Amdocs Limited (DOX) 20-F9 Dec 212021 FY Annual report (foreign)Financial data

Company Profile

Cover

Cover	12 Months Ended
Cover	Sep. 30, 2021shares
Document Information [Line Items]
Document Type	20-F
Amendment Flag	false
Document Period End Date	Sep. 30, 2021
Document Fiscal Year Focus	2021
Document Fiscal Period Focus	FY
Entity Registrant Name	AMDOCS LIMITED
Entity Central Index Key	0001062579
Current Fiscal Year End Date	--09-30
Entity Well-known Seasoned Issuer	Yes
Entity Current Reporting Status	Yes
Entity Filer Category	Large Accelerated Filer
Entity Shell Company	false
Entity Emerging Growth Company	false
Entity Voluntary Filers	No
Entity Interactive Data Current	Yes
Entity Incorporation, State or Country Code	Y7
Entity Address, Address Line One	Hirzel House
Entity Address, Address Line Two	Smith Street
Entity Address, City or Town	St. Peter Port
Entity Address Country	GG
Entity Address, Postal Zip Code	GY1 2NG
Document Registration Statement	false
Document Annual Report	true
Document Transition Report	false
Document Shell Company Report	false
Security Exchange Name	NASDAQ
Security 12(b) Title	Ordinary Shares, par value £0.01
Trading Symbol	DOX
Entity Common Stock, Shares Outstanding	124,866,230
Entity File Number	1-14840
Document Accounting Standard	U.S. GAAP
ICFR Auditor Attestation Flag	false
Contact Phone [Member]
Document Information [Line Items]
City Area Code	314
Local Phone Number	212-8328
Business Contact [Member]
Document Information [Line Items]
Contact Personnel Name	Matthew E. Smith
Entity Address, Address Line One	1390 Timberlake Manor Parkway
Entity Address, City or Town	Chesterfield
Entity Address, State or Province	MO
Entity Address, Postal Zip Code	63017
Contact Personnel Email Address	dox_info@amdocs.com

Consolidated Balance Sheets

Consolidated Balance Sheets - USD ($) $ in Thousands	Sep. 30, 2021	Sep. 30, 2020
Current assets:
Cash and cash equivalents	$ 709,064	$ 983,188
Short-term interest-bearing investments	256,527	752
Accounts receivable, net	866,819	861,033
Prepaid expenses and other current assets	235,089	229,604
Total current assets	2,067,499	2,074,577
Property and equipment, net	698,768	607,951
Lease assets	233,162	295,494
Goodwill	2,622,644	2,578,645
Intangible assets, net	259,032	296,334
Other noncurrent assets	630,669	488,620
Total assets	6,511,774	6,341,621
Current liabilities:
Accounts payable	121,199	110,142
Accrued expenses and other current liabilities	612,303	593,608
Accrued personnel costs	274,275	226,509
Short-term financing arrangements	0	100,000
Lease liabilities	58,714	59,100
Deferred revenue	237,374	126,841
Total current liabilities	1,303,865	1,216,200
Deferred income taxes and taxes payable	304,538	258,487
Lease liabilities	177,906	230,076
Long-term debt, net of unamortized debt issuance costs	644,553	644,023
Other noncurrent liabilities	445,728	327,680
Total liabilities	2,876,590	2,676,466
Amdocs Limited Shareholders' equity:
Preferred Shares — Authorized 25,000 shares; £0.01 par value; 0 shares issued and outstanding
Ordinary Shares — Authorized 700,000 shares; £0.01 par value; 281,945 and 279,578 issued and 124,866 and 131,535 outstanding, in 2021 and 2020, respectively	4,516	4,483
Additional paid-in capital	3,951,201	3,807,915
Treasury stock, at cost — 157,079 and 148,043 ordinary shares in 2021 and 2020, respectively	(6,223,317)	(5,543,321)
Accumulated other comprehensive income	9,338	11,662
Retained earnings	5,850,937	5,341,907
Total Amdocs Limited shareholders' equity	3,592,675	3,622,646
Noncontrolling interests	42,509	42,509
Total equity	3,635,184	3,665,155
Total liabilities and equity	$ 6,511,774	$ 6,341,621

Consolidated Balance Sheets (Pa

Consolidated Balance Sheets (Parenthetical) - £ / shares	Sep. 30, 2021	Sep. 30, 2020
Statement of Financial Position [Abstract]
Preferred Shares, authorized	25,000,000	25,000,000
Preferred Shares, par value	£ 0.01	£ 0.01
Preferred Shares, issued	0	0
Preferred Shares, outstanding	0	0
Ordinary Shares, authorized	700,000,000	700,000,000
Ordinary Shares, par value	£ 0.01	£ 0.01
Ordinary Shares, issued	281,945,000	279,578,000
Ordinary Shares, outstanding	124,866,000	131,535,000
Treasury stock, at cost, ordinary shares	157,079,000	148,043,000

Consolidated Statements of Inco

Consolidated Statements of Income - USD ($) $ in Thousands		12 Months Ended
Consolidated Statements of Income - USD ($) $ in Thousands		Sep. 30, 2021	Sep. 30, 2020	Sep. 30, 2019
Income Statement [Abstract]
Revenue		$ 4,288,640	$ 4,169,039	$ 4,086,669
Operating expenses:
Cost of revenue		2,810,967	2,755,563	2,653,172
Research and development		312,941	282,042	273,936
Selling, general and administrative		487,255	458,539	492,457
Amortization of purchased intangible assets and other		78,784	78,137	97,358
Total operating expenses		3,689,947	3,574,281	3,516,923
Operating income		598,693	594,758	569,746
Interest and other expense, net		(10,797)	(11,436)	(1,859)
Gain from sale of a business		226,410
Income before income taxes		814,306	583,322	567,887
Income taxes		125,932	85,482	88,441
Net income	[1]	$ 688,374	$ 497,840	$ 479,446
Basic earnings per share		$ 5.36	$ 3.73	$ 3.49
Diluted earnings per share		$ 5.32	$ 3.71	$ 3.47

[1]	In fiscal years 2021, 2020 and 2019, all of the Company’s net income is attributable to Amdocs Limited as the net income attributable to the Non-controlling interests is negligible.

Consolidated Statements of Comp

Consolidated Statements of Comprehensive Income - USD ($) $ in Thousands		12 Months Ended
		Sep. 30, 2021	Sep. 30, 2020	Sep. 30, 2019
Statement of Comprehensive Income [Abstract]
Net income	[1]	$ 688,374	$ 497,840	$ 479,446
Other comprehensive (loss) income, net of tax:
Net change in fair value of cash flow hedges	[2]	(5,063)	14,891	30,553
Net change in fair value of available-for-sale securities	[3]	(1,272)	(2)	1,592
Net actuarial gain (loss) on defined benefit plan	[4]	4,011	(680)	(1,961)
Other comprehensive (loss) income, net of tax		(2,324)	14,209	30,184
Comprehensive income		$ 686,050	$ 512,049	$ 509,630

[1]	In fiscal years 2021, 2020 and 2019, all of the Company’s net income is attributable to Amdocs Limited as the net income attributable to the Non-controlling interests is negligible.
[2]	Net of tax benefit (expense) of $3,369, $(2,371) and $(2,458) for the fiscal years ended September 30, 2021, 2020 and 2019, respectively.
[3]	Net of immaterial amount of tax benefit for the fiscal years ended September 30, 2021, 2020 and 2019.
[4]	Net of tax (expense) benefit of $(1,461), $(11) and $1,080 for the fiscal years ended September 30, 2021, 2020 and 2019, respectively.

Consolidated Statements of Co_2

Consolidated Statements of Comprehensive Income (Parenthetical) - USD ($) $ in Thousands	12 Months Ended
	Sep. 30, 2021	Sep. 30, 2020	Sep. 30, 2019
Statement of Comprehensive Income [Abstract]
Tax benefit (expense) on change in fair value of cash flow hedges	$ 3,369	$ (2,371)	$ (2,458)
Tax (expense) benefit on unrealized gain (loss) on defined benefit plan	$ (1,461)	$ (11)	$ 1,080

Consolidated Statements of Chan

Consolidated Statements of Changes in Shareholders' Equity - USD ($) shares in Thousands, $ in Thousands		Total	Cumulative Effect Adjustment	[1]	Ordinary Shares	Additional Paid-in Capital	Treasury Stock	Accumulated Other Comprehensive Income (Loss)	[2]	Retained Earnings	Retained EarningsCumulative Effect Adjustment	[1]	Total Amdocs Limited Shareholders' Equity	Total Amdocs Limited Shareholders' EquityCumulative Effect Adjustment	[1]	Non-controlling Interests	[3]
Balance at Sep. 30, 2018		$ 3,492,042	$ 10,434		$ 4,436	$ 3,587,625	$ (4,784,352)	$ (32,731)		$ 4,673,901	$ 10,434		$ 3,448,879	$ 10,434		$ 43,163
Balance, Shares at Sep. 30, 2018					140,177
Comprehensive income:
Net income	[3]	479,446								479,446			479,446
Other comprehensive income (loss), net of tax		30,184						30,184					30,184
Comprehensive income		509,630											509,630
Employee stock options exercised		41,498			$ 11	41,487							41,498
Employee stock options exercised, Shares					874
Repurchase of shares		(398,057)					(398,057)						(398,057)
Repurchase of shares, Shares					(6,656)
Cash dividends declared		(150,982)								(150,982)			(150,982)
Issuance of restricted stock, net of forfeitures		5			$ 5								5
Issuance of restricted stock, net of forfeitures, Shares					378
Equity-based compensation expense related to employees		38,550				38,550							38,550
Changes in Noncontrolling interests		(654)														(654)
Balance at Sep. 30, 2019		3,542,466			$ 4,452	3,667,662	(5,182,409)	(2,547)		5,012,799			3,499,957			42,509
Balance, Shares at Sep. 30, 2019					134,773
Comprehensive income:
Net income	[3]	497,840								497,840			497,840
Other comprehensive income (loss), net of tax		14,209						14,209					14,209
Comprehensive income		512,049											512,049
Employee stock options exercised		97,843			$ 24	97,819							97,843
Employee stock options exercised, Shares					1,871
Repurchase of shares		(360,912)					(360,912)						(360,912)
Repurchase of shares, Shares					(5,668)
Cash dividends declared		(168,732)								(168,732)			(168,732)
Issuance of restricted stock, net of forfeitures		7			$ 7								7
Issuance of restricted stock, net of forfeitures, Shares					559
Equity-based compensation expense related to employees		42,434				42,434							42,434
Balance at Sep. 30, 2020		$ 3,665,155			$ 4,483	3,807,915	(5,543,321)	11,662		5,341,907			3,622,646			42,509
Balance, Shares at Sep. 30, 2020		131,535			131,535
Comprehensive income:
Net income	[3]	$ 688,374								688,374			688,374
Other comprehensive income (loss), net of tax		(2,324)						(2,324)					(2,324)
Comprehensive income		686,050											686,050
Employee stock options exercised		$ 89,058			$ 21	89,037							89,058
Employee stock options exercised, Shares		1,541			1,541
Repurchase of shares		$ (679,996)					(679,996)						(679,996)
Repurchase of shares, Shares		(9,036)			(9,036)
Cash dividends declared		$ (179,344)								(179,344)			(179,344)
Issuance of restricted stock, net of forfeitures		12			$ 12								12
Issuance of restricted stock, net of forfeitures, Shares					826
Equity-based compensation expense related to employees		54,249				54,249							54,249
Balance at Sep. 30, 2021		$ 3,635,184			$ 4,516	$ 3,951,201	$ (6,223,317)	$ 9,338		$ 5,850,937			$ 3,592,675			$ 42,509
Balance, Shares at Sep. 30, 2021		124,866			124,866

[1]	The Cumulative effect adjustments as of October 1, 2018 include an increase of $14,294 to retained earnings due to the impact of adoptions of ASU No. 2014-09 (ASC 606) and decrease of $3,860 to retained earnings due to adoption of ASU No. 2016-16.
[2]	As of September 30, 2021, 2020 and 2019, accumulated other comprehensive income (loss) is comprised of unrealized gain on derivatives, net of tax, of $13,773, $18,836 and $3,945, unrealized loss on short-term interest-bearing investments, net of tax, of $(1,274), $(2) and $0 and unrealized loss on defined benefit plan, net of tax, of $(3,161), $(7,172) and $(6,492).
[3]	In fiscal years 2021, 2020 and 2019, all of the Company’s net income is attributable to Amdocs Limited as the net income attributable to the Non-controlling interests is negligible.

Consolidated Statements of Ch_2

Consolidated Statements of Changes in Shareholders' Equity (Parenthetical) - USD ($) $ in Thousands	Oct. 01, 2018	Sep. 30, 2021	Sep. 30, 2020	Sep. 30, 2019
Cash dividends declared per ordinary share		$ 1.4075	$ 1.2675	$ 1.105
Unrealized gain on derivatives, net of tax		$ 13,773	$ 18,836	$ 3,945
Unrealized loss on short-term interest-bearing investments, net of tax		(1,274)	(2)	0
Unrealized loss on defined benefit plan, net of tax		$ (3,161)	$ (7,172)	$ (6,492)
Accounting Standards Update 2014-09 [Member]
Increase in retained earnings	$ 14,294
Accounting Standards Update 2016-16 [Member]
Decrease in retained earnings	$ 3,860

Consolidated Statements of Cash

Consolidated Statements of Cash Flows - USD ($) $ in Thousands		12 Months Ended
		Sep. 30, 2021	Sep. 30, 2020	Sep. 30, 2019
Cash Flow from Operating Activities:
Net income	[1]	$ 688,374	$ 497,840	$ 479,446
Reconciliation of net income to net cash provided by operating activities:
Depreciation and amortization		208,830	198,409	205,772
Amortization of debt issuance cost		548	144
Equity-based compensation expense		54,249	42,434	38,550
Gain from sale of a business		(226,410)
Deferred income taxes		(50,605)	30,239	(13,950)
Loss from short-term interest-bearing investments		1,726	0	737
Net changes in operating assets and liabilities, net of amounts acquired:
Accounts receivable, net		(69,051)	134,584	6,589
Prepaid expenses and other current assets		(17,041)	(10,815)	25,907
Other noncurrent assets		(50,038)	(23,329)	(1,635)
Lease assets and liabilities, net		9,630	(7,881)
Accounts payable, accrued expenses and accrued personnel		122,224	(190,354)	(60,042)
Deferred revenue		193,655	(15,184)	(37,855)
Income taxes payable, net		26,814	(9,281)	6,025
Other noncurrent liabilities		32,902	11,330	6,833
Net cash provided by operating activities		925,807	658,136	656,377
Cash Flow from Investing Activities:
Purchase of property and equipment, net	[2]	(210,438)	(205,510)	(128,086)
Proceeds from sale of short-term interest-bearing investments		18,205	0	101,287
Purchase of short-term interest-bearing investments		(276,978)	(753)
Net cash paid for business and intangible assets acquisitions		(142,697)	(249,358)	(60,572)
Net cash received from sale of a business		288,990
Other		(6,082)	(6,104)	615
Net cash used in investing activities		(329,000)	(461,725)	(86,756)
Cash Flow from Financing Activities:
Borrowings under financing arrangements		0	450,000
Payments under financing arrangements		(100,000)	(350,000)
Proceeds from issuance of debt, net		0	643,919
Repurchase of shares		(679,996)	(360,912)	(398,057)
Proceeds from employee stock option exercises		89,056	97,850	41,483
Payments of dividends		(177,472)	(164,061)	(147,616)
Investment by noncontrolling interests, net	[2]	0	0	(4,776)
Payment of contingent consideration from a business acquisition		(2,519)	(1,411)	(7,470)
Other			(240)	(336)
Net cash (used in) provided by financing activities		(870,931)	315,145	(516,772)
Net (decrease) increase in cash and cash equivalents		(274,124)	511,556	52,849
Cash and cash equivalents at beginning of year		983,188	471,632	418,783
Cash and cash equivalents at end of year		709,064	983,188	471,632
Cash paid for:
Income taxes, net of refunds		146,442	45,398	75,790
Interest	[3]	$ 19,371	$ 5,392	$ 7,348

[1]	In fiscal years 2021, 2020 and 2019, all of the Company’s net income is attributable to Amdocs Limited as the net income attributable to the Non-controlling interests is negligible.
[2]	The amounts under “Purchase of property and equipment, net”, include proceeds from sale of property and equipment of $328, $194, and $151 for the year ended September 30, 2021, 2020 and 2019, respectively, and proceeds of $9,676 relating to refund of betterment levy for the year ended September 30, 2019 ($4,776 of which was a refund to the noncontrolling interest).
[3]	The amounts under “Interest” include payments of interest to financial institution, tax authorities and other.

Consolidated Statements of Ca_2

Consolidated Statements of Cash Flows (Parenthetical) - USD ($) $ in Thousands	12 Months Ended
	Sep. 30, 2021	Sep. 30, 2020	Sep. 30, 2019
Statement of Cash Flows [Abstract]
Proceeds from sale of property and equipment	$ 328	$ 194	$ 151
Proceeds Refund For Property Plant And Equipment			9,676
Proceeds Refund For Non Controlling Interest			$ 4,776

Nature of Entity

Nature of Entity	12 Months Ended
Nature of Entity	Sep. 30, 2021
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Nature of Entity	Note 1 — Nature of Entity Amdocs Limited (the “Company”) is a leading provider of software and services to communications, cable and satellite, entertainment and media industry service providers of all sizes throughout the world. The Company and its consolidated subsidiaries operate in one segment and design, develop, market, support, implement and operate its open and modular cloud portfolio. The Company is a Guernsey limited company, which directly or indirectly holds numerous subsidiaries around the world, the vast majority of which are wholly-owned. The majority of the Company’s customers are in North America, Europe, Asia-Pacific and the Latin America region. The Company’s main development facilities are located in Brazil, Canada, Cyprus, India, Ireland, Israel, Mexico, the Philippines, the United Kingdom and the United States.

Summary of Significant Accounti

Summary of Significant Accounting Policies	12 Months Ended
Summary of Significant Accounting Policies	Sep. 30, 2021
Accounting Policies [Abstract]
Summary of Significant Accounting Policies	Note 2 — Summary of Significant Accounting Policies Basis of Presentation The consolidated financial statements are prepared in accordance with U.S. generally accepted accounting principles, or GAAP and are denominated in U.S. dollars. Consolidation The consolidated financial statements include the accounts of the Company and its subsidiaries, the vast majority of which are wholly-owned. All intercompany transactions and balances have been eliminated in consolidation. In December 2017, the Company entered into agreements with Union Investments and Development Limited (“Union”) to partner through a legal entity that is equally owned by the Company and Union for the purpose of acquiring specific land which the Company expects to use as the site for a new campus in Ra’anana, Israel. On January 2, 2018 the Company completed the acquisition of the land. Pursuant to the agreements between the Company and Union, as the Company has control over the construction and ongoing operations of the new campus, the new entity’s financial information is consolidated into the Company’s consolidated financial statements with the portion not owned classified as non-controlling Use of Estimates The preparation of financial statements in conformity with GAAP requires management to make estimates and assumptions that affect the reported amounts of assets and liabilities and disclosure of contingent assets and liabilities at the dates of the financial statements, and the reported amounts of revenue and expenses during the reporting period. Actual results could differ from those estimates. Reclassifications From time to time, certain immaterial amounts in prior year financial statements may be reclassified to conform to the current year presentation. Functional Currency The Company manages its foreign subsidiaries as integral direct components of its operations. The operations of the Company’s foreign subsidiaries provide the same type of services with the same type of expenditures throughout the Amdocs group. The Company has determined that its functional currency is the U.S. dollar. The Company periodically assesses the applicability of the U.S. dollar as the Company’s functional currency by reviewing the salient indicators as indicated in the authoritative guidance for foreign currency matters. Cash and Cash Equivalents Cash and cash equivalents consist of cash and interest-bearing investments with insignificant interest rate risk and maturities from acquisition date of 90 days or less. Accounts Receivable Factoring From time to time, the Company uses non-recourse Investments The Company has short-term interest-bearing investments comprised of marketable securities and bank deposits. The Company classifies all of its marketable securities as available-for-sale available-for-sale available-for-sale Property and Equipment Property and equipment are stated at cost. Depreciation is computed using the straight-line method over the estimated useful life of the asset, which primarily ranges from three The Company capitalizes certain expenditures for software that is internally developed for use in the business, which is classified as computer equipment. Amortization of internal use software begins when the software is ready for service and continues on the straight-line method over the estimated useful life. The Company capitalizes the expenditures related to the new campus in Israel, which are classified as building and land. Amortization will begin when the new campus is ready for use and will be amortized on the straight-line basis over the estimated useful life. Leases Upon adoption ASU No. 2016-02, “Leases”, non-lease non-lease As a lessee, substantially all of the Company’s lease obligation is for office real estate. The significant judgments used in determining its lease obligation include whether a contract is or contains a lease and the determination of the discount rate used to calculate the lease liability. The Company’s leases may include the option to extend or terminate before the end of the contractual term and are often non-cancelable The lease assets and liabilities include these options in the lease term when it is reasonably certain that they will be exercised. In certain cases, the Company subleases excess office real estate to third-party tenants in immaterial amounts. Lease assets and liabilities recognized at the lease commencement date are determined predominantly as the present value of the payments due over the lease term. Unless the implicit rate can be determined, the Company uses its incremental borrowing rate on that date to calculate the present value. The incremental borrowing rate approximates the rate at which the Company could borrow, on a secured basis for a similar term, an amount equal to its lease payments in a similar economic environment. Effective October 1, 2019, when the Company is the lessee, all leases are recognized as lease liabilities and associated lease assets on the Consolidated Balance Sheet. Lease liabilities represent the Company’s obligation to make payments arising from the lease. Lease assets represent the Company’s right to use an underlying asset for the lease term and may also include advance payments, initial direct costs or lease incentives. Fixed and variable payments that depend upon an index or rate, such as the Consumer Price Index (CPI), are included in the recognition of lease assets and liabilities at the commencement-date rate. Other variable payments, such as common area maintenance, property and other taxes, utilities and insurance that are based on the lessor’s cost, are recognized in the Consolidated Income Statement in the period incurred. Operating lease expense is recorded on a straight-line basis over the lease term. Goodwill, Intangible Assets and Long-Lived Assets Goodwill and intangible assets deemed to have indefinite lives are subject to an annual impairment test or more frequently if impairment indicators are present. Goodwill impairment is deemed to exist if the net book value of a reporting unit exceeds its estimated fair value. The goodwill impairment test is performed by comparing the fair value of a reporting unit with its carrying amount. An impairment charge should be recognized for the amount by which the carrying amount exceeds the reporting unit’s fair value; however, the loss recognized should not exceed the total amount of goodwill allocated to that reporting unit. There was no impairment of goodwill in fiscal years 2021, 2020 or 2019. The total purchase price of business acquisitions accounted for using the purchase method is allocated first to identifiable assets and liabilities based on estimated fair values. The excess of the purchase price over the fair value of net assets of purchased businesses is recorded as goodwill. Other definite-life intangible assets consist primarily of core technology and customer relationships. Core technology acquired by the Company is amortized over its estimated useful life on a straight-line basis. Some of the acquired customer relationships are amortized over their estimated useful lives in proportion to the economic benefits realized. This accounting policy generally results in accelerated amortization of such customer relationships as compared to the straight-line method. All other acquired customer relationships are amortized over their estimated useful lives on a straight-line basis. The Company tests long-lived assets, including definite life intangible assets, for impairment whenever events or changes in circumstances indicate that the carrying amount of such assets may not be recoverable. Impairment indicators include any significant changes in the manner of its use of the assets or the strategy of its overall business, significant negative industry or economic trends and significant decline in our share price for a sustained period. Determination of recoverability of long-lived assets is based on an estimate of the undiscounted future cash flows resulting from the use of the cash generating unit and its eventual disposition. Measurement of an impairment loss for long-lived assets, including definite life intangible assets that management expects to hold and use is based on the fair value of the cash generating unit. Long-lived assets, including definite life intangible assets, to be disposed of are reported at the lower of carrying amount or fair value less costs to sell. There was no impairment of long-lived assets in fiscal years 2021, 2020 or 2019. Comprehensive Income Comprehensive income, net of related taxes where applicable, includes, in addition to net income: (i) net change in fair value of available-for-sale (ii) net change in fair value of cash flow hedges; and (iii) net actuarial gains and losses on defined benefit plans. Treasury Stock The Company repurchases its ordinary shares from time to time on the open market or in other transactions and holds such shares as treasury stock. The Company presents the cost to repurchase treasury stock as a reduction of equity. Business Combinations In accordance with business combinations accounting, assets acquired and liabilities assumed, as well as any contingent consideration that may be part of the acquisition agreement, are recorded at their respective fair values at the date of acquisition. The Company allocates the purchase price of acquired companies to the tangible and intangible assets acquired and liabilities assumed, as well as to in-process For acquisitions that include contingent consideration, the fair value is estimated on the acquisition date as the present value of the expected contingent payments, determined using weighted probabilities of possible payments. The Company remeasures the fair value of the contingent consideration at each reporting period until the contingency is resolved. Except for measurement period adjustments, the changes in fair value are recognized in the consolidated statements of income. The Company considers several factors when determining that contingent consideration liabilities are part of the purchase price, such as the following: the valuation of the acquisitions is not supported solely by the initial consideration paid, and the contingent consideration payments are not affected by employment termination. Any earn-out Although the Company believes the assumptions and estimates of fair value it has made in the past have been reasonable and appropriate, they are based in part on historical experience and information obtained from the management of the acquired companies and are inherently uncertain and subject to refinement. Critical estimates in valuing certain assets acquired and liabilities assumed include but are not limited to: future expected cash flows from license and service sales, maintenance, customer contracts and acquired developed technologies, expected costs to develop the in-process The Company estimates the fair values of its services, hardware, software license and maintenance obligations assumed. The estimated fair values of these performance obligations are determined utilizing a cost build-up build-up The Company may establish a valuation allowance for certain deferred tax assets and estimate the value of uncertain tax positions of a newly acquired entity. This process requires significant judgment and analysis. Income Taxes The Company records deferred income taxes to reflect the net tax effects of temporary differences between the carrying amounts of assets and liabilities for financial reporting and tax purposes. Deferred taxes are computed based on enacted tax rates anticipated to be in effect when the deferred taxes are expected to be paid or realized. A valuation allowance is provided for deferred tax assets if it is more likely than not, the Company will not be able to realize their benefit. In assessing the realizability of deferred tax assets, the Company considers whether it is more likely than not that some portion or all of the deferred tax assets will not be realized and adjust the valuation allowances accordingly. Factors considered in making this determination include the period of expiration of the tax asset, planned use of the tax asset, tax planning strategies and historical and projected taxable income as well as tax liabilities for the tax jurisdiction in which the tax asset is located. Valuation allowances will be subject to change in each future reporting period as a result of changes in one or more of these factors. Deferred tax liabilities and assets are classified as noncurrent on the balance sheet. Deferred tax liabilities also include anticipated withholding taxes due on subsidiaries’ earnings when paid as dividends to the Company. The Company recognizes the tax benefit from an uncertain tax position only if the weight of available evidence indicates that it is more likely than not that the position will be sustained on audit, including resolution of related appeals or litigation processes, if any. The tax benefits recognized in the financial statements from such a position is measured based on the largest benefit that has a greater than 50% likelihood of being realized upon ultimate settlement. Interest and penalties related to uncertain tax positions are recognized in the provision for income taxes. Significant judgment is required in evaluating the uncertain tax positions and determining the provision for income taxes. Although the Company believes its reserves are reasonable, no assurance can be given that the final tax outcome of these matters will not be different from that which is reflected in its historical income tax provisions and accruals. The Company adjusts these reserves in light of changing facts and circumstances, such as the closing of a tax audit, or changes in tax law. To the extent that the final tax outcome of these matters is different than the amounts recorded, such differences will affect the provision for income taxes in the period in which such determination is made. The provision for income taxes includes the effect of reserve provisions and changes to reserves that are considered appropriate. Please see Note 10 to the consolidated financial statements. The Company applies an estimated annual effective tax rate to its quarterly operating results to determine the interim provision for income tax expense. A change in judgment that impacts the measurement of a tax position taken in a prior year is recognized as a discrete item in the interim period in which the change occurs. In the event there is a significant unusual or infrequent item recognized in the quarterly operating results, the tax attributable to that item is recorded in the interim period in which it occurs. As a result, the Company’s quarterly effective tax rate may fluctuate throughout the course of a fiscal year. Revenue Recognition The Company recognizes revenue under the five-step methodology required under ASC 606, which requires the Company to identify the contract with the customer, identify the performance obligations in the contract, determine the transaction price, allocate the transaction price to the performance obligations identified, and recognize revenue when (or as) each performance obligation is satisfied. Revenue is recognized net of any revenue-based taxes assessed by a governmental authority that are both imposed on and concurrent with a specific revenue-producing transaction and collected by the Company from a customer (for example, sales, use and value added taxes). The Company’s primary revenue categories, related performance obligations, and associated recognition patterns are as follows: Revenue Recognition for projects As a significant portion of the Company’s revenue is satisfied over time as work progresses, the annual and quarterly operating results may be affected by the size and timing of the initiation of customer projects as well as the Company’s progress in completing such projects. Revenue Recognition for subsequent license fee Revenue Recognition for term-based license and perpetual license Revenue Recognition for maintenance Revenue Recognition for ongoing services — Revenue Recognition for managed services arrangements — end-to-end The revenue from managed services arrangements is recognized for each individual performance obligation according to its relevant revenue category, including but not limited to, revenue from the management of a customer’s operations, revenue from projects and revenue from ongoing support services. Revenue from the management of a customer’s operations pursuant to managed services arrangements, is recognized over time as services are performed, using one method of measuring performance such as time elapsed, output produced, volume of data processed or subscriber count that provides the most faithful depiction of the transfer of services, pursuant to the specific contract terms of the managed services arrangements. Typically, managed services arrangements are long term in duration and are not subject to significant seasonality. Revenue Recognition for third-party hardware software and services Arrangements with Multiple Performance Obligations offers its services in accordance with ASC 606. The determination of SSP requires the exercise of judgement. If a specific performance obligation is sold for a broad range of amounts (that is, the selling price is highly variable) or if the Company has not yet established a price for that good or service, and the good or service has not previously been sold on a standalone basis (that is, the selling price is uncertain), the Company applies the residual approach whereby all other performance obligations within a contract are first allocated a portion of the transaction price based upon their respective SSPs with any residual amount of transaction price allocated to the remaining specific performance obligation. Billing terms and conditions generally vary by contract category. Amounts are typically billed as work progresses in accordance with agreed-upon contractual terms, either at periodic intervals (e.g., monthly or quarterly) or upon achievement of contractual milestones. In cases where timing of revenue recognition significantly differs from the timing of invoicing, the Company considers whether a significant financing component exists. The Company elected to use the practical expedient in assessing the financing component in contracts where the time between cash collection and performance is less than one year. Accounts Receivable — Billed Accounts Receivable — Unbilled — Deferred Revenue — Assets Recognized from the Costs to Obtain a Contract with a Customer — pro-rata In certain circumstances where the Company enters into a contract with a customer for the provision of managed services for a defined period of time, the Company defers certain direct costs incurred at the inception of the contract. These costs include expenses incurred in association with the origination of a contract. In addition, if the revenue for a delivered item is not recognized because it is not separable from the undelivered item, then the Company also defers the cost of the delivered item. The deferred costs are amortized on a straight-line basis over the managed services period, or over the recognition period of the undelivered item. Revenue associated with these capitalized costs is deferred and is recognized over the same period. Cost of Revenue Cost of revenue consists of all costs associated with providing software licenses and services to customers, third-party hardware and software including identified losses on contracts. Estimated losses on contracts satisfied over time as work performed are recognized in the period in which the loss is identified. Cost of revenue also includes costs of third-party products associated with selling third-party computer hardware and software products to customers and other third-party services, when the related revenue is recorded at the gross amount. Customers purchasing third-party products and services from the Company generally do so in conjunction with the purchase of the Company’s software and services. Research and Development Research and development expenditures consist of costs incurred in the development of new software modules and product offerings, either as part of the Company’s internal product development programs, which are sold, leased or otherwise marketed. Research and development costs are expensed as incurred. Based on the Company’s product development process, technological feasibility is established upon completion of a detailed program design or, in the absence thereof, completion of a working model. Costs incurred by the Company after achieving technological feasibility and before the product is ready for customer release have been insignificant. Equity-Based Compensation The Company measures and recognizes the compensation expense for all equity-based payments to employees and directors based on their estimated fair values. The Company estimates the fair value of employee stock options at the date of grant using a Black-Scholes valuation model and values restricted stock including performance restricted stock based on the market value of the underlying shares at the date of grant. The Company recognizes compensation costs using the graded vesting attribution method that results in an accelerated recognition of compensation costs in comparison to the straight-line method. Performance restricted stock are subject to certain performance criteria; accordingly, compensation expense is recognized for such awards when it becomes probable that the related performance condition will be satisfied. The Company uses a combination of implied volatility of the Company’s traded options and historical stock price volatility (“blended volatility”) as the expected volatility assumption required in the Black-Scholes option valuation model. As equity-based compensation expense recognized in the Company’s consolidated statements of income is based on awards ultimately expected to vest, it has been reduced for estimated forfeitures. Concentrations of Credit Risk Financial instruments that potentially subject the Company to concentration of credit risk consist principally of cash and cash equivalents, short-term interest-bearing investments, trade receivables and unbilled receivable. Cash and cash equivalents are maintained with several financial institutions. Generally, these deposits may be redeemed upon demand and are maintained with financial institutions with reputable credit and therefore bear minimal credit risk. The Company seeks to mitigate its credit risks by spreading such risks across multiple financial institutions and monitoring the risk profiles of these counterparties. The Company has conservative investment policy guidelines under which it invests its excess cash primarily in highly liquid U.S. dollar-denominated securities. The Company’s revenue is generated primarily in North America. To a lesser extent, revenue is generated in Europe and the rest of the world. Most of the Company’s customers are among the largest communications and media companies in the world (or are owned by them). The Company’s business is subject to the effects of general global economic conditions and market conditions in the communications industry. The Company performs ongoing credit analyses of its customer base and generally does not require collateral. The Company evaluates accounts receivable and unbilled receivables to determine if they ultimately will be collected. Significant judgments and estimates are involved in performing this evaluation, which are based on factors that may affect a customer’s ability to pay, such as past experience, credit quality of the customer, age of the receivable balance and current economic conditions, reasonable and supportable forecasts of future economic conditions, and other factors that may affect its ability to collect from customers. The allowance for doubtful accounts, net of credit losses is for expected credit losses resulting from accounts receivable and unbilled receivables for which their collection is not reasonably probable. The allowance for doubtful accounts as of September 30, 2021 and 2020, was $20,065 and $23,419, respectively. As of September 30, 2021, the Company had two customers with accounts receivable balances of more than 10% of total accounts receivable, aggregating to 40%. As of September 30, 2020, the Company had one customer with an accounts receivable balance of more than 10% of total accounts receivable, amounting to 22%, please see Note 21. Earnings per Share Basic earnings per share is calculated using the weighted average number of shares outstanding during the period. Diluted earnings per share is computed on the basis of the weighted average number of shares outstanding and the effect of dilutive outstanding equity-based awards using the treasury stock method. The Company includes participating securities (unvested restricted shares that contain non-forfeitable two-class Derivatives and Hedging The Company carries out transactions involving foreign currency exchange derivative financial instruments. The transactions are designed to hedge the Company’s exposure in currencies other than the U.S. dollar. The Company recognizes derivative instruments as either assets or liabilities and measures those instruments at fair value. If a derivative meets the definition of a cash flow hedge and is so designated, changes in the fair value of the derivative are recognized in other comprehensive (loss) income until the hedged item is recognized in earnings. The ineffective portion of a derivative designated as a cash flow hedge is recognized in earnings. If a derivative does not meet the definition of a cash flow hedge, the changes in the fair value are included in earnings. Recent Accounting Standards In August 2021, the Financial Accounting Standards Board, or FASB, issued Accounting Standard Update, or ASU No. 2021-08, Business Combinations (Topic 805): Accounting for Contract Assets and Contract Liabilities from Contracts with Customers”. In March 2020, the FASB issued ASU No. 2020-04, Reference Rate Reform: Facilitation of the Effects of Reference Rate Reform on Financial Reporting”. exceptions on certain contract modifications, hedge relationships and other transactions that reference London Inter-Bank Offered Rate (“LIBOR”) or other reference rates expected to be discontinued due to the reference rate reform. This ASU is effective as of March 12, 2020 through December 31, 2022. The Company expects that the adoption of this ASU will not have a material impact on its consolidated financial statements. Adoption of New Accounting Standards In December 2019, the FASB issued ASU No. 2019-12, Simplifying the Accounting for Income Taxes In November 2018, the FASB issued ASU No. 2018-18 , “Collaborative Arrangements In August 2018, the FASB issued ASU No. 2018-15 , “Customer’s Accounting for Implementation Costs Incurred in a Cloud Computing Arrangement That Is a Service Contract”. The ASU amends the definition of hosting arrangement and requires a customer in a hosting arrangement that is a service contract to capitalize certain implementation costs as if the arrangement was an internal-use software project. The Company prospectively adopted this ASU effective October , . As of the date of the adoption there was no material impact on the Company’s consolidated financial statements. In August 2018, the FASB issued ASU No. 2018-13 , “Fair Value Measurement”. In August 2018, the FASB issued ASU No. 2018-14, Changes to the Disclosure Requirements for Defined Benefit Plans” In August 2017, the FASB issued ASU No. 2017-12, Targeted Improvements to Accounting for Hedging Activities ” In January 2017, the FASB issued ASU No. 2017-04, “Simplifying the Test for Goodwill Impairment” In June 2016, the FASB issued ASU No. 2016-13, Measurement of Credit Losses on Financial Instruments ” available-for-sale available-for-sale

Acquisitions and Divestiture of

Acquisitions and Divestiture of a Subsidiary	12 Months Ended
Acquisitions and Divestiture of a Subsidiary	Sep. 30, 2021
Business Combinations [Abstract]
Acquisitions and Divestiture of a Subsidiary	Note 3 — Acquisitions and Divestiture of a Subsidiary Divestiture of a Subsidiary On November 10, 2020, the Company signed an agreement for the divestiture of OpenMarket for approximately $300,000 cash with Infobip Limited, a company in which One Equity Partners is the primary institutional investor. With this transaction, the Company divested a non-strategic On December 31, 2020, the Company completed the divestiture. Based on the total consideration, the Company recorded pre-tax (net of immaterial transaction costs) in the Consolidated Statements of Income during the fiscal year ended September 30, 2021. In connection with this divestiture, $ of net assets and $ of goodwill, were disposed. The divestiture does not represent a strategic shift that will have a major effect on operations and financial results and, therefore, did not qualify for presentation as a discontinued operation, please see also Note 10. Acquisitions Entities acquired by the Company during the last three fiscal years have been consolidated into the Company’s results of operations since their respective acquisition dates. These acquisitions, individually and in the aggregate, were not material in any fiscal year. During fiscal year 2021, the Company acquired three technology companies, for an aggregate net consideration of $101,864 in cash, and additional contingent consideration subject to the achievement of certain performance metrics. Among them the largest of the three is Sourced, a leading global technology consultancy specializing in large-scale cloud transformations for sophisticated, high-end enterprise customers in different industries such as communications, financial services and others. During fiscal year 2020, the Company acquired three companies and other intangible assets for an aggregate net consideration of approximately among them the largest is Openet, which offers cloud-native capabilities, network pedigree, and deep 5G charging, policy and data management expertise and whose solutions complement the Amdocs portfolio.

Revenue

Revenue	12 Months Ended
Revenue	Sep. 30, 2021
Revenue from Contract with Customer [Abstract]
Revenue	Note 4 — Revenue Contract Balances The following table provides information about Accounts receivable, both billed and unbilled and deferred revenue: As of September 30, 2021 September 30, 2020 Accounts receivable — $ 704,541 $ 685,485 Accounts receivable — $ 162,278 $ 175,548 Accounts receivable — (non-current) $ 38,252 $ 42,089 Total Accounts receivable — $ 200,530 $ 217,637 Deferred revenue (current) $ (237,374 ) $ (126,841 ) Deferred revenue (non-current) $ (108,675 ) $ (16,529 ) Total Deferred revenue $ (346,049 ) $ (143,370 ) Revenue recognized during the year ended September 30, 2021, which was included in deferred revenue (current) as of September 30, 2020 was $115,474. Revenue recognized during the year ended September 30, 2020, which was included in deferred revenue (current) as of September 30, 2019 was $104,648. Remaining Performance Obligations from Contracts with Customer As of September 30, 2021, the aggregate amount of the transaction price allocated to remaining performance obligations that are unsatisfied or partially unsatisfied was approximately $6.7 billion. Remaining performance obligations typically include the remaining non-cancelable, . Disaggregation of Revenue The Company considers information that is regularly reviewed by its chief operating decision makers in evaluating financial performance to disaggregate revenue. Please see Note 21 — Segment Information and Sales to Significant Customers.

Fair Value Measurements

Fair Value Measurements	12 Months Ended
Fair Value Measurements	Sep. 30, 2021
Fair Value Disclosures [Abstract]
Fair Value Measurements	Note 5 — Fair Value Measurements The Company accounts for certain assets and liabilities at fair value. Fair value is the price that would be received from selling an asset or that would be paid to transfer a liability in an orderly transaction between market participants at the measurement date. When determining the fair value measurements for assets and liabilities required or permitted to be recorded at fair value, the Company considers the principal or most advantageous market in which it would transact and it considers assumptions that market participants would use when pricing the asset or liability. The hierarchy below lists three levels of fair value based on the extent to which inputs used in measuring fair value are observable in the market. The Company categorizes each of its fair value measurements in one of these three levels based on the lowest level input that is significant to the fair value measurement in its entirety. The three levels of inputs that may be used to measure fair value are as follows: Level 1: Level 2: Level 3: The following tables present the Company’s assets and liabilities measured at fair value on a recurring basis as of September 30, 2021 and 2020: As of September 30, 2021 Level 1 Level 2 Level 3 Total Available-for-sale Money market funds $ 209,026 $ — $ — $ 209,026 Corporate bonds — 190,437 — 190,437 U.S. government treasuries 54,752 — — 54,752 Supranational and sovereign debt — 7,453 — 7,453 Asset backed obligations — 3,885 — 3,885 Total available-for-sale 263,778 201,775 — 465,553 Equity Investments — — 37,581 37,581 Derivative financial instruments, net — 10,979 — 10,979 Other liabilities — — (51,590 ) (51,590 ) Total $ 263,778 $ 212,754 $ (14,009 ) $ 462,523 As of September 30, 2020 Level 1 Level 2 Level 3 Total Available-for-sale Money market funds $ 558,633 $ — $ — $ 558,633 Corporate bonds — 752 — 752 Total available-for-sale 558,633 752 — 559,385 Equity Investments — — 24,211 24,211 Derivative financial instruments, net — 20,636 — 20,636 Other liabilities — — (19,641 ) (19,641 ) Total $ 558,633 $ 21,388 $ 4,570 $ 584,591 Available-for-sale non-binding pay-out Fair Value of Financial Instruments The carrying amounts of cash and cash equivalents, accounts receivable, accounts payable, accrued expenses and other current liabilities, accrued personnel costs and short-term financing arrangements approximate their fair value because of the relatively short maturity of these items, for the fair value of the Senior Notes, please see Note 12.

Available-For-Sale Securities

Available-For-Sale Securities	12 Months Ended
Available-For-Sale Securities	Sep. 30, 2021
Investments, Debt and Equity Securities [Abstract]
Available-For-Sale Securities	Note 6 — Available-For-Sale Available-for-sale As of September 30, 2021 Amortized Gross Gross Fair Value Money market funds $ 209,026 $ — $ — $ 209,026 Corporate bonds 191,445 76 1,084 190,437 U.S. government treasuries 54,987 4 239 54,752 Supranational and sovereign debt 7,479 — 26 7,453 Asset backed obligations 3,890 — 5 3,885 Total(1) $ 466,827 $ 80 $ 1,354 $ 465,553 (1) Available-for-sale available-for-sale As of September 30, 2020 Amortized Gross Gross Fair Value Money market funds $ 558,633 $ — $ — $ 558,633 Corporate bonds 754 — 2 752 Total(1) $ 559,387 $ — $ 2 $ 559,385 (1) Available-for-sale available-for-sale As of September 30, 2021, the immaterial unrealized losses attributable to the Company’s available-for-sale As of September 30, 2021, the Company’s available-for-sale Market Value Due within one year $ 226,990 1 to 2 years 19,080 2 to 3 years 58,270 3 to 4 years 94,188 Thereafter 67,025 $ 465,553

Derivative Financial Instrument

Derivative Financial Instruments	12 Months Ended
Derivative Financial Instruments	Sep. 30, 2021
Derivative Instruments and Hedging Activities Disclosure [Abstract]
Derivative Financial Instruments	Note 7 — Derivative Financial Instruments The Company’s risk management strategy includes the use of derivative financial instruments to reduce the volatility of earnings and cash flows associated with changes in foreign currency exchange rates. The Company does not enter into derivative transactions for trading purposes. The Company’s derivatives expose it to credit risks from possible non-performance September 30, 2021. The Company has limited its credit risk by entering into derivative transactions exclusively with investment-grade rated financial institutions and monitors the creditworthiness of these financial institutions on an ongoing basis. The Company classifies cash flows from its derivative transactions as cash flows from operating activities in the consolidated statements of cash flow. The table below presents the total volume or notional amounts of the Company’s derivative instruments as of September 30, 2021. Notional values are in U.S. dollars and are translated and calculated based on forward rates as of September 30, 2021 for forward contracts, and based on spot rates as of September 30, 2021 for options. Notional Value* Foreign exchange contracts $ 1,260,450 (*) Gross notional amounts do not quantify risk or represent assets or liabilities of the Company but are used in the calculation of settlements under the contracts. The Company records all derivative instruments on the balance sheet at fair value. For further information, please see Note 5 to the consolidated financial statements. The fair value of the open foreign exchange contracts recorded as an asset or a liability by the Company on its consolidated balance sheets as of September 30, 2021 and September 30, 2020, is as follows: As of September 30, 2021 2020 Derivatives designated as hedging instruments Prepaid expenses and other current assets $ 6,962 $ 21,153 Other noncurrent assets 3,068 1,317 Accrued expenses and other current liabilities (70 ) (2,089 ) 9,960 20,381 Derivatives not designated as hedging instruments Prepaid expenses and other current assets 4,230 3,068 Accrued expenses and other current liabilities (3,211 ) (2,813 ) 1,019 255 Net fair value $ 10,979 $ 20,636 Cash Flow Hedges In order to reduce the impact of changes in foreign currency exchange rates on its results, the Company enters into foreign currency exchange forward and option contracts to purchase and sell foreign currencies to hedge a significant portion of its foreign currency net exposure resulting from revenue and expense transactions denominated in currencies other than the U.S. dollar. The Company designates these contracts for accounting purposes as cash flow hedges. The Company currently hedges its exposure to the variability in future cash flows for a maximum period of approximately three years. A significant portion of the forward and option contracts outstanding as of September 30, 2021 is scheduled to mature within the next 12 months. The effective portion of the gain or loss on the derivative instruments is initially recorded as a component of other comprehensive (loss) income, a separate component of equity, and subsequently reclassified into earnings in the same line item as the related forecasted transaction and in the same period or periods during which the hedged exposure affects earnings. The cash flow hedges are evaluated for effectiveness quarterly. As the critical terms of the forward contract or option and the hedged transaction are matched at inception, the hedge effectiveness is assessed generally based on changes in the fair value for cash flow hedges, as compared to the changes in the fair value of the cash flows associated with the underlying hedged transactions. Hedge ineffectiveness, if any, and hedge components, such as time value, excluded from assessment of effectiveness testing for hedges of estimated revenue from customers, are recognized immediately in interest and other expense, net. The effect of the Company’s cash flow hedging instruments in the consolidated statements of income for the fiscal years ended September 30, 2021, 2020 and 2019, respectively, which partially offsets the foreign currency impact from the underlying exposures, is summarized as follows: Gains (Losses) Reclassified from Accumulated Other Comprehensive Income (Loss) (Effective Portion) Year Ended September 30, 2021 2020 2019 Line item in consolidated statements of income: Revenue $ (473 ) $ 834 $ 19 Cost of revenue 20,209 4,166 (8,627 ) Research and development 6,069 1,646 (2,059 ) Selling, general and administrative 6,347 2,500 (2,309 ) Total $ 32,152 $ 9,146 $ (12,976 ) The activity related to the changes in net unrealized gains (losses) on cash flow hedges recorded in accumulated other comprehensive income (loss), net of tax, is as follows: Year Ended September 30, 2021 2020 2019 Net unrealized gain (loss) on cash flow hedges, net of tax, beginning of period $ 18,836 $ 3,945 $ (26,608 ) Changes in fair value of cash flow hedges, net of tax 24,239 21,903 19,228 Reclassification of (gain) loss into earnings, net of tax (29,302 ) (7,012 ) 11,325 Net unrealized gain (loss) on cash flow hedges, net of tax, end of period $ 13,773 $ 18,836 $ 3,945 Net unrealized gain (loss) from cash flow hedges recognized in other comprehensive (loss) income were $23,720, $26,408 and $20,035, or $24,239, $21,903 and $19,228, net of taxes, during the fiscal years ended September 30, 2021, 2020 and 2019, respectively. Of the net gains related to derivatives designated as cash flow hedges and recorded in accumulated other comprehensive income (loss) as of September 30, 2021, a net gain of $4,841 will be reclassified into earnings during fiscal 2022 and will partially offset the foreign currency impact from the underlying exposures. The amount ultimately realized in earnings will likely differ due to future changes in foreign exchange rates. The ineffective portion of the change in fair value of a cash flow hedge, including the time value portion excluded from effectiveness testing for the fiscal years ended September 30, 2021, 2020 and 2019, was not material. Cash flow hedges are required to be discontinued in the event it becomes probable that the underlying forecasted hedged transaction will not occur. The Company did not discontinue any cash flow hedges during any of the periods presented nor does the Company anticipate any such discontinuance in the normal course of business. Other Risk Management Derivatives The Company also enters into foreign currency exchange forward and option contracts that are not designated as hedging instruments under hedge accounting and are used to reduce the impact of foreign currency on certain balance sheet exposures and certain revenue and expense transactions. These instruments are generally short-term in nature, with typical maturities of less than 12 months, and are subject to fluctuations in foreign exchange rates. The effect of the Company’s derivative instruments not designated as hedging instruments in the consolidated statements of income for the fiscal years ended September 30, 2021, 2020 and 2019, respectively, which partially offsets the foreign currency impact from the underlying exposure, is summarized as follows: Gains (Losses) 2021 2020 2019 Line item in statements of income: Cost of revenue $ 4,786 $ (718 ) $ 401 Research and development 1,187 (341 ) 14 Selling, general and administrative 1,301 (559 ) 294 Interest and other expense, net 1,808 255 5,845 Income taxes (3,125 ) (679 ) (528 ) Total $ 5,957 $ (2,042 ) $ 6,026

Property and Equipment, Net

Property and Equipment, Net	12 Months Ended
Property and Equipment, Net	Sep. 30, 2021
Property, Plant and Equipment [Abstract]
Property and Equipment, Net	Note 8 — Property and Equipment, Net The components of property and equipment, net are: As of September 30, 2021 2020 Computers, related equipment and software $ 1,195,787 $ 1,163,807 Building and land 291,262 177,255 Leasehold improvements 244,858 234,777 Furniture, fixtures and other 55,353 51,831 Property and equipment, gross 1,787,260 1,627,670 Less accumulated depreciation (1,088,492 ) (1,019,719 ) Property and equipment, net $ 698,768 $ 607,951 (1) For more details, please see also note 2. Total depreciation expense for fiscal years 2021, 2020 and 2019, was $125,014, $117,632 and $111,387, respectively. As of September 30, 2021 and 2020, the costs, net of accumulated depreciation of software assets developed for internal use were $165,529 and $179,837, respectively.

Goodwill and Intangible Assets,

Goodwill and Intangible Assets, Net	12 Months Ended
Goodwill and Intangible Assets, Net	Sep. 30, 2021
Goodwill and Intangible Assets Disclosure [Abstract]
Goodwill and Intangible Assets, Net	Note 9 — Goodwill and Intangible Assets, Net The following table presents details of the Company’s total goodwill: As of September 30, 2019 $ 2,462,835 Goodwill resulting from acquisitions 118,628 Other (2,818 ) As of September 30, 2020 $ 2,578,645 Goodwill resulting from acquisitions 104,151 Decrease in goodwill as a result of divestiture (61,396 ) Other 1,244 As of September 30, 2021 $ 2,622,644 (1) Mainly relates to the acquisition of Openet. In allocating the total purchase price for Openet, based on estimated fair values, the Company recorded $110,347 of goodwill, $40,409 of customer relationships to be amortized over approximately eight years, $53,614 of core technology to be amortized over five years and $2,594 of trademark to be amortized over two years. (2) Mainly relates to the acquisition of Sourced. In allocating the total preliminary purchase price for Sourced, based on estimated fair values, the Company recorded $80,055 of goodwill, $18,211 of customer relationships to be amortized over approximately seven years and $3,056 of core technology to be amortized over three years. (3) Relates to the divestiture of OpenMarket completed on December 31, 2020, please see also Note 3. The Company performs an annual goodwill impairment test during the fourth quarter of each fiscal year, or more frequently if impairment indicators are present. The Company operates in one operating segment, and this segment comprises its only reporting unit. In calculating the fair value of the reporting unit, the Company uses its market capitalization and a discounted cash flow methodology. There was no impairment of goodwill in fiscal years 2021, 2020 or 2019. The following table p r Gross Accumulated Net September 30, 2021 Core technology $ 896,149 $ (777,419 ) $ 118,730 Customer relationships 689,754 (556,716 ) 133,038 Other 47,540 (40,276 ) 7,264 Total $ 1,633,443 $ (1,374,411 ) $ 259,032 September 30, 2020 Core technology $ 896,814 $ (735,534 ) $ 161,280 Customer relationships 642,575 (517,670 ) 124,905 Other 47,540 (37,391 ) 10,149 Total $ 1,586,929 $ (1,290,595 ) $ 296,334 The amortization expenses related to the Company’s definite-lived purchased intangible assets were $83,816, $80,777 and $94,385 for the years ended 2021, 2020 and 2019, respectively. The estimated future amortization expense of definite-lived purchased intangible assets as of September 30, 2021 is as follows: Amount Fiscal year: 2022 $ 72,119 2023 54,156 2024 45,882 2025 41,930 2026 25,505 Thereafter 19,440 Total $ 259,032

Income Taxes

Income Taxes	12 Months Ended
Income Taxes	Sep. 30, 2021
Income Tax Disclosure [Abstract]
Income Taxes	Note 10 — Income Taxes The provision (benefit) for income taxes consists of the following: Year Ended September 30, 2021 2020 2019 Current $ 176,537 $ 55,243 $ 102,391 Deferred (50,605 ) 30,239 (13,950 ) Income taxes $ 125,932 $ 85,482 $ 88,441 All income taxes are from continuing operations reported by the Company in the applicable taxing jurisdiction. Income taxes also include anticipated withholding taxes due on subsidiaries’ earnings when paid as dividends to the Company. The Company maintained a tax receivable balance of $53,925 and $58,336 as of September 30, 2021 and 2020, respectively, which is included in Prepaid expenses and other current assets. Deferred income taxes are comprised of the following components: As of September 30, 2021 2020 Deferred tax assets: Deferred revenue $ 25,282 $ 25,252 Employee compensation and benefits 76,020 75,689 Intangible assets, computer software and intellectual property 75,200 18,705 Tax credits, net capital and operating loss carryforwards 156,209 142,718 Lease liabilities 50,780 71,204 Other 46,372 52,611 Total deferred tax assets 429,863 386,179 Valuation allowances (65,550 ) (69,455 ) Total deferred tax assets, net 364,313 316,724 Deferred tax liabilities: Anticipated withholdings on subsidiaries’ earnings (84,755 ) (81,489 ) Intangible assets, computer software and intellectual property (109,526 ) (114,772 ) Lease assets (47,822 ) (69,215 ) Other (97,638 ) (90,825 ) Total deferred tax liabilities (339,741 ) (356,301 ) Net deferred tax assets (liabilities) $ 24,572 $ (39,577 ) The effective income tax rate varied from the statutory Guernsey tax rate as follows: Year Ended September 30, 2021 2020 2019 Statutory Guernsey tax rate 0 % 0 % 0 % Foreign taxes 15.5 14.7 15.6 Effective income tax rate 15.5 % 14.7 % 15.6 % As a Guernsey company subject to a corporate tax rate of zero percent, the Company’s overall effective tax rate is attributable to foreign taxes. The Company’s income before income tax expense is considered to be foreign income. (1) Foreign taxes for the year ended Sep 30, 2021: In fiscal year 2021, foreign taxes included an expense of $39,596 for the estimated additional tax charge as a result of the gain from sale of a business, please see also Note 3. Foreign taxes in fiscal year 2021 also included a benefit of $10,933 resulting from internal structural changes in certain jurisdictions in which the Company operates. Foreign taxes in fiscal year 2021 also included a total amount of releases, net of additions related to prior years, of gross unrecognized tax benefits of $7,701 relating to effectively settled arrangements with tax authorities, changes in facts and circumstances resulting in a change in measurement of certain positions and expiration of the periods set forth in statutes of limitations in certain jurisdictions. The net release was offset by decrease in tax assets and as a result the net impact on income tax expense for fiscal year 2021 was not material. Foreign taxes in fiscal year 2021 also included a benefit of $6,006 resulting from the release of valuation allowances on deferred tax assets at certain of the Company’s subsidiaries, which will, more likely than not, be realized due to the Company’s projections of future taxable income. (1) Foreign taxes for the year ended Sep 30, 2020: In fiscal year 2020, foreign taxes included a total amount of releases of gross unrecognized tax benefits of $47,582 relating to effectively settled arrangements with tax authorities, changes in facts and circumstances resulting in a change in measurement of certain positions and expiration of the periods set forth in statutes of limitations in certain jurisdictions. The majority of the release was offset by decrease in tax assets and increase in tax liabilities and as a result a net benefit of $14,971 was included within income tax expense for fiscal year 2020. Foreign taxes in fiscal year 2020 also included a benefit of $15,438 resulting from the release of valuation allowances on deferred tax assets at certain of the Company’s subsidiaries, which will, more likely than not, be realized due to the Company’s projections of future taxable income. On March 27, 2020, the U.S. government enacted the Coronavirus Aid, Relief, and Economic Security Act (“CARES Act”) to provide certain relief as a result of the COVID-19 tax-related Foreign taxes in fiscal year 2020 also included a tax benefit of $4,964 resulting from tax enactments related to the COVID-19 (1) Foreign taxes for the year ended Sep 30, 2019: In fiscal year 2019, foreign taxes included a benefit of $ that was primarily attributable to the expiration of the periods set forth in statutes of limitations and to a lesser extent from the conclusions of tax audits related to unrecognized tax benefits accumulated over several years in certain jurisdictions. Foreign taxes in fiscal year 2019 also included a benefit of $12,650 resulting from the release of valuation allowances on deferred tax assets at certain of the Company’s subsidiaries, which will, more likely than not, be realized due to the Company’s projections of future taxable income. As of September 30, 2021 and 2020, the Company continues to indefinitely reinvest certain undistributed earnings of its foreign subsidiary and as a result has not recorded deferred tax liabilities in an amount of $28,795. During fiscal year 2021, the net decrease in valuation allowances was $3,905 . The valuation allowances, related to the uncertainty of realizing tax benefits primarily for tax credits, net capital and operating loss carryforwards related to certain of the Company’s subsidiaries. As of September 30, 2021, the Company had tax credits, net capital and operating loss carryforwards of $ of which $ have expiration dates through 2041 During fiscal year 2020, the net decrease in valuation allowances was $16,078. The valuation allowances, related to the uncertainty of realizing tax benefits primarily for tax credits, net capital and operating loss carryforwards related to certain of the Company’s subsidiaries. As of September 30, 2020, the Company had tax credits, net capital and operating loss carryforwards of $829,260 of which $245,843 have expiration dates through 2040 The aggregate changes in the balance of the Company’s gross unrecognized tax benefits were as follows: Year Ended September 30, 2021 2020 2019 Balance at beginning of fiscal year $ 168,186 $ 169,322 $ 187,646 Additions based on tax positions related to the current year 25,662 23,154 19,530 Additions for tax positions of prior years 23,849 23,292 27,558 Reductions for tax positions of prior years (7,467 ) (15,214 ) (2,578 ) Settlements with tax authorities (10,245 ) (29,400 ) (37,672 ) Lapse of statute of limitations (4,789 ) (2,968 ) (25,162 ) Balance at end of fiscal year $ 195,196 $ 168,186 $ 169,322 (1) The changes in the year ended September 30, 2021, in the balance of the Company’s gross unrecognized tax benefits that relate to settlements with tax authorities is $10,245, the majority of which was offset by decrease in Tax Receivables and Deferred Tax Assets. The total amount of unrecognized tax benefits, which includes interest and penalties, was $195,196 as of September 30, 2021, and $168,186 as of September 30, 2020, all of which would affect the effective tax rate if realized. The Company recognizes interest and penalties related to unrecognized tax benefits in the provision for income taxes. As of September 30, 2021, the Company had accrued $ in income taxes payable for interest and penalties relating to unrecognized tax benefits, of which $ was recognized in the statements of income in fiscal year 2021, net of interest and penalty reversals. As of September 30, 2020, the Company had accrued $ in income taxes payable for interest and penalties relating to unrecognized tax benefits. Total amount of interest and penalty releases, net that was recognized in the statements of income in fiscal year 2020 was $ . The Company is currently under tax audit in several jurisdictions for the tax years 2007 and onwards. Timing of the resolution of audits is highly uncertain and therefore, as of September 30, 2021, the Company cannot estimate the change in unrecognized tax benefits resulting from these audits within the next 12 months. It is reasonably possible that the amount of unrecognized tax benefits may decrease by up to $3,559 during fiscal year 2022 as a result of lapse of statutes of limitations in jurisdictions in which the Company operates.

Repurchase of Shares

Repurchase of Shares	12 Months Ended
Repurchase of Shares	Sep. 30, 2021
Equity [Abstract]
Repurchase of Shares	Note 11 — Repurchase of Shares From time to time, the Company’s Board of Directors can adopt share repurchase plans authorizing the repurchase of the Company’s outstanding ordinary shares. On November 12, 2019, the Company’s Board of Directors adopted a share repurchase plan for the repurchase of up to of the Company’s outstanding ordinary shares with no expiration date. The November 2019 plan permitted the Company to purchase our ordinary shares in the open market or through privately negotiated transactions at times and prices that the Company considers appropriate. On May 12, 2021, the Company’s Board of Directors adopted a share repurchase plan for the repurchase of up to an additional $1,000,000 of the Company’s outstanding ordinary shares with no expiration date. The May 2021 plan permits the Company to purchase our ordinary shares in the open market or through privately negotiated transactions at times and prices that the Company considers appropriate. In September 2021, the Company completed the repurchase of the remaining authorized amount of ordinary shares under the November 2019 plan and initiated repurchases of the Company’s outstanding ordinary shares pursuant to the May 2021 plan. In the year ended September 30, 2021, the Company repurchased 9,036 ordinary shares at an average price of $75.24 per share (excluding broker and transaction fees). As of September 30, 2021, the Company had remaining authority to repurchase up to $998,484 of its outstanding ordinary shares under the May 2021 plan.

Financing Arrangements

Financing Arrangements	12 Months Ended
Financing Arrangements	Sep. 30, 2021
Debt Disclosure [Abstract]
Financing Arrangements	Note 12 — Financing Arrangements In December 2011, the Company entered into the unsecured $500,000 five-year revolving credit facility with a syndicate of banks (the “Revolving Credit Facility”). In December 2014, December 2017 and March 2021, the Revolving Credit Facility was amended and restated to, among other things, extend the maturity date of the facility to December 2019, December 2022 and March 2026, respectively. In March 2020, the Company drew an aggregate of $300,000 under the Revolving Credit Facility and repaid it in full in June 2020 in connection with the issuance of our Senior Notes. As of September 30, 2021, the Company was in compliance with the financial covenants and had no outstanding borrowings under the Revolving Credit Facility. In addition, unassociated with the Revolving Credit Facility discussed above, in the second quarter of fiscal year 2020, the Company entered into a $50,000 short-term loan and repaid it in full in June 2020 in connection with the issuance of our Senior Notes. In May 2020 the Company entered into an additional $100,000 one year loan which was repaid in full in May 2021. In June 2020, the Company issued an aggregate principal amount of $ in Senior Notes that will mature in June 2030 and bear interest at a fixed rate of percent per annum (the “Senior Notes”). The interest is payable semi-annually in June and December of each year, commencing in December 2020. The Company incurred issuance costs of $ in relation with the Senior Notes which are being amortized to interest expenses over the term of the Senior Notes using the effective interest rate. The Senior Notes are senior unsecured obligations of the Company and rank equally in right of payment with all existing and future senior indebtedness of the Company, including any indebtedness the Company may incur from time to time under the Revolving Credit Facility. The total interest expenses recognized in connection of the Senior Notes for the year ended September 30, 2021 were $17,034. The accrued interest on the Senior Notes is included in accrued expenses and other current liabilities and was $4,815 as of September 30, 2021. As of September 30, 2021, the noncurrent outstanding principal portion was $650,000. The total estimated fair value of the Senior Notes as of September 30, 2021 was $651,112. The fair value was determined based on the closing trading price of Senior Notes as of September 30, 2021 and is deemed a Level 2 liability within the fair value measurement framework. As of September 30, 2021, the Company had additional uncommitted lines of credit available for general corporate and other specific purposes and had outstanding letters of credit and bank guarantees from various banks totaling $78,084. These were supported by a combination of the uncommitted lines of credit that the Company maintains with various banks.

Accrued Expenses and Other Curr

Accrued Expenses and Other Current Liabilities	12 Months Ended
Accrued Expenses and Other Current Liabilities	Sep. 30, 2021
Accrued expenses and Other Current Liabilities [Abstract]
Accrued Expenses and Other Current Liabilities	Note 13 — Accrued Expenses and Other Current Liabilities Accrued expenses and other current liabilities consist of the following: As of September 30, 2021 2020 Ongoing accrued expenses $ 206,905 $ 217,133 Project-related provisions 125,612 121,658 Taxes payable 34,717 25,739 Dividends payable(1) 44,956 43,084 Derivative instruments(2) 3,281 4,902 Other 196,832 181,092 $ 612,303 $ 593,608 (1) The amounts payable as a result of the August 4, 2021 and the August 5, 2020 dividend declarations, please see Note 19 to the consolidated financial statements. (2) Includes derivatives that are designated as hedging instruments and derivatives that are not designated as hedging instruments, please see Note 7 to the consolidated financial statements.

Interest and other expense, net

Interest and other expense, net	12 Months Ended
Interest and other expense, net	Sep. 30, 2021
Interest and other expense, net
Interest and other expense, net	Note 14 — Interest and other expense, net Interest and other expense, net, consists of the following: Year Ended September 30, 2021 2020 2019 Interest income $ (4,822 ) $ (4,233 ) $ (6,225 ) Interest expense 21,275 10,427 3,911 Foreign exchange loss 1,110 3,382 7,860 Other, net (6,766 ) 1,860 (3,687 ) $ 10,797 $ 11,436 $ 1,859 (1) For further details, please see Note 12 to the consolidated financial statements.

Leases

Leases	12 Months Ended
Leases	Sep. 30, 2021
Leases [Abstract]
Leases	Note 15 — Leases As discussed in Note 2 No. 2016-02, “Leases”, Lease costs were as follows : Year Ended September 30, 2021 2020 Total net lease cost $ 97,169 $ 91,025 (1) Variable lease cost is immaterial. Supplemental information related to operating lease transactions was as follows: Year Ended September 30, 2021 2020 Lease liability payments $ 79,028 $ 88,272 Lease assets obtained in exchange for liabilities $ 14,580 $ 87,820 As of September 30, 2021 2020 Weighted average remaining lease term — Operating leases 6.4 Years 6.8 Years Weighted average discount rate — Operating leases 3.7 % 3.5 % The following maturity analysis presents future undiscounted cash outflows for operating leases as of September 30, 2021: For the year ended September 30, 2022 $ 66,791 2023 44,187 2024 34,473 2025 28,173 2026 22,814 Thereafter 86,134 Total lease payments $ 282,572 Less: imputed interest (45,952 ) Present value of lease liabilities $ 236,620 As of September 30, 2021 and September 30, 2020, the Company had no material finance leases. Rent expense per prior lease accounting (ASC 840), net of sublease income was approximately $65,692 for fiscal year 2019.

Contingencies and Commitments

Contingencies and Commitments	12 Months Ended
Contingencies and Commitments	Sep. 30, 2021
Commitments and Contingencies Disclosure [Abstract]
Contingencies and Commitments	Note 16 —Contingencies and Commitments Legal Proceedings The Company is involved in various legal claims and proceedings arising in the normal course of its business. The Company accrues for a loss contingency when it determines that it is probable, after consultation with counsel, that a liability has been incurred and the amount of such loss can be reasonably estimated. At this time, the Company believes that the results of any such contingencies, either individually or in the aggregate, will not have a material adverse effect on the Company’s financial position, results of operations or cash flows. In April 2021, two separate lawsuits alleging violations of the federal securities laws and pursuing remedies under Sections 10(b) and 20(a) of the Securities Exchange Act of 1934 (the “Exchange Act”) and Rule 10b-5 Glover v. Amdocs Ltd., et. al, 4:21-cv-00418, 2:21-cv-03078-CAS-PVC, Certain of the Company’s subsidiaries are currently in a dispute with a state-owned telecom enterprise in Ecuador, which appears to have political aspects. The Company’s counterparty has claimed monetary damages. The dispute is over contracts, under which the Company was providing certain services, which have been terminated by the counterparty in connection with such dispute and which are under scrutiny by certain local governmental authorities. The Company believes it has solid arguments and is vigorously defending its rights. To date, however, the Ecuadorian Courts have responded to such defense efforts, including motions alleging constitutional defects, in an inconsistent manner. While we have achieved some successes, the majority of the procedures are still ongoing. The Company is unable to reasonably estimate the ultimate outcome of the above dispute. Guarantor’s Accounting and Disclosure Requirements for Guarantees In the ordinary course of its business, the Company provides certain customers with financial performance guarantees which, in certain cases, are backed by lines of credit. The Company is only liable for the amounts of those guarantees in the event of the Company’s nonperformance, which would permit the customer to exercise the guarantee. The Company generally offers its products with a limited warranty. The Company’s policy is to accrue for warranty costs, if needed, based on historical trends in product failure. Based on the Company’s experience, only minimal warranty charges have been incurred after revenue was fully recognized and, as a result, the Company did not accrue any amounts for product warranty liability during fiscal years 2021, 2020 and 2019. The Company generally indemnifies its customers against claims made by third parties arising from the use of the Company’s software and certain other matters. To date, the Company has incurred and recorded immaterial costs as a result of such obligations in its consolidated financial statements.

Employee Benefits

Employee Benefits	12 Months Ended
Employee Benefits	Sep. 30, 2021
Retirement Benefits [Abstract]
Employee Benefits	Note 17 — Employee Benefits The Company accrues severance pay mainly for the employees of its Israeli operations in accordance with Israeli law and certain employment procedures on the basis of the latest monthly salary paid to these employees and the length of time that they have worked for the Israeli operations. The severance pay liability amounted to $298,044 and $270,985 as of September 30, 2021 and 2020, respectively, and is included as accrued employee costs in other noncurrent liabilities. This liability is partially funded by amounts on deposit with insurance companies that totaled $233,749 and $211,566 as of September 30, 2021 and 2020, respectively, and are included in other noncurrent assets. The accrued severance expenses were $35,015, $33,354 and $33,355 for fiscal years 2021, 2020 and 2019, respectively. The Company sponsors defined contribution plans covering certain employees around the world. The plans primarily provide for Company matching contributions based upon a percentage of the employees’ contributions. The Company’s contributions in fiscal years 2021, 2020 and 2019 under such plans were not material compared to total operating expenses. The Company maintains non-contributory pro-rated non-contributory

Stock Option and Incentive Plan

Stock Option and Incentive Plan	12 Months Ended
Stock Option and Incentive Plan	Sep. 30, 2021
Disclosure of Stock Option and Incentive Plan [Abstract]
Stock Option and Incentive Plan	Note 18 — Stock Option and Incentive Plan In January 1998, the Company adopted the 1998 Stock Option and Incentive Plan, or Equity Incentive Plan, which provides for the grant of restricted stock awards, stock options and other equity-based awards to employees, officers, directors, and consultants. Since its adoption, the Equity Incentive Plan has been amended on several occasions to, among other things, increase the number of ordinary shares issuable under the Equity Incentive Plan. In January 2020, the maximum number of ordinary shares authorized to be granted under the Equity Incentive Plan was increased from 67,550 to 70,550. Awards granted under the Equity Incentive Plan generally vest over a period of three The following table summarizes information about options to purchase the Company ’ Number of Weighted Average Outstanding as of October 1, 2020 5,716 $ 60.26 Granted 62 60.77 Exercised (1,541 ) 57.81 Forfeited (249 ) 63.63 Outstanding as of September 30, 2021(1) 3,988 $ 61.00 Exercisable as of September 30, 2021(1) 2,119 $ 57.55 (1) As of September 30, 2021, the weighted average remaining contractual life of outstanding and exercisable options was 6.42 and 5.40 years, respectively. The following table summarizes information relating to awards of restricted shares, as well as changes during the fiscal year ended September 30, 2021: Number of Weighted Average Outstanding as of October 1, 2020 1,097 $ 66.57 Granted 1,032 66.83 Vested (426 ) 65.40 Forfeited (116 ) 67.84 Outstanding as of September 30, 2021 1,587 $ 66.96 The total intrinsic value of options exercised during fiscal years 2021, 2020 and 2019 was $27,023, $31,220 and $ The value of restricted shares vested during fiscal years 2021, 2020 and 2019 was $28,682, $28,727 and $28,430, respectively. The aggregate intrinsic value of outstanding and exercisable stock options as of September 30, 2021 was $58,644 and $38,482, respectively. Employee pre-tax Year Ended September 30, 2021 2020 2019 Cost of revenue $ 22,691 $ 20,005 $ 19,879 Research and development 4,021 3,058 2,714 Selling, general and administrative 27,537 19,371 15,957 Total $ 54,249 $ 42,434 $ 38,550 The fair value of options granted was estimated on the date of grant using the Black-Scholes pricing model with the assumptions noted in the following table (all in weighted averages for options granted during the year): Year Ended September 30, 2021 2020 2019 Risk-free interest rate(1) 0.30 % 1.41 % 2.64 % Expected life of stock options(2) 4.50 4.50 4.50 Expected volatility(3) 21.3 % 17.3 % 17.8 % Expected dividend yield(4) 2.22 % 1.75 % 1.82 % Fair value per option $ 7.82 $ 8.85 $ 9.13 (1) Risk-free interest rate is based upon U.S. Treasury yield curve appropriate for the term of the Company’s employee stock options. (2) Expected life of stock options is based upon historical experience. (3) Expected volatility is based on blended volatility. (4) Expected dividend yield is based on the Company’s history and future expectation of dividend payouts.

Dividends

Dividends	12 Months Ended
Dividends	Sep. 30, 2021
Other Liabilities Disclosure [Abstract]
Dividends	Note 19 — Dividends The Company’s Board of Directors declared the following dividends during the fiscal years ended September 30, 2021, 2020 and 2019: Declaration Date Dividends Per Record Date Total Amount Payment Date August 4, 2021 $ 0.36 September 30, 2021 $ 44,956 October 29, 2021 May 12, 2021 $ 0.36 June 30, 2021 $ 45,580 July 23, 2021 February 2, 2021 $ 0.36 March 31, 2021 $ 45,958 April 23, 2021 November 10, 2020 $ 0.3275 December 31, 2020 $ 42,850 January 22, 2021 August 5, 2020 $ 0.3275 September 30, 2020 $ 43,084 October 23, 2020 May 7, 2020 $ 0.3275 June 30, 2020 $ 43,568 July 24, 2020 February 4, 2020 $ 0.3275 March 31, 2020 $ 43,723 April 24, 2020 November 12, 2019 $ 0.285 December 31, 2019 $ 38,357 January 24, 2020 August 7, 2019 $ 0.285 September 30, 2019 $ 38,413 October 25, 2019 May 14, 2019 $ 0.285 June 28, 2019 $ 38,730 July 19, 2019 February 5, 2019 $ 0.285 March 29, 2019 $ 39,084 April 19, 2019 November 8, 2018 $ 0.250 December 31, 2018 $ 34,755 January 18, 2019 The amounts payable as a result of the August 4, 2021, August 5, 2020 and August 7, 2019 declarations were included in accrued expenses and other current liabilities as of September 30, 2021, 2020 and 2019, respectively. On November 2, 2021, the Company’s Board of Directors approved quarterly dividend payment of $0.36 per share, and set December 31, 2021 as the record date for determining the shareholders entitled to receive the dividend, which is payable on January 28, 2022. On November 2, 2021, the Company’s Board of Directors also approved, subject to shareholder approval at the January 2022 annual general meeting of shareholders, an increase in the quarterly cash dividend to $0.395 per share, anticipated to be paid in April 2022.

Earnings Per Share

Earnings Per Share	12 Months Ended
Earnings Per Share	Sep. 30, 2021
Earnings Per Share [Abstract]
Earnings Per Share	Note 20 — Earnings Per Share The following table sets forth the computation of basic and diluted earnings per share: Year Ended September 30, 2021 2020 2019 Numerator: Net income $ 688,374 $ 497,840 $ 479,446 Net income and dividends attributable to participating restricted shares (7,052 ) (3,663 ) (3,295 ) Numerator for basic earnings per common share $ 681,322 $ 494,177 $ 476,151 Undistributed income allocated to participating restricted shares 5,199 2,417 2,252 Undistributed income reallocated to participating restricted shares (5,167 ) (2,406 ) (2,240 ) Numerator for diluted earnings per common share $ 681,354 $ 494,188 $ 476,163 Denominator: Weighted average number of shares outstanding — basic 128,495 133,590 137,418 Weighted average number of participating restricted shares (1,316 ) (983 ) (944 ) Weighted average number of common shares — basic 127,179 132,607 136,474 Effect of dilutive stock options granted 789 642 691 Weighted average number of common shares — diluted 127,968 133,249 137,165 Basic earnings per common share $ 5.36 $ 3.73 $ 3.49 Diluted earnings per common share $ 5.32 $ 3.71 $ 3.47 For the fiscal years ended September 30, 2021, 2020 and 2019, 858, 2,634 and 3,547 shares, respectively, on a weighted average basis, were attributable to antidilutive outstanding stock options and therefore were not included in the calculation of diluted earnings per share.

Segment Information and Sales t

Segment Information and Sales to Significant Customers	12 Months Ended
Segment Information and Sales to Significant Customers	Sep. 30, 2021
Segment Reporting [Abstract]
Segment Information and Sales to Significant Customers	Note 21 — Segment Information and Sales to Significant Customers The Company and its subsidiaries operate in one operating segment, providing software products and services for the communications, entertainment and media industry service providers. Geographic Information The following is a summary of revenue and long-lived assets by geographic area. Revenue is attributed to geographic region based on the location of the customers. Year Ended September 30, 2021 2020 2019 Revenue North America (mainly United States) $ 2,791,472 $ 2,720,911 $ 2,582,719 Europe 622,780 613,751 598,731 Rest of the world 874,388 834,377 905,219 Total $ 4,288,640 $ 4,169,039 $ 4,086,669 As of September 30, 2021 2020 Long-lived Assets (1) Europe $ 182,746 $ 211,292 North America 94,149 104,918 Rest of the world: Israel (2) 358,329 237,561 India 48,326 38,706 Others 15,218 15,474 Total $ 698,768 $ 607,951 (1) Property and equipment, net. (2) For more details, please see also note 2 Revenue by nature of activities Year Ended September 30, 2021 2020 2019 Managed services arrangements $ 2,546,330 $ 2,398,691 $ 2,246,279 Others 1,742,310 1,770,348 1,840,390 Total $ 4,288,640 $ 4,169,039 $ 4,086,669 Sales to Significant Customers The following table summarizes the percentage of sales to significant customer groups which accounted for at least ten percent of its total revenue in each of fiscal years 2021, 2020 and 2019. Year Ended September 30, 2021 2020 2019 Revenue Customer 1 25.0 % 25.8 % 23.4 % Customer 2 (*) 19.1 % 12.1 % () * Represents an amount of less than 10%. ** Starting April 1, 2020, following the merger of two significant customers, their respective revenue was consolidated. See also ITEM 5 — “The Amdocs Offerings.”

Selected Quarterly Results of O

Selected Quarterly Results of Operations (Unaudited)	12 Months Ended
Selected Quarterly Results of Operations (Unaudited)	Sep. 30, 2021
Quarterly Financial Information Disclosure [Abstract]
Selected Quarterly Results of Operations (Unaudited)	Note 22 — Selected Quarterly Results of Operations (Unaudited) The following are details of the unaudited quarterly results of operations for the three months ended: September 30, June 30, March 31, December 31, 2021 Revenue $ 1,087,309 $ 1,066,254 $ 1,048,734 $ 1,086,343 Operating income 154,330 154,919 149,244 140,200 Net income 123,525 146,150 119,067 299,632 Basic earnings per share 0.98 1.15 0.92 2.29 Diluted earnings per share 0.97 1.14 0.91 2.28 2020 Revenue $ 1,052,948 $ 1,026,201 $ 1,047,933 $ 1,041,957 Operating income 146,938 147,531 156,712 143,577 Net income 134,463 120,407 127,038 115,932 Basic earnings per share 1.02 0.90 0.95 0.86 Diluted earnings per share 1.01 0.90 0.94 0.85

Valuation and Qualifying Accoun

Valuation and Qualifying Accounts	12 Months Ended
Valuation and Qualifying Accounts	Sep. 30, 2021
SEC Schedule, 12-09, Valuation and Qualifying Accounts [Abstract]
Valuation and Qualifying Accounts	VALUATION AND QUALIFYING ACCOUNTS (dollar and share amounts in thousands, except per share data or as otherwise disclosed) Accounts Receivable Valuation Allowances on Balance as of September 30, 2018 $ 21,211 $ 112,727 Charged to costs and expenses 22,260 1,009 Charged to other accounts 2,406 6,008 (1) Deductions (9,756 )(3) (34,211 )(2) Balance as of September 30, 2019 36,121 85,533 Charged to costs and expenses 18,465 8,521 Charged to other accounts (3,523 ) 1,005 (1) Deductions (27,644 )(5) (25,604 )(4) Balance as of September 30, 2020 23,419 69,455 Charged to costs and expenses 10,345 6,382 Charged to other accounts 156 3,720 (1) Deductions (13,855 )(7) (14,007 )(6) Balance as of September 30, 2021 $ 20,065 $ 65,550 (1) Includes valuation allowances on deferred tax assets incurred in connection with an acquisition. (2) $7,588 of valuation allowances on deferred tax assets were written off against the related deferred tax assets, and the remaining deductions in the valuation allowances on net deferred tax assets were released to earnings. (3) $3,539 of accounts receivable allowances were written off against the related accounts receivables, and the remaining deductions in the accounts receivable allowances were released to earnings. (4) $2,283 of valuation allowances on deferred tax assets were written off against the related deferred tax assets, and the remaining deductions in the valuation allowances on net deferred tax assets were released to earnings. (5) $4,969 of accounts receivable allowances were written off against the related accounts receivables, $7,089 were written off against deferred revenue and the remaining deductions in the accounts receivable allowances were released to earnings. (6) $1,557 of valuation allowances on deferred tax assets were written off against the related deferred tax assets, and the remaining deductions in the valuation allowances on net deferred tax assets were released to earnings. (7) $8,486 of accounts receivable allowances were written off against the related accounts receivables, and the remaining deductions in the accounts receivable allowances were released to earnings.

Summary of Significant Accoun_2

Summary of Significant Accounting Policies (Policies)	12 Months Ended
Summary of Significant Accounting Policies (Policies)	Sep. 30, 2021
Accounting Policies [Abstract]
Basis of Presentation	Basis of Presentation The consolidated financial statements are prepared in accordance with U.S. generally accepted accounting principles, or GAAP and are denominated in U.S. dollars.
Consolidation	Consolidation The consolidated financial statements include the accounts of the Company and its subsidiaries, the vast majority of which are wholly-owned. All intercompany transactions and balances have been eliminated in consolidation. In December 2017, the Company entered into agreements with Union Investments and Development Limited (“Union”) to partner through a legal entity that is equally owned by the Company and Union for the purpose of acquiring specific land which the Company expects to use as the site for a new campus in Ra’anana, Israel. On January 2, 2018 the Company completed the acquisition of the land. Pursuant to the agreements between the Company and Union, as the Company has control over the construction and ongoing operations of the new campus, the new entity’s financial information is consolidated into the Company’s consolidated financial statements with the portion not owned classified as non-controlling
Use of Estimates	Use of Estimates The preparation of financial statements in conformity with GAAP requires management to make estimates and assumptions that affect the reported amounts of assets and liabilities and disclosure of contingent assets and liabilities at the dates of the financial statements, and the reported amounts of revenue and expenses during the reporting period. Actual results could differ from those estimates.
Reclassifications	Reclassifications From time to time, certain immaterial amounts in prior year financial statements may be reclassified to conform to the current year presentation.
Functional Currency	Functional Currency The Company manages its foreign subsidiaries as integral direct components of its operations. The operations of the Company’s foreign subsidiaries provide the same type of services with the same type of expenditures throughout the Amdocs group. The Company has determined that its functional currency is the U.S. dollar. The Company periodically assesses the applicability of the U.S. dollar as the Company’s functional currency by reviewing the salient indicators as indicated in the authoritative guidance for foreign currency matters.
Cash and Cash Equivalents	Cash and Cash Equivalents Cash and cash equivalents consist of cash and interest-bearing investments with insignificant interest rate risk and maturities from acquisition date of 90 days or less.
Accounts Receivable Factoring	Accounts Receivable Factoring From time to time, the Company uses non-recourse
Investments	Investments The Company has short-term interest-bearing investments comprised of marketable securities and bank deposits. The Company classifies all of its marketable securities as available-for-sale available-for-sale available-for-sale
Property and Equipment	Property and Equipment Property and equipment are stated at cost. Depreciation is computed using the straight-line method over the estimated useful life of the asset, which primarily ranges from three The Company capitalizes certain expenditures for software that is internally developed for use in the business, which is classified as computer equipment. Amortization of internal use software begins when the software is ready for service and continues on the straight-line method over the estimated useful life. The Company capitalizes the expenditures related to the new campus in Israel, which are classified as building and land. Amortization will begin when the new campus is ready for use and will be amortized on the straight-line basis over the estimated useful life.
Leases	Leases Upon adoption ASU No. 2016-02, “Leases”, non-lease non-lease As a lessee, substantially all of the Company’s lease obligation is for office real estate. The significant judgments used in determining its lease obligation include whether a contract is or contains a lease and the determination of the discount rate used to calculate the lease liability. The Company’s leases may include the option to extend or terminate before the end of the contractual term and are often non-cancelable The lease assets and liabilities include these options in the lease term when it is reasonably certain that they will be exercised. In certain cases, the Company subleases excess office real estate to third-party tenants in immaterial amounts. Lease assets and liabilities recognized at the lease commencement date are determined predominantly as the present value of the payments due over the lease term. Unless the implicit rate can be determined, the Company uses its incremental borrowing rate on that date to calculate the present value. The incremental borrowing rate approximates the rate at which the Company could borrow, on a secured basis for a similar term, an amount equal to its lease payments in a similar economic environment. Effective October 1, 2019, when the Company is the lessee, all leases are recognized as lease liabilities and associated lease assets on the Consolidated Balance Sheet. Lease liabilities represent the Company’s obligation to make payments arising from the lease. Lease assets represent the Company’s right to use an underlying asset for the lease term and may also include advance payments, initial direct costs or lease incentives. Fixed and variable payments that depend upon an index or rate, such as the Consumer Price Index (CPI), are included in the recognition of lease assets and liabilities at the commencement-date rate. Other variable payments, such as common area maintenance, property and other taxes, utilities and insurance that are based on the lessor’s cost, are recognized in the Consolidated Income Statement in the period incurred. Operating lease expense is recorded on a straight-line basis over the lease term.
Goodwill, Intangible Assets and Long-Lived Assets	Goodwill, Intangible Assets and Long-Lived Assets Goodwill and intangible assets deemed to have indefinite lives are subject to an annual impairment test or more frequently if impairment indicators are present. Goodwill impairment is deemed to exist if the net book value of a reporting unit exceeds its estimated fair value. The goodwill impairment test is performed by comparing the fair value of a reporting unit with its carrying amount. An impairment charge should be recognized for the amount by which the carrying amount exceeds the reporting unit’s fair value; however, the loss recognized should not exceed the total amount of goodwill allocated to that reporting unit. There was no impairment of goodwill in fiscal years 2021, 2020 or 2019. The total purchase price of business acquisitions accounted for using the purchase method is allocated first to identifiable assets and liabilities based on estimated fair values. The excess of the purchase price over the fair value of net assets of purchased businesses is recorded as goodwill. Other definite-life intangible assets consist primarily of core technology and customer relationships. Core technology acquired by the Company is amortized over its estimated useful life on a straight-line basis. Some of the acquired customer relationships are amortized over their estimated useful lives in proportion to the economic benefits realized. This accounting policy generally results in accelerated amortization of such customer relationships as compared to the straight-line method. All other acquired customer relationships are amortized over their estimated useful lives on a straight-line basis. The Company tests long-lived assets, including definite life intangible assets, for impairment whenever events or changes in circumstances indicate that the carrying amount of such assets may not be recoverable. Impairment indicators include any significant changes in the manner of its use of the assets or the strategy of its overall business, significant negative industry or economic trends and significant decline in our share price for a sustained period. Determination of recoverability of long-lived assets is based on an estimate of the undiscounted future cash flows resulting from the use of the cash generating unit and its eventual disposition. Measurement of an impairment loss for long-lived assets, including definite life intangible assets that management expects to hold and use is based on the fair value of the cash generating unit. Long-lived assets, including definite life intangible assets, to be disposed of are reported at the lower of carrying amount or fair value less costs to sell. There was no impairment of long-lived assets in fiscal years 2021, 2020 or 2019.
Comprehensive Income	Comprehensive Income Comprehensive income, net of related taxes where applicable, includes, in addition to net income: (i) net change in fair value of available-for-sale (ii) net change in fair value of cash flow hedges; and (iii) net actuarial gains and losses on defined benefit plans.
Treasury Stock	Treasury Stock The Company repurchases its ordinary shares from time to time on the open market or in other transactions and holds such shares as treasury stock. The Company presents the cost to repurchase treasury stock as a reduction of equity.
Business Combinations	Business Combinations In accordance with business combinations accounting, assets acquired and liabilities assumed, as well as any contingent consideration that may be part of the acquisition agreement, are recorded at their respective fair values at the date of acquisition. The Company allocates the purchase price of acquired companies to the tangible and intangible assets acquired and liabilities assumed, as well as to in-process For acquisitions that include contingent consideration, the fair value is estimated on the acquisition date as the present value of the expected contingent payments, determined using weighted probabilities of possible payments. The Company remeasures the fair value of the contingent consideration at each reporting period until the contingency is resolved. Except for measurement period adjustments, the changes in fair value are recognized in the consolidated statements of income. The Company considers several factors when determining that contingent consideration liabilities are part of the purchase price, such as the following: the valuation of the acquisitions is not supported solely by the initial consideration paid, and the contingent consideration payments are not affected by employment termination. Any earn-out Although the Company believes the assumptions and estimates of fair value it has made in the past have been reasonable and appropriate, they are based in part on historical experience and information obtained from the management of the acquired companies and are inherently uncertain and subject to refinement. Critical estimates in valuing certain assets acquired and liabilities assumed include but are not limited to: future expected cash flows from license and service sales, maintenance, customer contracts and acquired developed technologies, expected costs to develop the in-process The Company estimates the fair values of its services, hardware, software license and maintenance obligations assumed. The estimated fair values of these performance obligations are determined utilizing a cost build-up build-up The Company may establish a valuation allowance for certain deferred tax assets and estimate the value of uncertain tax positions of a newly acquired entity. This process requires significant judgment and analysis.
Income Taxes	Income Taxes The Company records deferred income taxes to reflect the net tax effects of temporary differences between the carrying amounts of assets and liabilities for financial reporting and tax purposes. Deferred taxes are computed based on enacted tax rates anticipated to be in effect when the deferred taxes are expected to be paid or realized. A valuation allowance is provided for deferred tax assets if it is more likely than not, the Company will not be able to realize their benefit. In assessing the realizability of deferred tax assets, the Company considers whether it is more likely than not that some portion or all of the deferred tax assets will not be realized and adjust the valuation allowances accordingly. Factors considered in making this determination include the period of expiration of the tax asset, planned use of the tax asset, tax planning strategies and historical and projected taxable income as well as tax liabilities for the tax jurisdiction in which the tax asset is located. Valuation allowances will be subject to change in each future reporting period as a result of changes in one or more of these factors. Deferred tax liabilities and assets are classified as noncurrent on the balance sheet. Deferred tax liabilities also include anticipated withholding taxes due on subsidiaries’ earnings when paid as dividends to the Company. The Company recognizes the tax benefit from an uncertain tax position only if the weight of available evidence indicates that it is more likely than not that the position will be sustained on audit, including resolution of related appeals or litigation processes, if any. The tax benefits recognized in the financial statements from such a position is measured based on the largest benefit that has a greater than 50% likelihood of being realized upon ultimate settlement. Interest and penalties related to uncertain tax positions are recognized in the provision for income taxes. Significant judgment is required in evaluating the uncertain tax positions and determining the provision for income taxes. Although the Company believes its reserves are reasonable, no assurance can be given that the final tax outcome of these matters will not be different from that which is reflected in its historical income tax provisions and accruals. The Company adjusts these reserves in light of changing facts and circumstances, such as the closing of a tax audit, or changes in tax law. To the extent that the final tax outcome of these matters is different than the amounts recorded, such differences will affect the provision for income taxes in the period in which such determination is made. The provision for income taxes includes the effect of reserve provisions and changes to reserves that are considered appropriate. Please see Note 10 to the consolidated financial statements. The Company applies an estimated annual effective tax rate to its quarterly operating results to determine the interim provision for income tax expense. A change in judgment that impacts the measurement of a tax position taken in a prior year is recognized as a discrete item in the interim period in which the change occurs. In the event there is a significant unusual or infrequent item recognized in the quarterly operating results, the tax attributable to that item is recorded in the interim period in which it occurs. As a result, the Company’s quarterly effective tax rate may fluctuate throughout the course of a fiscal year.
Revenue Recognition	Revenue Recognition The Company recognizes revenue under the five-step methodology required under ASC 606, which requires the Company to identify the contract with the customer, identify the performance obligations in the contract, determine the transaction price, allocate the transaction price to the performance obligations identified, and recognize revenue when (or as) each performance obligation is satisfied. Revenue is recognized net of any revenue-based taxes assessed by a governmental authority that are both imposed on and concurrent with a specific revenue-producing transaction and collected by the Company from a customer (for example, sales, use and value added taxes). The Company’s primary revenue categories, related performance obligations, and associated recognition patterns are as follows: Revenue Recognition for projects As a significant portion of the Company’s revenue is satisfied over time as work progresses, the annual and quarterly operating results may be affected by the size and timing of the initiation of customer projects as well as the Company’s progress in completing such projects. Revenue Recognition for subsequent license fee Revenue Recognition for term-based license and perpetual license Revenue Recognition for maintenance Revenue Recognition for ongoing services — Revenue Recognition for managed services arrangements — end-to-end The revenue from managed services arrangements is recognized for each individual performance obligation according to its relevant revenue category, including but not limited to, revenue from the management of a customer’s operations, revenue from projects and revenue from ongoing support services. Revenue from the management of a customer’s operations pursuant to managed services arrangements, is recognized over time as services are performed, using one method of measuring performance such as time elapsed, output produced, volume of data processed or subscriber count that provides the most faithful depiction of the transfer of services, pursuant to the specific contract terms of the managed services arrangements. Typically, managed services arrangements are long term in duration and are not subject to significant seasonality. Revenue Recognition for third-party hardware software and services Arrangements with Multiple Performance Obligations offers its services in accordance with ASC 606. The determination of SSP requires the exercise of judgement. If a specific performance obligation is sold for a broad range of amounts (that is, the selling price is highly variable) or if the Company has not yet established a price for that good or service, and the good or service has not previously been sold on a standalone basis (that is, the selling price is uncertain), the Company applies the residual approach whereby all other performance obligations within a contract are first allocated a portion of the transaction price based upon their respective SSPs with any residual amount of transaction price allocated to the remaining specific performance obligation. Billing terms and conditions generally vary by contract category. Amounts are typically billed as work progresses in accordance with agreed-upon contractual terms, either at periodic intervals (e.g., monthly or quarterly) or upon achievement of contractual milestones. In cases where timing of revenue recognition significantly differs from the timing of invoicing, the Company considers whether a significant financing component exists. The Company elected to use the practical expedient in assessing the financing component in contracts where the time between cash collection and performance is less than one year. Accounts Receivable — Billed Accounts Receivable — Unbilled — Deferred Revenue — Assets Recognized from the Costs to Obtain a Contract with a Customer — pro-rata In certain circumstances where the Company enters into a contract with a customer for the provision of managed services for a defined period of time, the Company defers certain direct costs incurred at the inception of the contract. These costs include expenses incurred in association with the origination of a contract. In addition, if the revenue for a delivered item is not recognized because it is not separable from the undelivered item, then the Company also defers the cost of the delivered item. The deferred costs are amortized on a straight-line basis over the managed services period, or over the recognition period of the undelivered item. Revenue associated with these capitalized costs is deferred and is recognized over the same period.
Cost of Revenue	Cost of Revenue Cost of revenue consists of all costs associated with providing software licenses and services to customers, third-party hardware and software including identified losses on contracts. Estimated losses on contracts satisfied over time as work performed are recognized in the period in which the loss is identified. Cost of revenue also includes costs of third-party products associated with selling third-party computer hardware and software products to customers and other third-party services, when the related revenue is recorded at the gross amount. Customers purchasing third-party products and services from the Company generally do so in conjunction with the purchase of the Company’s software and services.
Research and Development	Research and Development Research and development expenditures consist of costs incurred in the development of new software modules and product offerings, either as part of the Company’s internal product development programs, which are sold, leased or otherwise marketed. Research and development costs are expensed as incurred. Based on the Company’s product development process, technological feasibility is established upon completion of a detailed program design or, in the absence thereof, completion of a working model. Costs incurred by the Company after achieving technological feasibility and before the product is ready for customer release have been insignificant.
Equity-Based Compensation	Equity-Based Compensation The Company measures and recognizes the compensation expense for all equity-based payments to employees and directors based on their estimated fair values. The Company estimates the fair value of employee stock options at the date of grant using a Black-Scholes valuation model and values restricted stock including performance restricted stock based on the market value of the underlying shares at the date of grant. The Company recognizes compensation costs using the graded vesting attribution method that results in an accelerated recognition of compensation costs in comparison to the straight-line method. Performance restricted stock are subject to certain performance criteria; accordingly, compensation expense is recognized for such awards when it becomes probable that the related performance condition will be satisfied. The Company uses a combination of implied volatility of the Company’s traded options and historical stock price volatility (“blended volatility”) as the expected volatility assumption required in the Black-Scholes option valuation model. As equity-based compensation expense recognized in the Company’s consolidated statements of income is based on awards ultimately expected to vest, it has been reduced for estimated forfeitures.
Concentrations of Credit Risk	Concentrations of Credit Risk Financial instruments that potentially subject the Company to concentration of credit risk consist principally of cash and cash equivalents, short-term interest-bearing investments, trade receivables and unbilled receivable. Cash and cash equivalents are maintained with several financial institutions. Generally, these deposits may be redeemed upon demand and are maintained with financial institutions with reputable credit and therefore bear minimal credit risk. The Company seeks to mitigate its credit risks by spreading such risks across multiple financial institutions and monitoring the risk profiles of these counterparties. The Company has conservative investment policy guidelines under which it invests its excess cash primarily in highly liquid U.S. dollar-denominated securities. The Company’s revenue is generated primarily in North America. To a lesser extent, revenue is generated in Europe and the rest of the world. Most of the Company’s customers are among the largest communications and media companies in the world (or are owned by them). The Company’s business is subject to the effects of general global economic conditions and market conditions in the communications industry. The Company performs ongoing credit analyses of its customer base and generally does not require collateral. The Company evaluates accounts receivable and unbilled receivables to determine if they ultimately will be collected. Significant judgments and estimates are involved in performing this evaluation, which are based on factors that may affect a customer’s ability to pay, such as past experience, credit quality of the customer, age of the receivable balance and current economic conditions, reasonable and supportable forecasts of future economic conditions, and other factors that may affect its ability to collect from customers. The allowance for doubtful accounts, net of credit losses is for expected credit losses resulting from accounts receivable and unbilled receivables for which their collection is not reasonably probable. The allowance for doubtful accounts as of September 30, 2021 and 2020, was $20,065 and $23,419, respectively. As of September 30, 2021, the Company had two customers with accounts receivable balances of more than 10% of total accounts receivable, aggregating to 40%. As of September 30, 2020, the Company had one customer with an accounts receivable balance of more than 10% of total accounts receivable, amounting to 22%, please see Note 21.
Earnings per Share	Earnings per Share Basic earnings per share is calculated using the weighted average number of shares outstanding during the period. Diluted earnings per share is computed on the basis of the weighted average number of shares outstanding and the effect of dilutive outstanding equity-based awards using the treasury stock method. The Company includes participating securities (unvested restricted shares that contain non-forfeitable two-class
Derivatives and Hedging	Derivatives and Hedging The Company carries out transactions involving foreign currency exchange derivative financial instruments. The transactions are designed to hedge the Company’s exposure in currencies other than the U.S. dollar. The Company recognizes derivative instruments as either assets or liabilities and measures those instruments at fair value. If a derivative meets the definition of a cash flow hedge and is so designated, changes in the fair value of the derivative are recognized in other comprehensive (loss) income until the hedged item is recognized in earnings. The ineffective portion of a derivative designated as a cash flow hedge is recognized in earnings. If a derivative does not meet the definition of a cash flow hedge, the changes in the fair value are included in earnings.
Recent Accounting Standards	Recent Accounting Standards In August 2021, the Financial Accounting Standards Board, or FASB, issued Accounting Standard Update, or ASU No. 2021-08, Business Combinations (Topic 805): Accounting for Contract Assets and Contract Liabilities from Contracts with Customers”. In March 2020, the FASB issued ASU No. 2020-04, Reference Rate Reform: Facilitation of the Effects of Reference Rate Reform on Financial Reporting”.
Adoption of New Accounting Standards	Adoption of New Accounting Standards In December 2019, the FASB issued ASU No. 2019-12, Simplifying the Accounting for Income Taxes In November 2018, the FASB issued ASU No. 2018-18 , “Collaborative Arrangements In August 2018, the FASB issued ASU No. 2018-15 , “Customer’s Accounting for Implementation Costs Incurred in a Cloud Computing Arrangement That Is a Service Contract”. The ASU amends the definition of hosting arrangement and requires a customer in a hosting arrangement that is a service contract to capitalize certain implementation costs as if the arrangement was an internal-use software project. The Company prospectively adopted this ASU effective October , . As of the date of the adoption there was no material impact on the Company’s consolidated financial statements. In August 2018, the FASB issued ASU No. 2018-13 , “Fair Value Measurement”. In August 2018, the FASB issued ASU No. 2018-14, Changes to the Disclosure Requirements for Defined Benefit Plans” In August 2017, the FASB issued ASU No. 2017-12, Targeted Improvements to Accounting for Hedging Activities ” In January 2017, the FASB issued ASU No. 2017-04, “Simplifying the Test for Goodwill Impairment” In June 2016, the FASB issued ASU No. 2016-13, Measurement of Credit Losses on Financial Instruments ” available-for-sale available-for-sale

Revenue (Tables)

Revenue (Tables)	12 Months Ended
Revenue (Tables)	Sep. 30, 2021
Revenue from Contract with Customer [Abstract]
Summary of Accounts Receivable and Deferred Revenue	The following table provides information about Accounts receivable, both billed and unbilled and deferred revenue: As of September 30, 2021 September 30, 2020 Accounts receivable — $ 704,541 $ 685,485 Accounts receivable — $ 162,278 $ 175,548 Accounts receivable — (non-current) $ 38,252 $ 42,089 Total Accounts receivable — $ 200,530 $ 217,637 Deferred revenue (current) $ (237,374 ) $ (126,841 ) Deferred revenue (non-current) $ (108,675 ) $ (16,529 ) Total Deferred revenue $ (346,049 ) $ (143,370 )

Fair Value Measurements (Tables

Fair Value Measurements (Tables)	12 Months Ended
Fair Value Measurements (Tables)	Sep. 30, 2021
Fair Value Disclosures [Abstract]
Fair Value Measurement on Company's Assets and Liabilities	The following tables present the Company’s assets and liabilities measured at fair value on a recurring basis as of September 30, 2021 and 2020: As of September 30, 2021 Level 1 Level 2 Level 3 Total Available-for-sale Money market funds $ 209,026 $ — $ — $ 209,026 Corporate bonds — 190,437 — 190,437 U.S. government treasuries 54,752 — — 54,752 Supranational and sovereign debt — 7,453 — 7,453 Asset backed obligations — 3,885 — 3,885 Total available-for-sale 263,778 201,775 — 465,553 Equity Investments — — 37,581 37,581 Derivative financial instruments, net — 10,979 — 10,979 Other liabilities — — (51,590 ) (51,590 ) Total $ 263,778 $ 212,754 $ (14,009 ) $ 462,523 As of September 30, 2020 Level 1 Level 2 Level 3 Total Available-for-sale Money market funds $ 558,633 $ — $ — $ 558,633 Corporate bonds — 752 — 752 Total available-for-sale 558,633 752 — 559,385 Equity Investments — — 24,211 24,211 Derivative financial instruments, net — 20,636 — 20,636 Other liabilities — — (19,641 ) (19,641 ) Total $ 558,633 $ 21,388 $ 4,570 $ 584,591

Available-For-Sale Securities (

Available-For-Sale Securities (Tables)	12 Months Ended
Available-For-Sale Securities (Tables)	Sep. 30, 2021
Investments, Debt and Equity Securities [Abstract]
Interest-Bearing Investments in Available-for-Sale Securities	Available-for-sale As of September 30, 2021 Amortized Gross Gross Fair Value Money market funds $ 209,026 $ — $ — $ 209,026 Corporate bonds 191,445 76 1,084 190,437 U.S. government treasuries 54,987 4 239 54,752 Supranational and sovereign debt 7,479 — 26 7,453 Asset backed obligations 3,890 — 5 3,885 Total(1) $ 466,827 $ 80 $ 1,354 $ 465,553 (1) Available-for-sale available-for-sale As of September 30, 2020 Amortized Gross Gross Fair Value Money market funds $ 558,633 $ — $ — $ 558,633 Corporate bonds 754 — 2 752 Total(1) $ 559,387 $ — $ 2 $ 559,385 (1) Available-for-sale available-for-sale
Available-for-Sale Securities Debt Maturities Market Value	As of September 30, 2021, the Company’s available-for-sale Market Value Due within one year $ 226,990 1 to 2 years 19,080 2 to 3 years 58,270 3 to 4 years 94,188 Thereafter 67,025 $ 465,553

Derivative Financial Instrume_2

Derivative Financial Instruments (Tables)	12 Months Ended
Derivative Financial Instruments (Tables)	Sep. 30, 2021
Derivative Instruments and Hedging Activities Disclosure [Abstract]
Notional Amounts of Derivative Instruments	The table below presents the total volume or notional amounts of the Company’s derivative instruments as of September 30, 2021. Notional values are in U.S. dollars and are translated and calculated based on forward rates as of September 30, 2021 for forward contracts, and based on spot rates as of September 30, 2021 for options. Notional Value* Foreign exchange contracts $ 1,260,450 (*) Gross notional amounts do not quantify risk or represent assets or liabilities of the Company but are used in the calculation of settlements under the contracts.
Fair Value of Open Foreign Currency Exchange Contracts	The Company records all derivative instruments on the balance sheet at fair value. For further information, please see Note 5 to the consolidated financial statements. The fair value of the open foreign exchange contracts recorded as an asset or a liability by the Company on its consolidated balance sheets as of September 30, 2021 and September 30, 2020, is as follows: As of September 30, 2021 2020 Derivatives designated as hedging instruments Prepaid expenses and other current assets $ 6,962 $ 21,153 Other noncurrent assets 3,068 1,317 Accrued expenses and other current liabilities (70 ) (2,089 ) 9,960 20,381 Derivatives not designated as hedging instruments Prepaid expenses and other current assets 4,230 3,068 Accrued expenses and other current liabilities (3,211 ) (2,813 ) 1,019 255 Net fair value $ 10,979 $ 20,636
Effect of Cash Flow Hedging Instruments	The effect of the Company’s cash flow hedging instruments in the consolidated statements of income for the fiscal years ended September 30, 2021, 2020 and 2019, respectively, which partially offsets the foreign currency impact from the underlying exposures, is summarized as follows: Gains (Losses) Reclassified from Accumulated Other Comprehensive Income (Loss) (Effective Portion) Year Ended September 30, 2021 2020 2019 Line item in consolidated statements of income: Revenue $ (473 ) $ 834 $ 19 Cost of revenue 20,209 4,166 (8,627 ) Research and development 6,069 1,646 (2,059 ) Selling, general and administrative 6,347 2,500 (2,309 ) Total $ 32,152 $ 9,146 $ (12,976 )
Changes in Net Unrealized Gains (Losses) on Cash Flow Hedges	The activity related to the changes in net unrealized gains (losses) on cash flow hedges recorded in accumulated other comprehensive income (loss), net of tax, is as follows: Year Ended September 30, 2021 2020 2019 Net unrealized gain (loss) on cash flow hedges, net of tax, beginning of period $ 18,836 $ 3,945 $ (26,608 ) Changes in fair value of cash flow hedges, net of tax 24,239 21,903 19,228 Reclassification of (gain) loss into earnings, net of tax (29,302 ) (7,012 ) 11,325 Net unrealized gain (loss) on cash flow hedges, net of tax, end of period $ 13,773 $ 18,836 $ 3,945
Effect of Non-Designated as Hedging Instruments	The effect of the Company’s derivative instruments not designated as hedging instruments in the consolidated statements of income for the fiscal years ended September 30, 2021, 2020 and 2019, respectively, which partially offsets the foreign currency impact from the underlying exposure, is summarized as follows: Gains (Losses) 2021 2020 2019 Line item in statements of income: Cost of revenue $ 4,786 $ (718 ) $ 401 Research and development 1,187 (341 ) 14 Selling, general and administrative 1,301 (559 ) 294 Interest and other expense, net 1,808 255 5,845 Income taxes (3,125 ) (679 ) (528 ) Total $ 5,957 $ (2,042 ) $ 6,026

Property and Equipment, Net (Ta

Property and Equipment, Net (Tables)	12 Months Ended
Property and Equipment, Net (Tables)	Sep. 30, 2021
Property, Plant and Equipment [Abstract]
Components of Property and Equipment, Net	The components of property and equipment, net are: As of September 30, 2021 2020 Computers, related equipment and software $ 1,195,787 $ 1,163,807 Building and land 291,262 177,255 Leasehold improvements 244,858 234,777 Furniture, fixtures and other 55,353 51,831 Property and equipment, gross 1,787,260 1,627,670 Less accumulated depreciation (1,088,492 ) (1,019,719 ) Property and equipment, net $ 698,768 $ 607,951 (1) For more details, please see also note 2.

Goodwill and Intangible Asset_2

Goodwill and Intangible Assets, Net (Tables)	12 Months Ended
Goodwill and Intangible Assets, Net (Tables)	Sep. 30, 2021
Goodwill and Intangible Assets Disclosure [Abstract]
Details of Total Goodwill	The following table presents details of the Company’s total goodwill: As of September 30, 2019 $ 2,462,835 Goodwill resulting from acquisitions 118,628 Other (2,818 ) As of September 30, 2020 $ 2,578,645 Goodwill resulting from acquisitions 104,151 Decrease in goodwill as a result of divestiture (61,396 ) Other 1,244 As of September 30, 2021 $ 2,622,644 (1) Mainly relates to the acquisition of Openet. In allocating the total purchase price for Openet, based on estimated fair values, the Company recorded $110,347 of goodwill, $40,409 of customer relationships to be amortized over approximately eight years, $53,614 of core technology to be amortized over five years and $2,594 of trademark to be amortized over two years. (2) Mainly relates to the acquisition of Sourced. In allocating the total preliminary purchase price for Sourced, based on estimated fair values, the Company recorded $80,055 of goodwill, $18,211 of customer relationships to be amortized over approximately seven years and $3,056 of core technology to be amortized over three years. (3) Relates to the divestiture of OpenMarket completed on December 31, 2020, please see also Note 3.
Details Regarding Total Definite-Lived Purchased Intangible Assets	The following table p r Gross Accumulated Net September 30, 2021 Core technology $ 896,149 $ (777,419 ) $ 118,730 Customer relationships 689,754 (556,716 ) 133,038 Other 47,540 (40,276 ) 7,264 Total $ 1,633,443 $ (1,374,411 ) $ 259,032 September 30, 2020 Core technology $ 896,814 $ (735,534 ) $ 161,280 Customer relationships 642,575 (517,670 ) 124,905 Other 47,540 (37,391 ) 10,149 Total $ 1,586,929 $ (1,290,595 ) $ 296,334
Estimated Future Amortization Expense	The estimated future amortization expense of definite-lived purchased intangible assets as of September 30, 2021 is as follows: Amount Fiscal year: 2022 $ 72,119 2023 54,156 2024 45,882 2025 41,930 2026 25,505 Thereafter 19,440 Total $ 259,032

Income Taxes (Tables)

Income Taxes (Tables)	12 Months Ended
Income Taxes (Tables)	Sep. 30, 2021
Income Tax Disclosure [Abstract]
Provision (benefit) for Income Taxes	The provision (benefit) for income taxes consists of the following: Year Ended September 30, 2021 2020 2019 Current $ 176,537 $ 55,243 $ 102,391 Deferred (50,605 ) 30,239 (13,950 ) Income taxes $ 125,932 $ 85,482 $ 88,441
Components of Deferred Tax Assets and Liabilities	Deferred income taxes are comprised of the following components: As of September 30, 2021 2020 Deferred tax assets: Deferred revenue $ 25,282 $ 25,252 Employee compensation and benefits 76,020 75,689 Intangible assets, computer software and intellectual property 75,200 18,705 Tax credits, net capital and operating loss carryforwards 156,209 142,718 Lease liabilities 50,780 71,204 Other 46,372 52,611 Total deferred tax assets 429,863 386,179 Valuation allowances (65,550 ) (69,455 ) Total deferred tax assets, net 364,313 316,724 Deferred tax liabilities: Anticipated withholdings on subsidiaries’ earnings (84,755 ) (81,489 ) Intangible assets, computer software and intellectual property (109,526 ) (114,772 ) Lease assets (47,822 ) (69,215 ) Other (97,638 ) (90,825 ) Total deferred tax liabilities (339,741 ) (356,301 ) Net deferred tax assets (liabilities) $ 24,572 $ (39,577 )
Effective Income Tax Rate Varied from Statutory Guernsey Tax Rate	The effective income tax rate varied from the statutory Guernsey tax rate as follows: Year Ended September 30, 2021 2020 2019 Statutory Guernsey tax rate 0 % 0 % 0 % Foreign taxes 15.5 14.7 15.6 Effective income tax rate 15.5 % 14.7 % 15.6 % As a Guernsey company subject to a corporate tax rate of zero percent, the Company’s overall effective tax rate is attributable to foreign taxes. The Company’s income before income tax expense is considered to be foreign income. (1) Foreign taxes for the year ended Sep 30, 2021: In fiscal year 2021, foreign taxes included an expense of $39,596 for the estimated additional tax charge as a result of the gain from sale of a business, please see also Note 3. Foreign taxes in fiscal year 2021 also included a benefit of $10,933 resulting from internal structural changes in certain jurisdictions in which the Company operates. Foreign taxes in fiscal year 2021 also included a total amount of releases, net of additions related to prior years, of gross unrecognized tax benefits of $7,701 relating to effectively settled arrangements with tax authorities, changes in facts and circumstances resulting in a change in measurement of certain positions and expiration of the periods set forth in statutes of limitations in certain jurisdictions. The net release was offset by decrease in tax assets and as a result the net impact on income tax expense for fiscal year 2021 was not material. Foreign taxes in fiscal year 2021 also included a benefit of $6,006 resulting from the release of valuation allowances on deferred tax assets at certain of the Company’s subsidiaries, which will, more likely than not, be realized due to the Company’s projections of future taxable income. (1) Foreign taxes for the year ended Sep 30, 2020: In fiscal year 2020, foreign taxes included a total amount of releases of gross unrecognized tax benefits of $47,582 relating to effectively settled arrangements with tax authorities, changes in facts and circumstances resulting in a change in measurement of certain positions and expiration of the periods set forth in statutes of limitations in certain jurisdictions. The majority of the release was offset by decrease in tax assets and increase in tax liabilities and as a result a net benefit of $14,971 was included within income tax expense for fiscal year 2020. Foreign taxes in fiscal year 2020 also included a benefit of $15,438 resulting from the release of valuation allowances on deferred tax assets at certain of the Company’s subsidiaries, which will, more likely than not, be realized due to the Company’s projections of future taxable income. On March 27, 2020, the U.S. government enacted the Coronavirus Aid, Relief, and Economic Security Act (“CARES Act”) to provide certain relief as a result of the COVID-19 tax-related Foreign taxes in fiscal year 2020 also included a tax benefit of $4,964 resulting from tax enactments related to the COVID-19 (1) Foreign taxes for the year ended Sep 30, 2019: In fiscal year 2019, foreign taxes included a benefit of $ that was primarily attributable to the expiration of the periods set forth in statutes of limitations and to a lesser extent from the conclusions of tax audits related to unrecognized tax benefits accumulated over several years in certain jurisdictions. Foreign taxes in fiscal year 2019 also included a benefit of $12,650 resulting from the release of valuation allowances on deferred tax assets at certain of the Company’s subsidiaries, which will, more likely than not, be realized due to the Company’s projections of future taxable income.
Aggregate Changes in Balance of Company's Gross Unrecognized Tax Benefits	The aggregate changes in the balance of the Company’s gross unrecognized tax benefits were as follows: Year Ended September 30, 2021 2020 2019 Balance at beginning of fiscal year $ 168,186 $ 169,322 $ 187,646 Additions based on tax positions related to the current year 25,662 23,154 19,530 Additions for tax positions of prior years 23,849 23,292 27,558 Reductions for tax positions of prior years (7,467 ) (15,214 ) (2,578 ) Settlements with tax authorities (10,245 ) (29,400 ) (37,672 ) Lapse of statute of limitations (4,789 ) (2,968 ) (25,162 ) Balance at end of fiscal year $ 195,196 $ 168,186 $ 169,322 (1) The changes in the year ended September 30, 2021, in the balance of the Company’s gross unrecognized tax benefits that relate to settlements with tax authorities is $10,245, the majority of which was offset by decrease in Tax Receivables and Deferred Tax Assets.

Accrued Expenses and Other Cu_2

Accrued Expenses and Other Current Liabilities (Tables)	12 Months Ended
Accrued Expenses and Other Current Liabilities (Tables)	Sep. 30, 2021
Accrued expenses and Other Current Liabilities [Abstract]
Schedule of Accrued Expenses and Other Current Liabilities	Accrued expenses and other current liabilities consist of the following: As of September 30, 2021 2020 Ongoing accrued expenses $ 206,905 $ 217,133 Project-related provisions 125,612 121,658 Taxes payable 34,717 25,739 Dividends payable(1) 44,956 43,084 Derivative instruments(2) 3,281 4,902 Other 196,832 181,092 $ 612,303 $ 593,608 (1) The amounts payable as a result of the August 4, 2021 and the August 5, 2020 dividend declarations, please see Note 19 to the consolidated financial statements. (2) Includes derivatives that are designated as hedging instruments and derivatives that are not designated as hedging instruments, please see Note 7 to the consolidated financial statements.

Interest and other expense, n_2

Interest and other expense, net (Tables)	12 Months Ended
Interest and other expense, net (Tables)	Sep. 30, 2021
Interest and other expense, net
Interest and Other Expense, Net	Interest and other expense, net, consists of the following: Year Ended September 30, 2021 2020 2019 Interest income $ (4,822 ) $ (4,233 ) $ (6,225 ) Interest expense 21,275 10,427 3,911 Foreign exchange loss 1,110 3,382 7,860 Other, net (6,766 ) 1,860 (3,687 ) $ 10,797 $ 11,436 $ 1,859 (1) For further details, please see Note 12 to the consolidated financial statements.

Leases (Tables)

Leases (Tables)	12 Months Ended
Leases (Tables)	Sep. 30, 2021
Leases [Abstract]
Disclosure of Lease Cost	Lease costs were as follows : Year Ended September 30, 2021 2020 Total net lease cost $ 97,169 $ 91,025 (1) Variable lease cost is immaterial.
Summary of Supplemental Information Related to Operating Lease	Supplemental information related to operating lease transactions was as follows: Year Ended September 30, 2021 2020 Lease liability payments $ 79,028 $ 88,272 Lease assets obtained in exchange for liabilities $ 14,580 $ 87,820 As of September 30, 2021 2020 Weighted average remaining lease term — Operating leases 6.4 Years 6.8 Years Weighted average discount rate — Operating leases 3.7 % 3.5 %
Future Undiscounted Cash Outflows for Operating Leases Maturity	The following maturity analysis presents future undiscounted cash outflows for operating leases as of September 30, 2021: For the year ended September 30, 2022 $ 66,791 2023 44,187 2024 34,473 2025 28,173 2026 22,814 Thereafter 86,134 Total lease payments $ 282,572 Less: imputed interest (45,952 ) Present value of lease liabilities $ 236,620

Stock Option and Incentive Pl_2

Stock Option and Incentive Plan (Tables)	12 Months Ended
Stock Option and Incentive Plan (Tables)	Sep. 30, 2021
Disclosure of Stock Option and Incentive Plan [Abstract]
Summary of Option Activity	The following table summarizes information about options to purchase the Company ’ Number of Weighted Average Outstanding as of October 1, 2020 5,716 $ 60.26 Granted 62 60.77 Exercised (1,541 ) 57.81 Forfeited (249 ) 63.63 Outstanding as of September 30, 2021(1) 3,988 $ 61.00 Exercisable as of September 30, 2021(1) 2,119 $ 57.55 (1) As of September 30, 2021, the weighted average remaining contractual life of outstanding and exercisable options was 6.42 and 5.40 years, respectively.
Summary of Restricted Shares Activity	The following table summarizes information relating to awards of restricted shares, as well as changes during the fiscal year ended September 30, 2021: Number of Weighted Average Outstanding as of October 1, 2020 1,097 $ 66.57 Granted 1,032 66.83 Vested (426 ) 65.40 Forfeited (116 ) 67.84 Outstanding as of September 30, 2021 1,587 $ 66.96
Employee Equity-Based Compensation Pre-Tax Expense	Employee pre-tax Year Ended September 30, 2021 2020 2019 Cost of revenue $ 22,691 $ 20,005 $ 19,879 Research and development 4,021 3,058 2,714 Selling, general and administrative 27,537 19,371 15,957 Total $ 54,249 $ 42,434 $ 38,550
Assumptions Used in Calculating Fair Value of Options	The fair value of options granted was estimated on the date of grant using the Black-Scholes pricing model with the assumptions noted in the following table (all in weighted averages for options granted during the year): Year Ended September 30, 2021 2020 2019 Risk-free interest rate(1) 0.30 % 1.41 % 2.64 % Expected life of stock options(2) 4.50 4.50 4.50 Expected volatility(3) 21.3 % 17.3 % 17.8 % Expected dividend yield(4) 2.22 % 1.75 % 1.82 % Fair value per option $ 7.82 $ 8.85 $ 9.13 (1) Risk-free interest rate is based upon U.S. Treasury yield curve appropriate for the term of the Company’s employee stock options. (2) Expected life of stock options is based upon historical experience. (3) Expected volatility is based on blended volatility. (4) Expected dividend yield is based on the Company’s history and future expectation of dividend payouts.

Dividends (Tables)

Dividends (Tables)	12 Months Ended
Dividends (Tables)	Sep. 30, 2021
Other Liabilities Disclosure [Abstract]
Summary of Dividends Declared by Board of directors	The Company’s Board of Directors declared the following dividends during the fiscal years ended September 30, 2021, 2020 and 2019: Declaration Date Dividends Per Record Date Total Amount Payment Date August 4, 2021 $ 0.36 September 30, 2021 $ 44,956 October 29, 2021 May 12, 2021 $ 0.36 June 30, 2021 $ 45,580 July 23, 2021 February 2, 2021 $ 0.36 March 31, 2021 $ 45,958 April 23, 2021 November 10, 2020 $ 0.3275 December 31, 2020 $ 42,850 January 22, 2021 August 5, 2020 $ 0.3275 September 30, 2020 $ 43,084 October 23, 2020 May 7, 2020 $ 0.3275 June 30, 2020 $ 43,568 July 24, 2020 February 4, 2020 $ 0.3275 March 31, 2020 $ 43,723 April 24, 2020 November 12, 2019 $ 0.285 December 31, 2019 $ 38,357 January 24, 2020 August 7, 2019 $ 0.285 September 30, 2019 $ 38,413 October 25, 2019 May 14, 2019 $ 0.285 June 28, 2019 $ 38,730 July 19, 2019 February 5, 2019 $ 0.285 March 29, 2019 $ 39,084 April 19, 2019 November 8, 2018 $ 0.250 December 31, 2018 $ 34,755 January 18, 2019

Earnings Per Share (Tables)

Earnings Per Share (Tables)	12 Months Ended
Earnings Per Share (Tables)	Sep. 30, 2021
Earnings Per Share [Abstract]
Computation of Basic and Diluted Earnings Per Share	The following table sets forth the computation of basic and diluted earnings per share: Year Ended September 30, 2021 2020 2019 Numerator: Net income $ 688,374 $ 497,840 $ 479,446 Net income and dividends attributable to participating restricted shares (7,052 ) (3,663 ) (3,295 ) Numerator for basic earnings per common share $ 681,322 $ 494,177 $ 476,151 Undistributed income allocated to participating restricted shares 5,199 2,417 2,252 Undistributed income reallocated to participating restricted shares (5,167 ) (2,406 ) (2,240 ) Numerator for diluted earnings per common share $ 681,354 $ 494,188 $ 476,163 Denominator: Weighted average number of shares outstanding — basic 128,495 133,590 137,418 Weighted average number of participating restricted shares (1,316 ) (983 ) (944 ) Weighted average number of common shares — basic 127,179 132,607 136,474 Effect of dilutive stock options granted 789 642 691 Weighted average number of common shares — diluted 127,968 133,249 137,165 Basic earnings per common share $ 5.36 $ 3.73 $ 3.49 Diluted earnings per common share $ 5.32 $ 3.71 $ 3.47

Segment Information and Sales_2

Segment Information and Sales to Significant Customers (Tables)	12 Months Ended
	Sep. 30, 2021
Segment Reporting [Abstract]
Summary of Revenue by Geographic Area	Year Ended September 30, 2021 2020 2019 Revenue North America (mainly United States) $ 2,791,472 $ 2,720,911 $ 2,582,719 Europe 622,780 613,751 598,731 Rest of the world 874,388 834,377 905,219 Total $ 4,288,640 $ 4,169,039 $ 4,086,669
Summary of Long-Lived Assets by Geographic Area	As of September 30, 2021 2020 Long-lived Assets (1) Europe $ 182,746 $ 211,292 North America 94,149 104,918 Rest of the world: Israel (2) 358,329 237,561 India 48,326 38,706 Others 15,218 15,474 Total $ 698,768 $ 607,951 (1) Property and equipment, net. (2) For more details, please see also note 2
Revenue by Nature of Activities	Revenue by nature of activities Year Ended September 30, 2021 2020 2019 Managed services arrangements $ 2,546,330 $ 2,398,691 $ 2,246,279 Others 1,742,310 1,770,348 1,840,390 Total $ 4,288,640 $ 4,169,039 $ 4,086,669
Summary Sales to Significant Customers	The following table summarizes the percentage of sales to significant customer groups which accounted for at least ten percent of its total revenue in each of fiscal years 2021, 2020 and 2019. Year Ended September 30, 2021 2020 2019 Revenue Customer 1 25.0 % 25.8 % 23.4 % Customer 2 (*) 19.1 % 12.1 % () * Represents an amount of less than 10%. ** Starting April 1, 2020, following the merger of two significant customers, their respective revenue was consolidated. See also ITEM 5 — “The Amdocs Offerings.”

Selected Quarterly Results of_2

Selected Quarterly Results of Operations (Unaudited) (Tables)	12 Months Ended
	Sep. 30, 2021
Quarterly Financial Information Disclosure [Abstract]
Quarterly Results of Operations	The following are details of the unaudited quarterly results of operations for the three months ended: September 30, June 30, March 31, December 31, 2021 Revenue $ 1,087,309 $ 1,066,254 $ 1,048,734 $ 1,086,343 Operating income 154,330 154,919 149,244 140,200 Net income 123,525 146,150 119,067 299,632 Basic earnings per share 0.98 1.15 0.92 2.29 Diluted earnings per share 0.97 1.14 0.91 2.28 2020 Revenue $ 1,052,948 $ 1,026,201 $ 1,047,933 $ 1,041,957 Operating income 146,938 147,531 156,712 143,577 Net income 134,463 120,407 127,038 115,932 Basic earnings per share 1.02 0.90 0.95 0.86 Diluted earnings per share 1.01 0.90 0.94 0.85

Valuation and Qualifying Acco_2

Valuation and Qualifying Accounts (Tables)	12 Months Ended
Valuation and Qualifying Accounts (Tables)	Sep. 30, 2021
SEC Schedule, 12-09, Valuation and Qualifying Accounts [Abstract]
Valuation And Qualifying Accounts Disclosure Table Text Block	Accounts Receivable Valuation Allowances on Balance as of September 30, 2018 $ 21,211 $ 112,727 Charged to costs and expenses 22,260 1,009 Charged to other accounts 2,406 6,008 (1) Deductions (9,756 )(3) (34,211 )(2) Balance as of September 30, 2019 36,121 85,533 Charged to costs and expenses 18,465 8,521 Charged to other accounts (3,523 ) 1,005 (1) Deductions (27,644 )(5) (25,604 )(4) Balance as of September 30, 2020 23,419 69,455 Charged to costs and expenses 10,345 6,382 Charged to other accounts 156 3,720 (1) Deductions (13,855 )(7) (14,007 )(6) Balance as of September 30, 2021 $ 20,065 $ 65,550 (1) Includes valuation allowances on deferred tax assets incurred in connection with an acquisition. (2) $7,588 of valuation allowances on deferred tax assets were written off against the related deferred tax assets, and the remaining deductions in the valuation allowances on net deferred tax assets were released to earnings. (3) $3,539 of accounts receivable allowances were written off against the related accounts receivables, and the remaining deductions in the accounts receivable allowances were released to earnings. (4) $2,283 of valuation allowances on deferred tax assets were written off against the related deferred tax assets, and the remaining deductions in the valuation allowances on net deferred tax assets were released to earnings. (5) $4,969 of accounts receivable allowances were written off against the related accounts receivables, $7,089 were written off against deferred revenue and the remaining deductions in the accounts receivable allowances were released to earnings. (6) $1,557 of valuation allowances on deferred tax assets were written off against the related deferred tax assets, and the remaining deductions in the valuation allowances on net deferred tax assets were released to earnings. (7) $8,486 of accounts receivable allowances were written off against the related accounts receivables, and the remaining deductions in the accounts receivable allowances were released to earnings.

Nature of Entity - Additional I

Nature of Entity - Additional Information (Detail) - Segment	12 Months Ended
	Sep. 30, 2021	Sep. 30, 2020	Sep. 30, 2019
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Number of operating segment	1	1	1

Summary of Significant Accoun_3

Summary of Significant Accounting Policies - Consolidation and Property and Equipment - Additional Information (Detail) - USD ($) $ in Thousands	12 Months Ended
	Sep. 30, 2021	Sep. 30, 2020	Sep. 30, 2019
Property and Equipment, Net [Line Items]
Property and equipment, Depreciation methods	straight-line method
Impairment of long-lived assets	$ 0	$ 0	$ 0
Minimum [Member]
Property and Equipment, Net [Line Items]
Estimated useful life of assets	3 years
Maximum [Member]
Property and Equipment, Net [Line Items]
Estimated useful life of assets	10 years

Summary of Significant Accoun_4

Summary of Significant Accounting Policies - Revenue Recognition and Concentrations of Credit Risk - Additional Information (Detail) $ in Thousands	12 Months Ended
	Sep. 30, 2021USD ($)Customer	Sep. 30, 2020USD ($)Customer
Concentration Risk [Line Items]
Number of customers with an account receivable balance of more than 10% of total accounts receivable \| Customer	2	1
Allowance for doubtful accounts \| $	$ 20,065	$ 23,419
Accounts Receivable [Member] \| Customer [Member]
Concentration Risk [Line Items]
Aggregate account receivable of more than 10% of total accounts receivable	40.00%	22.00%

Acquisitions and Divestiture _2

Acquisitions and Divestiture of a Subsidiary - Additional Information (Detail) $ in Thousands	Nov. 10, 2020USD ($)	Sep. 30, 2021USD ($)Business	Sep. 30, 2020USD ($)Business
Acquisitions and Divestiture of a Subsidiary [Line Items]
Business acquisition		$ 101,864	$ 280,808
Number of businesses acquired \| Business		3	3
Signed agreement for the divestiture of Open Market	$ 300,000
Business divestiture pre-tax gain		$ 226,410
Disposal Group, Including Discontinued Operation, Net assets		9,194
Disposal Group, Including Discontinued Operation, Goodwill		$ 61,396

Revenue - Summary of Accounts R

Revenue - Summary of Accounts Receivable Billed and Unbilled and Deferred Revenue (Detail) - USD ($) $ in Thousands	Sep. 30, 2021	Sep. 30, 2020
Revenue from Contract with Customer [Abstract]
Accounts receivable —billed (net of allowances for doubtful accounts of $20,065 and $23,419 as of September 30, 2021 and 2020, respectively)	$ 704,541	$ 685,485
Accounts receivable — unbilled (current)	162,278	175,548
Accounts receivable — unbilled (non-current)	38,252	42,089
Total Accounts receivable — unbilled	200,530	217,637
Deferred revenue (current)	(237,374)	(126,841)
Deferred revenue (non-current)	(108,675)	(16,529)
Total Deferred revenue	$ (346,049)	$ (143,370)

Revenue - Summary of Accounts_2

Revenue - Summary of Accounts Receivable Billed and Unbilled and Deferred Revenue (Parenthetical) (Detail) - USD ($) $ in Thousands	Sep. 30, 2021	Sep. 30, 2020
Revenue from Contract with Customer [Abstract]
Allowance for doubtful accounts	$ 20,065	$ 23,419

Revenue - Additional Informatio

Revenue - Additional Information (Detail) - USD ($) $ in Thousands	12 Months Ended
	Sep. 30, 2021	Sep. 30, 2020
Deferred revenue recognized	$ 115,474	$ 104,648
Unsatisfied remaining performance obligations	$ 6,700,000
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2021-10-01
Remaining performance obligation, expected timing of recognized	3 years

Fair Value Measurements - Fair

Fair Value Measurements - Fair Value Measurement on Company's Assets and Liabilities (Detail) - USD ($) $ in Thousands	Sep. 30, 2021	Sep. 30, 2020
Available-for-sale securities:
Fair value, Measured on recurring basis, Investments	$ 465,553	$ 559,385
Money Market Funds [Member]
Available-for-sale securities:
Fair value, Measured on recurring basis, Investments	209,026	558,633
Corporate Bonds [Member]
Available-for-sale securities:
Fair value, Measured on recurring basis, Investments	190,437	752
U.S. Government Treasuries [Member]
Available-for-sale securities:
Fair value, Measured on recurring basis, Investments	54,752
Asset Backed Obligations [Member]
Available-for-sale securities:
Fair value, Measured on recurring basis, Investments	3,885
Supranational and Sovereign Debt [Member]
Available-for-sale securities:
Fair value, Measured on recurring basis, Investments	7,453
Recurring [Member]
Available-for-sale securities:
Fair value, Measured on recurring basis, Investments	465,553	559,385
Equity Investments	37,581	24,211
Derivative financial instruments, net	10,979	20,636
Other liabilities	(51,590)	(19,641)
Total	462,523	584,591
Recurring [Member] \| Money Market Funds [Member]
Available-for-sale securities:
Fair value, Measured on recurring basis, Investments	209,026	558,633
Recurring [Member] \| Corporate Bonds [Member]
Available-for-sale securities:
Fair value, Measured on recurring basis, Investments	190,437	752
Recurring [Member] \| U.S. Government Treasuries [Member]
Available-for-sale securities:
Fair value, Measured on recurring basis, Investments	54,752
Recurring [Member] \| Asset Backed Obligations [Member]
Available-for-sale securities:
Fair value, Measured on recurring basis, Investments	3,885
Recurring [Member] \| Supranational and Sovereign Debt [Member]
Available-for-sale securities:
Fair value, Measured on recurring basis, Investments	7,453
Level 1 [Member] \| Recurring [Member]
Available-for-sale securities:
Fair value, Measured on recurring basis, Investments	263,778	558,633
Total	263,778	558,633
Level 1 [Member] \| Recurring [Member] \| Money Market Funds [Member]
Available-for-sale securities:
Fair value, Measured on recurring basis, Investments	209,026	558,633
Level 1 [Member] \| Recurring [Member] \| U.S. Government Treasuries [Member]
Available-for-sale securities:
Fair value, Measured on recurring basis, Investments	54,752
Level 2 [Member] \| Recurring [Member]
Available-for-sale securities:
Fair value, Measured on recurring basis, Investments	201,775	752
Derivative financial instruments, net	10,979	20,636
Total	212,754	21,388
Level 2 [Member] \| Recurring [Member] \| Corporate Bonds [Member]
Available-for-sale securities:
Fair value, Measured on recurring basis, Investments	190,437	752
Level 2 [Member] \| Recurring [Member] \| Asset Backed Obligations [Member]
Available-for-sale securities:
Fair value, Measured on recurring basis, Investments	3,885
Level 2 [Member] \| Recurring [Member] \| Supranational and Sovereign Debt [Member]
Available-for-sale securities:
Fair value, Measured on recurring basis, Investments	7,453
Level 3 [Member] \| Recurring [Member]
Available-for-sale securities:
Equity Investments	37,581	24,211
Other liabilities	(51,590)	(19,641)
Total	$ (14,009)	$ 4,570

Fair Value Measurements - Addit

Fair Value Measurements - Additional Information (Details) $ in Thousands	12 Months Ended
	Sep. 30, 2021USD ($)
Changes in fair value [Member]
Fair value, measurement with unobservable inputs reconciliation, recurring basis, liability, period increase (decrease)	$ 18,939
Acquisition related liabilities payments [Member]
Fair value, measurement with unobservable inputs reconciliation, recurring basis, liability, period increase (decrease)	(16,070)
Goodwill [Member]
Fair value, measurement with unobservable inputs reconciliation, recurring basis, liability, period increase (decrease)	$ 29,080

Available-for-Sale Securities -

Available-for-Sale Securities - Interest-bearing Investments in Available-for-Sale Securities (Detail) - USD ($) $ in Thousands	Sep. 30, 2021	Sep. 30, 2020
Schedule of Available-for-sale Securities [Line Items]
Amortized Cost	$ 466,827	$ 559,387
Gross Unrealized Gains	80	0
Gross Unrealized Losses	1,354	2
Fair Value	465,553	559,385
Corporate Bonds [Member]
Schedule of Available-for-sale Securities [Line Items]
Amortized Cost	191,445	754
Gross Unrealized Gains	76	0
Gross Unrealized Losses	1,084	2
Fair Value	190,437	752
Money Market Funds [Member]
Schedule of Available-for-sale Securities [Line Items]
Amortized Cost	209,026	558,633
Gross Unrealized Gains	0	0
Gross Unrealized Losses	0	0
Fair Value	209,026	$ 558,633
U.S. Government Treasuries [Member]
Schedule of Available-for-sale Securities [Line Items]
Amortized Cost	54,987
Gross Unrealized Gains	4
Gross Unrealized Losses	239
Fair Value	54,752
Asset Backed Obligations [Member]
Schedule of Available-for-sale Securities [Line Items]
Amortized Cost	3,890
Gross Unrealized Losses	5
Fair Value	3,885
Supranational and Sovereign Debt [Member]
Schedule of Available-for-sale Securities [Line Items]
Amortized Cost	7,479
Gross Unrealized Losses	26
Fair Value	$ 7,453

Available-for-Sale Securities_2

Available-for-Sale Securities - Interest-bearing Investments in Available-for-Sale Securities (Parenthetical) (Detail) - USD ($) $ in Thousands	12 Months Ended
	Sep. 30, 2021	Sep. 30, 2020
Schedule of Available-for-sale Securities [Line Items]
Available-for-sale securities	$ 465,553	$ 559,385
Short Term Investments [Member]
Schedule of Available-for-sale Securities [Line Items]
Maturity period of Available-for-sale securities	longer than 90 days	longer than 90 days
Available-for-sale securities	$ 256,527	$ 752
Cash and Cash Equivalents [Member]
Schedule of Available-for-sale Securities [Line Items]
Maturity period of Available-for-sale securities	90 days or less	90 days or less
Available-for-sale securities	$ 209,026	$ 558,633

Available-for-Sale Securities_3

Available-for-Sale Securities - Available-for-Sale Securities Debt Maturities Market Value (Detail) - USD ($) $ in Thousands	Sep. 30, 2021	Sep. 30, 2020
Debt Securities, Available-for-sale, Fair Value, Fiscal Year Maturity [Abstract]
Due within one year	$ 226,990
1 to 2 years	19,080
2 to 3 years	58,270
3 to 4 years	94,188
Thereafter	67,025
Total	$ 465,553	$ 559,385

Derivative Financial Instrume_3

Derivative Financial Instruments - Additional Information (Detail) - USD ($) $ in Thousands	12 Months Ended
	Sep. 30, 2021	Sep. 30, 2020	Sep. 30, 2019
Derivative Instruments, Gain (Loss) [Line Item]
Maximum amount of loss due to credit risk	$ 12,022
Maximum length of time hedged in cash flow hedges	3 years
Maturity period of significant portion of forward and option contracts outstanding	12 months
Net unrealized gain (loss) from cash flow hedges recognized in other comprehensive (loss) income , net of taxes	$ 24,239	$ 21,903	$ 19,228
Typical maturity period of other risk management derivatives	less than 12 months
Foreign Exchange Contracts [Member]
Derivative Instruments, Gain (Loss) [Line Item]
Net unrealized gain (loss) from cash flow hedges recognized in other comprehensive (loss) income	$ 23,720	26,408	20,035
Net unrealized gain (loss) from cash flow hedges recognized in other comprehensive (loss) income , net of taxes	24,239	$ 21,903	$ 19,228
Foreign currency cash flow hedge, reclassified into earnings during fiscal year 2022	$ 4,841

Derivative Financial Instrume_4

Derivative Financial Instruments - Notional Amounts of Derivative Instruments (Detail) $ in Thousands	Sep. 30, 2021USD ($)
Derivative Instruments and Hedging Activities Disclosure [Abstract]
Notional amount of foreign exchange contracts	$ 1,260,450

Derivative Financial Instrume_5

Derivative Financial Instruments - Fair Value of Open Foreign Currency Exchange Contracts (Detail) - Foreign Exchange Contracts [Member] - USD ($) $ in Thousands	Sep. 30, 2021	Sep. 30, 2020
Derivatives, Fair Value [Line Items]
Net fair value	$ 10,979	$ 20,636
Derivatives Designated as Hedging Instruments [Member]
Derivatives, Fair Value [Line Items]
Net fair value	9,960	20,381
Derivatives Not Designated as Hedging Instruments [Member]
Derivatives, Fair Value [Line Items]
Net fair value	1,019	255
Prepaid Expenses and Other Current Assets [Member] \| Derivatives Designated as Hedging Instruments [Member]
Derivatives, Fair Value [Line Items]
Derivative Asset	6,962	21,153
Prepaid Expenses and Other Current Assets [Member] \| Derivatives Not Designated as Hedging Instruments [Member]
Derivatives, Fair Value [Line Items]
Derivative Asset	4,230	3,068
Other Noncurrent Assets [Member] \| Derivatives Designated as Hedging Instruments [Member]
Derivatives, Fair Value [Line Items]
Derivative Asset	3,068	1,317
Accrued Expenses and Other Current Liabilities [Member] \| Derivatives Designated as Hedging Instruments [Member]
Derivatives, Fair Value [Line Items]
Derivative Liability	(70)	(2,089)
Accrued Expenses and Other Current Liabilities [Member] \| Derivatives Not Designated as Hedging Instruments [Member]
Derivatives, Fair Value [Line Items]
Derivative Liability	$ (3,211)	$ (2,813)

Derivative Financial Instrume_6

Derivative Financial Instruments - Effect of Cash Flow Hedging Instruments (Detail) - USD ($) $ in Thousands	12 Months Ended
	Sep. 30, 2021	Sep. 30, 2020	Sep. 30, 2019
Derivative Instruments, Gain (Loss) [Line Item]
Gains (Losses) Reclassified from Accumulated Other Comprehensive Income (Loss) (Effective Portion)	$ 32,152	$ 9,146	$ (12,976)
Revenue [Member]
Derivative Instruments, Gain (Loss) [Line Item]
Gains (Losses) Reclassified from Accumulated Other Comprehensive Income (Loss) (Effective Portion)	(473)	834	19
Cost of Revenue [Member]
Derivative Instruments, Gain (Loss) [Line Item]
Gains (Losses) Reclassified from Accumulated Other Comprehensive Income (Loss) (Effective Portion)	20,209	4,166	(8,627)
Research and Development [Member]
Derivative Instruments, Gain (Loss) [Line Item]
Gains (Losses) Reclassified from Accumulated Other Comprehensive Income (Loss) (Effective Portion)	6,069	1,646	(2,059)
Selling, General and Administrative [Member]
Derivative Instruments, Gain (Loss) [Line Item]
Gains (Losses) Reclassified from Accumulated Other Comprehensive Income (Loss) (Effective Portion)	$ 6,347	$ 2,500	$ (2,309)

Derivative Financial Instrume_7

Derivative Financial Instruments - Changes in Net Unrealized Gains (Losses) on Cash Flow Hedges (Detail) - USD ($) $ in Thousands	12 Months Ended
	Sep. 30, 2021	Sep. 30, 2020	Sep. 30, 2019
Derivative Instruments and Hedging Activities Disclosure [Abstract]
Net unrealized gain (loss) on cash flow hedges, net of tax, beginning of period	$ 18,836	$ 3,945	$ (26,608)
Changes in fair value of cash flow hedges, net of tax	24,239	21,903	19,228
Reclassification of (gain) loss into earnings, net of tax	(29,302)	(7,012)	11,325
Net unrealized gain (loss) on cash flow hedges, net of tax, end of period	$ 13,773	$ 18,836	$ 3,945

Derivative Financial Instrume_8

Derivative Financial Instruments - Effect of Non-Designated as Hedging Instruments (Detail) - USD ($) $ in Thousands	12 Months Ended
	Sep. 30, 2021	Sep. 30, 2020	Sep. 30, 2019
Derivative Instruments, Gain (Loss) [Line Items]
Gains (Losses) Recognized in Income	$ 5,957	$ (2,042)	$ 6,026
Cost of Revenue [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Gains (Losses) Recognized in Income	4,786	(718)	401
Research and Development [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Gains (Losses) Recognized in Income	1,187	(341)	14
Selling, General and Administrative [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Gains (Losses) Recognized in Income	1,301	(559)	294
Interest and Other Expense, Net [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Gains (Losses) Recognized in Income	1,808	255	5,845
Income Taxes [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Gains (Losses) Recognized in Income	$ (3,125)	$ (679)	$ (528)

Property and Equipment, Net - C

Property and Equipment, Net - Components of Property and Equipment, Net (Detail) - USD ($) $ in Thousands	Sep. 30, 2021	Sep. 30, 2020
Property and Equipment, Net [Line Items]
Property and equipment, gross	$ 1,787,260	$ 1,627,670
Less accumulated depreciation	(1,088,492)	(1,019,719)
Property and equipment, net	698,768	607,951
Computers, Related Equipment and Software [Member]
Property and Equipment, Net [Line Items]
Property and equipment, gross	1,195,787	1,163,807
Building and Land [Member]
Property and Equipment, Net [Line Items]
Property and equipment, gross	291,262	177,255
Leasehold Improvements [Member]
Property and Equipment, Net [Line Items]
Property and equipment, gross	244,858	234,777
Furniture, Fixtures and Other [Member]
Property and Equipment, Net [Line Items]
Property and equipment, gross	$ 55,353	$ 51,831

Property and Equipment, Net - A

Property and Equipment, Net - Additional Information (Detail) - USD ($) $ in Thousands	12 Months Ended
	Sep. 30, 2021	Sep. 30, 2020	Sep. 30, 2019
Property and Equipment [Abstract]
Depreciation expense	$ 125,014	$ 117,632	$ 111,387
Software assets developed for internal use costs, net of accumulated depreciation	$ 165,529	$ 179,837

Goodwill and Intangible Asset_3

Goodwill and Intangible Assets, Net - Details of Total Goodwill (Detail) - USD ($) $ in Thousands		12 Months Ended
		Sep. 30, 2021		Sep. 30, 2020
Goodwill and Intangible Assets Disclosure [Abstract]
Goodwill, Beginning Balance		$ 2,578,645		$ 2,462,835
Goodwill resulting from acquisitions		104,151	[1]	118,628	[2]
Decrease in goodwill as a result of divestiture	[3]	(61,396)
Other		1,244		(2,818)
Goodwill, Ending Balance		$ 2,622,644		$ 2,578,645

[1]	Mainly relates to the acquisition of Sourced. In allocating the total preliminary purchase price for Sourced, based on estimated fair values, the Company recorded $80,055 of goodwill, $18,211 of customer relationships to be amortized over approximately seven years and $3,056 of core technology to be amortized over three years.
[2]	Mainly relates to the acquisition of Openet. In allocating the total purchase price for Openet, based on estimated fair values, the Company recorded $110,347 of goodwill, $40,409 of customer relationships to be amortized over approximately eight years, $53,614 of core technology to be amortized over five years and $2,594 of trademark to be amortized over two years.
[3]	Relates to the divestiture of OpenMarket completed on December 31, 2020, please see also Note 3.

Goodwill and Intangible Asset_4

Goodwill and Intangible Assets, Net - Details of Total Goodwill (Parenthetical) (Detail) - USD ($) $ in Thousands	12 Months Ended
	Sep. 30, 2021		Sep. 30, 2020
Goodwill [Line Items]
Goodwill resulting from acquisitions	$ 104,151	[1]	$ 118,628	[2]
Value of intangible asset	259,032		296,334
Core Technology [Member]
Goodwill [Line Items]
Value of intangible asset	118,730		161,280
Customer Relationships [Member]
Goodwill [Line Items]
Value of intangible asset	133,038		124,905
Openet [Member]
Goodwill [Line Items]
Goodwill resulting from acquisitions			110,347
Openet [Member] \| Trademark [Member]
Goodwill [Line Items]
Value of intangible asset			$ 2,594
Useful life of intangible assets			2 years
Openet [Member] \| Core Technology [Member]
Goodwill [Line Items]
Value of intangible asset			$ 53,614
Useful life of intangible assets			5 years
Openet [Member] \| Customer Relationships [Member]
Goodwill [Line Items]
Value of intangible asset			$ 40,409
Useful life of intangible assets			8 years
Sourced [Member]
Goodwill [Line Items]
Goodwill resulting from acquisitions	80,055
Sourced [Member] \| Core Technology [Member]
Goodwill [Line Items]
Value of intangible asset	$ 3,056
Useful life of intangible assets	3 years
Sourced [Member] \| Customer Relationships [Member]
Goodwill [Line Items]
Value of intangible asset	$ 18,211
Useful life of intangible assets	7 years

[1]	Mainly relates to the acquisition of Sourced. In allocating the total preliminary purchase price for Sourced, based on estimated fair values, the Company recorded $80,055 of goodwill, $18,211 of customer relationships to be amortized over approximately seven years and $3,056 of core technology to be amortized over three years.
[2]	Mainly relates to the acquisition of Openet. In allocating the total purchase price for Openet, based on estimated fair values, the Company recorded $110,347 of goodwill, $40,409 of customer relationships to be amortized over approximately eight years, $53,614 of core technology to be amortized over five years and $2,594 of trademark to be amortized over two years.

Goodwill and Intangible Asset_5

Goodwill and Intangible Assets, Net - Additional Information (Detail) $ in Thousands	12 Months Ended
	Sep. 30, 2021USD ($)Segment	Sep. 30, 2020USD ($)Segment	Sep. 30, 2019USD ($)Segment
Goodwill and Intangible Assets Disclosure [Abstract]
Impairment of goodwill	$ 0	$ 0	$ 0
Number of operating segment \| Segment	1	1	1
Amortization of definite-lived purchased intangible assets	$ 83,816	$ 80,777	$ 94,385

Goodwill and Intangible Asset_6

Goodwill and Intangible Assets, Net - Details Regarding Total Definite-Lived Purchased Intangible Assets (Detail) - USD ($) $ in Thousands	Sep. 30, 2021	Sep. 30, 2020
Definite-Lived Intangible Assets [Line Items]
Gross	$ 1,633,443	$ 1,586,929
Accumulated Amortization	(1,374,411)	(1,290,595)
Total	259,032	296,334
Core Technology [Member]
Definite-Lived Intangible Assets [Line Items]
Gross	896,149	896,814
Accumulated Amortization	(777,419)	(735,534)
Total	118,730	161,280
Customer Relationships [Member]
Definite-Lived Intangible Assets [Line Items]
Gross	689,754	642,575
Accumulated Amortization	(556,716)	(517,670)
Total	133,038	124,905
Other [Member]
Definite-Lived Intangible Assets [Line Items]
Gross	47,540	47,540
Accumulated Amortization	(40,276)	(37,391)
Total	$ 7,264	$ 10,149

Goodwill and Intangible Asset_7

Goodwill and Intangible Assets, Net - Estimated Future Amortization Expense (Detail) - USD ($) $ in Thousands	Sep. 30, 2021	Sep. 30, 2020
Goodwill and Intangible Assets Disclosure [Abstract]
2022	$ 72,119
2023	54,156
2024	45,882
2025	41,930
2026	25,505
Thereafter	19,440
Total	$ 259,032	$ 296,334

Income Taxes - Provision (Benef

Income Taxes - Provision (Benefit) for Income Taxes (Detail) - USD ($) $ in Thousands	12 Months Ended
	Sep. 30, 2021	Sep. 30, 2020	Sep. 30, 2019
Income Tax Disclosure [Abstract]
Current	$ 176,537	$ 55,243	$ 102,391
Deferred	(50,605)	30,239	(13,950)
Income taxes	$ 125,932	$ 85,482	$ 88,441

Income Taxes - Additional Infor

Income Taxes - Additional Information (Detail) - USD ($) $ in Thousands	12 Months Ended
	Sep. 30, 2021	Sep. 30, 2020	Sep. 30, 2019	Sep. 30, 2018
Income Taxes [Line Items]
Net decrease in valuation allowances	$ 3,905	$ 16,078
Tax credits, net capital and operating loss carryforwards	756,414	829,260
Tax credits, net capital and operating loss carryforwards having expiration date	$ 170,430	$ 245,843
Tax Credit net capital and operating loss Carryforwards Expiration Dates	Through 2041 for $170,430 tax credit, net capital and operating loss carryforwards	Through 2040 for $245,843 tax credit, net capital and operating loss carryforwards
Gross unrecognized tax benefits	$ 195,196	$ 168,186	$ 169,322	$ 187,646
Accrued income taxes payable for interest and penalties relating to unrecognized tax benefits	25,011	15,812
Tax benefit recognized in the statements of income, net of interest and penalty reversals	9,199	15,396
Tax benefit related to the release of withholding and income tax reserves for unremitting earnings	28,795	$ 28,795
Maximum [Member]
Income Taxes [Line Items]
Expected decrease in unrecognized tax benefits within next 12 months due to lapse of statutes of limitations	$ 3,559
GUERNSEY
Income Taxes [Line Items]
Statutory Guernsey tax rate	0.00%	0.00%	0.00%
Prepaid Expenses and Other Current Assets [Member]
Income Taxes [Line Items]
Tax receivable balance	$ 53,925	$ 58,336

Income Taxes - Components of De

Income Taxes - Components of Deferred Tax Assets and Liabilities (Detail) - USD ($) $ in Thousands	Sep. 30, 2021	Sep. 30, 2020
Deferred tax assets:
Deferred revenue	$ 25,282	$ 25,252
Employee compensation and benefits	76,020	75,689
Intangible assets, computer software and intellectual property	75,200	18,705
Tax credits, net capital and operating loss carryforwards	156,209	142,718
Lease liabilities	50,780	71,204
Other	46,372	52,611
Total deferred tax assets	429,863	386,179
Valuation allowances	(65,550)	(69,455)
Total deferred tax assets, net	364,313	316,724
Deferred tax liabilities:
Anticipated withholdings on subsidiaries' earnings	(84,755)	(81,489)
Intangible assets, computer software and intellectual property	(109,526)	(114,772)
Lease assets	(47,822)	(69,215)
Other	(97,638)	(90,825)
Total deferred tax liabilities	(339,741)	(356,301)
Net deferred tax assets (liabilities)	$ 24,572	$ (39,577)

Income Taxes - Effective Income

Income Taxes - Effective Income Tax Rate Varied from Statutory Guernsey Tax Rate (Detail)	12 Months Ended
	Sep. 30, 2021	Sep. 30, 2020	Sep. 30, 2019
Schedule of Effective Income Tax Rate Reconciliation [Line Items]
Foreign taxes (percentage)	15.50%	14.70%	15.60%
Effective income tax rate	15.50%	14.70%	15.60%
GUERNSEY
Schedule of Effective Income Tax Rate Reconciliation [Line Items]
Statutory Guernsey tax rate	0.00%	0.00%	0.00%

Income Taxes - Effective Inco_2

Income Taxes - Effective Income Tax Rate Varied from Statutory Guernsey Tax Rate (Parenthetical) (Detail) - USD ($) $ in Thousands	12 Months Ended
	Sep. 30, 2021	Sep. 30, 2020	Sep. 30, 2019
Schedule Of Effective Income Tax Rate Reconciliation [Line Items]
Releases of gross unrecognized tax benefits related to settled arrangements with tax authorities, change in measurement of certain positions and expiration of periods set forth in statutes of limitations	$ 7,701	$ 47,582
Tax benefit primarily attributable to expiration of periods set forth in statutes of limitations and conclusions of tax audits related to unrecognized tax benefits			$ 26,529
Tax benefit resulting from the release of valuation allowances on deferred tax assets	6,006	15,438	$ 12,650
Foreign tax benefit from internal structural changes	10,933
Foreign tax expense for the estimated additional tax charge of gain from sale of a business	$ 39,596
Release of gross unrecognized tax benefits offset by a net benefit included within income tax expense		14,971
Foreign tax benefit resulting from tax enactments related to COVID-19		$ 4,964

Income Taxes - Aggregate Change

Income Taxes - Aggregate Changes in Balance of Company's Gross Unrecognized Tax Benefits (Detail) - USD ($) $ in Thousands	12 Months Ended
	Sep. 30, 2021	Sep. 30, 2020	Sep. 30, 2019
Income Tax Disclosure [Abstract]
Unrecognized tax benefits, Beginning balance	$ 168,186	$ 169,322	$ 187,646
Additions based on tax positions related to the current year	25,662	23,154	19,530
Additions for tax positions of prior years	23,849	23,292	27,558
Reduction for tax positions of prior years	(7,467)	(15,214)	(2,578)
Settlements with tax authorities	(10,245)	(29,400)	(37,672)
Lapse of statute of limitations	(4,789)	(2,968)	(25,162)
Unrecognized tax benefits, Ending balance	$ 195,196	$ 168,186	$ 169,322

Income Taxes - Aggregate Chan_2

Income Taxes - Aggregate Changes in Balance of Company's Gross Unrecognized Tax Benefits (Parenthetical) (Detail) - USD ($) $ in Thousands	12 Months Ended
	Sep. 30, 2021	Sep. 30, 2020	Sep. 30, 2019
Income Tax Disclosure [Abstract]
Settlements with tax authorities	$ 10,245	$ 29,400	$ 37,672

Repurchase of Shares - Addition

Repurchase of Shares - Additional Information (Detail) - USD ($) $ / shares in Units, shares in Thousands	12 Months Ended
	Sep. 30, 2021	May 12, 2021	Nov. 12, 2019
Equity, Class of Treasury Stock [Line Items]
Repurchase of shares, Shares	9,036
Average price at which ordinary shares are repurchased	$ 75.24
Share Repurchase Program 2019 Plan [Member]
Equity, Class of Treasury Stock [Line Items]
Share repurchase program, Authorized amount			$ 800,000,000
Share Repurchase Program 2021 Plan [Member]
Equity, Class of Treasury Stock [Line Items]
Share repurchase program, Authorized amount		$ 1,000,000,000
Remaining authority to repurchase outstanding ordinary shares	$ 998,484,000

Financing Arrangements - Additi

Financing Arrangements - Additional Information (Detail) - USD ($) $ in Thousands	1 Months Ended					12 Months Ended
	May 31, 2021	Mar. 31, 2021	Jun. 30, 2020	Dec. 31, 2017	Dec. 31, 2014	Sep. 30, 2021	Sep. 30, 2020	May 31, 2020	Mar. 31, 2020	Dec. 31, 2011
Line of Credit Facility [Line Items]
Outstanding letters of credit and bank guarantees						$ 78,084
Short-term borrowing						0	$ 100,000
Senior Notes [Member]
Line of Credit Facility [Line Items]
Long-term debt			$ 650,000
Debt Interest rate			2.538%
Debt issue cost			$ 6,121
Interest Expense Debt						17,034
Long Term Debt Fair Value						651,112
Senior Notes [Member] \| Accrued Liabilities [Member]
Line of Credit Facility [Line Items]
Accrued Interest Current						4,815
Senior Notes [Member] \| Long-term Debt [Member]
Line of Credit Facility [Line Items]
Noncurrent outstanding principal portion						$ 650,000
Revolving Credit Facility [Member]
Line of Credit Facility [Line Items]
Five-year revolving credit facility										$ 500,000
Revolving credit facility, maturity term						5 years
Revolving credit facility, maturity period		2026-03		2022-12	2019-12
Borrowings under the revolving credit facility									$ 300,000
Repayments of revolving credit facility			300,000
Repayments of short term loans	$ 100,000		$ 50,000
Outstanding borrowings						$ 0
Short-term borrowing								$ 100,000	$ 50,000

Accrued Expenses and Other Cu_3

Accrued Expenses and Other Current Liabilities - Schedule of Accrued Expenses and Other Current Liabilities (Detail) - USD ($) $ in Thousands	Sep. 30, 2021	Sep. 30, 2020
Accrued expenses and Other Current Liabilities [Abstract]
Ongoing accrued expenses	$ 206,905	$ 217,133
Project-related provisions	125,612	121,658
Taxes payable	34,717	25,739
Dividends payable	44,956	43,084
Derivative instruments	3,281	4,902
Other	196,832	181,092
Total accrued expenses and other current liabilities	$ 612,303	$ 593,608

Interest and Other Expense, N_3

Interest and Other Expense, Net - Interest and Other Expense, Net (Detail) - USD ($) $ in Thousands	12 Months Ended
	Sep. 30, 2021	Sep. 30, 2020	Sep. 30, 2019
Interest and other expense, net
Interest income	$ (4,822)	$ (4,233)	$ (6,225)
Interest expense	21,275	10,427	3,911
Foreign exchange loss	1,110	3,382	7,860
Other, net	(6,766)	1,860	(3,687)
Total	$ 10,797	$ 11,436	$ 1,859

Leases - Disclosure of Lease Co

Leases - Disclosure of Lease Cost (Detail) - USD ($) $ in Thousands	12 Months Ended
	Sep. 30, 2021	Sep. 30, 2020
Lease, Cost [Abstract]
Total net lease cost	$ 97,169	$ 91,025

Leases - Summary of Supplementa

Leases - Summary of Supplemental Information Related to Operating Lease (Detail) - USD ($) $ in Thousands	12 Months Ended
	Sep. 30, 2021	Sep. 30, 2020
Supplemental Information Related to Operating Lease transactions [Line Items]
Lease liability payments	$ 79,028	$ 88,272
Lease assets obtained in exchange for liabilities	$ 14,580	$ 87,820
Weighted average remaining lease term — Operating leases	6 years 4 months 24 days	6 years 9 months 18 days
Weighted average discount rate — Operating leases	3.70%	3.50%

Leases - Future Undiscounted Ca

Leases - Future Undiscounted Cash Outflows for Operating Leases Maturity (Detail) $ in Thousands	Sep. 30, 2021USD ($)
Future undiscounted cash outflows for operating leases [Line Items]
2022	$ 66,791
2023	44,187
2024	34,473
2025	28,173
2026	22,814
Thereafter	86,134
Total lease payments	282,572
Less: imputed interest	(45,952)
Present value of lease liabilities	$ 236,620

Leases - Additional Information

Leases - Additional Information (Detail) $ in Thousands	12 Months Ended
Leases - Additional Information (Detail) $ in Thousands	Sep. 30, 2019USD ($)
Leases [Abstract]
Operating Leases, Rent Expense, Net	$ 65,692

Employee Benefits - Additional

Employee Benefits - Additional Information (Detail) - USD ($) $ in Thousands	12 Months Ended
	Sep. 30, 2021	Sep. 30, 2020	Sep. 30, 2019
Retirement Benefits [Abstract]
Severance pay liability	$ 298,044	$ 270,985
Deposit with insurance companies	233,749	211,566
Severance expenses	$ 35,015	$ 33,354	$ 33,355

Stock Option and Incentive Pl_3

Stock Option and Incentive Plan - Additional Information (Detail) - USD ($) shares in Thousands, $ in Thousands	12 Months Ended
	Sep. 30, 2021	Sep. 30, 2020	Sep. 30, 2019
Awards granted under the Equity Incentive Plan
Maximum number of shares authorized to be granted		70,550	67,550
Stock option awards, term	10 years
Total intrinsic value of options exercised	$ 27,023	$ 31,220	$ 13,081
Value of restricted shares vested	28,682	$ 28,727	$ 28,430
Aggregate intrinsic value of stock options outstanding	58,644
Aggregate intrinsic value of stock options exercisable	$ 38,482
Minimum [Member]
Awards granted under the Equity Incentive Plan
Awards granted under the Equity Incentive Plan, vesting period	3 years
Maximum [Member]
Awards granted under the Equity Incentive Plan
Awards granted under the Equity Incentive Plan, vesting period	4 years

Stock Option and Incentive Pl_4

Stock Option and Incentive Plan - Summary of Option Activity (Detail) shares in Thousands	12 Months Ended
	Sep. 30, 2021$ / sharesshares
Disclosure of Stock Option and Incentive Plan [Abstract]
Number of Share Options, Outstanding, Beginning Balance \| shares	5,716
Number of Share Options, Granted \| shares	62
Number of Share Options, Exercised \| shares	(1,541)
Number of Share Options, Forfeited \| shares	(249)
Number of Share Options, Outstanding, Ending Balance \| shares	3,988
Number of Share Options, Exercisable \| shares	2,119
Weighted Average Exercise Price, Outstanding, Beginning Balance \| $ / shares	$ 60.26
Weighted Average Exercise Price, Granted \| $ / shares	60.77
Weighted Average Exercise Price, Exercised \| $ / shares	57.81
Weighted Average Exercise Price, Forfeited \| $ / shares	63.63
Weighted Average Exercise Price, Outstanding, Ending Balance \| $ / shares	61
Weighted Average Exercise Price, Exercisable \| $ / shares	$ 57.55

Stock Option and Incentive Pl_5

Stock Option and Incentive Plan - Summary of Option Activity (Parenthetical) (Detail)	12 Months Ended
	Sep. 30, 2021
Disclosure of Stock Option and Incentive Plan [Abstract]
Weighted average remaining contractual life of outstanding options	6 years 5 months 1 day
Weighted average remaining contractual life of exercisable options	5 years 4 months 24 days

Stock Option and Incentive Pl_6

Stock Option and Incentive Plan - Summary of Restricted Shares Activity (Detail) shares in Thousands	12 Months Ended
	Sep. 30, 2021$ / sharesshares
Disclosure of Stock Option and Incentive Plan [Abstract]
Number of Restricted Shares, Outstanding, Beginning Balance \| shares	1,097
Number of Restricted Shares, Granted \| shares	1,032
Number of Restricted Shares, Vested \| shares	(426)
Number of Restricted Shares, Forfeited \| shares	(116)
Number of Restricted Shares, Ending Balance \| shares	1,587
Restricted Shares, Weighted Average Grant Date Fair Value, Beginning Balance \| $ / shares	$ 66.57
Restricted Shares, Weighted Average Grant Date Fair Value, Granted \| $ / shares	66.83
Restricted Shares, Weighted Average Grant Date Fair Value, Vested \| $ / shares	65.40
Restricted Shares, Weighted Average Grant Date Fair Value, Forfeited \| $ / shares	67.84
Restricted Shares, Weighted Average Grant Date Fair Value, Ending Balance \| $ / shares	$ 66.96

Stock Option and Incentive Pl_7

Stock Option and Incentive Plan - Employee Equity-Based Compensation Pre-Tax Expense (Detail) - USD ($) $ in Thousands	12 Months Ended
	Sep. 30, 2021	Sep. 30, 2020	Sep. 30, 2019
Share-based Compensation Arrangement by Share-based Payment Award, Compensation Cost [Line Items]
Equity-based compensation pre-tax expense	$ 54,249	$ 42,434	$ 38,550
Cost of Revenue [Member]
Share-based Compensation Arrangement by Share-based Payment Award, Compensation Cost [Line Items]
Equity-based compensation pre-tax expense	22,691	20,005	19,879
Research and Development [Member]
Share-based Compensation Arrangement by Share-based Payment Award, Compensation Cost [Line Items]
Equity-based compensation pre-tax expense	4,021	3,058	2,714
Selling, General and Administrative [Member]
Share-based Compensation Arrangement by Share-based Payment Award, Compensation Cost [Line Items]
Equity-based compensation pre-tax expense	$ 27,537	$ 19,371	$ 15,957

Stock Option and Incentive Pl_8

Stock Option and Incentive Plan - Assumptions Used in Calculating Fair Value of Options (Detail) - $ / shares		12 Months Ended
		Sep. 30, 2021	Sep. 30, 2020	Sep. 30, 2019
Disclosure of Stock Option and Incentive Plan [Abstract]
Risk-free interest rate	[1]	0.30%	1.41%	2.64%
Expected life of stock options	[2]	4 years 6 months	4 years 6 months	4 years 6 months
Expected volatility	[3]	21.30%	17.30%	17.80%
Expected dividend yield	[4]	2.22%	1.75%	1.82%
Fair value per option		$ 7.82	$ 8.85	$ 9.13

[1]	Risk-free interest rate is based upon U.S. Treasury yield curve appropriate for the term of the Company’s employee stock options.
[2]	Expected life of stock options is based upon historical experience.
[3]	Expected volatility is based on blended volatility.
[4]	Expected dividend yield is based on the Company’s history and future expectation of dividend payouts.

Dividends - Summary of Dividend

Dividends - Summary of Dividends Declared by Board of directors (Detail) - USD ($) $ / shares in Units, $ in Thousands	12 Months Ended
	Sep. 30, 2021	Sep. 30, 2020	Sep. 30, 2019
Dividends Payable [Line Items]
Dividends Per Ordinary Share	$ 1.4075	$ 1.2675	$ 1.105
Declaration Date, August 4, 2021 [Member]
Dividends Payable [Line Items]
Declaration Date	Aug. 4, 2021
Record Date	Sep. 30, 2021
Payment Date	Oct. 29, 2021
Dividends Per Ordinary Share	$ 0.36
Total Amount	$ 44,956
Declaration Date, August 5, 2020 [Member]
Dividends Payable [Line Items]
Declaration Date		Aug. 5, 2020
Record Date		Sep. 30, 2020
Payment Date		Oct. 23, 2020
Dividends Per Ordinary Share		$ 0.3275
Total Amount		$ 43,084
Declaration Date, May 12, 2021 [Member]
Dividends Payable [Line Items]
Declaration Date	May 12, 2021
Record Date	Jun. 30, 2021
Payment Date	Jul. 23, 2021
Dividends Per Ordinary Share	$ 0.36
Total Amount	$ 45,580
Declaration Date, February 2, 2021 [Member]
Dividends Payable [Line Items]
Declaration Date	Feb. 2, 2021
Record Date	Mar. 31, 2021
Payment Date	Apr. 23, 2021
Dividends Per Ordinary Share	$ 0.36
Total Amount	$ 45,958
Declaration Date, November 10, 2020 [Member]
Dividends Payable [Line Items]
Declaration Date	Nov. 10, 2020
Record Date	Dec. 31, 2020
Payment Date	Jan. 22, 2021
Dividends Per Ordinary Share	$ 0.3275
Total Amount	$ 42,850
Declaration Date, May 7, 2020 [Member]
Dividends Payable [Line Items]
Declaration Date		May 7, 2020
Record Date		Jun. 30, 2020
Payment Date		Jul. 24, 2020
Dividends Per Ordinary Share		$ 0.3275
Total Amount		$ 43,568
Declaration Date, February 4, 2020 [Member]
Dividends Payable [Line Items]
Declaration Date		Feb. 4, 2020
Record Date		Mar. 31, 2020
Payment Date		Apr. 24, 2020
Dividends Per Ordinary Share		$ 0.3275
Total Amount		$ 43,723
Declaration Date, November 12, 2019 [Member]
Dividends Payable [Line Items]
Declaration Date		Nov. 12, 2019
Record Date		Dec. 31, 2019
Payment Date		Jan. 24, 2020
Dividends Per Ordinary Share		$ 0.285
Total Amount		$ 38,357
Declaration Date, August 7, 2019 [Member]
Dividends Payable [Line Items]
Declaration Date			Aug. 7, 2019
Record Date			Sep. 30, 2019
Payment Date			Oct. 25, 2019
Dividends Per Ordinary Share			$ 0.285
Total Amount			$ 38,413
Declaration Date, May 14, 2019 [Member]
Dividends Payable [Line Items]
Declaration Date			May 14, 2019
Record Date			Jun. 28, 2019
Payment Date			Jul. 19, 2019
Dividends Per Ordinary Share			$ 0.285
Total Amount			$ 38,730
Declaration Date, February 5, 2019 [Member]
Dividends Payable [Line Items]
Declaration Date			Feb. 5, 2019
Record Date			Mar. 29, 2019
Payment Date			Apr. 19, 2019
Dividends Per Ordinary Share			$ 0.285
Total Amount			$ 39,084
Declaration Date, November 8, 2018 [Member]
Dividends Payable [Line Items]
Declaration Date			Nov. 8, 2018
Record Date			Dec. 31, 2018
Payment Date			Jan. 18, 2019
Dividends Per Ordinary Share			$ 0.250
Total Amount			$ 34,755

Dividends - Additional Informat

Dividends - Additional Information (Detail)	Nov. 02, 2021$ / shares
Dividends Payable [Line Items]
Quarterly dividend payment per share	$ 0.395
Cash dividend anticipated payable date	2022-04
First Installment [Member]
Dividends Payable [Line Items]
Dividends payable date declared	Nov. 2, 2021
Quarterly dividend payment per share	$ 0.36
Record Date	Dec. 31, 2021
Cash dividend payable date	Jan. 28, 2022

Earnings Per Share - Computatio

Earnings Per Share - Computation of Basic and Diluted Earnings Per Share (Detail) - USD ($) $ / shares in Units, shares in Thousands, $ in Thousands	3 Months Ended								12 Months Ended
	Sep. 30, 2021	Jun. 30, 2021	Mar. 31, 2021	Dec. 31, 2020	Sep. 30, 2020	Jun. 30, 2020	Mar. 31, 2020	Dec. 31, 2019	Sep. 30, 2021		Sep. 30, 2020		Sep. 30, 2019
Numerator
Net income	$ 123,525	$ 146,150	$ 119,067	$ 299,632	$ 134,463	$ 120,407	$ 127,038	$ 115,932	$ 688,374	[1]	$ 497,840	[1]	$ 479,446	[1]
Net income and dividends attributable to participating restricted shares									(7,052)		(3,663)		(3,295)
Numerator for basic earnings per common share									681,322		494,177		476,151
Undistributed income allocated to participating restricted shares									5,199		2,417		2,252
Undistributed income reallocated to participating restricted shares									(5,167)		(2,406)		(2,240)
Numerator for diluted earnings per common share									$ 681,354		$ 494,188		$ 476,163
Denominator
Weighted average number of shares outstanding - basic									128,495		133,590		137,418
Weighted average number of participating restricted shares									(1,316)		(983)		(944)
Weighted average number of common shares - basic									127,179		132,607		136,474
Effect of dilutive stock options granted									789		642		691
Weighted average number of common shares - diluted									127,968		133,249		137,165
Basic earnings per common share	$ 0.98	$ 1.15	$ 0.92	$ 2.29	$ 1.02	$ 0.90	$ 0.95	$ 0.86	$ 5.36		$ 3.73		$ 3.49
Diluted earnings per common share	$ 0.97	$ 1.14	$ 0.91	$ 2.28	$ 1.01	$ 0.90	$ 0.94	$ 0.85	$ 5.32		$ 3.71		$ 3.47

[1]	In fiscal years 2021, 2020 and 2019, all of the Company’s net income is attributable to Amdocs Limited as the net income attributable to the Non-controlling interests is negligible.

Earnings Per Share - Additional

Earnings Per Share - Additional Information (Detail) - shares shares in Thousands	12 Months Ended
	Sep. 30, 2021	Sep. 30, 2020	Sep. 30, 2019
Earnings Per Share [Abstract]
Weighted average number of shares attributable to antidilutive outstanding stock options not included in the calculation of diluted earnings per share	858	2,634	3,547

Segment Information and Sales_3

Segment Information and Sales to Significant Customers - Summary of Revenue by Geographic Area (Detail) - USD ($) $ in Thousands	3 Months Ended								12 Months Ended
	Sep. 30, 2021	Jun. 30, 2021	Mar. 31, 2021	Dec. 31, 2020	Sep. 30, 2020	Jun. 30, 2020	Mar. 31, 2020	Dec. 31, 2019	Sep. 30, 2021	Sep. 30, 2020	Sep. 30, 2019
Revenues from External Customers and Long-Lived Assets [Line Items]
Total revenue	$ 1,087,309	$ 1,066,254	$ 1,048,734	$ 1,086,343	$ 1,052,948	$ 1,026,201	$ 1,047,933	$ 1,041,957	$ 4,288,640	$ 4,169,039	$ 4,086,669
North America [Member]
Revenues from External Customers and Long-Lived Assets [Line Items]
Total revenue									2,791,472	2,720,911	2,582,719
Europe [Member]
Revenues from External Customers and Long-Lived Assets [Line Items]
Total revenue									622,780	613,751	598,731
Rest of the World [Member]
Revenues from External Customers and Long-Lived Assets [Line Items]
Total revenue									$ 874,388	$ 834,377	$ 905,219

Segment Information and Sales_4

Segment Information and Sales to Significant Customers - Summary of Long-lived Assets by Geographic Area (Detail) - USD ($) $ in Thousands	Sep. 30, 2021	Sep. 30, 2020
Revenues from External Customers and Long-Lived Assets [Line Items]
Total long-lived assets	$ 698,768	$ 607,951
North America [Member]
Revenues from External Customers and Long-Lived Assets [Line Items]
Total long-lived assets	94,149	104,918
Europe [Member]
Revenues from External Customers and Long-Lived Assets [Line Items]
Total long-lived assets	182,746	211,292
Israel [Member]
Revenues from External Customers and Long-Lived Assets [Line Items]
Total long-lived assets	358,329	237,561
India [Member]
Revenues from External Customers and Long-Lived Assets [Line Items]
Total long-lived assets	48,326	38,706
Others [Member]
Revenues from External Customers and Long-Lived Assets [Line Items]
Total long-lived assets	$ 15,218	$ 15,474

Segment Information and Sales_5

Segment Information and Sales to Significant Customers - Summary of Revenue by Nature of Activities (Detail) - USD ($) $ in Thousands	3 Months Ended								12 Months Ended
	Sep. 30, 2021	Jun. 30, 2021	Mar. 31, 2021	Dec. 31, 2020	Sep. 30, 2020	Jun. 30, 2020	Mar. 31, 2020	Dec. 31, 2019	Sep. 30, 2021	Sep. 30, 2020	Sep. 30, 2019
Revenues from External Customers and Long-Lived Assets [Line Items]
Total revenue	$ 1,087,309	$ 1,066,254	$ 1,048,734	$ 1,086,343	$ 1,052,948	$ 1,026,201	$ 1,047,933	$ 1,041,957	$ 4,288,640	$ 4,169,039	$ 4,086,669
Managed services arrangements [Member]
Revenues from External Customers and Long-Lived Assets [Line Items]
Total revenue									2,546,330	2,398,691	2,246,279
Other [Member]
Revenues from External Customers and Long-Lived Assets [Line Items]
Total revenue									$ 1,742,310	$ 1,770,348	$ 1,840,390

Segment Information and Sales_6

Segment Information and Sales to Significant Customers - Additional Information (Detail)	12 Months Ended
	Sep. 30, 2021	Sep. 30, 2020	Sep. 30, 2019
Revenue, Major Customer [Line Items]
Minimum percentage of total revenue accounted for one customer	10.00%	10.00%	10.00%

Segment Information and Sales_7

Segment Information and Sales to Significant Customers - Summary Sales to Significant Customers (Detail) - Revenue [Member]		12 Months Ended
		Sep. 30, 2021	Sep. 30, 2020	Sep. 30, 2019
Customer 1
Percentage of revenue from significant customer		25.00%	25.80%	23.40%
Customer 2
Percentage of revenue from significant customer	[1]	19.10%	12.10%

[1]	Starting April 1, 2020, following the merger of two significant customers, their respective revenue was consolidated.

Segment Information and Sales_8

Segment Information and Sales to Significant Customers - Summary Sales to Significant Customers (Parenthetical) (Detail)		Apr. 01, 2020	Sep. 30, 2021	Sep. 30, 2020
Concentration risk, Customer		Starting April 1, 2020, following the merger of two significant customers, their respective revenue was consolidated.
Revenue [Member] \| Customer two concentration risk [Member]
Percentage of revenue from significant customer	[1]		19.10%	12.10%
Revenue [Member] \| Customer two concentration risk [Member] \| Significant customers group [Member]
Percentage of revenue from significant customer			10.00%	10.00%

[1]	Starting April 1, 2020, following the merger of two significant customers, their respective revenue was consolidated.

Selected Quarterly Results of_3

Selected Quarterly Results of Operations - Quarterly Results of Operations (Detail) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended								12 Months Ended
	Sep. 30, 2021	Jun. 30, 2021	Mar. 31, 2021	Dec. 31, 2020	Sep. 30, 2020	Jun. 30, 2020	Mar. 31, 2020	Dec. 31, 2019	Sep. 30, 2021		Sep. 30, 2020		Sep. 30, 2019
Quarterly Financial Information Disclosure [Abstract]
Revenue	$ 1,087,309	$ 1,066,254	$ 1,048,734	$ 1,086,343	$ 1,052,948	$ 1,026,201	$ 1,047,933	$ 1,041,957	$ 4,288,640		$ 4,169,039		$ 4,086,669
Operating income	154,330	154,919	149,244	140,200	146,938	147,531	156,712	143,577	598,693		594,758		569,746
Net income	$ 123,525	$ 146,150	$ 119,067	$ 299,632	$ 134,463	$ 120,407	$ 127,038	$ 115,932	$ 688,374	[1]	$ 497,840	[1]	$ 479,446	[1]
Basic earnings per share	$ 0.98	$ 1.15	$ 0.92	$ 2.29	$ 1.02	$ 0.90	$ 0.95	$ 0.86	$ 5.36		$ 3.73		$ 3.49
Diluted earnings per share	$ 0.97	$ 1.14	$ 0.91	$ 2.28	$ 1.01	$ 0.90	$ 0.94	$ 0.85	$ 5.32		$ 3.71		$ 3.47

[1]	In fiscal years 2021, 2020 and 2019, all of the Company’s net income is attributable to Amdocs Limited as the net income attributable to the Non-controlling interests is negligible.

Schedule - Valuation and Qualif

Schedule - Valuation and Qualifying Accounts (Detail) - USD ($) $ in Thousands	12 Months Ended
	Sep. 30, 2021	Sep. 30, 2020	Sep. 30, 2019
Accounts Receivable Allowances [Member]
SEC Schedule, 12-09, Valuation and Qualifying Accounts Disclosure [Line Items]
Beginning Balance	$ 23,419	$ 36,121	$ 21,211
Charged to costs and expenses	10,345	18,465	22,260
Charged to other accounts	156	(3,523)	2,406
Deductions	(13,855)	(27,644)	(9,756)
Ending Balance	20,065	23,419	36,121
Valuation Allowances on Net Deferred Tax Assets [Member]
SEC Schedule, 12-09, Valuation and Qualifying Accounts Disclosure [Line Items]
Beginning Balance	69,455	85,533	112,727
Charged to costs and expenses	6,382	8,521	1,009
Charged to other accounts	3,720	1,005	6,008
Deductions	(14,007)	(25,604)	(34,211)
Ending Balance	$ 65,550	$ 69,455	$ 85,533

Schedule - Valuation and Qual_2

Schedule - Valuation and Qualifying Accounts (Parenthetical) (Detail) - USD ($) $ in Thousands	12 Months Ended
	Sep. 30, 2021	Sep. 30, 2020	Sep. 30, 2019
SEC Schedule, 12-09, Valuation and Qualifying Accounts [Abstract]
Valuation allowances on deferred tax assets written off against the deferred tax assets	$ 1,557	$ 2,283	$ 7,588
Accounts receivable allowances written off against related accounts receivables	$ 8,486	4,969	$ 3,539
Accounts receivable allowances written off mainly against deferred revenue		$ 7,089