach. Early adoption is permitted. We adopted this standard for the three and six months ended July 31, 2018 and the adoption of this standard did not materially impact our consolidated financial statements.
Recent Accounting Pronouncements Not Yet Adopted
In February 2016, the FASB issued ASU No. 2016-02, Leases (Topic 842) (ASU 2016-02). ASU 2016-02 requires lessees to recognize all leases with terms in excess of one year on their balance sheet as a right-of-use asset and a lease liability at the commencement date. The new standard also simplifies the accounting for sale and leaseback transactions. ASU 2016-02 requires the use of the modified retrospective method for leases existing at, or entered into after, the beginning of the earliest comparative period presented in the financial statements. In July 2018, the FASB issued ASU No. 2018-10, Leases (Topic 842), Codification Improvements to Topic 842, Leases (ASU 2018-10) and ASU No. 2018-11, Leases (Topic 842), Targeted Improvements (ASU 2018-11). ASU 2018-11 provides a new transition method in which an entity can initially apply the new lease standards at the adoption date and recognize a cumulative-effect adjustment to the opening balance of retained earnings in the period of adoption. These standards will be effective for us beginning on February 1, 2019 and early adoption is permitted. We expect to apply the new transition method prescribed by ASU 2018-11 at the adoption date. We are currently evaluating the impact of these standards on our consolidated financial statements.
In June 2016, the FASB issued ASU No. 2016-13, Financial Instruments-Credit Losses (Topic 326): Measurement of Credit Losses on Financial Instruments (ASU 2016-13). ASU 2016-13 amends guidance on reporting credit losses for assets held at amortized cost basis and available-for-sale debt securities to require that credit losses on available-for-sale debt securities be presented as an allowance rather than as a write-down. The measurement of credit losses for newly recognized financial assets and subsequent changes in the allowance for credit losses are recorded in the statements of operations. The amendments in this update will be effective for us beginning on February 1, 2020 with early adoption permitted on or after February 1, 2019. We are currently evaluating the impact of this standard on our consolidated financial statements.
In February 2018, the FASB issued ASU No. 2018-02, Income Statement - Reporting Comprehensive Income (Topic 220) - Reclassification of Certain Tax Effects from Accumulated Other Comprehensive Income. This standard allows a reclassification from accumulated other comprehensive income to retained earnings for stranded tax effects resulting from the Tax Cuts and Jobs Act of 2017 (the Tax Act) and requires certain disclosures about stranded tax effects. This standard will be effective for us beginning February 1, 2019 and should be applied either in the period of adoption or retrospectively. Early adoption is permitted. We do not expect this standard to have any impact on our consolidated financial statements.
Fair Value Measurements
Fair Value Measurements
We measure our cash equivalents, marketable securities, and restricted cash at fair value on a recurring basis. We define fair value as the exchange price that would be received from sale of an asset or paid to transfer a liability in the principal or most advantageous market for the asset or liability in an orderly transaction between market participants on the measurement date. We measure our financial assets and liabilities at fair value at each reporting period using a fair value hierarchy which requires us to maximize the use of observable inputs and minimize 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 fair value:

Level 1 - Observable inputs are unadjusted quoted prices in active markets for identical assets or liabilities;

Level 2 - Observable inputs are quoted prices for similar assets and liabilities in active markets or inputs other than quoted prices that are observable for the assets or liabilities, either directly or indirectly through market corroboration, for substantially the full term of the financial instruments; and

Level 3 - Unobservable inputs that are supported by little or no market activity and that are significant to the fair value of the assets or liabilities. These inputs are based on our own assumptions used to measure assets and liabilities at fair value and require significant management judgment or estimation.
We classify our cash equivalents, marketable securities and restricted cash within Level 1 or Level 2 because they are valued using either quoted market prices or inputs other than quoted prices which are directly or indirectly observable in the market, including readily-available pricing sources for the identical underlying security which may not be actively traded. Our fixed income available-for-sale securities consist of high quality, investment grade securities from diverse issuers. The valuation techniques used to measure the fair value of our marketable securities were derived from non-binding market consensus prices that are corroborated by observable market data or quoted market prices for similar instruments.
In addition to our cash equivalents, marketable securities, and restricted cash, we measure the fair value of our convertible senior notes (the Notes) on a quarterly basis for disclosure purposes. We consider the fair value of the Notes at July 31, 2018 to be a Level 2 measurement due to limited trading activity of the Notes. Refer to Note 5 for further information.
v3.10.0.1
Basis of Presentation and Summary of Significant Accounting Policies (Tables)
6 Months Ended
Jul. 31, 2018
Accounting Policies [Abstract]  
Deferred Commissions
Changes in total deferred commissions during the periods presented are as follows (in thousands):
 
Three Months Ended July 31, 2018
 
Six Months Ended July 31, 2018
 
 
 
 
Beginning balance (1)
$
86,044

 
$
87,313

Additions
24,582

 
40,003

Recognition of deferred commissions
(19,157
)
 
(35,847
)
Ending balance as of July 31, 2018
$
91,469

 
$
91,469


____________________ 
(1) Balance as of January 31, 2018 was adjusted to reflect the adoption of ASC 606.
Deferred Revenue
Changes in total deferred revenue during the periods presented are as follows (in thousands):
 
Three Months Ended July 31, 2018
 
Six Months Ended July 31, 2018
Beginning balance (1)
$
388,614

 
$
374,102

Additions
92,511

 
167,782

Recognition of deferred revenue
(67,878
)
 
(128,637
)
Ending balance as of July 31, 2018
$
413,247

 
$
413,247

____________________ 
(1) Balance as of January 31, 2018 was adjusted to reflect the adoption of ASC 606.
Schedule of Recently Adopted Accounting Pronouncements
The following line items on our condensed consolidated balance sheet as of January 31, 2018 have been adjusted to reflect the adoption of ASC 606 (in thousands):
 
As of January 31, 2018
 
As Previously Reported
 
Adjustment
 
As Adjusted
Assets
 
 
 
 
 
Deferred commissions, current
$
22,437

 
$
(1,349
)
 
$
21,088

Deferred commissions, non-current
20,288

 
45,937

 
66,225

Total deferred commissions
$
42,725

 
$
44,588

 
$
87,313

Liabilities
 
 
 
 
 
Deferred revenue, current
$
209,377

 
$
(18,148
)
 
$
191,229

Deferred revenue, non-current
196,632

 
(13,759
)
 
182,873

Total deferred revenue
$
406,009

 
$
(31,907
)
 
$
374,102

Stockholders' equity
 
 
 
 
 
Accumulated deficit
$
(980,082
)
 
$
76,495

 
$
(903,587
)

The following line items on our unaudited condensed consolidated statement of operations for the three and six months ended July 31, 2017 have been adjusted to reflect the adoption of ASC 606 (in thousands, except per share data):
 
Three Months Ended July 31, 2017
 
Six Months Ended July 31, 2017
 
As Previously Reported
 
Adjustment
 
As Adjusted
 
As Previously Reported
 
Adjustment
 
As Adjusted
Revenue:
 
 
 
 
 
 
 
 
 
 
 
Product
$
175,013

 
$
4,656

 
$
179,669

 
$
313,438

 
$
9,081

 
$
322,519

Support subscription
49,448

 
(4,447
)
 
45,001

 
93,654

 
(8,858
)
 
84,796

Total revenue
$
224,461

 
$
209

 
$
224,670

 
$
407,092

 
$
223

 
$
407,315

 
 
 
 
 
 
 
 
 
 
 
 
Gross profit
$
148,010

 
$
209

 
$
148,219

 
$
267,093

 
$
223

 
$
267,316

Sales and marketing
$
120,633

 
$
(3,081
)
 
$
117,552

 
$
217,597

 
$
(8,282
)
 
$
209,315

Total operating expenses
$
212,156

 
$
(3,081
)
 
$
209,075

 
$
394,644

 
$
(8,282
)
 
$
386,362

Loss from operations
$
(64,146
)
 
$
3,290

 
$
(60,856
)
 
$
(127,551
)
 
$
8,505

 
$
(119,046
)
Loss before provision for income taxes
$
(60,880
)
 
$
3,290

 
$
(57,590
)
 
$
(122,290
)
 
$
8,505

 
$
(113,785
)
Net loss
$
(61,701
)
 
$
3,290

 
$
(58,411
)
 
$
(124,075
)
 
$
8,505

 
$
(115,570
)
Net loss per share attributable to common stockholders, basic and diluted
$
(0.29
)
 
$
0.01

 
$
(0.28
)
 
$
(0.60
)
 
$
0.04

 
$
(0.56
)

Unaudited revenue by geographic location based on bill-to location, which reflects the adoption impact of ASC 606, are as follows (in thousands):
 
Three Months Ended July 31, 2017
 
Six Months Ended July 31, 2017
 
As Previously Reported
 
Adjustment
 
As Adjusted
 
As Previously Reported
 
Adjustment
 
As Adjusted
Revenue:
 
 
 
 
 
 
 
 
 
 
 
United States
$
165,466

 
$
154

 
$
165,620

 
$
311,960

 
$
165

 
$
312,125

Rest of the world
58,995

 
55

 
59,050

 
95,132

 
58

 
95,190

Total revenue
$
224,461

 
$
209

 
$
224,670

 
$
407,092

 
$
223

 
$
407,315

The following line items in our unaudited condensed consolidated statement of cash flows for the six months ended July 31, 2017 have been adjusted to reflect the adoption of ASU 2016-18 and ASC 606 (in thousands):
 
Six Months Ended July 31, 2017
 
As Previously Reported
 
Adjustment
 
As Adjusted
Net loss (1)
$
(124,075
)
 
$
8,505

 
$
(115,570
)
Adjustments to reconcile net loss to net cash provided by (used in) operating activities:
 
 
 
 
 
Deferred commissions (1)
$
(4,607
)
 
$
(4,980
)
 
$
(9,587
)
Accrued compensation and other liabilities (1)
$
310

 
$
(3,303
)
 
$
(2,993
)
Deferred revenue (1)
$
24,473

 
$
(222
)
 
$
24,251

Cash used in operating activities
$
(14,492
)
 
$

 
$
(14,492
)
Cash, cash equivalents and restricted cash, beginning of period (2)
$
183,675

 
$
12,734

 
$
196,409

Cash, cash equivalents and restricted cash, end of period (2)
$
171,894

 
$
12,734

 
$
184,628

_____________________________________________________
(1) Adjustment pertaining to the adoption of ASC 606.
(2) Adjustment pertaining to the adoption of ASU 2016-18.
v3.10.0.1
Financial Instruments (Tables)
6 Months Ended
Jul. 31, 2018
Investments, Debt and Equity Securities [Abstract]  
Summary of Cash Equivalents, Marketable Securities and Restricted Cash by Significant Investment Categories
The following tables summarize our cash equivalents, marketable securities and restricted cash by significant investment categories as of January 31, 2018 and July 31, 2018 (in thousands):
 
 
As of January 31, 2018
 
Amortized
Cost
 
Gross Unrealized
Gains
 
Gross Unrealized
Losses
 
Fair
Value
 
Cash Equivalents
 
Marketable Securities
 
Restricted Cash
Level 1
 

 
 

 
 

 
 

 
 

 
 
 
 

Money market accounts
$

 
$

 
$

 
$
32,057

 
$
17,294

 
$

 
$
14,763

Level 2
 
 
 
 
 
 
 
 
 
 
 
 
 
U.S. government treasury notes
131,643

 

 
(651
)
 
130,992

 
10,172

 
120,820

 

U.S. government agencies
47,229

 

 
(333
)
 
46,896

 

 
46,896

 

Corporate debt securities
186,506

 
116

 
(1,049
)
 
185,573

 

 
185,573

 

Total
$
365,378

 
$
116

 
$
(2,033
)
 
$
395,518

 
$
27,466

 
$
353,289

 
$
14,763


 
As of July 31, 2018
 
Amortized
Cost
 
Gross Unrealized
Gains
 
Gross Unrealized
Losses
 
Fair
Value
 
Cash Equivalents
 
Marketable
Securities
 
Restricted Cash
Level 1
 
 
 
 
 
 
 
 
 
 
 
 
 
Money market accounts
$

 
$

 
$

 
$
29,047

 
$
13,269

 
$

 
$
15,778

Level 2
 
 
 
 
 
 
 
 
 
 
 
 
 
U.S. government treasury notes
326,328

 

 
(839
)
 
325,489

 
58,320

 
267,169

 

U.S. government agencies
76,443

 

 
(374
)
 
76,069

 
1,194

 
74,875

 

Corporate debt securities
383,340

 
104

 
(1,713
)
 
381,731

 

 
381,731

 

Foreign government bonds
5,151

 
1

 
(3
)
 
5,149

 

 
5,149

 

Asset-backed securities
7,283

 

 
(2
)
 
7,281

 

 
7,281

 

Total
$
798,545

 
$
105

 
$
(2,931
)
 
$
824,766

 
$
72,783

 
$
736,205

 
$
15,778

Schedule of Amortized Cost and Estimated Fair Value of Marketable Securities by Contractual Maturity
The amortized cost and estimated fair value of our marketable securities are shown below by contractual maturity (in thousands):
 
 
As of July 31, 2018
 
Amortized Cost
 
Fair Value
Due within one year
$
373,160

 
$
372,316

Due in one to five years
365,867

 
363,889

Total
$
739,027

 
$
736,205

Schedule of Gross Unrealized Losses and Fair Values for Investments that were in Continuous Unrealized Loss Position for Less Than 12 Months, Aggregated by Investments Category
The following table presents gross unrealized losses and fair values for those investments that were in a continuous unrealized loss as of July 31, 2018, aggregated by investment category (in thousands):
 
 
Less than 12 months
 
Greater than 12 months
 
Total
 
Fair
Value
 
Unrealized
Loss
 
Fair
Value
 
Unrealized
Loss
 
Fair
Value
 
Unrealized
Loss
U.S. government treasury notes
$
271,578

 
$
(483
)
 
$
48,941

 
$
(356
)
 
$
320,519

 
$
(839
)
U.S. government agencies
55,695

 
(227
)
 
20,374

 
(147
)
 
76,069

 
(374
)
Corporate debt securities
271,946

 
(1,454
)
 
30,654

 
(259
)
 
302,600

 
(1,713
)
Foreign government bonds
2,944

 
(3
)
 

 

 
2,944

 
(3
)
Asset-backed securities
5,016

 
(2
)
 

 

 
5,016

 
(2
)
Total
$
607,179

 
$
(2,169
)
 
$
99,969

 
$
(762
)
 
$
707,148

 
$
(2,931
)
v3.10.0.1
Balance Sheet Components (Tables)
6 Months Ended
Jul. 31, 2018
Balance Sheet Components Disclosure [Abstract]  
Schedule of Inventory
Inventory consists of the following (in thousands):
 
As of
January 31, 2018
 
As of
July 31, 2018
Raw materials
$
1,181

 
$
2,828

Finished goods
33,316

 
38,845

Inventory
$
34,497

 
$
41,673

Schedule of Property and Equipment, Net
Property and equipment, net, consists of the following (in thousands):
 
 
As of
January 31, 2018
 
As of
July 31, 2018
Test equipment
$
142,311

 
$
156,040

Computer equipment and software
72,329

 
92,863

Furniture and fixtures
5,363

 
5,482

Leasehold improvements
15,032

 
23,763

Total property and equipment
235,035

 
278,148

Less: accumulated depreciation and amortization
(145,893
)
 
(176,430
)
Property and equipment, net
$
89,142

 
$
101,718

Schedule of Intangible Assets, Net
Intangible assets, net, consist of the following (in thousands):
 
 
As of
January 31, 2018
 
As of
July 31, 2018
Technology patents
$
10,125

 
$
10,125

Accumulated amortization
(5,068
)
 
(5,820
)
Intangible assets, net
$
5,057

 
$
4,305

Schedule of Expected Amortization Expenses for Intangible Assets
As of July 31, 2018, future expected amortization expense for intangible assets is as follows (in thousands):
 
Fiscal Years Ending January 31,
Estimated 
Future
Amortization
Expense
Remainder of 2019
$
752

2020
1,504

2021
1,504

2022
545

Total
$
4,305

Schedule of Accrued Expenses and Other Liabilities
Accrued expenses and other liabilities consist of the following (in thousands):
 
 
As of
January 31, 2018
 
As of
July 31, 2018
Taxes payable
$
4,052

 
$
3,801

Accrued marketing
5,928

 
5,017

Accrued travel and entertainment expenses
4,386

 
2,556

Other accrued liabilities
12,463

 
15,675

Total accrued expenses and other liabilities
$
26,829

 
$
27,049

v3.10.0.1
Convertible Senior Notes (Tables)
6 Months Ended
Jul. 31, 2018
Debt Disclosure [Abstract]  
Convertible Debt
The Notes consisted of the following (in thousands):
 
As of
July 31, 2018
Liability:
 
Principal
$
575,000

Less: debt discount, net of amortization
(128,976
)
Less: debt issuance costs, net of amortization
(9,337
)
Net carrying amount of the Notes
$
436,687

 
 
Stockholders' equity:
 
Allocated value of the conversion feature
$
136,333

Less: debt issuance costs
(3,068
)
Additional paid-in capital
$
133,265

Interest Expense
The following table sets forth total interest expense recognized related to the Notes for the three and six months ended July 31, 2018 (in thousands):
 
Three Months Ended July 31, 2018
 
Six Months Ended July 31, 2018
Amortization of debt discount
$
6,000

 
$
7,357

Amortization of debt issuance costs
434

 
532

Total amortization of debt discount and debt issuance costs
6,434

 
7,889

Contractual interest expense
181

 
224

Total interest expense related to the Notes
$
6,615

 
$
8,113

 
 
 
 
Effective interest rate of the liability component
5.6
%
 
5.6
%
v3.10.0.1
Equity Incentive Plans (Tables)
6 Months Ended
Jul. 31, 2018
Disclosure of Compensation Related Costs, Share-based Payments [Abstract]  
Summary of Stock Option Activity Under Equity Incentive Plans and Related Information
A summary of stock option activity under our equity incentive plans and related information is as follows:
 
 
Options Outstanding
 
Number of
Shares
 
Weighted-
Average
Exercise Price
 
Weighted-
Average
Remaining
Contractual Life (In Years)
 
Aggregate
Intrinsic
Value (in thousands)
Balance as of January 31, 2018
46,359,949

 
$
7.75

 
6.3
 
$
574,224

Options exercised
(5,884,173
)
 
4.94

 
 
 
 

Options forfeited/canceled
(1,191,720
)
 
9.36

 
 
 
 

Balance as of July 31, 2018
39,284,056

 
$
8.12

 
5.9
 
$
531,664

Vested and exercisable as of July 31, 2018
26,675,832

 
$
6.00

 
5.4
 
$
417,651

Summary of Restricted Stock Unit Activity Under 2015 Plan
A summary of the restricted stock unit activity under our 2015 Plan and related information is as follows:
 
Number of Restricted Stock Units Outstanding
 
Weighted-
Average
Grant Date
Fair Value
 
Aggregate
Intrinsic
Value (in thousands)
Unvested balance as of January 31, 2018
17,682,646

 
$
12.60

 
$
356,117

Granted
7,751,921

 
20.79

 


Vested
(4,117,282
)
 
12.50

 


Forfeited
(858,561
)
 
14.18

 


Converted
(1,142,838
)
 
11.86

 
 
Unvested balance as of July 31, 2018
19,315,886

 
$
15.87

 
$
418,359

Summarizes the Components of Stock-Based Compensation
The following table summarizes the components of stock-based compensation expense recognized in the condensed consolidated statements of operations (in thousands):
 
 
Three Months Ended July 31,
 
Six Months Ended July 31,
 
2017
 
2018
 
2017
 
2018
Cost of revenue—product
$
358

 
$
720

 
$
755

 
$
1,328

Cost of revenue—support subscription
2,245

 
2,929

 
4,019

 
5,613

Research and development
17,971

 
22,232

 
33,559

 
43,322

Sales and marketing
11,439

 
17,269

 
22,065

 
31,209

General and administrative
4,825

 
10,504

 
8,659

 
16,137

Total stock-based compensation expense
$
36,838

 
$
53,654

 
$
69,057

 
$
97,609

v3.10.0.1
Net Loss per Share Attributable to Common Stockholders (Tables)
6 Months Ended
Jul. 31, 2018
Earnings Per Share [Abstract]  
Summary of Computation of Basic and Diluted Net Loss per Share Attributable to Common Stockholders
The following table sets forth the computation of basic and diluted net loss per share attributable to common stockholders (in thousands, except per share data):
 
 
Three Months Ended July 31,
 
Six Months Ended July 31,
 
2017
 
2018
 
2017
 
2018
 
(As Adjusted*)
 
 
 
(As Adjusted*)
 
 
Net loss
$
(58,411
)
 
$
(60,123
)
 
$
(115,570
)
 
$
(124,427
)
Weighted-average shares used in computing net loss per share attributable to common stockholders, basic and diluted
209,193

 
229,359

 
207,515

 
226,609

Net loss per share attributable to common stockholders, basic and diluted
$
(0.28
)
 
$
(0.26
)
 
$
(0.56
)
 
$
(0.55
)


* Prior period information has been adjusted to reflect the adoption impact of ASC 606, which we adopted on February 1, 2018.

Summary of Weighted-average Outstanding Shares Excluded from Computation of Diluted Net Loss per Share Attributable to Common Stockholders
The following weighted-average outstanding shares of common stock equivalents were excluded from the computation of diluted net loss per share attributable to common stockholders for the periods presented because including them would have been anti-dilutive (in thousands):
 
 
Three Months Ended July 31,
 
Six Months Ended July 31,
 
2017
 
2018
 
2017
 
2018
Stock options to purchase common stock
53,878

 
40,920

 
54,864

 
42,923

Restricted stock units
15,710

 
19,957

 
13,759

 
19,486

Restricted stock and early exercised stock options
279

 
3,327

 
333

 
2,585

Employee stock purchase plan
898

 
1,154

 
898

 
1,127

Total
70,765

 
65,358

 
69,854

 
66,121

v3.10.0.1
Segment Information (Tables)
6 Months Ended
Jul. 31, 2018
Segment Reporting [Abstract]  
Schedule of Revenue by Geographic Area
The following table depicts the disaggregation of revenue by geographic area based on the billing address of our customers and is consistent with how we evaluate our financial performance (in thousands):
 
 
Three Months Ended July 31,
 
Six Months Ended July 31,
 
2017
 
2018
 
2017
 
2018
 
(As Adjusted*)
 
 
 
(As Adjusted*)
 
 
United States
$
165,620

 
$
229,760

 
$
312,125

 
$
414,678

Rest of the world
59,050

 
79,124

 
95,190

 
150,151

Total revenue
$
224,670

 
$
308,884

 
$
407,315

 
$
564,829


* Prior period information has been adjusted to reflect the adoption impact of ASC 606, which we adopted on February 1, 2018.

Schedule of Long-Lived Assets by Geographic Area
Long-lived assets by geographic area are summarized as follows (in thousands):
 
 
As of
January 31, 2018
 
As of
July 31, 2018
United States
$
85,430

 
$
97,250

Rest of the world
3,712

 
4,468

Total long-lived assets
$
89,142

 
$
101,718

v3.10.0.1
Basis of Presentation and Summary of Significant Accounting Policies - Restricted Cash (Details) - USD ($)
$ in Thousands
Jul. 31, 2018
Jan. 31, 2018
Jul. 31, 2017
Accounting Policies [Abstract]      
Restricted cash $ 15,778 $ 14,763 [1] $ 12,734 [2]
[1] *Prior period information has been adjusted to reflect the adoption impact of Accounting Standards Codification 606, Revenue from Contracts with Customers (ASC 606), which we adopted on February 1, 2018.
[2] * Prior period information has been adjusted to reflect the adoption impact of ASC 606 and ASU 2016-18, which we adopted on February 1, 2018
v3.10.0.1
Basis of Presentation and Summary of Significant Accounting Policies - Deferred Commissions (Details) - USD ($)
3 Months Ended 6 Months Ended
Jul. 31, 2018
Jul. 31, 2017
Jul. 31, 2018
Jul. 31, 2017
Accounting Policies [Abstract]        
Remaining amortization period     6 years  
Contract Assets        
Beginning balance $ 86,044,000   $ 87,313,000  
Additions 24,582,000   40,003,000  
Recognition of deferred commissions (19,157,000)   (35,847,000)  
Ending balance as of July 31, 2018 91,469,000   91,469,000  
Impairment loss, capitalized commissions $ 0 $ 0 $ 0 $ 0
v3.10.0.1
Basis of Presentation and Summary of Significant Accounting Policies - Deferred Commissions (Typed Dimensions) (Details) - Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2018-08-01
6 Months Ended
Jul. 31, 2018
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items]  
Remaining performance obligation, percentage 26.00%
Remaining performance obligation, expected timing 1 year
v3.10.0.1
Basis of Presentation and Summary of Significant Accounting Policies - Deferred Revenue (Details) - USD ($)
$ in Thousands
3 Months Ended 6 Months Ended
Jul. 31, 2018
Jul. 31, 2017
Jul. 31, 2018
Jul. 31, 2017
Contract Liability        
Beginning balance $ 388,614   $ 374,102  
Additions 92,511   167,782  
Recognition of deferred revenue 67,878   128,637  
Ending balance as of July 31, 2018 413,247   413,247  
Product Revenue and Support Subscription Revenue        
Contract Liability        
Deferred revenue recognized $ 60,900 $ 44,100 $ 106,200 $ 75,100
v3.10.0.1
Basis of Presentation and Summary of Significant Accounting Policies - Deferred Revenue (Typed Dimensions) (Details) - Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2018-08-01
6 Months Ended
Jul. 31, 2018
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items]  
Remaining performance obligation, percentage 52.00%
Remaining performance obligation, expected timing 1 year
v3.10.0.1
Basis of Presentation and Summary of Significant Accounting Policies - Recently Adopted Accounting Pronouncements (Balance Sheet) (Details) - USD ($)
$ in Thousands
Jul. 31, 2018
Apr. 30, 2018
Jan. 31, 2018
Assets      
Deferred commissions, current     $ 21,088
Deferred commissions, non-current     66,225
Total deferred commissions $ 91,469 $ 86,044 87,313
Liabilities      
Deferred revenue, current     191,229
Deferred revenue, non-current     182,873
Total deferred revenue 413,247 $ 388,614 374,102
Stockholders' equity      
Accumulated deficit $ (1,028,014)   (903,587) [1]
As Previously Reported      
Assets      
Deferred commissions, current     22,437
Deferred commissions, non-current     20,288
Total deferred commissions     42,725
Liabilities      
Deferred revenue, current     209,377
Deferred revenue, non-current     196,632
Total deferred revenue     406,009
Stockholders' equity      
Accumulated deficit     (980,082)
Adjustment | Accounting Standards Update 2014-09      
Assets      
Deferred commissions, current     (1,349)
Deferred commissions, non-current     45,937
Total deferred commissions     44,588
Liabilities      
Deferred revenue, current     (18,148)
Deferred revenue, non-current     (13,759)
Total deferred revenue     (31,907)
Stockholders' equity      
Accumulated deficit     $ 76,495
[1] *Prior period information has been adjusted to reflect the adoption impact of Accounting Standards Codification 606, Revenue from Contracts with Customers (ASC 606), which we adopted on February 1, 2018.
v3.10.0.1
Basis of Presentation and Summary of Significant Accounting Policies - Recently Adopted Accounting Pronouncements (Statement of Operations) (Details) - USD ($)
$ / shares in Units, $ in Thousands
3 Months Ended 6 Months Ended
Jul. 31, 2018
Jul. 31, 2017
Jul. 31, 2018
Jul. 31, 2017
Revenue:        
Product $ 241,137 $ 179,669 [1] $ 436,586 $ 322,519
Support subscription 67,747 45,001 [1] 128,243 84,796
Total revenue 308,884 224,670 [1] 564,829 407,315
Gross profit 206,165 148,219 [1] 372,480 267,316
Sales and marketing 143,749 117,552 [1] 266,116 209,315
Total operating expenses 261,371 209,075 [1] 489,560 386,362
Loss from operations (55,206) (60,856) [1] (117,080) (119,046)
Loss before provision for income taxes (59,238) (57,590) [1] (122,111) (113,785)
Net loss $ (60,123) $ (58,411) [1],[2] $ (124,427) $ (115,570) [3]
Net loss per share attributable to common stockholders, basic and diluted (in dollars per share) $ (0.26) $ (0.28) [1] $ (0.55) $ (0.56)
As Previously Reported        
Revenue:        
Product   $ 175,013   $ 313,438
Support subscription   49,448   93,654
Total revenue   224,461   407,092
Gross profit   148,010   267,093
Sales and marketing   120,633   217,597
Total operating expenses   212,156   394,644
Loss from operations   (64,146)   (127,551)
Loss before provision for income taxes   (60,880)   (122,290)
Net loss   $ (61,701)   $ (124,075)
Net loss per share attributable to common stockholders, basic and diluted (in dollars per share)   $ (0.29)   $ (0.60)
Adjustment | Accounting Standards Update 2014-09        
Revenue:        
Product   $ 4,656   $ 9,081
Support subscription   (4,447)   (8,858)
Total revenue   209   223
Gross profit   209   223
Sales and marketing   (3,081)   (8,282)
Total operating expenses   (3,081)   (8,282)
Loss from operations   3,290   8,505
Loss before provision for income taxes   3,290   8,505
Net loss   $ 3,290   $ 8,505
Net loss per share attributable to common stockholders, basic and diluted (in dollars per share)   $ 0.01   $ 0.04
[1] * Prior period information has been adjusted to reflect the adoption impact of ASC 606, which we adopted on February 1, 2018.
[2] * Prior period information has been adjusted to reflect the adoption impact of ASC 606, which we adopted on February 1, 2018.
[3] * Prior period information has been adjusted to reflect the adoption impact of ASC 606 and ASU 2016-18, which we adopted on February 1, 2018
v3.10.0.1
Basis of Presentation and Summary of Significant Accounting Policies - Recently Adopted Accounting Pronouncements (Revenue) (Details) - USD ($)
$ in Thousands
3 Months Ended 6 Months Ended
Jul. 31, 2018
Jul. 31, 2017
Jul. 31, 2018
Jul. 31, 2017
Revenue:        
Total revenue $ 308,884 $ 224,670 [1] $ 564,829 $ 407,315
As Previously Reported        
Revenue:        
Total revenue   224,461   407,092
Adjustment | Accounting Standards Update 2014-09        
Revenue:        
Total revenue   209   223
United States        
Revenue:        
Total revenue 229,760 165,620 414,678 312,125
United States | As Previously Reported        
Revenue:        
Total revenue   165,466   311,960
United States | Adjustment | Accounting Standards Update 2014-09        
Revenue:        
Total revenue   154   165
Rest of the world        
Revenue:        
Total revenue $ 79,124 59,050 $ 150,151 95,190
Rest of the world | As Previously Reported        
Revenue:        
Total revenue   58,995   95,132
Rest of the world | Adjustment | Accounting Standards Update 2014-09        
Revenue:        
Total revenue   $ 55   $ 58
[1] * Prior period information has been adjusted to reflect the adoption impact of ASC 606, which we adopted on February 1, 2018.
v3.10.0.1
Basis of Presentation and Summary of Significant Accounting Policies - Recently Adopted Accounting Pronouncements (Statement of Cash Flows) (Details) - USD ($)
$ in Thousands
3 Months Ended 6 Months Ended
Jul. 31, 2018
Jul. 31, 2017
Jul. 31, 2018
Jul. 31, 2017
Revenue, Initial Application Period Cumulative Effect Transition [Line Items]        
Net loss $ (60,123) $ (58,411) [1],[2] $ (124,427) $ (115,570) [3]
Adjustments to reconcile net loss to net cash provided by (used in) operating activities:        
Deferred commissions     (4,155) (9,587) [3]
Accrued compensation and other liabilities     (7,458) (2,993) [3]
Deferred revenue     39,144 24,251 [3]
Cash used in operating activities     27,080 (14,492) [3]
Cash, cash equivalents and restricted cash, beginning of period     258,820 196,409 [3]
Cash, cash equivalents and restricted cash, end of period $ 386,235 184,628 [3] $ 386,235 184,628 [3]
As Previously Reported        
Revenue, Initial Application Period Cumulative Effect Transition [Line Items]        
Net loss   (61,701)   (124,075)
Adjustments to reconcile net loss to net cash provided by (used in) operating activities:        
Deferred commissions       (4,607)
Accrued compensation and other liabilities       310
Deferred revenue       24,473
Cash used in operating activities       (14,492)
Cash, cash equivalents and restricted cash, beginning of period       183,675
Cash, cash equivalents and restricted cash, end of period   171,894   171,894
Adjustment | Accounting Standards Update 2014-09        
Revenue, Initial Application Period Cumulative Effect Transition [Line Items]        
Net loss   3,290   8,505
Adjustments to reconcile net loss to net cash provided by (used in) operating activities:        
Deferred commissions       (4,980)
Accrued compensation and other liabilities       (3,303)
Deferred revenue       (222)
Cash used in operating activities       0
Adjustment | Accounting Standards Update 2016-18        
Adjustments to reconcile net loss to net cash provided by (used in) operating activities:        
Cash, cash equivalents and restricted cash, beginning of period       12,734
Cash, cash equivalents and restricted cash, end of period   $ 12,734   $ 12,734
[1] * Prior period information has been adjusted to reflect the adoption impact of ASC 606, which we adopted on February 1, 2018.
[2] * Prior period information has been adjusted to reflect the adoption impact of ASC 606, which we adopted on February 1, 2018.
[3] * Prior period information has been adjusted to reflect the adoption impact of ASC 606 and ASU 2016-18, which we adopted on February 1, 2018
v3.10.0.1
Financial Instruments - Summary of Cash Equivalents, Marketable Securities and Restricted Cash by Significant Investment Categories (Details) - USD ($)
$ in Thousands
Jul. 31, 2018
Jan. 31, 2018
Schedule Of Available For Sale Securities [Line Items]    
Amortized Cost $ 798,545 $ 365,378
Gross Unrealized Gains 105 116
Gross Unrealized Losses (2,931) (2,033)
Fair Value 824,766 395,518
Cash Equivalents 72,783 27,466
Marketable Securities 736,205 353,289 [1]
Restricted Cash 15,778 14,763
Money market accounts | Level 1    
Schedule Of Available For Sale Securities [Line Items]    
Amortized Cost 0 0
Gross Unrealized Gains 0 0
Gross Unrealized Losses 0 0
Fair Value 29,047 32,057
Cash Equivalents 13,269 17,294
Marketable Securities 0 0
Restricted Cash 15,778 14,763
U.S. government treasury notes | Level 2    
Schedule Of Available For Sale Securities [Line Items]    
Amortized Cost 326,328 131,643
Gross Unrealized Gains 0 0
Gross Unrealized Losses (839) (651)
Fair Value 325,489 130,992
Cash Equivalents 58,320 10,172
Marketable Securities 267,169 120,820
Restricted Cash 0 0
U.S. government agencies | Level 2    
Schedule Of Available For Sale Securities [Line Items]    
Amortized Cost 76,443 47,229
Gross Unrealized Gains 0 0
Gross Unrealized Losses (374) (333)
Fair Value 76,069 46,896
Cash Equivalents 1,194 0
Marketable Securities 74,875 46,896
Restricted Cash 0 0
Corporate debt securities | Level 2    
Schedule Of Available For Sale Securities [Line Items]    
Amortized Cost 383,340 186,506
Gross Unrealized Gains 104 116
Gross Unrealized Losses (1,713) (1,049)
Fair Value 381,731 185,573
Cash Equivalents 0 0
Marketable Securities 381,731 185,573
Restricted Cash 0 $ 0
Foreign government bonds | Level 2    
Schedule Of Available For Sale Securities [Line Items]    
Amortized Cost 5,151  
Gross Unrealized Gains 1  
Gross Unrealized Losses (3)  
Fair Value 5,149  
Cash Equivalents 0  
Marketable Securities 5,149  
Restricted Cash 0  
Asset-backed securities | Level 2    
Schedule Of Available For Sale Securities [Line Items]    
Amortized Cost 7,283  
Gross Unrealized Gains 0  
Gross Unrealized Losses (2)  
Fair Value 7,281  
Cash Equivalents 0  
Marketable Securities 7,281  
Restricted Cash $ 0  
[1] *Prior period information has been adjusted to reflect the adoption impact of Accounting Standards Codification 606, Revenue from Contracts with Customers (ASC 606), which we adopted on February 1, 2018.
v3.10.0.1
Financial Instruments - Schedule of Amortized Cost and Estimated Fair Value of Marketable Securities by Contractual Maturity (Details)
$ in Thousands
Jul. 31, 2018
USD ($)
Investments, Debt and Equity Securities [Abstract]  
Due within one year, Amortized Cost $ 373,160
Due in one to five years, Amortized Cost 365,867
Total, Amortized Cost 739,027
Due within one year, Fair Value 372,316
Due in one to five years, Fair Value 363,889
Total, Fair Value $ 736,205
v3.10.0.1
Financial Instruments - Schedule of Gross Unrealized Losses and Fair Values for Investments that were in Continuous Unrealized Loss Position for Less Than 12 Months, Aggregated by Investments Category (Details)
$ in Thousands
Jul. 31, 2018
USD ($)
Fair Value  
Less than 12 months $ 607,179
Greater than 12 months 99,969
Total 707,148
Unrealized Loss  
Less than 12 months (2,169)
Greater than 12 months (762)
Total (2,931)
U.S. government treasury notes  
Fair Value  
Less than 12 months 271,578
Greater than 12 months 48,941
Total 320,519
Unrealized Loss  
Less than 12 months (483)
Greater than 12 months (356)
Total (839)
U.S. government agencies  
Fair Value  
Less than 12 months 55,695
Greater than 12 months 20,374
Total 76,069
Unrealized Loss  
Less than 12 months (227)
Greater than 12 months (147)
Total (374)
Corporate debt securities  
Fair Value  
Less than 12 months 271,946
Greater than 12 months 30,654
Total 302,600
Unrealized Loss  
Less than 12 months (1,454)
Greater than 12 months (259)
Total (1,713)
Foreign government bonds  
Fair Value  
Less than 12 months 2,944
Greater than 12 months 0
Total 2,944
Unrealized Loss  
Less than 12 months (3)
Greater than 12 months 0
Total (3)
Asset-backed securities  
Fair Value  
Less than 12 months 5,016
Greater than 12 months 0
Total 5,016
Unrealized Loss  
Less than 12 months (2)
Greater than 12 months 0
Total $ (2)
v3.10.0.1
Balance Sheet Components - Schedule of Inventory (Details) - USD ($)
$ in Thousands
Jul. 31, 2018
Jan. 31, 2018
Balance Sheet Components Disclosure [Abstract]    
Raw materials $ 2,828 $ 1,181
Finished goods 38,845 33,316
Inventory $ 41,673 $ 34,497
v3.10.0.1
Balance Sheet Components - Schedule of Property and Equipment, Net (Details) - USD ($)
$ in Thousands
Jul. 31, 2018
Jan. 31, 2018
Property Plant And Equipment [Line Items]    
Total property and equipment $ 278,148 $ 235,035
Less: accumulated depreciation and amortization (176,430) (145,893)
Property and equipment, net 101,718 89,142 [1]
Test equipment    
Property Plant And Equipment [Line Items]    
Total property and equipment 156,040 142,311
Computer equipment and software    
Property Plant And Equipment [Line Items]    
Total property and equipment 92,863 72,329
Furniture and fixtures    
Property Plant And Equipment [Line Items]    
Total property and equipment 5,482 5,363
Leasehold improvements    
Property Plant And Equipment [Line Items]    
Total property and equipment $ 23,763 $ 15,032
[1] *Prior period information has been adjusted to reflect the adoption impact of Accounting Standards Codification 606, Revenue from Contracts with Customers (ASC 606), which we adopted on February 1, 2018.
v3.10.0.1
Balance Sheet Components - Additional Information (Details) - USD ($)
$ in Millions
3 Months Ended 6 Months Ended
Jul. 31, 2018
Jul. 31, 2017
Jul. 31, 2018
Jul. 31, 2017
Balance Sheet Components Disclosure [Abstract]        
Depreciation and amortization $ 16.8 $ 14.8 $ 32.8 $ 29.2
Intangible assets amortization expense $ 0.4 $ 0.4 $ 0.8 $ 0.8
Finite-Lived Intangible Assets [Line Items]        
Weighted-average remaining useful life     2 years 10 months 24 days  
v3.10.0.1
Balance Sheet Components - Schedule of Intangible Assets, Net (Details) - USD ($)
$ in Thousands
Jul. 31, 2018
Jan. 31, 2018
Finite-Lived Intangible Assets [Line Items]    
Intangible assets, net $ 4,305 $ 5,057 [1]
Technology patents    
Finite-Lived Intangible Assets [Line Items]    
Technology patents 10,125 10,125
Accumulated amortization (5,820) (5,068)
Intangible assets, net $ 4,305 $ 5,057
[1] *Prior period information has been adjusted to reflect the adoption impact of Accounting Standards Codification 606, Revenue from Contracts with Customers (ASC 606), which we adopted on February 1, 2018.
v3.10.0.1
Balance Sheet Components - Schedule of Expected Amortization Expenses for Intangible Assets (Details) - USD ($)
$ in Thousands
Jul. 31, 2018
Jan. 31, 2018
[1]
Balance Sheet Components Disclosure [Abstract]    
Remainder of 2019 $ 752  
2020 1,504  
2021 1,504  
2022 545  
Intangible assets, net $ 4,305 $ 5,057
[1] *Prior period information has been adjusted to reflect the adoption impact of Accounting Standards Codification 606, Revenue from Contracts with Customers (ASC 606), which we adopted on February 1, 2018.
v3.10.0.1
Balance Sheet Components - Schedule of Accrued Expenses and Other Liabilities (Details) - USD ($)
$ in Thousands
Jul. 31, 2018
Jan. 31, 2018
Balance Sheet Components Disclosure [Abstract]    
Taxes payable $ 3,801 $ 4,052
Accrued marketing 5,017 5,928
Accrued travel and entertainment expenses 2,556 4,386
Other accrued liabilities 15,675 12,463
Total accrued expenses and other liabilities $ 27,049 $ 26,829
v3.10.0.1
Convertible Senior Notes (Details)
1 Months Ended 6 Months Ended
Apr. 30, 2018
USD ($)
day
shares
$ / shares
Jul. 31, 2018
USD ($)
$ / shares
Jul. 31, 2017
USD ($)
[1]
Apr. 04, 2018
$ / shares
Debt Instrument [Line Items]        
Proceeds from issuance of convertible senior notes, net of issuance costs   $ 562,062,000 $ 0  
Debt issuance costs, net of amortization $ 12,900,000      
Closing price of stock (in dollars per share) | $ / shares   $ 21.66    
Payment to enter into agreement   $ 64,630,000 $ 0  
Capped Call        
Debt Instrument [Line Items]        
Payment to enter into agreement 64,600,000      
Convertible Senior Notes        
Debt Instrument [Line Items]        
Debt issuance costs, net of amortization 9,800,000 9,337,000    
Additional Paid-in Capital        
Debt Instrument [Line Items]        
Debt issuance costs, net of amortization $ 3,100,000 $ 3,068,000    
Class A        
Debt Instrument [Line Items]        
Closing price of stock (in dollars per share) | $ / shares   $ 21.66   $ 19.83
Class A | Capped Call        
Debt Instrument [Line Items]        
Exercise price (in dollars per share) | $ / shares $ 39.66      
Exercise price premium percentage over last reported sales price       100.00%
Convertible Senior Notes        
Debt Instrument [Line Items]        
Principal amount $ 575,000,000.0      
Interest rate 0.125%      
Proceeds from issuance of convertible senior notes, net of issuance costs $ 562,100,000      
Conversion percentage of principal amount plus accrued and unpaid contingent interest 100.00%      
Convertible debt, fair value based on the closing trading price per $100 of the Notes   $ 607,200,000    
If-converted value   $ 474,000,000    
Convertible Senior Notes | Class A        
Debt Instrument [Line Items]        
Number of convertible shares at initial conversion rate (in shares) | shares 21,884,155      
Conversion ratio (in shares per $1,000 principal amount) 38.0594      
Conversion price (in dollars per share) | $ / shares $ 26.27      
Redemption percentage of principal amount of Notes to be redeemed 100.00%      
Convertible Senior Notes | Class A | Any Fiscal Quarter Commencing After The Fiscal Quarter Ending On July 31, 2018        
Debt Instrument [Line Items]        
Threshold trading days | day 20      
Threshold consecutive trading days | day 30      
Threshold percentage of stock price trigger 130.00%      
Convertible Senior Notes | Class A | Five Business Day Period After Any Five Consecutive Trading Day Period        
Debt Instrument [Line Items]        
Threshold consecutive trading days | day 5      
Threshold percentage of stock price trigger 98.00%      
Threshold business days | day 5      
Convertible Senior Notes | Class A | Immediately Preceding The Date On Which We Provide Notice Of Redemption        
Debt Instrument [Line Items]        
Threshold trading days | day 2      
[1] * Prior period information has been adjusted to reflect the adoption impact of ASC 606 and ASU 2016-18, which we adopted on February 1, 2018
v3.10.0.1
Convertible Senior Notes - Allocation of Notes (Details) - USD ($)
$ in Thousands
Apr. 30, 2018
Jul. 31, 2018
Liability:    
Less: debt issuance costs, net of amortization $ (12,900)  
Stockholders' equity:    
Less: debt issuance costs (12,900)  
Convertible Senior Notes    
Liability:    
Principal   $ 575,000
Less: debt discount, net of amortization   (128,976)
Less: debt issuance costs, net of amortization (9,800) (9,337)
Net carrying amount of the Notes   436,687
Stockholders' equity:    
Less: debt issuance costs (9,800) (9,337)
Additional Paid-in Capital    
Liability:    
Less: debt issuance costs, net of amortization (3,100) (3,068)
Stockholders' equity:    
Allocated value of the conversion feature 136,333  
Less: debt issuance costs (3,100) $ (3,068)
Additional paid-in capital $ 133,265  
v3.10.0.1
Convertible Senior Notes - Interest Expense (Details) - USD ($)
$ in Thousands
3 Months Ended 6 Months Ended
Jul. 31, 2018
Jul. 31, 2018
Jul. 31, 2017
[1]
Debt Instrument [Line Items]      
Total amortization of debt discount and debt issuance costs   $ 7,889 $ 0
Convertible Senior Notes      
Debt Instrument [Line Items]      
Amortization of debt discount $ 6,000 7,357  
Amortization of debt issuance costs 434 532  
Total amortization of debt discount and debt issuance costs 6,434 7,889  
Contractual interest expense 181 224  
Total interest expense related to the Notes $ 6,615 $ 8,113  
Effective interest rate of the liability component 5.60% 5.60%  
[1] * Prior period information has been adjusted to reflect the adoption impact of ASC 606 and ASU 2016-18, which we adopted on February 1, 2018
v3.10.0.1
Commitments and Contingencies - Additional Information (Details) - USD ($)
Jul. 31, 2018
Mar. 31, 2018
Jan. 31, 2018
Commitments and Contingencies Disclosure [Abstract]      
Base rent obligation $ 153,700,000   $ 113,000,000
Lessee, Lease, Description [Line Items]      
Outstanding letters of credit $ 10,800,000   $ 9,600,000
Letter of Credit      
Lessee, Lease, Description [Line Items]      
Principal amount   $ 1,500,000.0  
v3.10.0.1
Stockholders' Equity - Additional Information (Details)
$ / shares in Units, $ in Millions
1 Months Ended
Apr. 30, 2018
USD ($)
shares
Jul. 31, 2018
class
$ / shares
shares
Apr. 04, 2018
$ / shares
Jan. 31, 2018
$ / shares
shares
[1]
Class Of Stock [Line Items]        
Preferred stock, shares authorized (in shares)   20,000,000   20,000,000
Preferred stock, shares issued (in shares)   0   0
Preferred stock, shares outstanding (in shares)   0   0
Number of classes of stock | class   2    
Common stock, shares authorized (in shares)   2,250,000,000   2,250,000,000
Common stock, par value per share (in dollars per share) | $ / shares   $ 0.0001   $ 0.0001
Common stock, shares issued (in shares)   235,412,000   220,979,000
Common stock, shares outstanding (in shares)   235,412,000   220,979,000
Closing price of stock (in dollars per share) | $ / shares   $ 21.66    
Class A        
Class Of Stock [Line Items]        
Common stock, shares authorized (in shares)   2,000,000,000   2,000,000,000
Common stock, par value per share (in dollars per share) | $ / shares   $ 0.0001   $ 0.0001
Common stock, shares issued (in shares)   204,051,868   129,502,000
Common stock, shares outstanding (in shares)   204,051,868   129,502,000
Stock repurchased and retired during period (in shares) 1,008,573      
Stock repurchased and retired during period, value | $ $ 20.0      
Closing price of stock (in dollars per share) | $ / shares   $ 21.66 $ 19.83  
Class B        
Class Of Stock [Line Items]        
Common stock, shares authorized (in shares)   250,000,000   250,000,000
Common stock, par value per share (in dollars per share) | $ / shares   $ 0.0001   $ 0.0001
Common stock, shares issued (in shares)   31,359,938   91,477,000
Common stock, shares outstanding (in shares)   31,359,938   91,477,000
[1] *Prior period information has been adjusted to reflect the adoption impact of Accounting Standards Codification 606, Revenue from Contracts with Customers (ASC 606), which we adopted on February 1, 2018.
v3.10.0.1
Equity Incentive Plans - Additional Information (Details)
1 Months Ended 3 Months Ended 6 Months Ended
Mar. 16, 2016
Aug. 31, 2015
USD ($)
period
shares
Jul. 31, 2018
USD ($)
Jul. 31, 2017
USD ($)
Apr. 30, 2017
USD ($)
Jul. 31, 2018
USD ($)
plan
Jul. 31, 2017
USD ($)
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]              
Number of equity incentive plans | plan           2  
Total stock-based compensation expense     $ 53,654,000 $ 36,838,000   $ 97,609,000 $ 69,057,000
Compensation cost, weighted average term           2 years 1 month 6 days  
2015 Equity Incentive Plan              
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]              
Equity awards of vest expire period (no later than)           10 years  
2015 Equity Incentive Plan | Minimum              
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]              
Purchase price as percentage of fair market value of common stock           100.00%  
Equity awards of vest period           2 years  
2015 Equity Incentive Plan | Maximum              
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]              
Equity awards of vest period           4 years  
2015 Employee Stock Purchase Plan              
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]              
Employee stock purchase plan offering period 24 months            
Number of purchase periods | period   4          
Purchase period, term   6 months          
Total stock-based compensation expense     7,900,000 $ 3,800,000   $ 14,600,000 $ 7,900,000
Unrecognized stock-based compensation expense     $ 23,900,000     $ 23,900,000  
Compensation cost, weighted average term           10 months 24 days  
2015 Employee Stock Purchase Plan | Class A              
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]              
Purchase price as percentage of fair market value of common stock   85.00%          
Payroll deductions percentage   30.00%          
Share cap for ESPP at purchase date (in shares) | shares   3,000          
Calendar year gap for ESPP contribution amount   $ 25,000          
Modification charges         $ 9,000,000    
v3.10.0.1
Equity Incentive Plans - Stock Options (Details) - USD ($)
$ / shares in Units, $ in Thousands
6 Months Ended 12 Months Ended
Jul. 31, 2018
Jan. 31, 2017
Apr. 04, 2018
Jan. 31, 2018
Options Outstanding, Number of Shares        
Beginning balance (in shares) 46,359,949      
Options exercised (in shares) (5,884,173)      
Options forfeited/cancelled (in shares) (1,191,720)      
Ending balance (in shares) 39,284,056      
Options Outstanding, Number of Shares, Vested and exercisable (in shares) 26,675,832      
Options Outstanding, Weighted Average Exercise Price        
Beginning balance (in dollars per share) $ 7.75      
Options exercised (in dollars per share) 4.94      
Options forfeited/cancelled (in dollars per share) 9.36      
Ending balance (in dollars per share) 8.12      
Weighted Average Exercise Price, Vested and exercisable (in dollars per share) $ 6.00      
Weighted- Average Remaining Contractual Life        
Weighted Average Remaining Contractual Life 5 years 10 months 24 days 6 years 3 months 18 days    
Weighted Average Remaining Contractual Life, Vested and exercisable 5 years 4 months 24 days      
Aggregate Intrinsic Value        
Aggregate Intrinsic Value $ 531,664     $ 574,224
Aggregate Intrinsic Value, Vested and exercisable $ 417,651      
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]        
Closing price of stock (in dollars per share) $ 21.66      
Unrecognized compensation cost, stock options $ 49,600      
Compensation cost, weighted average term 2 years 1 month 6 days      
Class A        
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]        
Closing price of stock (in dollars per share) $ 21.66   $ 19.83  
v3.10.0.1
Equity Incentive Plans - Restricted Stock Units (Details) - USD ($)
$ / shares in Units, $ in Thousands
1 Months Ended 3 Months Ended 6 Months Ended
Mar. 31, 2018
Aug. 31, 2017
Mar. 30, 2017
Jul. 31, 2018
Jul. 31, 2017
Jul. 31, 2018
Jul. 31, 2017
Jan. 31, 2018
Weighted-Average Grant Date Fair Value                
Compensation cost, weighted average term           2 years 1 month 6 days    
Stock-based compensation expense       $ 53,654 $ 36,838 $ 97,609 $ 69,057  
Restricted Stock Units                
Number of Restricted Stock Units Outstanding                
Unvested, Beginning balance (in shares)           17,682,646    
Granted (in shares)           7,751,921    
Vested (in shares)           (4,117,282)    
Forfeited (in shares)           (858,561)    
Converted (in shares)           (1,142,838)    
Unvested, Ending balance (in shares) 1,375,210     19,315,886   19,315,886    
Weighted-Average Grant Date Fair Value                
Beginning balance (in dollars per share)           $ 12.60    
Granted (in dollars per share)           20.79    
Vested (in dollars per share)           12.50    
Forfeited (in dollars per share)           14.18    
Converted (in dollars per share)           11.86    
Ending balance (in dollars per share)       $ 15.87   $ 15.87    
Aggregate Intrinsic Value       $ 418,359   $ 418,359   $ 356,117
Compensation not yet recognized       273,300   $ 273,300    
Compensation cost, weighted average term           3 years    
Performance Shares | Granted March 2017                
Number of Restricted Stock Units Outstanding                
Granted (in shares)     750,000          
Forfeited (in shares)     (77,000)          
Weighted-Average Grant Date Fair Value                
Earned (in shares) 780,000              
Stock-based compensation expense       $ 500 $ 1,200 $ 1,500 $ 1,600  
Performance Shares | Granted March 2017 | Minimum                
Weighted-Average Grant Date Fair Value                
Award vesting rights, percentage     0.00%          
Performance Shares | Granted March 2017 | Maximum                
Weighted-Average Grant Date Fair Value                
Award vesting rights, percentage     150.00%          
Performance Shares | Granted August 2017                
Number of Restricted Stock Units Outstanding                
Granted (in shares)   464,744            
Weighted-Average Grant Date Fair Value                
Award vesting rights, percentage   100.00%            
Performance Shares | Granted August 2017 | Minimum                
Weighted-Average Grant Date Fair Value                
Award vesting rights, percentage   0.00%            
Performance Shares | Granted August 2017 | Maximum                
Weighted-Average Grant Date Fair Value                
Award vesting rights, percentage   150.00%            
v3.10.0.1
Equity Incentive Plans - Restricted Stock (Details) - USD ($)
$ in Thousands
3 Months Ended 6 Months Ended
Jul. 31, 2018
Jul. 31, 2017
Jul. 31, 2018
Jul. 31, 2017
Mar. 31, 2018
Jan. 31, 2018
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]            
Stock-based compensation expense $ 53,654 $ 36,838 $ 97,609 $ 69,057    
Compensation cost, weighted average term     2 years 1 month 6 days      
Restricted Stock Units            
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]            
Award balance (in shares) 19,315,886   19,315,886   1,375,210 17,682,646
Issued (in shares)     7,751,921      
Compensation cost, weighted average term     3 years      
Restricted Stock            
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]            
Stock-based compensation expense $ 6,700   $ 10,200      
Unrecognized stock-based compensation expense $ 31,700   $ 31,700      
Compensation cost, weighted average term     2 years 7 months 6 days      
Restricted Stock | Performance Vesting Conditions            
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]            
Award balance (in shares)         697,116  
Restricted Stock | Service Vesting Conditions            
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]            
Award balance (in shares)         678,094  
Restricted Stock | Performance Vesting At Maximum            
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]            
Issued (in shares) 21,047   1,954,908      
Restricted Stock | Maximum | Performance Vesting At Maximum            
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]            
Award vesting rights, percentage     180.00%      
Restricted Stock | Minimum | Performance Vesting At Maximum            
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]            
Award vesting rights, percentage     0.00%      
v3.10.0.1
Equity Incentive Plans - Stock-Based Compensation Expenses (Details) - USD ($)
$ in Thousands
3 Months Ended 6 Months Ended
Jul. 31, 2018
Jul. 31, 2017
Jul. 31, 2018
Jul. 31, 2017
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]        
Total stock-based compensation expense $ 53,654 $ 36,838 $ 97,609 $ 69,057
Cost of revenue—product        
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]        
Total stock-based compensation expense 720 358 1,328 755
Cost of revenue—support subscription        
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]        
Total stock-based compensation expense 2,929 2,245 5,613 4,019
Research and development        
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]        
Total stock-based compensation expense 22,232 17,971 43,322 33,559
Sales and marketing        
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]        
Total stock-based compensation expense 17,269 11,439 31,209 22,065
General and administrative        
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]        
Total stock-based compensation expense $ 10,504 $ 4,825 $ 16,137 $ 8,659
v3.10.0.1
Net Loss per Share Attributable to Common Stockholders - Summary of Computation of Basic and Diluted Net Loss per Share Attributable to Common Stockholders (Details) - USD ($)
$ / shares in Units, shares in Thousands, $ in Thousands
3 Months Ended 6 Months Ended
Jul. 31, 2018
Jul. 31, 2017
[1]
Jul. 31, 2018
Jul. 31, 2017
Earnings Per Share [Abstract]        
Net loss $ (60,123) $ (58,411) [2] $ (124,427) $ (115,570) [3]
Weighted-average shares used in computing net loss per share attributable to common stockholders, basic and diluted (in shares) 229,359 209,193 226,609 207,515
Net loss per share attributable to common stockholders, basic and diluted (in dollars per share) $ (0.26) $ (0.28) $ (0.55) $ (0.56)
[1] * Prior period information has been adjusted to reflect the adoption impact of ASC 606, which we adopted on February 1, 2018.
[2] * Prior period information has been adjusted to reflect the adoption impact of ASC 606, which we adopted on February 1, 2018.
[3] * Prior period information has been adjusted to reflect the adoption impact of ASC 606 and ASU 2016-18, which we adopted on February 1, 2018
v3.10.0.1
Net Loss per Share Attributable to Common Stockholders - Summary of Weighted-average Outstanding Shares Excluded from Computation of Diluted Net Loss per Share Attributable to Common Stockholders (Details) - shares
shares in Thousands
3 Months Ended 6 Months Ended
Jul. 31, 2018
Jul. 31, 2017
Jul. 31, 2018
Jul. 31, 2017
Antidilutive Securities Excluded From Computation Of Earnings Per Share [Line Items]        
Anti-dilutive securities excluded from computation of earnings per share, amount (in shares) 65,358 70,765 66,121 69,854
Stock options to purchase common stock        
Antidilutive Securities Excluded From Computation Of Earnings Per Share [Line Items]        
Anti-dilutive securities excluded from computation of earnings per share, amount (in shares) 40,920 53,878 42,923 54,864
Restricted stock units        
Antidilutive Securities Excluded From Computation Of Earnings Per Share [Line Items]        
Anti-dilutive securities excluded from computation of earnings per share, amount (in shares) 19,957 15,710 19,486 13,759
Restricted stock and early exercised stock options        
Antidilutive Securities Excluded From Computation Of Earnings Per Share [Line Items]        
Anti-dilutive securities excluded from computation of earnings per share, amount (in shares) 3,327 279 2,585 333
Employee stock purchase plan        
Antidilutive Securities Excluded From Computation Of Earnings Per Share [Line Items]        
Anti-dilutive securities excluded from computation of earnings per share, amount (in shares) 1,154 898 1,127 898
v3.10.0.1
Segment Information - Additional Information (Details)
6 Months Ended
Jul. 31, 2018
segment
Segment Reporting [Abstract]  
Number of business activity 1
Number of reportable segments 1
v3.10.0.1
Segment Information - Schedule of Revenue by Geographic Area (Details) - USD ($)
$ in Thousands
3 Months Ended 6 Months Ended
Jul. 31, 2018
Jul. 31, 2017
Jul. 31, 2018
Jul. 31, 2017
Revenues From External Customers And Long Lived Assets [Line Items]        
Total revenue $ 308,884 $ 224,670 [1] $ 564,829 $ 407,315
United States        
Revenues From External Customers And Long Lived Assets [Line Items]        
Total revenue 229,760 165,620 414,678 312,125
Rest of the world        
Revenues From External Customers And Long Lived Assets [Line Items]        
Total revenue $ 79,124 $ 59,050 $ 150,151 $ 95,190
[1] * Prior period information has been adjusted to reflect the adoption impact of ASC 606, which we adopted on February 1, 2018.
v3.10.0.1
Segment Information - Schedule of Long-Lived Assets by Geographic Area (Details) - USD ($)
$ in Thousands
Jul. 31, 2018
Jan. 31, 2018
Revenues From External Customers And Long Lived Assets [Line Items]    
Total long-lived assets $ 101,718 $ 89,142 [1]
United States    
Revenues From External Customers And Long Lived Assets [Line Items]    
Total long-lived assets 97,250 85,430
Rest of the world    
Revenues From External Customers And Long Lived Assets [Line Items]    
Total long-lived assets $ 4,468 $ 3,712
[1] *Prior period information has been adjusted to reflect the adoption impact of Accounting Standards Codification 606, Revenue from Contracts with Customers (ASC 606), which we adopted on February 1, 2018.
v3.10.0.1
Subsequent Event (Details)
$ in Millions
1 Months Ended
Aug. 31, 2018
USD ($)
Subsequent Event | StorReduce, Inc.  
Subsequent Event [Line Items]  
Cash consideration $ 25