Basis of Presentation and Summary of Significant Accounting Policies	6 Months Ended
Jul. 31, 2017
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, 2017. 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 2018 or any future period. 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 best estimate of selling price included in multiple-element revenue arrangements, sales commissions, useful lives of intangible assets and property and equipment, fair values of stock-based awards, provision for income taxes, including related reserves, and contingent liabilities, among others. 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 for a vendor credit card program and letters of credit related to our facility leases. As of both January 31, 2017 and July 31, 2017, we had restricted cash of $12.7 million, which was included in other assets, non-current, in 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 other comprehensive income (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, net, in the condensed consolidated statements of operations. Deferred Commissions Deferred commissions consist of direct and incremental costs paid to our sales force related to customer contracts. The deferred commission amounts are recoverable through the revenue streams that will be recognized under the related customer contracts. Direct sales commissions are deferred when earned and amortized over the same period that revenue is recognized from the related customer contract. Amortization of deferred commissions is included in sales and marketing expense in the condensed consolidated statements of operations. As of January 31, 2017 and July 31, 2017, we recorded deferred commissions, current, of $15.8 million and $19.7 million, and deferred commissions, non-current, of $14.9 million and $15.6 million, in other assets, non-current, in the condensed consolidated balance sheets. We recognized sales commission expenses of $19.6 million and $25.5 million during the three months ended July 31, 2016 and 2017, and $37.2 million and $46.0 million during the six months July 31, 2016 and 2017, respectively. Recent Accounting Pronouncements Not Yet Adopted 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), 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. ASU 2014-09 will supersede nearly all existing revenue recognition guidance under U.S. GAAP when it becomes effective. In August 2015, the FASB issued ASU No. 2015-14, Revenue from Contracts with Customers, deferring the effective date for ASU 2014-09 by one year. The new standard will be effective for us beginning on February 1, 2018 which is the mandatory adoption date and we do not plan to early adopt. This standard may be adopted using either the full or modified retrospective methods. We currently anticipate adopting the standard retrospectively to all prior periods presented. We are evaluating the impact of the new standard on our accounting policies, processes, and system requirements, and have assigned internal and external resources to assist in our evaluation and system implementation. We have made and will continue to make investments in systems to enable timely and accurate reporting under the new standard. We are also evaluating the potential impact that the implementation of this standard will have on our consolidated financial statements. 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. The amendments in this update will be effective for us beginning on February 1, 2019 and must be adopted using a modified retrospective method for leases existing at, or entered into after, the beginning of the earliest comparative period presented in the financial statements. Early adoption is permitted. We are currently evaluating adoption methods and the impact of this standard 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 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 amounts generally described as restricted cash or restricted cash equivalents. Therefore, amounts generally described as restricted cash and restricted cash equivalents should be 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. ASU 2016-18 will be effective for us beginning on February 1, 2018 and will be applied on a retrospective basis. Early adoption is permitted. We do not expect the adoption of this standard to have any material impact on our consolidated financial statements. In May 2017, the FASB issued ASU No 2017-09, Compensation—Stock Compensation (Topic 718) — Scope of Modification Accounting, to clarify when to account for a change to the terms or conditions of a share-based payment award as a modification. Under the new standard, modification is required only if the fair value, the vesting conditions, or the classification of an award as equity or liability changes as a result of the change in terms or conditions. ASU 2017-09 will be effective for us beginning February 1, 2018 and will be applied prospectively. Early adoption is permitted. We are currently evaluating the impact of this standard on our consolidated financial statements.

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, 2017.

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 2018 or any future period.

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 best estimate of selling price included in multiple-element revenue arrangements, sales commissions, useful lives of intangible assets and property and equipment, fair values of stock-based awards, provision for income taxes, including related reserves, and contingent liabilities, among others. 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 for a vendor credit card program and letters of credit related to our facility leases. As of both January 31, 2017 and July 31, 2017, we had restricted cash of $12.7 million, which was included in other assets, non-current, in 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 other comprehensive income (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, net, in the condensed consolidated statements of operations.

Deferred Commissions

Deferred commissions consist of direct and incremental costs paid to our sales force related to customer contracts. The deferred commission amounts are recoverable through the revenue streams that will be recognized under the related customer contracts. Direct sales commissions are deferred when earned and amortized over the same period that revenue is recognized from the related customer contract. Amortization of deferred commissions is included in sales and marketing expense in the condensed consolidated statements of operations.

As of January 31, 2017 and July 31, 2017, we recorded deferred commissions, current, of $15.8 million and $19.7 million, and deferred commissions, non-current, of $14.9 million and $15.6 million, in other assets, non-current, in the condensed consolidated balance sheets. We recognized sales commission expenses of $19.6 million and $25.5 million during the three months ended July 31, 2016 and 2017, and $37.2 million and $46.0 million during the six months July 31, 2016 and 2017, respectively.

Recent Accounting Pronouncements Not Yet Adopted

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), 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. ASU 2014-09 will supersede nearly all existing revenue recognition guidance under U.S. GAAP when it becomes effective. In August 2015, the FASB issued ASU No. 2015-14, Revenue from Contracts with Customers, deferring the effective date for ASU 2014-09 by one year. The new standard will be effective for us beginning on February 1, 2018 which is the mandatory adoption date and we do not plan to early adopt. This standard may be adopted using either the full or modified retrospective methods. We currently anticipate adopting the standard retrospectively to all prior periods presented. We are evaluating the impact of the new standard on our accounting policies, processes, and system requirements, and have assigned internal and external resources to assist in our evaluation and system implementation. We have made and will continue to make investments in systems to enable timely and accurate reporting under the new standard. We are also evaluating the potential impact that the implementation of this standard will have on our consolidated financial statements.

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. The amendments in this update will be effective for us beginning on February 1, 2019 and must be adopted using a modified retrospective method for leases existing at, or entered into after, the beginning of the earliest comparative period presented in the financial statements. Early adoption is permitted. We are currently evaluating adoption methods and the impact of this standard 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 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 amounts generally described as restricted cash or restricted cash equivalents. Therefore, amounts generally described as restricted cash and restricted cash equivalents should be 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. ASU 2016-18 will be effective for us beginning on February 1, 2018 and will be applied on a retrospective basis. Early adoption is permitted. We do not expect the adoption of this standard to have any material impact on our consolidated financial statements.

In May 2017, the FASB issued ASU No 2017-09, Compensation—Stock Compensation (Topic 718) — Scope of Modification Accounting, to clarify when to account for a change to the terms or conditions of a share-based payment award as a modification. Under the new standard, modification is required only if the fair value, the vesting conditions, or the classification of an award as equity or liability changes as a result of the change in terms or conditions. ASU 2017-09 will be effective for us beginning February 1, 2018 and will be applied prospectively. Early adoption is permitted. We are currently evaluating the impact of this standard on our consolidated financial statements.