F5 (FFIV) 10-Q 4 Feb 22 2022 Q1 Quarterly report Financial data

Cover Page

Cover Page - shares	3 Months Ended
	Dec. 31, 2021	Jan. 28, 2022
Cover [Abstract]
Document Type	10-Q
Document Quarterly Report	true
Document Period End Date	Dec. 31, 2021
Document Transition Report	false
Entity File Number	000-26041
Entity Registrant Name	F5, INC.
Entity Incorporation, State or Country Code	WA
Entity Tax Identification Number	91-1714307
Entity Address, Address Line One	801 5th Avenue
Entity Address, City or Town	Seattle
Entity Address, State or Province	WA
Entity Address, Postal Zip Code	98104
City Area Code	206
Local Phone Number	272-5555
Title of 12(b) Security	Common stock, no par value
Trading Symbol	FFIV
Security Exchange Name	NASDAQ
Entity Current Reporting Status	Yes
Entity Interactive Data Current	Yes
Entity Filer Category	Large Accelerated Filer
Entity Small Business	false
Entity Emerging Growth Company	false
Entity Shell Company	false
Entity Central Index Key	0001048695
Current Fiscal Year End Date	--09-30
Document Fiscal Year Focus	2022
Document Fiscal Period Focus	Q1
Amendment Flag	false
Entity Common Stock, Shares Outstanding		60,738,170

Consolidated Balance Sheets

Consolidated Balance Sheets - USD ($) $ in Thousands	Dec. 31, 2021	Sep. 30, 2021
Current assets
Cash and cash equivalents	$ 512,406	$ 580,977
Short-term investments	346,548	329,630
Accounts receivable, net of allowances of $3,262 and $3,696	419,282	340,536
Inventories	20,795	22,055
Other current assets	388,942	337,902
Total current assets	1,687,973	1,611,100
Property and equipment, net	185,355	191,164
Operating lease right-of-use assets	237,341	244,934
Long-term investments	76,991	132,778
Deferred tax assets	148,333	128,193
Goodwill	2,260,407	2,216,553
Other assets, net	490,508	472,558
Total assets	5,086,908	4,997,280
Current liabilities
Accounts payable	58,253	62,096
Accrued liabilities	314,845	341,487
Deferred revenue	1,039,515	968,669
Current portion of long-term debt	19,275	19,275
Total current liabilities	1,431,888	1,391,527
Deferred tax liabilities	2,723	2,414
Deferred revenue, long-term	536,984	521,173
Operating lease liabilities, long-term	287,596	296,945
Long-term debt	344,954	349,772
Other long-term liabilities	77,402	75,236
Total long-term liabilities	1,249,659	1,245,540
Commitments and contingencies (Note 9)
Shareholders' equity
Preferred stock, no par value; 10,000 shares authorized, no shares outstanding	0	0
Common stock, no par value; 200,000 shares authorized, 60,711 and 60,652 shares issued and outstanding	145,189	192,458
Accumulated other comprehensive loss	(21,215)	(20,073)
Retained earnings	2,281,387	2,187,828
Total shareholders' equity	2,405,361	2,360,213
Total liabilities and shareholders' equity	$ 5,086,908	$ 4,997,280

Consolidated Balance Sheets (Pa

Consolidated Balance Sheets (Parenthetical) - USD ($) $ in Thousands	Dec. 31, 2021	Sep. 30, 2021
Statement of Financial Position [Abstract]
Accounts receivable, allowances	$ 3,262	$ 3,696
Preferred stock, par value (dollars per share)	$ 0	$ 0
Preferred stock, shares authorized	10,000,000	10,000,000
Preferred stock, shares outstanding	0	0
Common stock, par value (dollars per share)	$ 0	$ 0
Common stock, shares authorized	200,000,000	200,000,000
Common stock, shares issued	60,711,000	60,652,000

Consolidated Income Statements

Consolidated Income Statements - USD ($) shares in Thousands, $ in Thousands	3 Months Ended
	Dec. 31, 2021	Dec. 31, 2020
Net revenues
Revenue from contract with customer, excluding assessed tax	$ 687,100	$ 624,617
Cost of net revenues
Cost of net revenues	135,073	114,979
Gross profit	552,027	509,638
Operating expenses
Sales and marketing	234,035	214,546
Research and development	130,271	114,191
General and administrative	65,661	63,153
Restructuring charges	7,909	0
Total	437,876	391,890
Income from operations	114,151	117,748
Other expense, net	(2,431)	(683)
Income before income taxes	111,720	117,065
Provision for income taxes	18,161	29,387
Net income	$ 93,559	$ 87,678
Net income per share — basic (dollars per share)	$ 1.54	$ 1.43
Weighted average shares — basic (shares)	60,810	61,440
Net income per share — diluted (dollars per share)	$ 1.51	$ 1.41
Weighted average shares — diluted (shares)	61,882	62,282
Product
Net revenues
Revenue from contract with customer, excluding assessed tax	$ 343,149	$ 288,045
Cost of net revenues
Cost of net revenues	81,662	67,038
Service
Net revenues
Revenue from contract with customer, excluding assessed tax	343,951	336,572
Cost of net revenues
Cost of net revenues	$ 53,411	$ 47,941

Consolidated Statements Of Comp

Consolidated Statements Of Comprehensive Income - USD ($) $ in Thousands	3 Months Ended
	Dec. 31, 2021	Dec. 31, 2020
Statement of Comprehensive Income [Abstract]
Net income	$ 93,559	$ 87,678
Other comprehensive (loss) income:
Foreign currency translation adjustment	(517)	1,278
Available-for-sale securities:
Unrealized losses on securities, net of taxes of $(74) and $(50) for the three months ended December 31, 2021 and 2020, respectively	(621)	(420)
Reclassification adjustment for realized (losses) gains included in net income, net of taxes of $2 and $0 for the three months ended December 31, 2021 and 2020, respectively	(4)	3
Net change in unrealized losses on available-for-sale securities, net of tax	(625)	(417)
Total other comprehensive (loss) income	(1,142)	861
Comprehensive income	$ 92,417	$ 88,539

Consolidated Statements Of Co_2

Consolidated Statements Of Comprehensive Income (Parenthetical) - USD ($) $ in Thousands	3 Months Ended
	Dec. 31, 2021	Dec. 31, 2020
Statement of Comprehensive Income [Abstract]
Tax effect of unrealized gain (loss) on securities	$ (74)	$ (50)
Tax effect of reclassification adjustment for realized (gains) losses	$ 2	$ 0

Consolidated Statements of Shar

Consolidated Statements of Shareholders' Equity Statement - USD ($) shares in Thousands, $ in Thousands	Total	Common Stock	AOCI Attributable to Parent	Retained Earnings
Beginning Balance (in shares) at Sep. 30, 2020		61,099
Beginning Balance at Sep. 30, 2020	$ 2,232,268	$ 305,453	$ (18,716)	$ 1,945,531
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Exercise of employee stock options (in shares)		39
Exercise of employee stock options	1,118	$ 1,118
Issuance of stock under employee stock purchase plan (in shares)		231
Issuance of stock under employee stock purchase plan	26,077	$ 26,077
Issuance of restricted stock (in shares)		297
Issuance of restricted stock	0
Stock Repurchased and Retired During Period, Value	0
Cost of Issuance of Treasury Stock, Shares		(34)
Cost of Issuance of Treasury Stock	(4,481)	$ (4,481)
Stock-based compensation	58,069	$ 58,069
Net income	87,678			87,678
Other Comprehensive Income (Loss)	861		861
Ending Balance ( in shares) at Dec. 31, 2020		61,632
Ending Balance at Dec. 31, 2020	$ 2,401,590	$ 386,236	(17,855)	2,033,209
Beginning Balance (in shares) at Sep. 30, 2021	60,652	60,652
Beginning Balance at Sep. 30, 2021	$ 2,360,213	$ 192,458	(20,073)	2,187,828
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Exercise of employee stock options (in shares)		50
Exercise of employee stock options	1,255	$ 1,255
Issuance of stock under employee stock purchase plan (in shares)		169
Issuance of stock under employee stock purchase plan	26,325	$ 26,325
Issuance of restricted stock (in shares)		442
Issuance of restricted stock	0
Stock Repurchased and Retired During Period, Shares		(539)
Stock Repurchased and Retired During Period, Value	(125,011)	$ (125,011)
Cost of Issuance of Treasury Stock, Shares		(63)
Cost of Issuance of Treasury Stock	(13,595)	$ (13,595)
Stock-based compensation	63,757	$ 63,757
Net income	93,559			93,559
Other Comprehensive Income (Loss)	$ (1,142)		(1,142)
Ending Balance ( in shares) at Dec. 31, 2021	60,711	60,711
Ending Balance at Dec. 31, 2021	$ 2,405,361	$ 145,189	$ (21,215)	$ 2,281,387

Consolidated Statements Of Cash

Consolidated Statements Of Cash Flows - USD ($) $ in Thousands	3 Months Ended
	Dec. 31, 2021	Dec. 31, 2020
Operating activities
Net income	$ 93,559	$ 87,678
Adjustments to reconcile net income to net cash provided by operating activities:
Stock-based compensation	63,757	58,069
Depreciation and amortization	30,260	27,660
Non-cash operating lease costs	9,663	9,698
Deferred income taxes	(6,407)	(694)
Impairment of assets	6,175	6,873
Other	(1,123)	307
Changes in operating assets and liabilities (excluding effects of the acquisition of businesses):
Accounts receivable	(77,223)	(54,416)
Inventories	1,260	1,443
Other current assets	(44,286)	(23,250)
Other assets	(21,774)	(26,654)
Accounts payable and accrued liabilities	(25,387)	(23,925)
Deferred revenue	76,065	86,193
Lease liabilities	(14,173)	(11,619)
Net cash provided by operating activities	90,366	137,363
Investing activities
Purchases of investments	(36,205)	(42,765)
Maturities of investments	38,138	69,352
Sales of investments	34,549	0
Acquisition of businesses, net of cash acquired	(67,911)	(1,247)
Purchases of property and equipment	(10,564)	(4,697)
Net cash (used in) provided by investing activities	(41,993)	20,643
Financing activities
Proceeds from the exercise of stock options and purchases of stock under employee stock purchase plan	27,581	27,196
Payments for Repurchase of Common Stock	(125,011)	0
Payments on term debt agreement	(5,000)	(5,000)
Cost of Issuance of Treasury Stock	(13,595)	(4,481)
Net cash (used in) provided by financing activities	(116,025)	17,715
Net (decrease) increase in cash, cash equivalents and restricted cash	(67,652)	175,721
Effect of exchange rate changes on cash, cash equivalents and restricted cash	(861)	1,655
Cash, cash equivalents and restricted cash, beginning of period	584,333	852,826
Cash, cash equivalents and restricted cash, end of period	515,820	1,030,202
Supplemental disclosures of cash flow information
Cash paid for amounts included in the measurement of operating lease liabilities	16,500	15,032
Cash paid for interest on long-term debt	1,252	1,370
Supplemental disclosures of non-cash activities
Right-of-use assets obtained in exchange for lease obligations	$ 818	$ 1,614

Summary of Significant Accounti

Summary of Significant Accounting Policies	3 Months Ended
	Dec. 31, 2021
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 material changes to the Company's significant accounting policies as of and for the three months ended December 31, 2021. 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. The ongoing impact of this standard will be fact dependent on the transactions within its scope.

Revenue from Contracts with Cus

Revenue from Contracts with Customers	3 Months Ended
	Dec. 31, 2021
Revenue from Contract with Customer [Abstract]
Revenue from Contracts with Customers	Revenue from Contracts with Customers Capitalized Contract Acquisition Costs The table below shows significant movements in capitalized contract acquisition costs (current and noncurrent) for the three months ended December 31, 2021 and 2020 (in thousands): Three months ended 2021 2020 Balance, beginning of period $ 77,836 $ 70,396 Additional capitalized contract acquisition costs 10,512 9,725 Amortization of capitalized contract acquisition costs (9,414) (8,152) Balance, end of period $ 78,934 $ 71,969 Amortization of capitalized contract acquisition costs was $9.4 million and $8.2 million for the three months ended December 31, 2021 and 2020, respectively, and is recorded in Sales and Marketing expense in the accompanying consolidated income statements. There was no impairment of any capitalized contract acquisition costs during any period presented. Contract Balances Timing may differ between the satisfaction of performance obligations and the invoicing and collection of amounts related to the Company's contracts with customers. Liabilities are recorded for amounts that the Company has the unconditional right to transfer goods and services under contracts with customers. These liabilities are classified as current and non-current deferred revenue. The table below shows significant movements in the deferred revenue balances (current and noncurrent) for the three months ended December 31, 2021 and 2020 (in thousands): Three months ended 2021 2020 Balance, beginning of period $ 1,489,842 $ 1,272,632 Amounts added but not recognized as revenues 441,591 421,918 Deferred revenue acquired through acquisition of businesses 10,591 — Revenues recognized related to the opening balance of deferred revenue (365,525) (335,725) Balance, end of period $ 1,576,499 $ 1,358,825 Remaining Performance Obligations Remaining performance obligations represent the amount of the transaction price under contracts with customers that are attributable to performance obligations that are unsatisfied or partially satisfied at the reporting date. As of December 31, 2021, the total non-cancelable remaining performance obligations under the Company's contracts with customers was approximately $1.6 billion and the Company expects to recognize revenues on approximately 65.9% of these remaining performance obligations over the next 12 months, 21.1% in year two, and the remaining balance thereafter. See Note 13, Segment Information, for disaggregated revenue by significant customer and geographic region, as well as disaggregated product revenue by systems and software.

Fair Value Measurements

Fair Value Measurements	3 Months Ended
	Dec. 31, 2021
Fair Value Disclosures [Abstract]
Fair Value Measurements	Fair Value Measurements In accordance with the authoritative guidance on fair value measurements and disclosure under GAAP, the Company determines fair value using a fair value hierarchy that distinguishes between market participant assumptions developed based on market data obtained from sources independent of the reporting entity, and the reporting entity’s own assumptions about market participant assumptions developed based on the best information available in the circumstances and expands disclosure about fair value measurements. Fair value is the price that would be received to sell an asset or paid to transfer a liability in the principal or most advantageous market for the asset or liability in an orderly transaction between market participants at the measurement date, essentially the exit price. The levels of fair value hierarchy are: Level 1: Quoted prices in active markets for identical assets and liabilities at the measurement date that the Company has the ability to access. Level 2: Observable inputs other than quoted prices included in Level 1, such as quoted prices for similar assets and liabilities in active markets; quoted prices for identical or similar assets and liabilities in markets that are not active; or other inputs that are observable or can be corroborated by observable market data. Level 3: Unobservable inputs for which there is little or no market data available. These inputs reflect management's assumptions of what market participants would use in pricing the asset or liability. Level 1 investments are valued based on quoted market prices in active markets and include the Company's cash equivalent investments. Level 2 investments, which include investments that are valued based on quoted prices in markets that are not active, broker or dealer quotations, actual trade data, benchmark yields or alternative pricing sources with reasonable levels of price transparency, include the Company's certificates of deposit, corporate bonds and notes, municipal bonds and notes, U.S. government securities, U.S. government agency securities and international government securities. Fair values for the Company's level 2 investments are based on similar assets without applying significant judgments. In addition, all of the Company's level 2 investments have a sufficient level of trading volume to demonstrate that the fair values used are appropriate for these investments. A financial instrument's level within the fair value hierarchy is based upon the lowest level of any input that is significant to the fair value measurement. However, the determination of what constitutes "observable" requires significant judgment by the Company. The Company considers observable data to be market data which is readily available, regularly distributed or updated, reliable and verifiable, not proprietary, and provided by independent sources that are actively involved in the relevant market. Assets and Liabilities Measured and Recorded at Fair Value on a Recurring Basis The Company's financial assets measured at fair value on a recurring basis subject to the disclosure requirements at December 31, 2021, were as follows (in thousands): Fair Value Measurements at Reporting Date Using Quoted Prices in Active Markets for Identical Securities Significant Other Significant Fair Value at Cash equivalents $ 19,265 $ 779 $ — $ 20,044 Short-term investments Available-for-sale securities — certificates of deposits — 992 — 992 Available-for-sale securities — corporate bonds and notes — 177,093 — 177,093 Available-for-sale securities — municipal bonds and notes — 15,359 — 15,359 Available-for-sale securities — U.S. government securities — 135,934 — 135,934 Available-for-sale securities — U.S. government agency securities — 17,170 — 17,170 Long-term investments Available-for-sale securities — corporate bonds and notes — 48,638 — 48,638 Available-for-sale securities — municipal bonds and notes — 2,239 — 2,239 Available-for-sale securities — U.S. government securities — 24,341 — 24,341 Available-for-sale securities — U.S. government agency securities — 1,773 — 1,773 Total $ 19,265 $ 424,318 $ — $ 443,583 The Company's financial assets measured at fair value on a recurring basis subject to the disclosure requirements at September 30, 2021, were as follows (in thousands): Fair Value Measurements at Reporting Date Using Quoted Prices in Active Markets Significant Significant Fair Value at Cash equivalents $ 17,150 $ 4,397 $ — $ 21,547 Short-term investments Available-for-sale securities — certificates of deposits — 255 — 255 Available-for-sale securities — corporate bonds and notes — 186,107 — 186,107 Available-for-sale securities — municipal bonds and notes — 13,566 — 13,566 Available-for-sale securities — U.S. government securities — 102,615 — 102,615 Available-for-sale securities — U.S. government agency securities — 27,087 — 27,087 Long-term investments Available-for-sale securities — corporate bonds and notes — 53,107 — 53,107 Available-for-sale securities — municipal bonds and notes — 11,111 — 11,111 Available-for-sale securities — U.S. government securities — 59,608 — 59,608 Available-for-sale securities — U.S. government agency securities — 8,952 — 8,952 Total $ 17,150 $ 466,805 $ — $ 483,955 The Company uses the fair value hierarchy for financial assets and liabilities. The carrying amounts of other current financial assets and other current financial liabilities approximate fair value due to their short-term nature. Assets Measured and Recorded at Fair Value on a Non-Recurring Basis The Company's non-financial assets and liabilities, which include goodwill, intangible assets, and long-lived assets, are not required to be carried at fair value on a recurring basis. These non-financial assets and liabilities are measured at fair value on a non-recurring basis when there is an indicator of impairment, and they are recorded at fair value only when impairment is recognized. The Company reviews goodwill for impairment annually, during the second quarter of each fiscal year, or as circumstances indicate the possibility of impairment. The Company monitors the carrying value of tangible and intangible long-lived assets for impairment whenever events or changes in circumstances indicate its carrying amount may not be recoverable. Included in the Company’s impairment considerations for non-financial assets and liabilities in the current quarter were the potential impacts of the COVID-19 pandemic. As a result of a planned change in the use of the asset, the Company recorded an impairment of $6.2 million against the Shape trade name intangible asset, which was reflected in the Sales and Marketing line item on the Company's consolidated income statement for the three months ended December 31, 2021. The Company did not recognize any impairment charges related to its intangible assets in the first quarter of fiscal 2021. In the first quarter of fiscal 2021, the Company recorded an impairment of $6.7 million against the operating lease right-of-use asset related to the integration of the former Shape headquarters in Santa Clara, California. Impairment charges for the first quarter of fiscal 2021 also included $0.2 million for other fixed assets associated with the Shape headquarters in Santa Clara, California. The Company calculated the fair value of the right-of-use assets, tenant improvements and other fixed assets based on estimated future discounted cash flows and classified the fair value as a Level 3 measurement due to the significance of unobservable inputs, which included the amount and timing of estimated sublease rental receipts that the Company could reasonably obtain over the remaining lease term and the discount rate. The impairment charges for the three months ended December 31, 2020 were allocated to various expense line items on the Company’s consolidated income statements based on the teams that previously worked out of the exited space. Impairment charges were allocated to the following income statement line items for the three months ended December 31, 2021 and 2020 (in thousands): Three months ended 2021 2020 Cost of net product revenue $ — $ 1,968 Cost of net service revenue — 1 Sales and marketing 6,175 1,259 Research and development — 3,129 General and administrative — 516 Total impairment charges $ 6,175 $ 6,873 During the three months ended December 31, 2021 and 2020, the Company did not recognize any impairment charges related to goodwill.

Short-Term and Long-Term Invest

Short-Term and Long-Term Investments	3 Months Ended
	Dec. 31, 2021
Investments, Debt and Equity Securities [Abstract]
Short-Term and Long-Term Investments	Short-Term and Long-Term Investments Short-term investments consist of the following (in thousands): December 31, 2021 Cost or Gross Gross Fair Value Certificates of deposits $ 992 $ — $ — $ 992 Corporate bonds and notes 177,248 10 (165) 177,093 Municipal bonds and notes 15,377 — (18) 15,359 U.S. government securities 136,091 — (157) 135,934 U.S. government agency securities 17,193 — (23) 17,170 $ 346,901 $ 10 $ (363) $ 346,548 September 30, 2021 Cost or Gross Gross Fair Value Certificates of deposits $ 255 $ — $ — $ 255 Corporate bonds and notes 186,043 116 (52) 186,107 Municipal bonds and notes 13,570 1 (5) 13,566 U.S. government securities 102,607 12 (4) 102,615 U.S. government agency securities 27,096 — (9) 27,087 $ 329,571 $ 129 $ (70) $ 329,630 Long-term investments consist of the following (in thousands): December 31, 2021 Cost or Gross Gross Fair Value Corporate bonds and notes $ 48,845 $ — $ (207) $ 48,638 Municipal bonds and notes 2,262 — (23) 2,239 U.S. government securities 24,426 — (85) 24,341 U.S. government agency securities 1,783 — (10) 1,773 $ 77,316 $ — $ (325) $ 76,991 September 30, 2021 Cost or Gross Gross Fair Value Corporate bonds and notes $ 53,128 $ 13 $ (34) $ 53,107 Municipal bonds and notes 11,114 1 (4) 11,111 U.S. government securities 59,614 2 (8) 59,608 U.S. government agency securities 8,957 — (5) 8,952 $ 132,813 $ 16 $ (51) $ 132,778 Interest income from investments was $0.3 million and $1.1 million for the three months ended December 31, 2021 and 2020, respectively. Interest income is included in other income (expense), net on the Company's consolidated income statements. The following table summarizes investments that have been in a continuous unrealized loss position for less than 12 months and those that have been in a continuous unrealized loss position for more than 12 months as of December 31, 2021 (in thousands): Less Than 12 Months 12 Months or Greater Total December 31, 2021 Fair Value Gross Fair Value Gross Fair Value Gross Corporate bonds and notes $ 196,228 $ (372) $ — $ — $ 196,228 $ (372) Municipal bonds and notes 16,144 (41) — — 16,144 (41) U.S. government securities 160,275 (242) — — 160,275 (242) U.S. government agency securities 18,943 (33) — — 18,943 (33) Total $ 391,590 $ (688) $ — $ — $ 391,590 $ (688) The following table summarizes investments that have been in a continuous unrealized loss position for less than 12 months and those that have been in a continuous unrealized loss position for more than 12 months as of September 30, 2021 (in thousands): Less Than 12 Months 12 Months or Greater Total September 30, 2021 Fair Value Gross Fair Value Gross Fair Value Gross Corporate bonds and notes $ 151,986 $ (86) $ — $ — $ 151,986 $ (86) Municipal bonds and notes 13,764 (9) — — 13,764 (9) U.S. government securities 77,401 (12) — — 77,401 (12) U.S. government agency securities 31,384 (14) — — 31,384 (14) Total $ 274,535 $ (121) $ — $ — $ 274,535 $ (121) The Company invests in securities that are rated investment grade. The Company reviews the individual securities in its portfolio to determine whether a credit loss exists by comparing the extent to which the fair value is less than the amortized cost and considering any changes to ratings of a security by a ratings agency. The Company determined that as of December 31, 2021, there were no credit losses on any investments within its portfolio.

Business Combinations

Business Combinations	3 Months Ended
	Dec. 31, 2021
Business Combinations [Abstract]
Business Combinations	Business Combinations Fiscal Year 2022 Acquisition of Threat Stack, Inc. In September 2021, the Company entered into a Merger Agreement (the “Threat Stack Merger Agreement”) with Threat Stack, Inc. ("Threat Stack"), a provider of cloud security and workload protection solutions. The transaction closed on October 1, 2021 with Threat Stack becoming a wholly-owned subsidiary of F5. The addition of Threat Stack’s cloud security capabilities to F5’s application and API protection solutions is expected to enhance visibility across application infrastructure and workloads to deliver more actionable security insights for customers. Pursuant to the Threat Stack Merger Agreement, at the effective time of the Merger, the capital stock of Threat Stack and the vested outstanding and unexercised stock options in Threat Stack were cancelled and converted to the right to receive approximately $68.9 million in cash, subject to certain adjustments and conditions set forth in the Threat Stack Merger Agreement. In addition, the Company incurred $1.5 million of transaction costs associated with the acquisition which was included in General and Administrative expenses in the fourth fiscal quarter of 2021 and first fiscal quarter of 2022. As a result of the acquisition, the Company acquired all the assets and assumed all the liabilities of Threat Stack. The goodwill related to the Threat Stack acquisition is comprised primarily of expected synergies from combining operations and the acquired intangible assets that do not qualify for separate recognition. Goodwill related to the Threat Stack acquisition is not expected to be deductible for tax purposes. The results of operations of Threat Stack have been included in the Company's consolidated financial statements from the date of acquisition.  The allocated purchase consideration to assets acquired and liabilities assumed based on preliminary estimated fair values is presented in the following table (in thousands): Estimated Useful Life Assets acquired Deferred tax assets $ 13,366 Other net tangible assets acquired, at fair value 5,481 Cash, cash equivalents, and restricted cash 912 Identifiable intangible assets: Developed technology 11,400 5 years Customer relationships 4,400 5 years Goodwill 43,956 Total assets acquired $ 79,515 Liabilities assumed Deferred revenue $ (10,591) Total liabilities assumed $ (10,591) Net assets acquired $ 68,924 The initial allocation of the purchase price was based on preliminary valuations and assumptions and is subject to change within the measurement period. The Company expects to finalize the allocation of the purchase price as soon as practicable and no later than one year from the acquisition date. The developed technology intangible asset will be amortized on a straight-line basis over its estimated useful life of five years and included in cost of net product revenues. The customer relationships intangible asset will be amortized on a straight-line basis over its estimated useful life of five years and included in sales and marketing expenses. The weighted-average life of the amortizable intangible assets recognized from the Threat Stack acquisition was five years as of October 1, 2021, the date the transaction closed. The estimated useful lives for the acquired intangible assets were based on the expected future cash flows associated with the respective asset. Since the Threat Stack acquisition was completed on October 1, 2021, the F5 and Threat Stack teams have been executing a plan to integrate ongoing operations. The pro forma financial information, as well as the revenue and earnings generated by Threat Stack, were not material to the Company's operations for the periods presented. Fiscal Year 2021 Acquisition of Volterra, Inc. On January 5, 2021, the Company entered into a Merger Agreement (the “Volterra Merger Agreement”) with Volterra, Inc. ("Volterra"), a provider of edge-as-a-service platform solutions. The transaction closed on January 22, 2021 with Volterra becoming a wholly-owned subsidiary of F5. With the addition of Volterra’s technology platform, F5 is creating an edge platform built for enterprises and service providers that will be security-first and app-driven with unlimited scale. Pursuant to the Volterra Merger Agreement, at the effective time of the Merger, the capital stock of Volterra and the vested outstanding and unexercised stock options in Volterra were cancelled and converted to the right to receive approximately $427.2 million in cash, subject to certain adjustments and conditions set forth in the Volterra Merger Agreement. The unvested stock options and restricted stock units in Volterra held by continuing employees of Volterra were assumed by F5, on the terms and conditions set forth in the Volterra Merger Agreement. The Company incurred $9.5 million of transaction costs associated with the acquisition which was included in General and Administrative expenses in fiscal 2021. As a result of the acquisition, the Company acquired all the assets and assumed all the liabilities of Volterra. The goodwill related to the Volterra acquisition is comprised primarily of expected synergies from combining operations and the acquired intangible assets that do not qualify for separate recognition. Goodwill related to the Volterra acquisition is not expected to be deductible for tax purposes. The results of operations of Volterra have been included in the Company's consolidated financial statements from the date of acquisition. The allocated purchase consideration to assets acquired and liabilities assumed based on preliminary estimated fair values is presented in the following table (in thousands): Estimated Useful Life Assets acquired Cash, cash equivalents, and restricted cash $ 14,012 Other tangible assets acquired, at fair value 7,499 Identifiable intangible assets: Developed technology 59,500 7 years Customer relationships 500 1 year Goodwill 351,417 Total assets acquired 432,928 Liabilities assumed (5,686) Net assets acquired $ 427,242 The measurement period for the Volterra acquisition will lapse during the second quarter of fiscal 2022. The developed technology intangible asset is being amortized on a straight-line basis over its estimated useful life of seven years and included in cost of net product revenues. The customer relationships intangible asset is being amortized on a straight-line basis over its estimated useful life of one year and included in sales and marketing expenses. The weighted-average life of the amortizable intangible assets recognized from the Volterra acquisition was 6.95 years as of January 22, 2021, the date the transaction closed. The estimated useful lives for the acquired intangible assets were based on the expected future cash flows associated with the respective asset. Since the Volterra acquisition was completed on January 22, 2021, the F5 and Volterra teams have been executing a plan to integrate ongoing operations. The pro forma financial information, as well as the revenue and earnings generated by Volterra, were not material to the Company's operations for the periods presented.

Balance Sheet Details

Balance Sheet Details	3 Months Ended
	Dec. 31, 2021
Balance Sheet Details [Abstract]
Balance Sheet Details	Balance Sheet Details Cash, Cash Equivalents and Restricted Cash The following table provides a reconciliation of the Company's cash and cash equivalents and restricted cash reported within the consolidated balance sheets that sum to the total cash, cash equivalents and restricted cash shown in the Company's consolidated statements of cash flows for the periods presented (in thousands): December 31, September 30, Cash and cash equivalents $ 512,406 $ 580,977 Restricted cash included in other assets, net 3,414 3,356 Total cash, cash equivalents and restricted cash $ 515,820 $ 584,333 Inventories Inventories consist of the following (in thousands): December 31, September 30, Finished goods $ 15,734 $ 13,081 Raw materials 5,061 8,974 $ 20,795 $ 22,055 Other Current Assets Other current assets consist of the following (in thousands): December 31, September 30, Unbilled receivables $ 236,042 $ 215,396 Prepaid expenses 94,024 59,636 Capitalized contract acquisition costs 34,689 34,265 Other 24,187 28,605 $ 388,942 $ 337,902 Other Assets Other assets, net consist of the following (in thousands): December 31, September 30, Intangible assets $ 237,528 $ 237,178 Unbilled receivables 171,787 158,885 Capitalized contract acquisition costs 44,245 43,571 Other 36,948 32,924 $ 490,508 $ 472,558 Accrued Liabilities Accrued liabilities consist of the following (in thousands): December 31, September 30, Payroll and benefits $ 149,552 $ 179,147 Operating lease liabilities, current 46,889 49,286 Income and other tax accruals 51,669 44,075 Other 66,735 68,979 $ 314,845 $ 341,487 Other Long-term Liabilities Other long-term liabilities consist of the following (in thousands): December 31, September 30, Income taxes payable $ 68,234 $ 66,081 Other 9,168 9,155 $ 77,402 $ 75,236

Debt Facilities

Debt Facilities	3 Months Ended
	Dec. 31, 2021
Debt Disclosure [Abstract]
Debt Facilities	Debt Facilities Term Credit Agreement In connection with the acquisition of Shape, on January 24, 2020, the Company entered into a Term Credit Agreement ("Term Credit Agreement") with certain institutional lenders that provides for a senior unsecured term loan facility in an aggregate principal amount of $400.0 million (the "Term Loan Facility"). The proceeds from the Term Loan Facility were primarily used to finance the acquisition of Shape and related expenses. In connection with the Term Loan Facility, the Company incurred $2.2 million in debt issuance costs, which are recorded as a reduction to the carrying value of the principal amount of the debt. Borrowings under the Term Loan Facility bear interest at a rate equal to, at the Company's option, (a) LIBOR, adjusted for customary statutory reserves, plus an applicable margin of 1.125% to 1.75% depending on the Company's leverage ratio, or (b) an alternate base rate determined in accordance with the Term Credit Agreement, plus an applicable margin of 0.125% to 0.750% depending on the Company's leverage ratio. Interest on the outstanding principal of borrowings is currently due quarterly in arrears. As of December 31, 2021, the margin for LIBOR-based loans was 1.125% and the margin for alternate base rate loans was 0.125%. The Term Loan Facility matures on January 24, 2023 with quarterly installments (commencing with the first full fiscal quarter ended after January 24, 2020) equal to 1.25% of the original principal amount of the Term Loan Facility. The remaining outstanding principal of borrowings under the Term Loan Facility is due upon maturity on January 24, 2023. Borrowings under the Term Loan Facility may be voluntarily prepaid, in whole or in part, without penalty or premium. Borrowings repaid or prepaid under the Term Loan Facility may not be reborrowed. Among certain affirmative and negative covenants provided in the Term Credit Agreement, there is a financial covenant that requires the Company to maintain a leverage ratio, calculated as of the last day of each fiscal quarter, of consolidated total indebtedness to consolidated EBITDA. This covenant may result in a higher interest rate on its outstanding principal borrowings on the Term Loan Facility in future periods, depending on the Company's performance. As of December 31, 2021, the Company was in compliance with all covenants. As of December 31, 2021, $365.0 million of principal amount under the Term Loan Facility was outstanding, excluding unamortized debt issuance costs of $0.8 million. The weighted average interest rate on the principal amount under the Term Loan Facility outstanding balance was 1.282% and 1.390% for the three months ended December 31, 2021 and 2020, respectively. The following table presents the scheduled principal maturities as of December 31, 2021 (in thousands): Fiscal Years Ending September 30: Amount 2022 (remainder) $ 15,000 2023 350,000 Total $ 365,000 Revolving Credit Agreement On January 31, 2020, the Company entered into a Revolving Credit Agreement (the "Revolving Credit Agreement") that provides for a senior unsecured revolving credit facility in an aggregate principal amount of $350.0 million (the "Revolving Credit Facility"). The Company has the option to increase commitments under the Revolving Credit Facility from time to time, subject to certain conditions, by up to $150.0 million. Borrowings under the Revolving Credit Facility bear interest at a rate equal to, at the Company's option, (a) LIBOR, adjusted for customary statutory reserves, plus an applicable margin of 1.125% to 1.75% depending on the Company's leverage ratio, or (b) an alternate base rate determined in accordance with the Revolving Credit Agreement, plus an applicable margin of 0.125% to 0.750% depending on the Company's leverage ratio. The Revolving Credit Agreement also requires payment of a commitment fee calculated at a rate per annum of 0.125% to 0.300% depending on the Company's leverage ratio on the undrawn portion of the Revolving Credit Facility. Commitment fees incurred during the three months ended December 31, 2021 were not material.

Leases

Leases	3 Months Ended
	Dec. 31, 2021
Leases [Abstract]
Leases	Leases The majority of the Company's operating lease payments relate to its corporate headquarters in Seattle, Washington, which includes approximately 515,000 square feet of office space. The lease commenced in April 2019 and expires in 2033 with an option for renewal. The Company also leases additional office and lab space for product development and sales and support personnel in the United States and internationally. The Company's lease agreements do not contain any material residual value guarantees or material restrictive covenants. The components of the Company's operating lease expenses for the three months ended December 31, 2021 and 2020 were as follows (in thousands): Three months ended 2021 2020 Operating lease expense $ 11,914 $ 12,181 Short-term lease expense 556 986 Variable lease expense 6,244 7,026 Total lease expense $ 18,714 $ 20,193 Variable lease expense primarily consists of common area maintenance, real estate taxes and parking expenses. Supplemental balance sheet information related to the Company's operating leases was as follows (in thousands, except lease term and discount rate): December 31, 2021 September 30, 2021 Operating lease right-of-use assets, net $ 237,341 $ 244,934 Operating lease liabilities, current 1 46,889 49,286 Operating lease liabilities, long-term 287,596 296,945 Total operating lease liabilities $ 334,485 $ 346,231 Weighted average remaining lease term (in years) 9.6 9.7 Weighted average discount rate 2.60 % 2.60 % (1) Current portion of operating lease liabilities is included in accrued liabilities on the Company's consolidated balance sheets. As of December 31, 2021, the future operating lease payments for each of the next five years and thereafter is as follows (in thousands): Fiscal Years Ending September 30: Operating Lease 2022 (remainder) $ 41,840 2023 50,162 2024 41,519 2025 33,599 2026 26,583 2027 26,224 Thereafter 164,890 Total lease payments 384,817 Less: imputed interest (50,332) Total lease liabilities $ 334,485 Operating lease liabilities above do not include sublease income. As of December 31, 2021, the Company expects to receive sublease income of approximately $17.5 million, which consists of $5.1 million to be received for the remainder of fiscal 2022 and $12.4 million to be received over the three fiscal years thereafter. In the first quarter of fiscal 2021, the Company recorded an impairment of $6.7 million against the right-of-use asset related to the integration of the former Shape headquarters in Santa Clara, California. There were no impairments against right-of-use assets for the three months ended December 31, 2021.

Commitments and Contingencies

Commitments and Contingencies	3 Months Ended
	Dec. 31, 2021
Commitments and Contingencies Disclosure [Abstract]
Commitments and Contingencies	Commitments and Contingencies Guarantees and Product Warranties In the normal course of business to facilitate sales of its products, the Company indemnifies other parties, including customers, resellers, lessors, and parties to other transactions with the Company, with respect to certain matters. The Company has agreed to hold the other party harmless against losses arising from a breach of representations or covenants, or out of intellectual property infringement or other claims made against certain parties. These agreements may limit the time within which an indemnification claim can be made and the amount of the claim. The Company has entered into indemnification agreements with its officers and directors and certain other employees, and the Company's bylaws contain similar indemnification obligations to the Company's agents. It is not possible to determine the maximum potential amount under these indemnification agreements due to the limited history of prior indemnification claims and the unique facts and circumstances involved in each particular agreement. The Company generally offers warranties of one year for hardware for those customers without service contracts, with the option of purchasing additional warranty coverage in yearly increments. The Company accrues for warranty costs as part of its cost of sales based on associated material product costs and technical support labor costs. Accrued warranty costs as of December 31, 2021 and September 30, 2021 were not material. Commitments As of December 31, 2021, the Company's principal commitments consisted of borrowings under the Term Loan Facility and obligations outstanding under operating leases. Refer to Note 7 for the scheduled principal maturities of the Term Loan Facility as of December 31, 2021. The Company leases its facilities under operating leases that expire at various dates through 2033. There have been no material changes in the Company's lease obligations compared to those discussed in Note 8 to its annual consolidated financial statements. Legal Proceedings 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 asserts 26 causes of action against the various defendants, including copyright infringement, violation of trademark law, tortious interference, conspiracy, and fraud. The complaint seeks damages, disgorgement of profits, fees and costs, 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 all claims asserted against them in the lawsuit. While these motions were pending, the Court ordered Lynwood to select ten of its twenty-six claims to litigate through trial while the remaining sixteen claims would be stayed pending resolution of the ten selected claims. On March 25 and 30, 2021, the Court dismissed the ten selected claims and granted Lynwood leave to cure the deficiencies in its complaint though it expressed doubt about Lynwood’s ability to do so. The Court further ruled that Lynwood may not add new causes of action or add new parties without stipulation or leave of court, and that unless Lynwood corrects “all the defects” identified in the Court’s orders and the Company’s and other defendants’ motions to dismiss, the Court will dismiss the ten claims with prejudice. On April 6, the Court referred the parties to private mediation to be completed by June 1, 2021. Pursuant to the Court’s order, the parties held a private mediation on May 27, 2021. The matter did not resolve. On April 29, Lynwood filed its amended complaint, 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 claims Lynwood had selected to proceed to litigate through trial, reserving their right to move to dismiss the 16 stayed claims once the Court lifts the stay. The motion to dismiss was set to be heard by the Court on October 14, 2021, but on October 11, 2021, the Court vacated the hearing and gave notice that it will decide the motion on the papers without oral argument. This case has recently been assigned to a new judge. The new judge has not indicated when the motion will be ruled upon. Proven Networks LLC Litigations Proven Networks LLC (“Proven”) is a non-practicing entity (NPE) whose sole business is acquiring patents and filing lawsuits alleging infringement of those patents to extract licensing fees. Proven acquired a portfolio of Alcatel-Lucent patents and asserted various patents from that portfolio against more than a dozen technology companies in courts in California and Texas, in the International Trade Commission and in foreign courts. Proven brought three actions against the Company, one in California, one in the International Trade Commission, and one in Germany. These cases against the Company were resolved through a global settlement that was not material to the Company, the terms of which are confidential.

Income Taxes

Income Taxes	3 Months Ended
	Dec. 31, 2021
Income Tax Disclosure [Abstract]
Income Taxes	Income Taxes The Company's tax provision for interim periods is determined using an estimated annual effective tax rate, adjusted for discrete items in the related period. The effective tax rate was 16.3% and 25.1% for the three months ended December 31, 2021 and 2020, respectively. The decrease in the effective tax rate for the three months ended December 31, 2021 as compared to the three months ended December 31, 2020 is primarily due to the tax impact of stock based compensation. At December 31, 2021, the Company had $72.7 million of unrecognized tax benefits that, if recognized, would affect the effective tax rate. It is anticipated that the Company’s existing liabilities for unrecognized tax benefits will change within the next twelve months due to audit settlements or the expiration of statutes of limitations. The Company does not expect these changes to be material to the consolidated financial statements. The Company recognizes interest and, if applicable, penalties for any uncertain tax positions as a component of income tax expense. The Company and its subsidiaries are subject to U.S. federal income tax as well as the income tax of multiple state and foreign jurisdictions. The Company has concluded all U.S. federal income tax matters for fiscal years through September 30, 2017. Major jurisdictions where there are wholly owned subsidiaries of F5, Inc. which require income tax filings include the United Kingdom, Singapore, and Israel. The earliest periods open for review by local taxing authorities are fiscal years 2020 for the United Kingdom, 2017 for Singapore, and 2013 for Israel. The Company is currently under audit by various states for fiscal

Shareholders' Equity

Shareholders' Equity	3 Months Ended
	Dec. 31, 2021
Equity [Abstract]
Stockholders' Equity Note Disclosure	Shareholders' Equity Common Stock Repurchase On October 31, 2018, the Company announced that its Board of Directors authorized an additional $1.0 billion for its common stock share repurchase program. This authorization is incremental to the existing $4.4 billion program, initially approved in October 2010 and expanded in each fiscal year thereafter. Acquisitions for the share repurchase programs will be made from time to time in private transactions, accelerated share repurchase programs, or open market purchases as permitted by securities laws and other legal requirements. The programs can be terminated at any time. The following table summarizes the Company's repurchases and retirements of its common stock under its Stock Repurchase Program (in thousands, except per share data): Three months ended 2021 2020 Shares repurchased 539 — Average price per share $ 232.14 $ — Amount repurchased $ 125,011 $ — As of December 31, 2021, the Company had $647.5 million remaining authorized to purchase shares under its share repurchase program.

Net Income Per Share

Net Income Per Share	3 Months Ended
	Dec. 31, 2021
Net Income Per Share [Abstract]
Net Income Per Share	Net Income Per Share Basic net income per share is computed by dividing net income by the weighted average number of common shares outstanding during the period. Diluted net income per share is computed by dividing net income by the weighted average number of common and dilutive common stock equivalent shares outstanding during the period. The Company's nonvested restricted stock units do not have nonforfeitable rights to dividends or dividend equivalents and are not considered participating securities that should be included in the computation of earnings per share under the two-class method. The following table sets forth the computation of basic and diluted net income per share (in thousands, except per share data): Three months ended 2021 2020 Numerator Net income $ 93,559 $ 87,678 Denominator Weighted average shares outstanding — basic 60,810 61,440 Dilutive effect of common shares from stock options and restricted stock units 1,072 842 Weighted average shares outstanding — diluted 61,882 62,282 Basic net income per share $ 1.54 $ 1.43 Diluted net income per share $ 1.51 $ 1.41 Anti-dilutive stock-based awards excluded from the calculations of diluted earnings per share were not material for the three months ended December 31, 2021 and 2020.

Segment Information

Segment Information	3 Months Ended
	Dec. 31, 2021
Segment Reporting [Abstract]
Segment Information	Segment InformationOperating segments are defined as components of an enterprise for which separate financial information is available and evaluated regularly by the chief operating decision-maker, or decision-making group, in deciding how to allocate resources and in assessing performance. Management has determined that the Company is organized as, and operates in, one reportable operating segment: the development, marketing and sale of application security and delivery services across multi-cloud environments. Revenues by Geographic Location and Other Information The Company does business in three main geographic regions: the Americas (primarily the United States); Europe, the Middle East, and Africa (EMEA); and the Asia Pacific region (APAC). The Company's chief operating decision-maker reviews financial information presented on a consolidated basis accompanied by information about revenues by geographic region. The Company's foreign offices conduct sales, marketing and support activities. Revenues are attributed by geographic location based on the location of the customer. The following presents revenues by geographic region (in thousands): Three months ended 2021 2020 Americas: United States $ 381,289 $ 320,343 Other 21,702 22,793 Total Americas 402,991 343,136 EMEA 162,062 162,084 Asia Pacific 122,047 119,397 $ 687,100 $ 624,617 The Company generates revenues from the sale of products and services. The Company continues to offer its products through a range of consumption models, from physical systems to software solutions and managed services. The following presents net product revenues by systems and software (in thousands): Three months ended 2021 2020 Net product revenues Systems revenue $ 180,157 $ 178,571 Software revenue 162,992 109,474 Total net product revenue $ 343,149 $ 288,045 The following distributors of the Company's products accounted for more than 10% of total net revenue: Three months ended 2021 2020 Ingram Micro, Inc. 18.7 % 18.1 % Synnex Corporation 12.2 % 10.0 % The Company tracks assets by physical location. Long-lived assets consist of property and equipment, net, and are shown below (in thousands): December 31, September 30, United States $ 147,012 $ 153,030 EMEA 20,953 20,526 Other countries 17,390 17,608 $ 185,355 $ 191,164

Restructuring Charges

Restructuring Charges	3 Months Ended
	Dec. 31, 2021
Restructuring Charges [Abstract]
Restructuring Charges	Restructuring ChargesIn the first quarter of fiscal 2022, the Company initiated a restructuring plan to match strategic and financial objectives and optimize resources for long term growth, including a reduction in force program affecting approximately 70 positions. The Company recorded a restructuring charge of $7.9 million in the first quarter of fiscal 2022. The Company does not expect to record any significant future charges related to the restructuring plan. During the three months ended December 31, 2021, the following activity was recorded (in thousands): Employee Severance, Benefits and Related Costs Accrued expenses, October 1, 2021 $ — Restructuring charges 7,909 Cash payments (4,027) Accrued expenses, December 31, 2021 $ 3,882

Summary of Significant Accoun_2

Summary of Significant Accounting Policies (Policies)	3 Months Ended
	Dec. 31, 2021
Accounting Policies [Abstract]
Description of Business	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	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.
Recent Accounting Pronouncements	There have been no material changes to the Company's significant accounting policies as of and for the three months ended December 31, 2021. 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. The ongoing impact of this standard will be fact dependent on the transactions within its scope.

Revenue from Contracts with C_2

Revenue from Contracts with Customers (Tables)	3 Months Ended
	Dec. 31, 2021
Revenue from Contract with Customer [Abstract]
Capitalized Contract Cost	The table below shows significant movements in capitalized contract acquisition costs (current and noncurrent) for the three months ended December 31, 2021 and 2020 (in thousands): Three months ended 2021 2020 Balance, beginning of period $ 77,836 $ 70,396 Additional capitalized contract acquisition costs 10,512 9,725 Amortization of capitalized contract acquisition costs (9,414) (8,152) Balance, end of period $ 78,934 $ 71,969
Contract with Customer, Asset and Liability	The table below shows significant movements in the deferred revenue balances (current and noncurrent) for the three months ended December 31, 2021 and 2020 (in thousands): Three months ended 2021 2020 Balance, beginning of period $ 1,489,842 $ 1,272,632 Amounts added but not recognized as revenues 441,591 421,918 Deferred revenue acquired through acquisition of businesses 10,591 — Revenues recognized related to the opening balance of deferred revenue (365,525) (335,725) Balance, end of period $ 1,576,499 $ 1,358,825

Fair Value Measurements (Tables

Fair Value Measurements (Tables)	3 Months Ended
	Dec. 31, 2021
Fair Value Disclosures [Abstract]
Schedule of Financial Assets Measured at Fair Value on a Recurring Basis	The Company's financial assets measured at fair value on a recurring basis subject to the disclosure requirements at December 31, 2021, were as follows (in thousands): Fair Value Measurements at Reporting Date Using Quoted Prices in Active Markets for Identical Securities Significant Other Significant Fair Value at Cash equivalents $ 19,265 $ 779 $ — $ 20,044 Short-term investments Available-for-sale securities — certificates of deposits — 992 — 992 Available-for-sale securities — corporate bonds and notes — 177,093 — 177,093 Available-for-sale securities — municipal bonds and notes — 15,359 — 15,359 Available-for-sale securities — U.S. government securities — 135,934 — 135,934 Available-for-sale securities — U.S. government agency securities — 17,170 — 17,170 Long-term investments Available-for-sale securities — corporate bonds and notes — 48,638 — 48,638 Available-for-sale securities — municipal bonds and notes — 2,239 — 2,239 Available-for-sale securities — U.S. government securities — 24,341 — 24,341 Available-for-sale securities — U.S. government agency securities — 1,773 — 1,773 Total $ 19,265 $ 424,318 $ — $ 443,583 The Company's financial assets measured at fair value on a recurring basis subject to the disclosure requirements at September 30, 2021, were as follows (in thousands): Fair Value Measurements at Reporting Date Using Quoted Prices in Active Markets Significant Significant Fair Value at Cash equivalents $ 17,150 $ 4,397 $ — $ 21,547 Short-term investments Available-for-sale securities — certificates of deposits — 255 — 255 Available-for-sale securities — corporate bonds and notes — 186,107 — 186,107 Available-for-sale securities — municipal bonds and notes — 13,566 — 13,566 Available-for-sale securities — U.S. government securities — 102,615 — 102,615 Available-for-sale securities — U.S. government agency securities — 27,087 — 27,087 Long-term investments Available-for-sale securities — corporate bonds and notes — 53,107 — 53,107 Available-for-sale securities — municipal bonds and notes — 11,111 — 11,111 Available-for-sale securities — U.S. government securities — 59,608 — 59,608 Available-for-sale securities — U.S. government agency securities — 8,952 — 8,952 Total $ 17,150 $ 466,805 $ — $ 483,955
Property, Plant and Equipment	Impairment charges were allocated to the following income statement line items for the three months ended December 31, 2021 and 2020 (in thousands): Three months ended 2021 2020 Cost of net product revenue $ — $ 1,968 Cost of net service revenue — 1 Sales and marketing 6,175 1,259 Research and development — 3,129 General and administrative — 516 Total impairment charges $ 6,175 $ 6,873

Short-Term and Long-Term Inve_2

Short-Term and Long-Term Investments (Tables)	3 Months Ended
	Dec. 31, 2021
Investments, Debt and Equity Securities [Abstract]
Schedule of Short-Term and Long-Term Investments	Short-term investments consist of the following (in thousands): December 31, 2021 Cost or Gross Gross Fair Value Certificates of deposits $ 992 $ — $ — $ 992 Corporate bonds and notes 177,248 10 (165) 177,093 Municipal bonds and notes 15,377 — (18) 15,359 U.S. government securities 136,091 — (157) 135,934 U.S. government agency securities 17,193 — (23) 17,170 $ 346,901 $ 10 $ (363) $ 346,548 September 30, 2021 Cost or Gross Gross Fair Value Certificates of deposits $ 255 $ — $ — $ 255 Corporate bonds and notes 186,043 116 (52) 186,107 Municipal bonds and notes 13,570 1 (5) 13,566 U.S. government securities 102,607 12 (4) 102,615 U.S. government agency securities 27,096 — (9) 27,087 $ 329,571 $ 129 $ (70) $ 329,630 Long-term investments consist of the following (in thousands): December 31, 2021 Cost or Gross Gross Fair Value Corporate bonds and notes $ 48,845 $ — $ (207) $ 48,638 Municipal bonds and notes 2,262 — (23) 2,239 U.S. government securities 24,426 — (85) 24,341 U.S. government agency securities 1,783 — (10) 1,773 $ 77,316 $ — $ (325) $ 76,991 September 30, 2021 Cost or Gross Gross Fair Value Corporate bonds and notes $ 53,128 $ 13 $ (34) $ 53,107 Municipal bonds and notes 11,114 1 (4) 11,111 U.S. government securities 59,614 2 (8) 59,608 U.S. government agency securities 8,957 — (5) 8,952 $ 132,813 $ 16 $ (51) $ 132,778
Schedule of Investments That Have Been in a Continuous Unrealized Loss Position	The following table summarizes investments that have been in a continuous unrealized loss position for less than 12 months and those that have been in a continuous unrealized loss position for more than 12 months as of December 31, 2021 (in thousands): Less Than 12 Months 12 Months or Greater Total December 31, 2021 Fair Value Gross Fair Value Gross Fair Value Gross Corporate bonds and notes $ 196,228 $ (372) $ — $ — $ 196,228 $ (372) Municipal bonds and notes 16,144 (41) — — 16,144 (41) U.S. government securities 160,275 (242) — — 160,275 (242) U.S. government agency securities 18,943 (33) — — 18,943 (33) Total $ 391,590 $ (688) $ — $ — $ 391,590 $ (688) The following table summarizes investments that have been in a continuous unrealized loss position for less than 12 months and those that have been in a continuous unrealized loss position for more than 12 months as of September 30, 2021 (in thousands): Less Than 12 Months 12 Months or Greater Total September 30, 2021 Fair Value Gross Fair Value Gross Fair Value Gross Corporate bonds and notes $ 151,986 $ (86) $ — $ — $ 151,986 $ (86) Municipal bonds and notes 13,764 (9) — — 13,764 (9) U.S. government securities 77,401 (12) — — 77,401 (12) U.S. government agency securities 31,384 (14) — — 31,384 (14) Total $ 274,535 $ (121) $ — $ — $ 274,535 $ (121)

Business Combinations (Tables)

Business Combinations (Tables)	3 Months Ended
	Dec. 31, 2021
Business Combinations [Abstract]
Schedule of Recognized Identified Assets Acquired and Liabilities Assumed	The allocated purchase consideration to assets acquired and liabilities assumed based on preliminary estimated fair values is presented in the following table (in thousands): Estimated Useful Life Assets acquired Deferred tax assets $ 13,366 Other net tangible assets acquired, at fair value 5,481 Cash, cash equivalents, and restricted cash 912 Identifiable intangible assets: Developed technology 11,400 5 years Customer relationships 4,400 5 years Goodwill 43,956 Total assets acquired $ 79,515 Liabilities assumed Deferred revenue $ (10,591) Total liabilities assumed $ (10,591) Net assets acquired $ 68,924 The allocated purchase consideration to assets acquired and liabilities assumed based on preliminary estimated fair values is presented in the following table (in thousands): Estimated Useful Life Assets acquired Cash, cash equivalents, and restricted cash $ 14,012 Other tangible assets acquired, at fair value 7,499 Identifiable intangible assets: Developed technology 59,500 7 years Customer relationships 500 1 year Goodwill 351,417 Total assets acquired 432,928 Liabilities assumed (5,686) Net assets acquired $ 427,242

Balance Sheet Details (Tables)

Balance Sheet Details (Tables)	3 Months Ended
	Dec. 31, 2021
Balance Sheet Details [Abstract]
Cash and Cash Equivalents	The following table provides a reconciliation of the Company's cash and cash equivalents and restricted cash reported within the consolidated balance sheets that sum to the total cash, cash equivalents and restricted cash shown in the Company's consolidated statements of cash flows for the periods presented (in thousands): December 31, September 30, Cash and cash equivalents $ 512,406 $ 580,977 Restricted cash included in other assets, net 3,414 3,356 Total cash, cash equivalents and restricted cash $ 515,820 $ 584,333
Inventories	Inventories consist of the following (in thousands): December 31, September 30, Finished goods $ 15,734 $ 13,081 Raw materials 5,061 8,974 $ 20,795 $ 22,055
Other Current Assets	Other current assets consist of the following (in thousands): December 31, September 30, Unbilled receivables $ 236,042 $ 215,396 Prepaid expenses 94,024 59,636 Capitalized contract acquisition costs 34,689 34,265 Other 24,187 28,605 $ 388,942 $ 337,902
Other Assets, Noncurrent	Other assets, net consist of the following (in thousands): December 31, September 30, Intangible assets $ 237,528 $ 237,178 Unbilled receivables 171,787 158,885 Capitalized contract acquisition costs 44,245 43,571 Other 36,948 32,924 $ 490,508 $ 472,558
Accrued Liabilities	Accrued liabilities consist of the following (in thousands): December 31, September 30, Payroll and benefits $ 149,552 $ 179,147 Operating lease liabilities, current 46,889 49,286 Income and other tax accruals 51,669 44,075 Other 66,735 68,979 $ 314,845 $ 341,487
Noncurrent Liabilities	Other long-term liabilities consist of the following (in thousands): December 31, September 30, Income taxes payable $ 68,234 $ 66,081 Other 9,168 9,155 $ 77,402 $ 75,236

Debt Facilities (Tables)

Debt Facilities (Tables)	3 Months Ended
	Dec. 31, 2021
Debt Disclosure [Abstract]
Schedule of Maturities of Long-term Debt	The following table presents the scheduled principal maturities as of December 31, 2021 (in thousands): Fiscal Years Ending September 30: Amount 2022 (remainder) $ 15,000 2023 350,000 Total $ 365,000

Leases (Tables)

Leases (Tables)	3 Months Ended
	Dec. 31, 2021
Leases [Abstract]
Lease, Cost	The components of the Company's operating lease expenses for the three months ended December 31, 2021 and 2020 were as follows (in thousands): Three months ended 2021 2020 Operating lease expense $ 11,914 $ 12,181 Short-term lease expense 556 986 Variable lease expense 6,244 7,026 Total lease expense $ 18,714 $ 20,193
Assets And Liabilities Lessee	Supplemental balance sheet information related to the Company's operating leases was as follows (in thousands, except lease term and discount rate): December 31, 2021 September 30, 2021 Operating lease right-of-use assets, net $ 237,341 $ 244,934 Operating lease liabilities, current 1 46,889 49,286 Operating lease liabilities, long-term 287,596 296,945 Total operating lease liabilities $ 334,485 $ 346,231 Weighted average remaining lease term (in years) 9.6 9.7 Weighted average discount rate 2.60 % 2.60 % (1) Current portion of operating lease liabilities is included in accrued liabilities on the Company's consolidated balance sheets.
Lessee, Operating Lease, Liability, Maturity	As of December 31, 2021, the future operating lease payments for each of the next five years and thereafter is as follows (in thousands): Fiscal Years Ending September 30: Operating Lease 2022 (remainder) $ 41,840 2023 50,162 2024 41,519 2025 33,599 2026 26,583 2027 26,224 Thereafter 164,890 Total lease payments 384,817 Less: imputed interest (50,332) Total lease liabilities $ 334,485

Shareholders' Equity (Tables)

Shareholders' Equity (Tables)	3 Months Ended
	Dec. 31, 2021
Equity [Abstract]
Class of Treasury Stock	The following table summarizes the Company's repurchases and retirements of its common stock under its Stock Repurchase Program (in thousands, except per share data): Three months ended 2021 2020 Shares repurchased 539 — Average price per share $ 232.14 $ — Amount repurchased $ 125,011 $ —

Net Income Per Share (Tables)

Net Income Per Share (Tables)	3 Months Ended
	Dec. 31, 2021
Net Income Per Share [Abstract]
Schedule of Earnings Per Share, Basic and Diluted	The following table sets forth the computation of basic and diluted net income per share (in thousands, except per share data): Three months ended 2021 2020 Numerator Net income $ 93,559 $ 87,678 Denominator Weighted average shares outstanding — basic 60,810 61,440 Dilutive effect of common shares from stock options and restricted stock units 1,072 842 Weighted average shares outstanding — diluted 61,882 62,282 Basic net income per share $ 1.54 $ 1.43 Diluted net income per share $ 1.51 $ 1.41

Segment Information (Tables)

Segment Information (Tables)	3 Months Ended
	Dec. 31, 2021
Segment Reporting [Abstract]
Schedule of Revenues by Geographic Region	The following presents revenues by geographic region (in thousands): Three months ended 2021 2020 Americas: United States $ 381,289 $ 320,343 Other 21,702 22,793 Total Americas 402,991 343,136 EMEA 162,062 162,084 Asia Pacific 122,047 119,397 $ 687,100 $ 624,617
Schedule of Product Revenues by Systems and Software	The following presents net product revenues by systems and software (in thousands): Three months ended 2021 2020 Net product revenues Systems revenue $ 180,157 $ 178,571 Software revenue 162,992 109,474 Total net product revenue $ 343,149 $ 288,045
Schedule of Revenue by Major Customers by Reporting Segments	The following distributors of the Company's products accounted for more than 10% of total net revenue: Three months ended 2021 2020 Ingram Micro, Inc. 18.7 % 18.1 % Synnex Corporation 12.2 % 10.0 %
Long-lived Assets by Geographic Areas	The Company tracks assets by physical location. Long-lived assets consist of property and equipment, net, and are shown below (in thousands): December 31, September 30, United States $ 147,012 $ 153,030 EMEA 20,953 20,526 Other countries 17,390 17,608 $ 185,355 $ 191,164

Restructuring Charges (Tables)

Restructuring Charges (Tables)	3 Months Ended
	Dec. 31, 2021
Restructuring Charges [Abstract]
Restructuring and Related Costs	During the three months ended December 31, 2021, the following activity was recorded (in thousands): Employee Severance, Benefits and Related Costs Accrued expenses, October 1, 2021 $ — Restructuring charges 7,909 Cash payments (4,027) Accrued expenses, December 31, 2021 $ 3,882

Revenue from Contracts with C_3

Revenue from Contracts with Customers - Capitalized contract acquisition costs (Details) - USD ($) $ in Thousands	3 Months Ended
	Dec. 31, 2021	Dec. 31, 2020
Changes In Capitalized Contract Cost [Roll Forward]
Beginning Balance	$ 77,836	$ 70,396
Additional capitalized contract acquisition costs	10,512	9,725
Amortization of capitalized contract acquisition costs	(9,414)	(8,152)
Ending Balance	$ 78,934	$ 71,969

Revenue from Contracts with C_4

Revenue from Contracts with Customers - Contract Assets and Liabilities (Details) - USD ($) $ in Thousands	3 Months Ended
	Dec. 31, 2021	Dec. 31, 2020
Change in Contract with Customer, Liability [Roll Forward]
Beginning Balance	$ 1,489,842	$ 1,272,632
Amounts added but not recognized as revenues	441,591	421,918
Deferred revenue acquired through acquisition of businesses	10,591	0
Revenues recognized related to the opening balance of deferred revenue	(365,525)	(335,725)
Ending Balance	$ 1,576,499	$ 1,358,825

Revenue from Contracts with C_5

Revenue from Contracts with Customers - Narrative (Details) - USD ($)	3 Months Ended
	Dec. 31, 2021	Dec. 31, 2020
Revenue from Contract with Customer [Abstract]
Amortization of capitalized contract acquisition costs	$ 9,414,000	$ 8,152,000
Capitalized Contract Cost, Impairment Loss	$ 0	$ 0

Revenue from Contracts with C_6

Revenue from Contracts with Customers - Remaining Performance Obligations (Details) $ in Billions	Dec. 31, 2021USD ($)
Revenue from Contract with Customer [Abstract]
Revenue, remaining performance obligation, amount	$ 1.6
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2021-01-01
Revenue from Contract with Customer [Abstract]
Revenue, remaining performance obligation, percentage	65.90%
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items]
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Period	12 months
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2022-01-01
Revenue from Contract with Customer [Abstract]
Revenue, remaining performance obligation, percentage	21.10%
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items]
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Period	12 months

Fair Value Measurements - Sched

Fair Value Measurements - Schedule of Financial Assets Measured at Fair Value on a Recurring Basis (Details) - Fair Value, Recurring - USD ($) $ in Thousands	Dec. 31, 2021	Sep. 30, 2021
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis, Valuation Techniques [Line Items]
Cash equivalents, fair value	$ 20,044	$ 21,547
Investments, fair value	443,583	483,955
Certificates of Deposit
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis, Valuation Techniques [Line Items]
Debt Securities, Available-for-sale, Current	992	255
Corporate Bonds and Notes
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis, Valuation Techniques [Line Items]
Debt Securities, Available-for-sale, Current	177,093	186,107
Debt Securities, Available-for-sale, Noncurrent	48,638	53,107
Municipal Bonds and Notes
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis, Valuation Techniques [Line Items]
Debt Securities, Available-for-sale, Current	15,359	13,566
Debt Securities, Available-for-sale, Noncurrent	2,239	11,111
U.S. Government Securities
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis, Valuation Techniques [Line Items]
Debt Securities, Available-for-sale, Current	135,934	102,615
Debt Securities, Available-for-sale, Noncurrent	24,341	59,608
U.S. Government Agency Securities
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis, Valuation Techniques [Line Items]
Debt Securities, Available-for-sale, Current	17,170	27,087
Debt Securities, Available-for-sale, Noncurrent	1,773	8,952
Level 1
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis, Valuation Techniques [Line Items]
Cash equivalents, fair value	19,265	17,150
Investments, fair value	19,265	17,150
Level 1 | Certificates of Deposit
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis, Valuation Techniques [Line Items]
Debt Securities, Available-for-sale, Current	0	0
Level 1 | Corporate Bonds and Notes
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis, Valuation Techniques [Line Items]
Debt Securities, Available-for-sale, Current	0	0
Debt Securities, Available-for-sale, Noncurrent	0	0
Level 1 | Municipal Bonds and Notes
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis, Valuation Techniques [Line Items]
Debt Securities, Available-for-sale, Current	0	0
Debt Securities, Available-for-sale, Noncurrent	0	0
Level 1 | U.S. Government Securities
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis, Valuation Techniques [Line Items]
Debt Securities, Available-for-sale, Current	0	0
Debt Securities, Available-for-sale, Noncurrent	0	0
Level 1 | U.S. Government Agency Securities
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis, Valuation Techniques [Line Items]
Debt Securities, Available-for-sale, Current	0	0
Debt Securities, Available-for-sale, Noncurrent	0	0
Level 2
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis, Valuation Techniques [Line Items]
Cash equivalents, fair value	779	4,397
Investments, fair value	424,318	466,805
Level 2 | Certificates of Deposit
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis, Valuation Techniques [Line Items]
Debt Securities, Available-for-sale, Current	992	255
Level 2 | Corporate Bonds and Notes
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis, Valuation Techniques [Line Items]
Debt Securities, Available-for-sale, Current	177,093	186,107
Debt Securities, Available-for-sale, Noncurrent	48,638	53,107
Level 2 | Municipal Bonds and Notes
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis, Valuation Techniques [Line Items]
Debt Securities, Available-for-sale, Current	15,359	13,566
Debt Securities, Available-for-sale, Noncurrent	2,239	11,111
Level 2 | U.S. Government Securities
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis, Valuation Techniques [Line Items]
Debt Securities, Available-for-sale, Current	135,934	102,615
Debt Securities, Available-for-sale, Noncurrent	24,341	59,608
Level 2 | U.S. Government Agency Securities
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis, Valuation Techniques [Line Items]
Debt Securities, Available-for-sale, Current	17,170	27,087
Debt Securities, Available-for-sale, Noncurrent	1,773	8,952
Level 3
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis, Valuation Techniques [Line Items]
Cash equivalents, fair value	0	0
Investments, fair value	0	0
Level 3 | Certificates of Deposit
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis, Valuation Techniques [Line Items]
Debt Securities, Available-for-sale, Current	0	0
Level 3 | Corporate Bonds and Notes
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis, Valuation Techniques [Line Items]
Debt Securities, Available-for-sale, Current	0	0
Debt Securities, Available-for-sale, Noncurrent	0	0
Level 3 | Municipal Bonds and Notes
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis, Valuation Techniques [Line Items]
Debt Securities, Available-for-sale, Current	0	0
Debt Securities, Available-for-sale, Noncurrent	0	0
Level 3 | U.S. Government Securities
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis, Valuation Techniques [Line Items]
Debt Securities, Available-for-sale, Current	0	0
Debt Securities, Available-for-sale, Noncurrent	0	0
Level 3 | U.S. Government Agency Securities
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis, Valuation Techniques [Line Items]
Debt Securities, Available-for-sale, Current	0	0
Debt Securities, Available-for-sale, Noncurrent	$ 0	$ 0

Fair Value Measurements - Sch_2

Fair Value Measurements - Schedule of Impairment Charges by Income Statement Line Item (Details) - USD ($) $ in Thousands	3 Months Ended
	Dec. 31, 2021	Dec. 31, 2020
Property, Plant and Equipment [Line Items]
Impairment of assets	$ 6,175	$ 6,873
Cost of net product revenue
Property, Plant and Equipment [Line Items]
Impairment of assets	0	1,968
Cost of net service revenue
Property, Plant and Equipment [Line Items]
Impairment of assets	0	1
Selling and Marketing Expense
Property, Plant and Equipment [Line Items]
Impairment of assets	6,175	1,259
Research and Development Expense
Property, Plant and Equipment [Line Items]
Impairment of assets	0	3,129
General and Administrative Expense
Property, Plant and Equipment [Line Items]
Impairment of assets	$ 0	$ 516

Fair Value Measurements - Narra

Fair Value Measurements - Narrative (Details) - Fair Value, Nonrecurring [Member] - USD ($) $ in Millions	3 Months Ended
	Dec. 31, 2021	Dec. 31, 2020
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Impairment of Intangible Assets (Excluding Goodwill)	$ 6.2
Level 3
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Operating Lease, Impairment Loss		$ 6.7
Tangible Asset Impairment Charges		$ 0.2

Short-Term and Long-Term Inve_3

Short-Term and Long-Term Investments - Schedule of Short-Term and Long-Term Investments (Details) - USD ($) $ in Thousands	3 Months Ended
	Dec. 31, 2021	Dec. 31, 2020	Sep. 30, 2021
Schedule of Investments [Line Items]
Interest income from investments	$ 300	$ 1,100
Short-Term Investments
Schedule of Investments [Line Items]
Cost or amortized cost	346,901		$ 329,571
Gross unrealized gains	10		129
Gross unrealized losses	(363)		(70)
Fair value	346,548		329,630
Short-Term Investments | Certificates of Deposit
Schedule of Investments [Line Items]
Cost or amortized cost	992		255
Gross unrealized gains	0		0
Gross unrealized losses	0		0
Fair value	992		255
Short-Term Investments | Corporate Bonds and Notes
Schedule of Investments [Line Items]
Cost or amortized cost	177,248		186,043
Gross unrealized gains	10		116
Gross unrealized losses	(165)		(52)
Fair value	177,093		186,107
Short-Term Investments | Municipal Bonds and Notes
Schedule of Investments [Line Items]
Cost or amortized cost	15,377		13,570
Gross unrealized gains	0		1
Gross unrealized losses	(18)		(5)
Fair value	15,359		13,566
Short-Term Investments | U.S. Government Securities
Schedule of Investments [Line Items]
Cost or amortized cost	136,091		102,607
Gross unrealized gains	0		12
Gross unrealized losses	(157)		(4)
Fair value	135,934		102,615
Short-Term Investments | U.S. Government Agency Securities
Schedule of Investments [Line Items]
Cost or amortized cost	17,193		27,096
Gross unrealized gains	0		0
Gross unrealized losses	(23)		(9)
Fair value	17,170		27,087
Long-Term Investments
Schedule of Investments [Line Items]
Cost or amortized cost	77,316		132,813
Gross unrealized gains	0		16
Gross unrealized losses	(325)		(51)
Fair value	76,991		132,778
Long-Term Investments | Corporate Bonds and Notes
Schedule of Investments [Line Items]
Cost or amortized cost	48,845		53,128
Gross unrealized gains	0		13
Gross unrealized losses	(207)		(34)
Fair value	48,638		53,107
Long-Term Investments | Municipal Bonds and Notes
Schedule of Investments [Line Items]
Cost or amortized cost	2,262		11,114
Gross unrealized gains	0		1
Gross unrealized losses	(23)		(4)
Fair value	2,239		11,111
Long-Term Investments | U.S. Government Securities
Schedule of Investments [Line Items]
Cost or amortized cost	24,426		59,614
Gross unrealized gains	0		2
Gross unrealized losses	(85)		(8)
Fair value	24,341		59,608
Long-Term Investments | U.S. Government Agency Securities
Schedule of Investments [Line Items]
Cost or amortized cost	1,783		8,957
Gross unrealized gains	0		0
Gross unrealized losses	(10)		(5)
Fair value	$ 1,773		$ 8,952

Short-Term and Long-Term Inve_4

Short-Term and Long-Term Investments - Schedule of Investments That Have Been in a Continuous Unrealized Loss Position (Details) - USD ($) $ in Thousands	Dec. 31, 2021	Sep. 30, 2021
Fair Value
Less than 12 months	$ 391,590	$ 274,535
12 months or greater	0	0
Total	391,590	274,535
Gross Unrealized Losses
Less than 12 months	(688)	(121)
12 months or greater	0	0
Total	(688)	(121)
Corporate Bonds and Notes
Fair Value
Less than 12 months	196,228	151,986
12 months or greater	0	0
Total	196,228	151,986
Gross Unrealized Losses
Less than 12 months	(372)	(86)
12 months or greater	0	0
Total	(372)	(86)
Municipal Bonds And Notes [Member]
Fair Value
Less than 12 months	16,144	13,764
12 months or greater	0	0
Total	16,144	13,764
Gross Unrealized Losses
Less than 12 months	(41)	(9)
12 months or greater	0	0
Total	(41)	(9)
U.S. Government Securities
Fair Value
Less than 12 months	160,275	77,401
12 months or greater	0	0
Total	160,275	77,401
Gross Unrealized Losses
Less than 12 months	(242)	(12)
12 months or greater	0	0
Total	(242)	(12)
U.S. Government Agency Securities
Fair Value
Less than 12 months	18,943	31,384
12 months or greater	0	0
Total	18,943	31,384
Gross Unrealized Losses
Less than 12 months	(33)	(14)
12 months or greater	0	0
Total	$ (33)	$ (14)

Business Combinations - Purchas

Business Combinations - Purchase Price Allocation (Details) - USD ($) $ in Thousands	Oct. 01, 2021	Jan. 22, 2021	Dec. 31, 2021	Sep. 30, 2021
Fair Value of intangible Assets [Abstract]
Goodwill			$ 2,260,407	$ 2,216,553
Threat Stack
Assets Acquired [Abstract]
Deferred tax assets	$ 13,366
Other net tangible assets acquired, at fair value	5,481
Cash, cash equivalents, and restricted cash	$ 912
Fair Value of intangible Assets [Abstract]
Identifiable intangible assets useful life	5 years
Goodwill	$ 43,956
Total assets acquired	79,515
Liabilities Assumed Abstract [Abstract]
Deferred revenue	(10,591)
Total liabilities assumed	(10,591)
Net assets acquired	68,924
Threat Stack | Developed Technology Rights
Fair Value of intangible Assets [Abstract]
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Finite-Lived Intangibles	$ 11,400
Identifiable intangible assets useful life	5 years
Threat Stack | Customer Relationships
Fair Value of intangible Assets [Abstract]
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Finite-Lived Intangibles	$ 4,400
Identifiable intangible assets useful life	5 years
Volterra [Member]
Assets Acquired [Abstract]
Other net tangible assets acquired, at fair value		$ 7,499
Cash, cash equivalents, and restricted cash		$ 14,012
Fair Value of intangible Assets [Abstract]
Identifiable intangible assets useful life		6 years 11 months 12 days
Goodwill		$ 351,417
Total assets acquired		432,928
Liabilities Assumed Abstract [Abstract]
Total liabilities assumed		(5,686)
Net assets acquired		427,242
Volterra [Member] | Developed Technology Rights
Fair Value of intangible Assets [Abstract]
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Finite-Lived Intangibles		$ 59,500
Identifiable intangible assets useful life		7 years
Volterra [Member] | Customer Relationships
Fair Value of intangible Assets [Abstract]
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Finite-Lived Intangibles		$ 500
Identifiable intangible assets useful life		1 year

Business Combinations - Narrati

Business Combinations - Narrative (Details) - USD ($) $ in Millions	Oct. 01, 2021	Jan. 22, 2021	Dec. 31, 2021
Threat Stack
Business Acquisition [Line Items]
Total purchase price	$ 68.9
Identifiable intangible assets useful life	5 years
Threat Stack | General and Administrative Expense
Business Acquisition [Line Items]
Transaction costs			$ 1.5
Volterra [Member]
Business Acquisition [Line Items]
Total purchase price		$ 427.2
Identifiable intangible assets useful life		6 years 11 months 12 days
Volterra [Member] | General and Administrative Expense
Business Acquisition [Line Items]
Transaction costs			$ 9.5
Developed Technology Rights | Threat Stack
Business Acquisition [Line Items]
Identifiable intangible assets useful life	5 years
Developed Technology Rights | Volterra [Member]
Business Acquisition [Line Items]
Identifiable intangible assets useful life		7 years
Customer Relationships | Threat Stack
Business Acquisition [Line Items]
Identifiable intangible assets useful life	5 years
Customer Relationships | Volterra [Member]
Business Acquisition [Line Items]
Identifiable intangible assets useful life		1 year

Balance Sheet Details - Cash an

Balance Sheet Details - Cash and Cash Equivalent (Details) - USD ($) $ in Thousands	Dec. 31, 2021	Sep. 30, 2021	Dec. 31, 2020	Sep. 30, 2020
Balance Sheet Details [Abstract]
Cash and cash equivalents	$ 512,406	$ 580,977
Restricted cash included in other assets, net	3,414	3,356
Total cash, cash equivalents and restricted cash	$ 515,820	$ 584,333	$ 1,030,202	$ 852,826

Balance Sheet Details - Invento

Balance Sheet Details - Inventories (Details) - USD ($) $ in Thousands	Dec. 31, 2021	Sep. 30, 2021
Balance Sheet Details [Abstract]
Finished goods	$ 15,734	$ 13,081
Raw materials	5,061	8,974
Inventories	$ 20,795	$ 22,055

Balance Sheet Details - Other C

Balance Sheet Details - Other Current Assets (Details) - USD ($) $ in Thousands	Dec. 31, 2021	Sep. 30, 2021
Balance Sheet Details [Abstract]
Unbilled receivables	$ 236,042	$ 215,396
Prepaid expenses	94,024	59,636
Capitalized contract acquisition costs	34,689	34,265
Other	24,187	28,605
Other Assets, Current	$ 388,942	$ 337,902

Balance Sheet Details - Other A

Balance Sheet Details - Other Assets (Details) - USD ($) $ in Thousands	Dec. 31, 2021	Sep. 30, 2021
Balance Sheet Details [Abstract]
Intangible assets	$ 237,528	$ 237,178
Unbilled receivables	171,787	158,885
Capitalized contract acquisition costs	44,245	43,571
Other	36,948	32,924
Other Assets, Noncurrent	$ 490,508	$ 472,558

Balance Sheet Details - Accrued

Balance Sheet Details - Accrued Liabilities (Details) - USD ($) $ in Thousands	Dec. 31, 2021	Sep. 30, 2021
Balance Sheet Details [Abstract]
Payroll and benefits	$ 149,552	$ 179,147
Operating lease liabilities, current	46,889	49,286
Income and other tax accruals	51,669	44,075
Other	66,735	68,979
Accrued Liabilities, Current	$ 314,845	$ 341,487

Balance Sheet Details - Other L

Balance Sheet Details - Other Long-term Liabilities (Details) - USD ($) $ in Thousands	Dec. 31, 2021	Sep. 30, 2021
Balance Sheet Details [Abstract]
Income taxes payable	$ 68,234	$ 66,081
Other	9,168	9,155
Other long-term liabilities	$ 77,402	$ 75,236

Debt Facilities - Narrative (De

Debt Facilities - Narrative (Details)	Jan. 31, 2020USD ($)	Jan. 24, 2020USD ($)	Dec. 31, 2021USD ($)extension	Dec. 31, 2020
Term Loan Facility
Debt Instrument [Line Items]
Aggregate principal amount		$ 400,000,000
Debt issuance costs		$ 2,200,000	$ 800,000
Redemption percentage		1.25%
Long-term line of credit			$ 365,000,000
Line of Credit Facility, Interest Rate During Period			1.282%	1.39%
Term Loan Facility | London Interbank Offered Rate (LIBOR)
Debt Instrument [Line Items]
Basis spread on variable rate			1.125%
Term Loan Facility | London Interbank Offered Rate (LIBOR) | Minimum
Debt Instrument [Line Items]
Basis spread on variable rate		1.125%
Term Loan Facility | London Interbank Offered Rate (LIBOR) | Maximum
Debt Instrument [Line Items]
Basis spread on variable rate		1.75%
Term Loan Facility | Alternate Base Rate
Debt Instrument [Line Items]
Basis spread on variable rate			0.125%
Term Loan Facility | Alternate Base Rate | Minimum
Debt Instrument [Line Items]
Basis spread on variable rate		0.125%
Term Loan Facility | Alternate Base Rate | Maximum
Debt Instrument [Line Items]
Basis spread on variable rate		0.75%
Revolving Credit Facility
Debt Instrument [Line Items]
Aggregate principal amount	$ 350,000,000
Long-term line of credit			$ 0
Conditional increase in borrowing capacity	$ 150,000,000
Number of extensions | extension			2
Length of extension period			1 year
Outstanding line of credit balance			$ 350,000,000
Revolving Credit Facility | Minimum
Debt Instrument [Line Items]
Commitment fee percentage	0.125%
Revolving Credit Facility | Maximum
Debt Instrument [Line Items]
Commitment fee percentage	0.30%
Revolving Credit Facility | London Interbank Offered Rate (LIBOR) | Minimum
Debt Instrument [Line Items]
Basis spread on variable rate	1.125%
Revolving Credit Facility | London Interbank Offered Rate (LIBOR) | Maximum
Debt Instrument [Line Items]
Basis spread on variable rate	1.75%
Revolving Credit Facility | Alternate Base Rate | Minimum
Debt Instrument [Line Items]
Basis spread on variable rate	0.125%
Revolving Credit Facility | Alternate Base Rate | Maximum
Debt Instrument [Line Items]
Basis spread on variable rate	0.75%

Debt Facilities - Long-term Deb

Debt Facilities - Long-term Debt Maturities (Details) - Term Loan Facility $ in Thousands	Dec. 31, 2021USD ($)
Debt Instrument [Line Items]
2022 (remainder)	$ 15,000
2023	350,000
Total	$ 365,000

Leases - Operating Lease Expens

Leases - Operating Lease Expense (Details) - USD ($) $ in Thousands	3 Months Ended
	Dec. 31, 2021	Dec. 31, 2020
Leases [Abstract]
Operating lease expense	$ 11,914	$ 12,181
Short-term lease expense	556	986
Variable lease expense	6,244	7,026
Total lease expense	$ 18,714	$ 20,193

Leases - Supplemental Balance S

Leases - Supplemental Balance Sheet (Details) - USD ($) $ in Thousands	Dec. 31, 2021	Sep. 30, 2021
Leases [Abstract]
Operating lease right-of-use assets	$ 237,341	$ 244,934
Operating lease liabilities, current	46,889	49,286
Operating lease liabilities, long-term	287,596	296,945
Total lease liabilities	$ 334,485	$ 346,231
Weighted average remaining lease term (in years)	9 years 7 months 6 days	9 years 8 months 12 days
Weighted average discount rate	2.60%	2.60%

Leases - Maturities of Lease Li

Leases - Maturities of Lease Liabilities (Details) - USD ($) $ in Thousands	Dec. 31, 2021	Sep. 30, 2021
Leases [Abstract]
2022 (remainder)	$ 41,840
2023	50,162
2024	41,519
2025	33,599
2026	26,583
2027	26,224
Thereafter	164,890
Total lease payments	384,817
Less: imputed interest	(50,332)
Total lease liabilities	$ 334,485	$ 346,231

Leases - Narrative (Details)

Leases - Narrative (Details) ft² in Thousands, $ in Millions	3 Months Ended
	Dec. 31, 2021USD ($)ft²	Dec. 31, 2020USD ($)
Lessee, Lease, Description [Line Items]
Sublease Income	$ 17.5
Sublease income payment remainder of fiscal year	5.1
Payment to be received in year one to three	$ 12.4
Level 3 | Fair Value, Nonrecurring [Member]
Lessee, Lease, Description [Line Items]
Operating Lease, Impairment Loss		$ 6.7
Office Building
Lessee, Lease, Description [Line Items]
Operating lease, number of square feet | ft²	515

Commitments And Contingencies (

Commitments And Contingencies (Details)	3 Months Ended
	Dec. 31, 2021
Commitments and Contingencies Disclosure [Abstract]
Product warranty period	1 year

Income Taxes (Details)

Income Taxes (Details) - USD ($) $ in Millions	3 Months Ended
	Dec. 31, 2021	Dec. 31, 2020
Income Tax Disclosure [Abstract]
Effective tax rate	16.30%	25.10%
Unrecognized tax benefit	$ 72.7

Shareholders' Equity - Class of

Shareholders' Equity - Class of Treasury Stock (Details) - USD ($) $ / shares in Units, shares in Thousands, $ in Thousands	3 Months Ended
	Dec. 31, 2021	Dec. 31, 2020
Equity, Class of Treasury Stock [Line Items]
Treasury Stock Acquired, Average Cost Per Share	$ 232.14	$ 0
Stock Repurchased and Retired During Period, Value	$ 125,011	$ 0
October Twenty Six Two Thousand Ten Program
Equity, Class of Treasury Stock [Line Items]
Stock Repurchased and Retired During Period, Shares	539	0

Shareholders' Equity - Narrativ

Shareholders' Equity - Narrative (Details) - October Twenty Six Two Thousand Ten Program - USD ($) $ in Millions	Dec. 31, 2021	Oct. 31, 2018	Oct. 26, 2010
Equity, Class of Treasury Stock [Line Items]
Stock Repurchase Program, Authorized Amount		$ 1,000	$ 4,400
Stock Repurchase Program, Remaining Authorized Repurchase Amount	$ 647.5

Net Income Per Share (Details)

Net Income Per Share (Details) - USD ($) $ / shares in Units, shares in Thousands, $ in Thousands	3 Months Ended
	Dec. 31, 2021	Dec. 31, 2020
Numerator
Net income	$ 93,559	$ 87,678
Denominator
Weighted average shares outstanding — basic (shares)	60,810	61,440
Dilutive effect of common shares from stock options and restricted stock units	1,072	842
Weighted average shares outstanding — diluted (shares)	61,882	62,282
Basic net income per share (dollars per share)	$ 1.54	$ 1.43
Diluted net income per share (dollars per share)	$ 1.51	$ 1.41

Segment Information (Details)

Segment Information (Details) $ in Thousands	3 Months Ended
	Dec. 31, 2021USD ($)segmentgeographic_region	Dec. 31, 2020USD ($)	Sep. 30, 2021USD ($)
Segment Reporting Information [Line Items]
Number of reportable segments | segment	1
Number of geographic regions | geographic_region	3
Net revenues	$ 687,100	$ 624,617
Long-lived assets	$ 185,355		$ 191,164
Net Revenue | Geographic Concentration | Ingram Micro, Inc.
Segment Reporting Information [Line Items]
Concentration risk percentage	18.70%	18.10%
Net Revenue | Geographic Concentration | Synnex Corporation
Segment Reporting Information [Line Items]
Concentration risk percentage	12.20%	10.00%
Product
Segment Reporting Information [Line Items]
Net revenues	$ 343,149	$ 288,045
Product | Systems [Member]
Segment Reporting Information [Line Items]
Net revenues	180,157	178,571
Product | Software [Member]
Segment Reporting Information [Line Items]
Net revenues	162,992	109,474
United States
Segment Reporting Information [Line Items]
Net revenues	381,289	320,343
Long-lived assets	147,012		153,030
Other
Segment Reporting Information [Line Items]
Net revenues	21,702	22,793
Total Americas
Segment Reporting Information [Line Items]
Net revenues	402,991	343,136
EMEA
Segment Reporting Information [Line Items]
Net revenues	162,062	162,084
Long-lived assets	20,953		20,526
Asia Pacific
Segment Reporting Information [Line Items]
Net revenues	122,047	$ 119,397
Other countries
Segment Reporting Information [Line Items]
Long-lived assets	$ 17,390		$ 17,608

Restructuring Charges - Restruc

Restructuring Charges - Restructuring Activity (Details) - USD ($) $ in Thousands	3 Months Ended
	Dec. 31, 2021	Dec. 31, 2020
Restructuring Reserve [Roll Forward]
Accrued expenses (Beginning balance)	$ 0
Restructuring charges	7,909	$ 0
Cash payments	(4,027)
Accrued expenses (Ending balance)	$ 3,882

Restructuring Charges - Narrati

Restructuring Charges - Narrative (Details) $ in Thousands	3 Months Ended
	Dec. 31, 2021USD ($)employee	Dec. 31, 2020USD ($)
Restructuring Charges [Abstract]
Approximate Number of Employee Positions in Reduction of Force Program | employee	70
Restructuring charges | $	$ 7,909	$ 0