Description of Business and Summary of Significant Accounting Policies (Policies)	9 Months Ended
	Sep. 30, 2017
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Description of Business	Description of Business A10 Networks, Inc. (together with our subsidiaries, “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 our customers to secure and optimize the performance of their data center and cloud applications and secure their users, applications and infrastructure from internet, web and network threats at scale. Our product portfolio consists of six advanced application delivery and security products: Application Delivery Controllers (“ADC”), Lightning Application Delivery Controller (“Lightning ADC”), Carrier Grade Network Address Translation (“CGN”), Threat Protection System (“TPS”), SSL Insight (“SSLi”) and Convergent Firewall (“CFW”). They are available in a variety of form factors, such as optimized hardware appliances, bare metal software, virtual appliances, and cloud-native software.
Basis of Presentation	Basis of Presentation The accompanying unaudited condensed consolidated financial statements include those of A10 Networks, Inc. and its subsidiaries after elimination of all intercompany accounts and transactions. We have prepared the accompanying unaudited condensed consolidated financial statements pursuant to the rules and regulations of the United States Securities and Exchange Commission (the “SEC”). As permitted under these rules and regulations, we have condensed or omitted certain financial information and footnote disclosures we normally include in our annual consolidated financial statements prepared in accordance with accounting principles generally accepted in the United States of America (“GAAP”). These financial statements have been prepared on the same basis as our annual financial statements and, in management's opinion, reflect all adjustments consisting only of normal recurring adjustments that are necessary for a fair presentation of our financial information. Our 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 financial statements and accompanying notes thereto in our Annual Report on Form 10-K for the year ended December 31, 2016 on file with the SEC (our “Annual Report”).
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, fair value of marketable securities, contingencies and litigation, acquisition related purchase price allocations, accrued liabilities, and the 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.
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, marketable securities and accounts receivable. Our cash, cash equivalents and marketable securities are held and invested in high-credit quality financial instruments by recognized financial institutions and therefore subject to minimum credit risk. 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 based on a number of factors, including past transaction experience, evaluation of credit history 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. R
Recently Adopted Accounting Guidance/Recent Accounting Pronouncements Not Yet Effective	Recent Accounting Pronouncements Not Yet Effective In May 2014, the Financial Accounting Standards Board (“FASB”) issued Accounting Standard Update (“ASU”) No. 2014-09, Revenue from Contracts with Customers (Topic 606), which will supersede most of the existing revenue recognition guidance under U.S. GAAP. This ASU requires 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 in exchange for those goods or services and requires the capitalization of incremental customer acquisition costs and amortization of these costs over the contract period or estimated customer life which will result in the recognition of a contract asset on our condensed consolidated balance sheet. This standard is effective for annual periods beginning after December 15, 2017 and interim periods within that reporting period. The ASU allows for either full retrospective or modified retrospective adoption. We intend to adopt the standard in the first quarter of 2018 applying the modified retrospective method. While we are continuing to assess all potential impacts of the new standard, we currently do not believe this standard will have a material impact on revenue recognized in our condensed consolidated financial statements. However, the cumulative adjustment to recognize a contract asset relating to the capitalization of incremental customer acquisition costs is expected to be material. Also on the adoption of this ASU, the incremental customer acquisition costs will be recognized in our condensed statement of operations as the related performance obligations are met as compared to the current recognition to expense as incurred. We are in the process of evaluating the impact of the disclosure requirements relating to this standard. In February 2016, the FASB issued ASU No. 2016-02, Leases (Topic 842). This new accounting standard primarily requires lessees to recognize most leases on their balance sheets but record expenses on their income statements in a manner similar to current accounting. For lessors, the guidance modifies the classification criteria and the accounting for sales-type and direct financing leases. This standard is effective for annual periods beginning after December 15, 2018 with early adoption permitted. We are currently evaluating the impact of this guidance on our condensed consolidated financial statements. In January 2017, the FASB issued ASU No. 2017-04, Intangibles - Goodwill and Other (Topic 350): Simplifying the Test for Goodwill Impairment, which removes the requirement to compare the implied fair value of goodwill with its carrying amount as part of step 2 of the goodwill impairment test. As a result, under this ASU, an entity should perform its annual, or interim, goodwill impairment test by comparing the fair value of a reporting unit with its carrying amount and should recognize an impairment charge for the amount by which the carrying amount exceeds the reporting unit’s fair value; however, the impairment loss recognized should not exceed the total amount of goodwill allocated to that reporting unit. This standard is effective prospectively for annual periods beginning after December 15, 2019. Early adoption is permitted for interim or annual goodwill impairment tests performed after January 1, 2017. We are currently evaluating the impact of this guidance on our condensed consolidated financial statements and related disclosures. In May 2017, the FASB issued ASU No. 2017-09, Compensation-Stock Compensation (Topic 718): Scope of Modification Accounting, to provide guidance about which changes to the terms or conditions of a share-based payment award require an entity to apply modification accounting. This standard is effective for annual periods beginning after December 15, 2017 and interim periods within that reporting period. Early adoption is permitted, including adoption in any interim period. The amendments will be applied prospectively to an award modified on or after the adoption date. We do not believe this standard will have a material impact on our condensed consolidated financial statements. There have been no other recent accounting pronouncements or changes in accounting pronouncements that are of significance or potential significance to us.