Commitments And Contingencies	12 Months Ended
Commitments And Contingencies	Sep. 30, 2024
Commitments and Contingencies Disclosure [Abstract]
Commitments And Contingencies	Commitments and Contingencies Purchase Obligations In October 2022, the Company entered into an unconditional purchase commitment with one of its suppliers for the delivery of systems components. Under the terms of the agreement, the Company is obligated to purchase $10 million of component inventory annually, with a total committed amount of $40 million over a four-year term. As of September 30, 2024, the Company had no remaining purchase commitments under the second year of the agreement. The Company's total non-cancelable long-term purchase commitments outstanding as of September 30, 2024 was $20.0 million. Litigation Lynwood Investment CY Limited v. F5 Networks et al. On June 8, 2020, Lynwood Investment CY Limited (“Lynwood”) filed a lawsuit in the United States District Court for the Northern District of California against the Company and certain affiliates, along with other defendants. In its complaint, Lynwood claims to be the assignee of all rights and interests of Rambler Internet Holding LLC (“Rambler”), and alleges that the intellectual property in the NGINX software originally released by the co-founder of NGINX in 2004 belongs to Rambler (and therefore Lynwood, by assignment) because the software was created and developed while the co-founder was employed by Rambler. Lynwood asserted 26 causes of action against the various defendants, including copyright infringement, violation of trademark law, tortious interference, conspiracy, and fraud. The complaint sought damages, disgorgement of profits, declarations of copyright and trademark ownership, trademark cancellations, and injunctive relief. Lynwood also initiated several trademark opposition and cancellation proceedings before the Trademark Trial and Appeal Board of the United States Patent and Trademark Office, which have all since been suspended. In August and October 2020, the Company and the other defendants filed motions to dismiss Lynwood’s case. On March 25 and 30, 2021, the Court granted the Company’s and the other defendants’ motions to dismiss with leave to amend. Lynwood filed its amended complaint on April 29, 2021, seeking the same relief against the Company and other defendants. On May 27, 2021, the Company and other defendants filed a consolidated motion to dismiss. The Court granted the consolidated motion to dismiss without leave to amend on August 16, 2022 and entered final judgment against Lynwood on September 9, 2022. On September 14, 2022, Lynwood filed a notice of appeal to the Ninth Circuit Court of Appeals to appeal the dismissal. Lynwood filed its opening brief on December 16, 2022. The Company filed its opening appellate brief on April 10, 2023, and Lynwood filed its reply on May 31, 2023. Following the Court’s order granting the consolidated motion to dismiss and final judgment in the Company’s favor, the Court subsequently granted the Company attorneys' fees of over $0.8 million, which Lynwood appealed to the Ninth Circuit Court of Appeals. The dismissal appeal and the fees appeal were heard by the Ninth Circuit Court of Appeals on December 7, 2023. On November 7, 2024, the Court of Appeals partially affirmed the dismissal by affirming dismissal of the state law claims and remanding a portion of the copyright claim to the District Court. The Court of Appeals also vacated the fees award because of the remand. In addition to the above matters, the Company is subject to a variety of legal proceedings, claims, investigations, and litigation arising in the ordinary course of business, including intellectual property litigation. Management believes that the Company has meritorious defenses to the allegations made in its pending cases and intends to vigorously defend these lawsuits; however, the Company is unable to currently determine if an unfavorable outcome is probable or estimate any potential amount or range of possible loss of these or similar matters. There are many uncertainties associated with any litigation and these actions or other third-party claims against the Company may cause it to incur costly litigation and/or substantial settlement charges that could have a material adverse effect on the Company's business, financial condition, results of operations, and cash flows. The Company records an accrual for loss contingencies for legal proceedings when it believes that an unfavorable outcome is both (a) probable and (b) the amount or range of any possible loss is reasonably estimable. The Company has not recorded any accrual for loss contingencies associated with such legal proceedings or the investigations discussed above.