Basis of Presentation and Summary of Significant Accounting Policies	9 Months Ended
Sep. 30, 2016
Accounting Policies [Abstract]
Basis of Presentation and Summary of Significant Accounting Policies	1. Basis of Presentation and Summary of Significant Accounting Policies Business Imperva, Inc. (together with its subsidiaries, the “Company”) was incorporated in April 2002 in Delaware. The Company is headquartered in Redwood Shores, California and has subsidiaries located throughout the world including Israel, Asia and Europe. The Company is engaged in the development, marketing, sales, service and support of cyber-security solutions that protect business-critical data and applications whether in the cloud or on premises. Basis of Presentation The Company has prepared the accompanying unaudited Condensed Consolidated Financial Statements in accordance with Article 10 of Regulation S-X and pursuant to the rules and regulations for Form 10-Q of the Securities and Exchange Commission (the “SEC”). Pursuant to those rules and regulations, the Company has condensed or omitted certain information and footnote disclosure it normally includes in its annual consolidated financial statements prepared in accordance with U.S. generally accepted accounting principles (“GAAP”). In management’s opinion, the Company has made all adjustments (consisting only of normal, recurring adjustments, except as otherwise indicated) necessary to fairly present its consolidated financial position, results of operations, and cash flows. The Company’s interim period operating results do not necessarily indicate the results that may be expected for any other interim period or for the full fiscal year. These financial statements and accompanying notes should be read in conjunction with the consolidated financial statements and notes thereto in the Company’s Annual Report on Form 10-K for the year ended December 31, 2015, which was filed with the SEC on February 26, 2016 (the “Annual Report”). The condensed consolidated financial statements include the accounts of the Company and its wholly-owned subsidiaries. All intercompany balances and transactions have been eliminated in consolidation. Concentration of Revenue and Accounts Receivable Significant customers are those which represent 10% or more of the Company’s total revenue or gross accounts receivable balance at each respective balance sheet date. For the three and nine months ended September 30, 2016, the Company had one customer that represented 13% and 13% of the Company’s total revenue respectively and the same customer represented 15% and 21% of accounts receivable as of September 30, 2016 and December 31, 2015 respectively. For the three and nine months ended September 30, 2015, the Company had one customer that represented 19% and 18% of the Company’s total revenue, respectively. Significant Accounting Policies There have been no material changes to the Company’s significant accounting policies as compared to the significant accounting policies described in the Company’s Annual Report on Form 10-K for the year ended December 31, 2015. Recent Accounting Pronouncements In August 2016, the Financial Accounting Standards Board ("FASB") issued Accounting Standards Update ("ASU") No. 2016-15, Statement of Cash Flows (Topic 230): Classification of Certain Cash Receipts and Cash Payments. The new standard will make eight targeted changes to how cash receipts and cash payments are presented and classified in the statement of cash flows. The standard will be effective for the Company beginning January 1, 2018, with early application permitted. The standard will require adoption on a retrospective basis unless it is impracticable to apply, in which case we would be required to apply the amendments prospectively as of the earliest date practicable. We are evaluating the impact of adopting this new accounting guidance 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. The new standard requires financial assets measured at amortized cost be presented at the net amount expected to be collected, through an allowance for credit losses that is deducted from the amortized cost basis. The standard will be effective for the Company beginning January 1, 2020, with early application permitted. The Company is evaluating the impact of adopting this new accounting guidance on its consolidated financial statements. In March 2016, the FASB Issued ASU No. 2016-09, Compensation-Stock Compensation (Topic 718): Improvements to Employee Share-Based Payment Accounting. The updated guidance changes how companies account for certain aspects of share-based payment awards to employees, including the accounting for income taxes, forfeitures, and statutory tax withholding requirements, as well as classification in the statement of cash flows. The standard will be effective for the Company beginning January 1, 2017, with early application permitted. The Company is evaluating the impact of adopting this new accounting guidance on its consolidated financial statements. In February 2016, the FASB issued Accounting Standards Update No. 2016-02 regarding ASC Topic 842 "Leases." The amendments in this guidance require balance sheet recognition of lease assets and lease liabilities by lessees for leases classified as operating leases, with an optional policy election to not recognize lease assets and lease liabilities for leases with a term of 12 months or less. The amendments also require new disclosures, including qualitative and quantitative requirements, providing additional information about the amounts recorded in the financial statements. The standard will be effective for the Company beginning January 1, 2019. The amendments require a modified retrospective approach with optional practical expedients. The Company is evaluating the impact of adopting this new accounting guidance on its consolidated financial statements. In May 2014, the FASB issued ASU No. 2014-09—Revenue (Topic 606): Revenue from Contracts with Customers. ASU No. 2014-09 will replace most existing U.S. GAAP guidance on this topic. The new revenue recognition standard provides a unified model to determine when and how revenue is recognized. The core principle is that a company should recognize revenue to depict the transfer of promised goods or services to customers in an amount that reflects the consideration for which the entity expects to be entitled in exchange for those goods or services. In July 2015, the FASB approved a one-year deferral of the effective date for the new revenue reporting standard for entities reporting under U.S. GAAP. In accordance with the deferral, this guidance will be effective for the Company beginning January 1, 2018 and can be applied either retrospectively to each period presented or as a cumulative-effect adjustment as of the date of adoption. Early adoption is permitted beginning January 1, 2017. The Company is evaluating the impact of adopting this new accounting standard on its consolidated financial statements and has not selected a transition method.

1. Basis of Presentation and Summary of Significant Accounting Policies

Business

Imperva, Inc. (together with its subsidiaries, the “Company”) was incorporated in April 2002 in Delaware. The Company is headquartered in Redwood Shores, California and has subsidiaries located throughout the world including Israel, Asia and Europe. The Company is engaged in the development, marketing, sales, service and support of cyber-security solutions that protect business-critical data and applications whether in the cloud or on premises.

Basis of Presentation

The Company has prepared the accompanying unaudited Condensed Consolidated Financial Statements in accordance with Article 10 of Regulation S-X and pursuant to the rules and regulations for Form 10-Q of the Securities and Exchange Commission (the “SEC”). Pursuant to those rules and regulations, the Company has condensed or omitted certain information and footnote disclosure it normally includes in its annual consolidated financial statements prepared in accordance with U.S. generally accepted accounting principles (“GAAP”). In management’s opinion, the Company has made all adjustments (consisting only of normal, recurring adjustments, except as otherwise indicated) necessary to fairly present its consolidated financial position, results of operations, and cash flows. The Company’s interim period operating results do not necessarily indicate the results that may be expected for any other interim period or for the full fiscal year. These financial statements and accompanying notes should be read in conjunction with the consolidated financial statements and notes thereto in the Company’s Annual Report on Form 10-K for the year ended December 31, 2015, which was filed with the SEC on February 26, 2016 (the “Annual Report”).

The condensed consolidated financial statements include the accounts of the Company and its wholly-owned subsidiaries. All intercompany balances and transactions have been eliminated in consolidation.

Concentration of Revenue and Accounts Receivable

Significant customers are those which represent 10% or more of the Company’s total revenue or gross accounts receivable balance at each respective balance sheet date. For the three and nine months ended September 30, 2016, the Company had one customer that represented 13% and 13% of the Company’s total revenue respectively and the same customer represented 15% and 21% of accounts receivable as of September 30, 2016 and December 31, 2015 respectively. For the three and nine months ended September 30, 2015, the Company had one customer that represented 19% and 18% of the Company’s total revenue, respectively.

Significant Accounting Policies

There have been no material changes to the Company’s significant accounting policies as compared to the significant accounting policies described in the Company’s Annual Report on Form 10-K for the year ended December 31, 2015.

Recent Accounting Pronouncements

In August 2016, the Financial Accounting Standards Board ("FASB") issued Accounting Standards Update ("ASU") No. 2016-15, Statement of Cash Flows (Topic 230): Classification of Certain Cash Receipts and Cash Payments. The new standard will make eight targeted changes to how cash receipts and cash payments are presented and classified in the statement of cash flows. The standard will be effective for the Company beginning January 1, 2018, with early application permitted. The standard will require adoption on a retrospective basis unless it is impracticable to apply, in which case we would be required to apply the amendments prospectively as of the earliest date practicable. We are evaluating the impact of adopting this new accounting guidance 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. The new standard requires financial assets measured at amortized cost be presented at the net amount expected to be collected, through an allowance for credit losses that is deducted from the amortized cost basis. The standard will be effective for the Company beginning January 1, 2020, with early application permitted. The Company is evaluating the impact of adopting this new accounting guidance on its consolidated financial statements.

In March 2016, the FASB Issued ASU No. 2016-09, Compensation-Stock Compensation (Topic 718): Improvements to Employee Share-Based Payment Accounting. The updated guidance changes how companies account for certain aspects of share-based payment awards to employees, including the accounting for income taxes, forfeitures, and statutory tax withholding requirements, as well as classification in the statement of cash flows. The standard will be effective for the Company beginning January 1, 2017, with early application permitted. The Company is evaluating the impact of adopting this new accounting guidance on its consolidated financial statements.

In February 2016, the FASB issued Accounting Standards Update No. 2016-02 regarding ASC Topic 842 "Leases." The amendments in this guidance require balance sheet recognition of lease assets and lease liabilities by lessees for leases classified as operating leases, with an optional policy election to not recognize lease assets and lease liabilities for leases with a term of 12 months or less. The amendments also require new disclosures, including qualitative and quantitative requirements, providing additional information about the amounts recorded in the financial statements. The standard will be effective for the Company beginning January 1, 2019. The amendments require a modified retrospective approach with optional practical expedients. The Company is evaluating the impact of adopting this new accounting guidance on its consolidated financial statements.

In May 2014, the FASB issued ASU No. 2014-09—Revenue (Topic 606): Revenue from Contracts with Customers. ASU No. 2014-09 will replace most existing U.S. GAAP guidance on this topic. The new revenue recognition standard provides a unified model to determine when and how revenue is recognized. The core principle is that a company should recognize revenue to depict the transfer of promised goods or services to customers in an amount that reflects the consideration for which the entity expects to be entitled in exchange for those goods or services. In July 2015, the FASB approved a one-year deferral of the effective date for the new revenue reporting standard for entities reporting under U.S. GAAP. In accordance with the deferral, this guidance will be effective for the Company beginning January 1, 2018 and can be applied either retrospectively to each period presented or as a cumulative-effect adjustment as of the date of adoption. Early adoption is permitted beginning January 1, 2017. The Company is evaluating the impact of adopting this new accounting standard on its consolidated financial statements and has not selected a transition method.