Description of Business and Summary of Significant Accounting Policies (Policies)	9 Months Ended
	Sep. 30, 2015
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Description of Business	Description of Business A10 Networks, Inc. (together with our subsidiaries, the “Company”, “we”, “our” or “us”) was incorporated in California in 2004 and reincorporated in Delaware in March 2014. We are headquartered in San Jose, California and have wholly-owned subsidiaries throughout the world including Asia and Europe. Our solutions enable enterprises, service providers, Web giants and government organizations to accelerate, secure and optimize the performance of their data center applications and networks. We currently offer three software based advanced application networking solutions. These are Application Delivery Controllers, or ADCs, to optimize data center performance; Carrier Grade Network Address Translation, or CGN, to provide address and protocol translation services for service provider networks; and a Distributed Denial of Service Threat Protection System, or TPS, for network-wide security protection. We deliver these solutions both on optimized hardware appliances and as virtual appliances across our Thunder Series and AX Series product families.
Basis of Presentation	Basis of Presentation The accompanying unaudited condensed consolidated financial statements include the accounts of A10 Networks, Inc., and our wholly owned subsidiaries. All inter-company balances and transactions have been eliminated in consolidation. We had no comprehensive income (loss) other than our net income (loss), hence our comprehensive income (loss) is the same as the net income (loss) for all periods presented. Pursuant to the accounting guidance provided by Accounting Standard Codification ("ASC") 220 Comprehensive Income, we did not present statements of comprehensive income (loss) for the periods presented. The accompanying unaudited condensed consolidated financial statements have been prepared in accordance with accounting principles generally accepted in the United States of America (“U.S. GAAP”) and following the requirements of the Securities and Exchange Commission (“SEC”) for interim reporting. As permitted under those rules, certain notes or other financial information that are normally required by U.S. GAAP can be condensed or omitted. These financial statements have been prepared on the same basis as our annual financial statements and, in the opinion of management, reflect all adjustments, consisting only of normal recurring adjustments that are necessary for a fair presentation of our financial information. The results of operations for the three and nine months ended September 30, 2015 are not necessarily indicative of the results to be expected for the year ending December 31, 2015 or for any other interim period or for any other future year. The balance sheet as of December 31, 2014 has been derived from audited financial statements at that date but does not include all of the information required by U.S. GAAP for complete financial statements. The accompanying unaudited condensed consolidated financial statements should be read in conjunction with our audited consolidated financial statements for the year ended December 31, 2014, which are included in the Annual Report on Form 10-K filed with the SEC on March 11, 2015.
Use of Estimates	Use of Estimates The preparation of the condensed consolidated financial statements in conformity with U.S. GAAP requires us to make estimates and assumptions that affect the amounts reported in the condensed consolidated financial statements and accompanying notes. Those estimates and assumptions affect revenue recognition and deferred revenue, allowance for doubtful accounts, sales return reserve, valuation of inventory, contingencies and litigation, and determination of fair value of stock-based compensation. These estimates are based on information available as of the date of the condensed consolidated financial statements; therefore, actual results could differ from management’s estimates.
Summary of Significant Accounting Policies	Summary of Significant Accounting Policies There have been no changes to the significant accounting policies described in the 2014 Annual Report on Form 10-K that have had a material impact on our condensed consolidated financial statements and related notes.
Concentration of Credit Risk and Significant Customers	Concentration of Credit Risk and Significant Customers Financial instruments that potentially subject us to concentrations of credit risk consist of cash, cash equivalents and accounts receivable. Our cash and cash equivalents are invested in high-credit quality financial instruments with banks and financial institutions. Management believes that the financial institutions that hold our cash and cash equivalents are financially sound and, accordingly, are subject to minimal credit risk. Such deposits may be in excess of insured limits provided on such deposits. Our accounts receivable are unsecured and represent amounts due to us based on contractual obligations of our customers. We mitigate credit risk in respect to accounts receivable by performing periodic credit evaluations of our customers to assess the probability of accounts receivable collection based on a number of factors, including past transaction experience with the customer, evaluation of their credit history, limiting the credit extended and review of the invoicing terms of the contract. We generally do not require our customers to provide collateral to support accounts receivable. Significant customers, including distribution channel partners and direct customers, are those which represent more than 10% of our total revenue for each period presented or our gross accounts receivable balance as of each respective balance sheet date.
Recent Accounting Pronouncements	Recent Accounting Pronouncements In May 2014, the Financial Accounting Standards Board ("FASB") issued Accounting Standard Update ("ASU") No. 2014-09, Revenue from Contracts with Customers, which provides new guidance on the recognition of revenue and states that an entity should recognize revenue to depict the transfer of promised goods or services to customers in an amount that reflects the consideration to which the entity expects to be entitled in exchange for those goods or services. The updated standard will replace most existing revenue recognition guidance in U.S. GAAP when it becomes effective and permits the use of either the retrospective or cumulative effect transition method. The original effective date of this accounting standard was annual reporting periods beginning after December 15, 2016, including interim periods within that reporting period. In August 2015, the FASB issued ASU No. 2015-14, Revenue from Contracts with Customers: Deferral of the Effective Date, which deferred the effective date of the new revenue standard for periods beginning after December 15, 2016 to December 15, 2017, with early adoption permitted but not earlier than the original effective date. This updated standard is effective for us on January 1, 2018. We are currently evaluating the impact of the adoption of this accounting standard update on our consolidated financial position or results of operations and method of adoption. In April 2015, the FASB issued 2015-03 Interest—Imputation of Interest (Subtopic 835-30) Simplifying the Presentation of Debt Issuance Costs and during August 2015, the FASB issued ASU No. 2015-15, Presentation and Subsequent Measurement of Debt Issuance Costs Associated with Line-of-Credit Arrangements, which clarifies the treatment of debt issuance costs from line-of-credit arrangements after adoption of ASU No. 2015-03. This accounting guidance requires debt issuance costs be presented on the balance sheet as a direct reduction from the carrying amount of the related debt liability. ASU No. 2015-15 clarifies that the SEC staff would not object to an entity deferring and presenting debt issuance costs as an asset and subsequently amortizing the deferred debt issuance costs ratably over the term of the line-of-credit arrangement, regardless of whether there are any outstanding borrowings on the line-of-credit arrangement. ASU No. 2015-03 is effective for fiscal years, and interim periods within those fiscal years, beginning after December 15, 2015. We believe the adoption of ASU No. 2015-15 will not have a material effect on our consolidated financial statements. In July 2015, the FASB issued ASU No. 2015-11, Inventory (Topic 330): Simplifying the Measurement of Inventory. Under this accounting guidance, inventory will be measured at the lower of cost and net realizable value and other options that currently exist for market value will be eliminated. ASU No. 2015-11 defines net realizable value as the estimated selling prices in the ordinary course of business, less reasonably predictable costs of completion, disposal, and transportation. No other changes were made to the current guidance on inventory measurement. This accounting guidance is effective for us in the first quarter of 2017. Early adoption is permitted. We are currently evaluating the impact of the adoption of this accounting standard update on our consolidated financial statements. There have been no other recent accounting pronouncements or changes in accounting pronouncements during the nine months ended September 30, 2015, as compared to the recent accounting pronouncements described in our Annual Report on Form 10-K for the year ended December 31, 2014 filed with SEC on March 11, 2015, that are of significance or potential significance to us.