Summary of Significant Accounting Policies	9 Months Ended
Summary of Significant Accounting Policies	Jun. 30, 2022
Accounting Policies [Abstract]
Summary of Significant Accounting Policies	Summary of Significant Accounting Policies Description of Business F5, Inc. (the "Company") is a leading provider of multi-cloud application security and delivery solutions which enable its customers to develop, deploy, operate, secure, and govern applications in any architecture, from on-premises to the public cloud. The Company's cloud, software, and hardware solutions enable its customers to deliver digital experiences to their customers faster, reliably, and at scale. The Company's enterprise-grade application services are available as cloud-based, software-as-a-service, and software-only solutions optimized for multi-cloud environments, with modules that can run independently, or as part of an integrated solution on its high-performance appliances. In connection with its solutions, the Company offers a broad range of professional services, including consulting, training, installation, maintenance, and other technical support services. On October 1, 2021, the Company completed its acquisition of Threat Stack, Inc. ("Threat Stack"), a provider of cloud security and workload protection solutions. Basis of Presentation The year-end consolidated balance sheet data was derived from audited financial statements but does not include all disclosures required by accounting principles generally accepted in the United States of America ("GAAP"). In the opinion of management, the unaudited consolidated financial statements reflect all adjustments, consisting only of normal recurring adjustments, necessary for their fair statement in conformity with accounting principles generally accepted in the United States of America. Certain information and footnote disclosures normally included in annual financial statements have been condensed or omitted in accordance with the rules and regulations of the Securities and Exchange Commission ("SEC"). The information included in this Form 10-Q should be read in conjunction with Management’s Discussion and Analysis of Financial Condition and Results of Operations and financial statements and notes thereto included in the Company’s Annual Report on Form 10-K for the fiscal year ended September 30, 2021. There have been no changes to the Company's significant accounting policies as of and for the three and nine months ended June 30, 2022, except for the accounting policy for investments, which has been updated to include equity investments. Investments The Company classifies its debt investments as available-for-sale. Debt investments, consisting of certificates of deposit, corporate and municipal bonds and notes, the United States government and agency securities and international government securities are reported at fair value with the related unrealized gains and losses included as a component of accumulated other comprehensive income (loss) in shareholders’ equity. Realized gains and losses, credit allowances and impairments due to credit losses are included in other income (expense) in the Company’s consolidated income statements. Debt investments with maturities of less than one year or where management’s intent is to use the investments to fund current operations are classified as short-term investments. Debt investments with maturities of greater than one year are classified as long-term investments. As an approximation to fair value, equity investments are measured using net asset value (“NAV”) and are classified as long-term investments. Unrealized and realized gains and losses are recorded in other income (expense) in the Company's consolidated income statements. Recently Adopted Accounting Standards In October 2021, the FASB issued ASU 2021-08, Business Combinations (Topic 805): Accounting for Contract Assets and Contract Liabilities from Contracts with Customers. The new guidance requires contract assets and contract liabilities acquired in a business combination to be recognized and measured by the acquirer on the acquisition date in accordance with ASC 606, Revenue from Contracts with Customers. The Company early adopted this accounting standard update beginning in the first quarter of fiscal 2022 and it did not have a material impact on the Company's consolidated financial statements.