Paychex (PAYX) 10-K 15 Jul 22 2022 FY Annual report Financial data

Document and Entity Information

Document and Entity Information - USD ($)	12 Months Ended
	May 31, 2022	Jun. 30, 2022	Nov. 30, 2021
Cover [Abstract]
Document Type	10-K
Document Annual Report	true
Document Fiscal Period Focus	FY
Current Fiscal Year End Date	--05-31
Document Fiscal Year Focus	2022
Document Period End Date	May 31, 2022
Document Transition Report	false
Entity File Number	0-11330
Entity Registrant Name	Paychex, Inc.
Entity Incorporation, State or Country Code	DE
Entity Tax Identification Number	16-1124166
Entity Address, Address Line One	911 Panorama Trail South
Entity Address, City or Town	Rochester
Entity Address, State or Province	NY
Entity Address, Postal Zip Code	14625-2396
City Area Code	585
Local Phone Number	385-6666
Title of 12(b) Security	Common Stock, $0.01 par value
Trading Symbol	PAYX
Security Exchange Name	NASDAQ
Entity Well-known Seasoned Issuer	Yes
Entity Voluntary Filers	No
Entity Current Reporting Status	Yes
Entity Interactive Data Current	Yes
Entity Filer Category	Large Accelerated Filer
Entity Small Business	false
Entity Emerging Growth Company	false
ICFR Auditor Attestation Flag	true
Entity Shell Company	false
Entity Public Float			$ 30,609,113,270
Entity Common Stock, Shares Outstanding		359,906,888
Documents Incorporated by Reference	Portions of the registrant’s definitive proxy statement to be issued in connection with its Annual Meeting of Stockholders to be held on or about October 13, 2022, to the extent not set forth herein, are incorporated by reference into Part III, Items 10 through 14, inclusive.
Amendment Flag	false
Entity Central Index Key	0000723531
Auditor Name	PricewaterhouseCoopers LLP
Auditor Location	Rochester, New York
Auditor Firm ID	238

Consolidated Statements of Inco

Consolidated Statements of Income and Comprehensive Income - USD ($) shares in Millions, $ in Millions	12 Months Ended
	May 31, 2022	May 31, 2021	May 31, 2020
Revenue:
Total service revenue	$ 4,554	$ 3,997.5	$ 3,953.6
Interest on funds held for clients	57.7	59.3	86.9
Total revenue	4,611.7	4,056.8	4,040.5
Expenses:
Cost of service revenue	1,356.3	1,271.2	1,280.8
Selling, general and administrative expenses	1,415.4	1,324.9	1,299.2
Total expenses	2,771.7	2,596.1	2,580
Operating income	1,840	1,460.7	1,460.5
Other expense, net	(15.4)	(26.5)	(23.4)
Income before income taxes	1,824.6	1,434.2	1,437.1
Income taxes	431.8	336.7	339
Net income	1,392.8	1,097.5	1,098.1
Other comprehensive (loss)/income, net of tax	(185.7)	(4.7)	56.4
Comprehensive income	$ 1,207.1	$ 1,092.8	$ 1,154.5
Basic earnings per share	$ 3.86	$ 3.05	$ 3.06
Diluted earnings per share	$ 3.84	$ 3.03	$ 3.04
Weighted-average common shares outstanding	360.6	359.9	358.5
Weighted-average common shares outstanding, assuming dilution	363.1	362.1	361
Management Solutions [Member]
Revenue:
Total service revenue	$ 3,442.7	$ 3,023.4	$ 2,963
PEO And Insurance Solutions [Member]
Revenue:
Total service revenue	$ 1,111.3	$ 974.1	$ 990.6

Consolidated Balance Sheets

Consolidated Balance Sheets - USD ($) $ in Millions	May 31, 2022	May 31, 2021
Assets
Cash and cash equivalents	$ 370	$ 995.2
Restricted cash	50.3	51.3
Corporate investments	853.9	36.7
Interest receivable	22.3	24.4
Accounts receivable, net of allowance for credit losses	723.8	578.3
PEO unbilled receivables, net of advance collections	572.1	450.9
Prepaid income taxes	34	33.5
Prepaid expenses and other current assets	272.3	249.2
Current assets before funds held for clients	2,898.7	2,419.5
Funds held for clients	3,682.9	3,750
Total current assets	6,581.6	6,169.5
Long-term restricted cash	25.5	37
Long-term corporate investments	5	7.1
Property and equipment, net of accumulated depreciation	401.3	395.8
Operating lease right-of-use assets, net of accumulated amortization	78.7	103
Intangible assets, net of accumulated amortization	224.6	275.8
Goodwill	1,831.5	1,820.7
Long-term deferred costs	433.3	384.1
Other long-term assets	53.7	34.2
Total assets	9,635.2	9,227.2
Liabilities
Accounts payable	105.7	89
Accrued corporate compensation and related items	225.4	209.7
Accrued worksite employee compensation and related items	683.4	586.4
Short-term borrowings	8.7	7.4
Deferred revenue	38.4	37.9
Other current liabilities	388.4	336.8
Current liabilities before client fund obligations	1,450	1,267.2
Client fund obligations	3,819.2	3,671
Total current liabilities	5,269.2	4,938.2
Accrued income taxes	58.1	25.8
Deferred income taxes	165.5	218
Long-term borrowings, net of debt issuance costs	797.7	797.3
Operating lease liabilities	74.8	92.4
Other long-term liabilities	184.7	207.5
Total liabilities	6,550	6,279.2
Commitments and contingencies - Note P
Stockholders' equity
Common stock, $0.01 par value; Authorized: 600.0 shares; Issued and outstanding: 359.9 shares as of May 31, 2022 and 359.8 shares as of May 31, 2021	3.6	3.6
Additional paid-in capital	1,545.9	1,446.7
Retained earnings	1,669.6	1,445.9
Accumulated other comprehensive (loss)/income	(133.9)	51.8
Total stockholders' equity	3,085.2	2,948
Total liabilities and stockholders' equity	$ 9,635.2	$ 9,227.2

Consolidated Balance Sheets (Pa

Consolidated Balance Sheets (Parenthetical) - $ / shares	May 31, 2022	May 31, 2021
Stockholders' equity
Common stock, par value	$ 0.01	$ 0.01
Common stock, shares authorized	600,000,000	600,000,000
Common stock, shares issued	359,900,000	359,800,000
Common stock, shares outstanding	359,900,000	359,800,000

Consolidated Statements of Stoc

Consolidated Statements of Stockholders' Equity - USD ($) shares in Millions, $ in Millions		Total	Common Stock [Member]	Additional Paid-in Capital [Member]	Retained Earnings [Member]	Accumulated Other Comprehensive Income/(Loss) [Member]
Beginning balance, Shares at May. 31, 2019			359.3
Beginning balance at May. 31, 2019		$ 2,619.5	$ 3.6	$ 1,206.3	$ 1,409.5	$ 0.1
Net income		1,098.1			1,098.1
Unrealized (losses) gains on securities, net of tax (benefit) expense		68.9				68.9
Reclassification adjustment for realized gains on securities, net of tax expense	[1]	(8.5)				(8.5)
Dividends declared		(889.4)			(889.4)
Repurchases of common shares, Shares	[2]		(2)
Repurchases of common shares	[2]	(171.9)		(3.7)	(168.2)
Stock-based compensation		47.4		47.4
Foreign currency translation adjustment		(4)				(4)
Activity related to equity-based plans, Shares			1.5
Activity related to equity-based plans		21.3		39.9	(18.6)
Ending balance, Shares at May. 31, 2020			358.8
Ending balance at May. 31, 2020		2,781.4	$ 3.6	1,289.9	1,431.4	56.5
Net income		1,097.5			1,097.5
Unrealized (losses) gains on securities, net of tax (benefit) expense		(14.7)				(14.7)
Reclassification adjustment for realized gains on securities, net of tax expense	[1]	(0.9)				(0.9)
Dividends declared		(908.7)			(908.7)
Repurchases of common shares, Shares	[2]		(1.7)
Repurchases of common shares	[2]	(155.7)		(3.1)	(152.6)
Stock-based compensation		52.5		52.5
Foreign currency translation adjustment		10.9				10.9
Activity related to equity-based plans, Shares			2.7
Activity related to equity-based plans		$ 85.7		107.4	(21.7)
Ending balance, Shares at May. 31, 2021		359.8	359.8
Ending balance at May. 31, 2021		$ 2,948	$ 3.6	1,446.7	1,445.9	51.8
Net income		1,392.8			1,392.8
Unrealized (losses) gains on securities, net of tax (benefit) expense		(162.3)				(162.3)
Reclassification adjustment for realized gains on securities, net of tax expense	[1]	(0.1)				(0.1)
Dividends declared		(1,000.1)			(1,000.1)
Repurchases of common shares, Shares	[2]		(1.2)
Repurchases of common shares	[2]	(145.2)		(5.2)	(140)
Stock-based compensation		52.8		52.8
Foreign currency translation adjustment		(23.3)				(23.3)
Activity related to equity-based plans, Shares			1.3
Activity related to equity-based plans		$ 22.6		51.6	(29)
Ending balance, Shares at May. 31, 2022		359.9	359.9
Ending balance at May. 31, 2022		$ 3,085.2	$ 3.6	$ 1,545.9	$ 1,669.6	$ (133.9)
[1] Reclassification adjustments out of accumulated other comprehensive income/(loss) for realized gains, net of tax, on the sale of available-for-sale (“AFS”) securities are reflected in interest on funds held for clients and other expense, net on the Consolidated Statements of Income and Comprehensive Income. The Company maintained a program to repurchase up to $ 400.0 million of its common stock through May 31, 2022 , which was repurchased before the program expired. The Company maintains a separate program to repurchase up to $ 400.0 million of its common stock, with authorization expiring January 31, 2024 . The purpose of these programs is to manage common stock dilution. All shares of common stock repurchased were retired.

Consolidated Statements of St_2

Consolidated Statements of Stockholders' Equity (Parenthetical) - USD ($) $ in Millions	12 Months Ended
	May 31, 2022	May 31, 2021	May 31, 2020
Unrealized (losses) gains on securities, tax	$ (53.1)	$ (4.8)	$ 22.6
Reclassification adjustment for realized gains on securities, tax	$ 0.1	$ 0.3	$ 2.8
Dividends declared, per share	$ 2.77	$ 2.52	$ 2.48
Authorized In May 2019 [Member]
Approved repurchase amount	$ 400	$ 400	$ 400
Expiration date	May 31, 2022	May 31, 2022	May 31, 2022
Authorized In July 2021 [Member]
Approved repurchase amount	$ 400	$ 400	$ 400
Expiration date	Jan. 31, 2024	Jan. 31, 2024	Jan. 31, 2024

Consolidated Statements of Cash

Consolidated Statements of Cash Flows - USD ($) $ in Millions	12 Months Ended
	May 31, 2022	May 31, 2021	May 31, 2020
Operating activities
Net income	$ 1,392.8	$ 1,097.5	$ 1,098.1
Adjustments to reconcile net income to net cash provided by operating activities:
Depreciation and amortization	191.8	192	209.7
Amortization of premiums and discounts on AFS securities, net	28.9	35.8	40.8
Amortization of deferred contract costs	202.1	191.4	186.1
Stock-based compensation costs	52.8	52.5	47.4
Provision for/(benefit from) deferred income taxes	2.3	(21)	(4)
Provision for credit losses	10.5	8	7.8
Net realized gains on sales of AFS securities	(0.2)	(1.2)	(11.3)
Changes in operating assets and liabilities:
Interest receivable	2.1	1.8	1.2
Accounts receivable and PEO unbilled receivables, net	(277)	(272.9)	55.1
Prepaid expenses and other current assets	(7.7)	(15.8)	(1.6)
Accounts payable and other current liabilities	151.8	169	(4.9)
Deferred costs	(267.1)	(208)	(196.6)
Net change in other long-term assets and liabilities	26.3	32.1	12.7
Net change in operating lease right-of-use assets and liabilities	(3.9)	(0.9)	0.4
Net cash provided by operating activities	1,505.5	1,260.3	1,440.9
Investing activities
Purchases of AFS securities	(17,807.7)	(6,089.7)	(25,218.1)
Proceeds from sales and maturities of AFS securities	16,554.9	5,771.9	26,132.9
Purchases of property and equipment, net of proceeds from sales	(132.6)	(114.6)	(127)
Acquisition of businesses, net of cash acquired	(24.9)	(19.5)	(6.1)
Purchases of other assets	(10.6)	(8.7)	(9.8)
Net cash (used in)/provided by investing activities	(1,420.9)	(460.6)	771.9
Financing activities
Net change in client fund obligations	143.2	340	(453.3)
Net proceeds from short-term borrowings	1.3	2.3	5.1
Dividends paid	(999.6)	(908.7)	(889.4)
Repurchases of common shares	(145.2)	(155.7)	(171.9)
Contingent consideration paid for acquisitions	(1.6)
Activity related to equity-based plans	22.6	85.7	21.3
Net cash used in financing activities	(979.3)	(636.4)	(1,488.2)
Net change in cash, restricted cash, and equivalents	(894.7)	163.3	724.6
Cash, restricted cash, and equivalents, beginning of fiscal year	1,823.1	1,659.8	935.2
Cash, restricted cash, and equivalents, end of fiscal year	928.4	1,823.1	1,659.8
Reconciliation of cash, restricted cash, and equivalents
Cash and cash equivalents	370	995.2	905.2
Restricted cash	75.8	88.3	71.1
Restricted cash and restricted cash equivalents included in funds held for clients	482.6	739.6	683.5
Total cash, restricted cash, and equivalents	$ 928.4	$ 1,823.1	$ 1,659.8

Description of Business, Basis

Description of Business, Basis of Presentation, and Significant Accounting Policies	12 Months Ended
	May 31, 2022
Accounting Policies [Abstract]
Description of Business, Basis of Presentation, and Significant Accounting Policies	Note A — Description of Business, Basis of Presentation, and Significant Accounting Policies Description of business: Paychex, Inc. and its wholly owned subsidiaries (collectively, the “Company” or “Paychex”) is a leading human resource (“HR”) software and services company, offering integrated human capital management (“HCM”) solutions for HR, payroll, benefits, and insurance services for small- to medium-sized businesses in the United States (“U.S.”). The Company also has operations in parts of Europe and India. Paychex, a Delaware corporation formed i n 1979, reports as one segment. Substantially all of the Company’s revenue is generated within the U.S. Approximately one percent of the Company’s total revenue was generated within Europe for each of the fiscal years ended May 31, 2022 (“fiscal 2022”), May 31, 2021 (“fiscal 2021”), and May 31, 2020 (“fiscal 2020 ”). Long-lived assets in Europe were approximately 6 % and 7 % of total long-lived assets of the Company as of May 31, 2022 and 2021 , respectively. Long-lived assets in India were less than 1 % of total long-lived assets of the Company as of May 31, 2022 and 2021. Within Paychex’s HCM solutions, Paychex offers a comprehensive portfolio of services and products that allow its clients to meet their diverse HR and payroll needs. Clients can select services on an á la carte basis or as part of various product bundles. Paychex’s offerings often leverage the information gathered in its base payroll processing service, allowing the Company to provide comprehensive outsourcing services covering the HCM spectrum. Paychex supports its small business clients utilizing its proprietary, robust, software as a service (“SaaS”) Paychex Flex ® platform and the Company’s SurePayroll ® SaaS-based products. Both products allow users to process payroll when they want, how they want, and on any type of device (desktop, tablet, and mobile phone). Paychex’s medium-sized clients generally have more complex payroll and employee benefit needs and can opt for an integrated suite of HCM solutions, which allows them to choose the services and software that will meet the needs of their businesses. Total revenue is comprised of service revenue and interest on funds held for clients. Service revenue is comprised primarily of the fees earned on the portfolio of HCM services, which include payroll processing, complementary HR management and administration services, professional employer organization (“PEO”) solutions, and insurance agency commissions. Refer to Note B of this Item 8 for further discussion of the Company’s service revenue. Basis of presentation: The consolidated financial statements include the accounts of Paychex, Inc., and its wholly owned subsidiaries. All intercompany accounts and transactions have been eliminated in consolidation. Certain disclosures are reported as zero balances due to rounding. Reclassifications: Certain prior year amounts have been reclassified to conform to the current period presentation. These reclassifications had no effect on reported consolidated earnings. Cash and cash equivalents: Cash and cash equivalents consist of available cash, money market securities, and other investments with a maturity of 90 days or less at acquisition. Cash and cash equivalents include funds collected from the Company’s PEO clients for the payment of worksite employee payrolls and associated payroll taxes. Funds of $ 89.7 million and $ 150.5 million collected from PEO clients are included in cash and cash equivalents on the Company’s Consolidated Balance Sheets as of May 31, 2022 and 2021 , respectively. Restricted cash and restricted cash equivalents: Restricted cash and restricted cash equivalents are recorded at fair value, and consist of cash and cash equivalents, primarily money market securities, included in funds held for clients and cash that is restricted in use for payment of workers’ compensation claims. Accounts receivable, net of allowance for credit losses: Accounts receivable balances are shown on the Consolidated Balance Sheets net of the allowance for credit losses of $ 18.2 million and $ 16.0 million as of May 31, 2022 and 2021, respectively. These balances include trade receivables for services provided to clients and purchased receivables related to payroll funding arrangements with clients in the temporary staffing industry. Trade receivables were $ 123.2 million and $ 98.4 million as of May 31, 2022 and 2021, respectively. Purchased receivables were $ 618.8 million and $ 495.9 million as of May 31, 2022 and 2021, respectively. The Company is exposed to credit losses through the sale of services, payment of client obligations, and collection of purchased receivables. To mitigate this credit risk, the Company has multiple programs in place to assess and continuously monitor each client’s ability to pay for these products and services. Credit monitoring programs include, but are not limited to, new client credit reviews, establishing appropriate credit limits, monitoring of credit distressed clients, and early electronic wire and collection procedures. The Company also considers contract terms and conditions, client business type or strategy and may require collateralized asset support or prepayment to mitigate credit risk. Accounts receivable are written off and charged against the allowance for credit losses when the Company has exhausted all collection efforts without success. The Company estimates its allowance for credit losses based on historical loss activity adjusted for current economic conditions and reasonable and supportable forecast factors, when applicable. The provision for the allowance for credit losses and accounts written off were no t material for the fiscal years ended May 31, 2022, 2021 and 2020 , respectively. No single client had a material impact on total accounts receivable as of May 31, 2022 or 2021 . No single client had a material impact on service revenue or results of operations for the fiscal years ended May 31, 2022, 2021 and 2020 . PEO unbilled receivables, net of advance collections: The Company recognizes a liability for worksite employee gross wages and related payroll tax liabilities at the end of the period in which the worksite employee performs work, and where it assumes, under applicable state regulations, the obligation for the payment of payroll and payroll tax liabilities. The estimated payroll and payroll tax liabilities are recorded in accrued worksite employee compensation and related items on the Company’s Consolidated Balance Sheets. The associated unbilled receivables, including estimated revenues, offset by advance collections from clients, are recorded as PEO unbilled receivables, net of advance collections on the Company’s Consolidated Balance Sheets. As of May 31, 2022 and 2021, advance collections included in PEO unbilled receivables, net of advance collections were $ 2.6 million and $ 2.5 million , respectively. Funds held for clients and corporate investments: Marketable securities included in funds held for clients and corporate investments consist primarily of securities classified as AFS and are recorded at fair value obtained from an independent pricing service. The funds held for clients portfolio also includes cash and cash equivalents such as money market securities. Unrealized gains and losses, net of applicable income taxes, are reported as other comprehensive income in the Consolidated Statements of Income and Comprehensive Income. Realized gains and losses on the sale of AFS securities are determined by specific identification of the cost basis of each security. On the Consolidated Statements of Income and Comprehensive Income, realized gains and losses from the funds held for clients portfolio and corporate investments portfolio are included in interest on funds held for clients and other expense, net, respectively. Concentrations: Substantially all the Company’s deposited cash is maintained at large well-capitalized (as defined by their regulators) financial institutions. These deposits may exceed the amount of any insurance provided. All the Company’s deliverable securities, primarily municipal bond securities, are held in custody with certain of the aforementioned financial institutions, for which that institution bears the risk of custodial loss. Non-deliverable securities are primarily time deposits and money market funds. Property and equipment, net of accumulated depreciation: Property and equipment is stated at cost, less accumulated depreciation. Depreciation is based on the estimated useful lives of property and equipment using the straight-line method. The estimated useful lives of depreciable assets are generally as follows: Category Depreciable life Buildings and improvements 10 to 35 years or the remaining life, whichever is shorter Data processing equipment 3 to 4 years Furniture, fixtures, and equipment 2 to 7 years Leasehold improvements 10 years or the life of the lease, whichever is shorter Software 3 to 12 years Normal and recurring repairs and maintenance costs are charged to expense as incurred. The Company reviews the carrying value of property and equipment for impairment when events or changes in circumstances indicate that the carrying value of such assets may not be recoverable. Software development and enhancements: Expenditures for software purchases and software developed for internal use are capitalized and depreciated on a straight-line basis over the estimated useful lives, which are generally 3 to 5 years. Software developed as part of the Company’s main processing platform is depreciated over 12 years. For software developed for internal use, certain costs are capitalized, including external direct costs of materials and services associated with developing or obtaining the software, and payroll and payroll-related costs for employees who are directly associated with internal-use software projects. Capitalization of these costs ceases no later than the point at which the project is substantially complete and ready for its intended use. Costs associated with preliminary project stage activities, training, maintenance, and other post-implementation stage activities are expensed as incurred. The carrying value of software and development costs is reviewed for impairment when events or changes in circumstances indicate that the carrying value of such assets may not be recoverable. Goodwill and other intangible assets, net of accumulated amortization: Goodwill is not amortized, but instead is tested for impairment on an annual basis and between annual tests if an event occurs or circumstances change in a way to indicate that there has been a potential decline in the fair value of a reporting unit. The Company performs its annual impairment testing in its fiscal fourth quarter. During fiscal 2022, a qualitative assessment was performed for our Paychex, Inc., excluding Purchased Receivables, reporting unit, and a quantitative assessment was performed on the Purchased Receivable reporting unit to determine if it is more-likely-than-not that the fair value of the reporting units had declined below their carrying value. A qualitative analysis was performed for all reporting units in fiscal 2021 and 2020 . The qualitative assessment considered various financial, macroeconomic, industry, and reporting unit specific qualitative factors. Based on the results of the Company’s testing, no impairment loss was recognized in the results of operations for fiscal 2022, 2021, or 2020. Subsequent to the latest review, there have been no events or circumstances that indicate any potential impairment of the Company’s goodwill balance. Intangible assets are comprised primarily of client list acquisitions and are reported net of accumulated amortization on the Consolidated Balance Sheets. Intangible assets are amortized over periods generally ranging from 3 to 12 years. Certain client lists use an accelerated method, while other intangible assets use the straight-line method of amortization. In addition, the Company has intangible assets with indefinite useful lives, which are tested for impairment on an annual basis and between annual tests if an event occurs or circumstances change in a way to indicate that the carrying value may not be recoverable. The Company has determined, using qualitative assessments, there is no impairment of intangible assets with indefinite useful lives for fiscal 2022, 2021, or 2020 . Impairment of Long-Lived Assets: Long-lived assets, including intangible assets with finite lives and operating lease right-of-use (“ROU”) assets, are reviewed for impairment when events or changes in circumstances indicate that the carrying amount of an asset may not be recoverable. Recoverability of assets to be held and used is measured by a comparison of the carrying amount of an asset to estimated undiscounted future cash flows expected to be generated by the asset. If the carrying amount of an asset exceeds its estimated future cash flows, an impairment charge is recognized for the amount by which the carrying amount of the asset exceeds the estimated fair value of the asset. The Company has determined that there was no impairment of long-lived assets for fiscal 2022, 2021, or 2020 . Foreign Currency: The financial statements of the Company’s foreign subsidiaries have been translated into U.S. dollars. Assets and liabilities are translated into U.S. dollars at period-end exchange rates. Income and expenses are translated at the average exchange rate for the reporting period. The resulting non-cash foreign currency translation adjustments, representing unrealized gains or losses, are included in Consolidated Statements of Stockholders’ Equity as a component of accumulated other comprehensive (loss)/income, net of tax. The Company did no t have any material realized gains or losses resulting from foreign exchange transactions during fiscal 2022, 2021, or 2020 . Revenue recognition: Revenues are primarily attributable to fees for providing services as well as investment income earned on funds held for clients. Fees associated with services are recognized in the period services are rendered and earned under service arrangements with clients where service fees are fixed or determinable and collectability is reasonably assured. The Company’s service revenue is largely attributable to processing services where the fee is based on a fixed amount per processing period or a fixed amount per processing period plus a fee per employee or transaction processed. Insurance Solutions revenues are recognized when commissions are earned on premiums billed and collected. Fees earned for funding payrolls of our clients in the temporary staffing agency via the purchase of accounts receivable are based on a percentage of funding amounts as specified in the client contract. These fees are then recognized over the average collection period of 46 to 48 days. The revenue earned from delivery service for the distribution of certain client payroll checks and reports is included in service revenue, and the costs for the delivery are included in cost of service revenue on the Consolidated Statements of Income and Comprehensive Income. The Company receives advance payments for set-up fees from its clients. Advance payments received for certain of the Company’s service offerings for set-up fees are considered a material right. Therefore, the Company defers the revenue associated with these advance payments, recognizing the revenue and related expenses over the expected period to which the material right exists. PEO Solutions revenue is included in service revenue and is reported net of certain pass-through costs billed and incurred, which include payroll wages, payroll taxes, including federal and state unemployment insurance, and certain health insurance benefit premiums, primarily costs related to the Company’s guaranteed cost benefit plans. Direct costs related to workers’ compensation and certain benefit plans where the Company retains risk are recognized as cost of service revenue rather than as a reduction in service revenue. Refer to Note B of this Item 8 for further discussion of the PEO pass-through costs. Interest on funds held for clients is earned primarily on funds that are collected from clients before due dates for payroll tax administration services and for employee payment services and invested until remittance to the applicable tax or regulatory agencies or client employees. The interest earned on these funds is included in total revenue on the Consolidated Statements of Income and Comprehensive Income because the collecting, holding, and remitting of these funds are components of providing these services. Assets Recognized from the Costs to Obtain and Fulfill Contracts: The Company recognizes an asset for the incremental costs of obtaining a contract with a client if it is expected that the economic benefit and amortization period will be longer than one year. Incremental costs of obtaining a contract include only those costs that are directly related to the acquisition of new contracts and that would not have been incurred if the contract had not been obtained. The Company does not incur incremental costs to obtain a contract renewal. The Company determined that certain sales commissions and bonuses, including related fringe benefits, meet the capitalization criteria under Accounting Standards Codification (“ASC”) Subtopic 340-40, “Other Assets and Deferred Costs: Contracts with Customers” (“ASC 340-40”). The Company also recognizes an asset for the costs to fulfill a contract with a client if the costs are specifically identifiable, generate or enhance resources used to satisfy future performance obligations, and are expected to be recovered. The Company determined that substantially all costs related to implementation activities are administrative in nature and meet the capitalization criteria under ASC 340-40. These capitalized costs to fulfill a contract principally relate to upfront direct costs that are expected to be recovered and enhance the Company’s ability to satisfy future performance obligations. The assets related to both costs to obtain and costs to fulfill contracts with clients are capitalized and amortized using an accelerated method over an eight-year life to closely align with the pattern of client attrition over the estimated life of the client relationship. The Company regularly reviews its deferred costs for potential impairment and did no t recognize an impairment loss during fiscal 2022, 2021, or 2020 . Cost of service revenue: The Company’s costs and expenses applicable to total service revenue represent direct costs associated with providing HR, payroll, benefits, and insurance services. This includes labor-related costs, direct costs related to certain PEO offerings, postage and delivery costs, facility costs, professional services, and depreciation and amortization of property and equipment, including internally developed software. Selling, general and administrative expenses: The Company’s selling, general and administrative expenses represent labor-related costs, including amortization of deferred sales commissions and bonuses, corporate asset depreciation and amortization, marketing, and other general and administrative expenses incurred by the Company. PEO insurance reserves: As part of the PEO solution, the Company offers workers’ compensation insurance and health insurance to clients for the benefit of client employees. Workers’ compensation insurance is primarily provided under fully insured high deductible workers’ compensation insurance policies. Workers’ compensation insurance reserves are established to provide for the estimated costs of paying claims up to per occurrence liability limits. These reserves include estimates of certain expenses associated with processing and settling these claims. In establishing the PEO workers’ compensation insurance reserves, the Company uses an independent actuarial estimate of undiscounted future cash payments that would be made to settle claims. The determination of estimated ultimate losses by the Company’s independent actuary are based on accepted actuarial methods and assumptions. The estimated ultimate losses are primarily based upon loss development factors, and other factors such as the nature of employees’ job responsibilities, the historical frequency and severity of workers’ compensation claims, and an estimate of future cost trends. Each reporting period, changes in actuarial assumptions resulting from changes in actual claims experience and other trends are incorporated into our workers’ compensation claims cost estimates. For fiscal 2022 , the Company has an aggregate maximum liability of $ 2.0 million for claims exceeding $ 1.0 million, and once met, the maximum individual claims liability is $ 1.0 million. The Company’s maximum individual claims liability under its PEO workers’ compensation insurance policies was $ 1.0 million for fiscal 2021. As of May 31, 2022 and 2021, the Company had recorded current liabilities of $ 64.1 million and $ 65.3 million , respectively, and long-term liabilities of $ 125.6 million and $ 117.8 million , respectively, on its Consolidated Balance Sheets for workers’ compensation insurance reserves. The amounts were recorded in the other current liabilities and other long-term liabilities sections, respectively, of the Consolidated Balance Sheets. With respect to the PEO health insurance, the Company offers various health insurance plans that take the form of either fully insured guaranteed cost plans or fully insured insurance arrangements where the Company retains risk. A reserve for insurance arrangements where the Company retains risk is established to provide for the payment of claims in accordance with the Company’s service contract with the carrier. The claims liability includes estimates for reported losses, plus amounts for those claims incurred but not reported, and estimates of certain expenses associated with processing and settling the claims. The Company’s maximum individual claims liability was $ 0.5 million and $ 0.3 million under its policies durin g both fiscal 2022 and fiscal 2021, respectively. Amounts accrued related to the health insurance and dental and vision plan reserves were $ 46.2 million and $ 43.9 million as of May 31, 2022 and 2021, respectively. These amounts are included in current liabilities on the Consolidated Balance Sheets. Estimating the ultimate cost of future claims is an uncertain and complex process based upon historical loss experience and independent actuarial loss projections, and is subject to change due to multiple factors, including economic trends, changes in legal liability law, and damage awards, all of which could materially impact the reserves as reported in the consolidated financial statements. Accordingly, final claim settlements may vary from the present estimates, particularly with workers’ compensation insurance where those payments may not occur until well into the future. The Company regularly reviews the adequacy of its estimated insurance reserves. Adjustments to previously established reserves are reflected in the results of operations for the period in which the adjustment is identified. Such adjustments could be significant, reflecting any combination of new and adverse or favorable trends. Adjustments to previously established reserves were not material for fiscal 2022, 2021, or 2020 . Leases: The Company adopted the requirements of Accounting Standards Updates (“ASUs”) No. 2016-02 on June 1, 2019. At contract inception, the Company determines if the new contractual arrangement is a lease or contains a leasing arrangement. If a contract contains a lease whose term is greater than one year, the Company evaluates whether it should be classified as an operating or a finance lease. Currently, all the Company’s leases have been classified as operating leases. Upon modification of a contract, the Company will reassess to determine if a contract is or contains a leasing arrangement. The Company records lease liabilities based on the future estimated cash payments discounted over the lease term, defined as the non-cancellable time period of the lease, together with all the following: • periods covered by an option to extend the lease if the Company is reasonably certain to exercise the extension option; and • periods covered by an option to terminate the lease if the Company is reasonably certain not to exercise the termination option. Leases may also include options to terminate the arrangement or options to purchase the underlying lease property. The Company does not separate lease and non-lease components of contracts. Lease components provide the Company with the right to use an identified asset, which consist of the Company’s real estate properties and office equipment. Non-lease components consist primarily of maintenance services. As an implicit discount rate is typically not readily determinable in the Company’s lease agreements, the Company uses its estimated secured incremental borrowing rate based on the information available at the lease commencement date in determining the present value of future lease payments. The incremental borrowing rate is determined using a portfolio approach utilizing publicly available information related to our unsecured borrowing rates. For certain leases with original terms of 12 months or less, the Company recognizes lease expense as incurred and does not recognize any lease liabilities. Short-term and long-term portions of operating lease liabilities are classified as other current liabilities and operating lease liabilities, respectively, in the Company’s Consolidated Balance Sheets. An ROU asset is measured as the amount of the lease liability with adjustments, if applicable, for lease incentives, initial direct costs incurred by the Company, and lease prepayments made prior to or at lease commencement. ROU assets are classified as operating lease ROU assets, net of accumulated amortization, on the Company’s Consolidated Balance Sheets. The Company evaluates the carrying value of ROU assets if there are indicators of potential impairment and performs the analysis concurrent with the review of the recoverability of the related asset group. If the carrying value of the asset group is determined to not be fully recoverable and is in excess of its estimated fair value, the Company will record an impairment loss in its Consolidated Statements of Income and Comprehensive Income. The Company did no t recognize an impairment loss during fiscal 2022, fiscal 2021 or fiscal 2020. Fixed lease expense payments are recognized on a straight-line basis over the lease term. Variable lease payments vary because of changes in facts or circumstances occurring after the commencement date, other than the passage of time, and are often due to changes in an external market rate or the value of an index (e.g. Consumer Price Index). Variable lease payments are expensed as incurred in the Company’s Consolidated Statements of Income and Comprehensive Income. Stock-based compensation costs: All stock-based awards to employees are recognized as compensation costs in the consolidated financial statements based on their fair values measured as of the date of grant. The Company estimates the fair value of stock option grants using a Black-Scholes option pricing model. This model requires various assumptions as inputs including expected volatility of the Paychex stock price and expected option life. Volatility is estimated based on a combination of historical volatility, using stock prices over a period equal to the expected option life, and implied market volatility. Expected option life is estimated based on historical exercise behavior. The Company periodically reassesses its assumptions as well as its choice of valuation model. The Company will reconsider use of this model if additional information becomes available in the future indicating that another model would provide a more accurate estimate of fair value or if characteristics of future grants would warrant such a change. The fair value of stock awards is determined based on the stock price at the date of grant. For grants that do not accrue dividends or dividend equivalents, the fair value is the stock price reduced by the present value of estimated dividends over the vesting period or performance period. The Company’s policy is to estimate forfeitures and only record compensation costs for those awards that are expected to vest. The assumptions for forfeitures are determined based on type of award and historical experience. Forfeiture assumptions are adjusted at the point in time a significant change is identified, with any adjustment recorded in the period of change, and the final adjustment at the end of the requisite service period to equal actual forfeitures. The assumptions of volatility, expected option life, and forfeitures all require significant judgment and are subject to change in the future due to factors such as employee exercise behavior, stock price trends, and changes to type or provisions of stock-based awards. Any material change in one or more of these assumptions could have an impact on the estimated fair value of a future award. Refer to Note E of this Item 8 for further discussion of the Company’s stock-based compensation plans. Income taxes: The Company accounts for deferred taxes by recognizing deferred tax assets and liabilities for the expected future tax consequences of events that have been included in the consolidated financial statements or tax returns. Under this method, deferred tax assets and liabilities are determined based on the difference between the financial statement and tax basis of assets and liabilities, using enacted tax rates in effect for the fiscal year in which the differences are expected to reverse. The Company also maintains a reserve for uncertain tax positions. The Company evaluates tax positions taken or expected to be taken in a tax return for recognition in its consolidated financial statements. Prior to recording the related tax benefit in the consolidated financial statements, the Company must conclude that tax positions will be more-likely-than-not to be sustained, assuming those positions will be examined by taxing authorities with full knowledge of all relevant information. The benefit recognized in the consolidated financial statements is the amount the Company expects to realize after examination by taxing authorities. If a tax position drops below the more-likely-than-not standard, the benefit can no longer be recognized. Assumptions, judgment, and the use of estimates are required in determining if the more-likely-than-not standard has been met when developing the provision for income taxes and in determining the expected benefit. A change in the assessment of the more-likely-than-not standard could materially impact the Company’s results of operations or financial position. Refer to Note K of this Item 8 for further discussion of the Company’s reserve for uncertain tax positions. Use of estimates: The preparation of financial statements in conformity with U.S. generally accepted accounting principles requires management to make estimates, judgments, and assumptions that affect reported amounts of assets, liabilities, revenue, and expenses during the reporting period. Actual amounts and results could differ from these estimates. Recently adopted accounting pronouncements: In June 2021 , the Company adopted the following ASUs, no ne of which had a material impact on its consolidated financial statements: • ASU No. 2020-08, “Codification Improvements to Subtopic 310-20, Receivables – Nonrefundable Fees and Other Costs;” and • ASU No. 2019-12, “Income Taxes (Topic 740): Simplifying the Accounting for Income Taxes.” Recently issued accounting pronouncements: In November 2021, the Financial Accounting Standards Board (“FASB”) issued ASU No. 2021-10 “Government Assistance (Topic 832): Disclosures by Business Entities about Government Assistance.” This ASU will improve the transparency of government assistance received by most business entities by requiring the disclosure of: (1) the types of government assistance received; (2) the accounting for such assistance; and (3) the effect of the assistance on a business entity’s financial statements. ASU No. 2021-10 is effective for financial statements issued for annual periods beginning after December 15, 2021, with early application permitted. This ASU is applicable to the Company's fiscal year beginning June 1, 2022. The adoption o

Service Revenue

Service Revenue	12 Months Ended
	May 31, 2022
Revenue from Contract with Customer [Abstract]
Service Revenue	Note B — Service Revenue Service revenue is primarily attributable to fees for providing services to the Company’s clients and is recognized when control of the contracted services is transferred to its clients, in an amount that reflects the consideration it expects to receive in exchange for such services. Insurance Solutions revenue is commissions earned on premiums collected and remitted to insurance carriers. The Company’s contracts generally do not contain specified contract periods and may be terminated by either party with 30 -days notice of termination. Sales and other applicable non-payroll related taxes are excluded from service revenue. Based upon similar operational and economic characteristics, the Company’s service revenue is disaggregated by Management Solutions and PEO and Insurance Solutions as reported in the Company’s Consolidated Statements of Income and Comprehensive Income. The Company believes these revenue categories depict how the nature, amount, timing, and uncertainty of its revenue and cash flows are affected by economic factors. Management Solutions Revenue Management Solutions revenue is primarily derived from the Company’s integrated HCM and HR outsourcing solutions. Clients can select services on an á la carte basis or as part of various product bundles. The Company’s offerings often leverage the information gathered in its base payroll processing service, allowing it to provide comprehensive outsourcing services covering the HCM spectrum. Management Solutions revenue is generally recognized over time as services are performed and the customer simultaneously receives and controls the benefits from these services. Revenue earned from delivery service for the distribution of certain client payroll checks and reports is also included in Management Solutions revenue in the Company’s Consolidated Statements of Income and Comprehensive Income. Delivery service revenue is recognized at a point in time following the delivery of payroll checks, reports, quarter-end packages, and tax returns to the Company’s clients. PEO and Insurance Solutions Revenue PEO solutions are sold through the Company’s registered and licensed subsidiaries and offer businesses HCM and HR outsourcing solutions. The Company serves as a co-employer of its clients’ employees, offers health insurance coverage to client employees, and assumes the risks and rewards of workers’ compensation insurance and certain health insurance offerings. PEO Solutions revenue is recognized over time as the services are performed and the customer simultaneously receives and controls the benefits from these services. PEO Solutions revenue is reported net of certain pass-through costs billed and incurred, which include payroll wages, payroll taxes, including federal and state unemployment insurance, and health insurance premiums on guaranteed cost benefit plans. For workers’ compensation and health insurance plans where the Company retains risk, revenues and costs are recorded on a gross basis. PEO pass-through costs netted within the PEO and Insurance Solutions revenue are as follows: Year ended May 31, In millions 2022 2021 2020 Payroll wages and payroll taxes $ 24,070.2 $ 20,587.1 $ 20,463.8 State unemployment insurance (included in payroll wages and $ 139.1 $ 119.0 $ 85.7 Guaranteed cost benefit plans $ 641.4 $ 586.4 $ 647.0 Insurance solutions are sold through the Company’s licensed insurance agency, Paychex Insurance Agency, Inc., which provides insurance through a variety of carriers, allowing companies to expand their employee benefit offerings at an affordable cost. Insurance offerings include property and casualty coverage such as workers’ compensation, business-owner policies, commercial auto, cyber security, and health and benefits coverage, including health, dental, vision, and life. Insurance Solutions revenue reflects commissions earned on remitted insurance services premiums billed and is recognized over time as services are performed and the customer simultaneously receives and controls the benefits from these services. Contract Balances The timing of revenue recognition for Management Solutions and PEO and Insurance Solutions is consistent with the invoicing of clients as they both occur during the respective client payroll period for which the services are provided. Therefore, the Company does not recognize a contract asset or liability resulting from the timing of revenue recognition and invoicing. Payments received for certain of the Company’s service offerings for set-up fees are considered a material right. Therefore, the Company defers revenue associated with these performance obligations, which exceed one year, and subsequently recognizes them as future services are provided, over approximately three years to four years . Changes in deferred revenue related to material rights that exceed one year were as follows: Year ended May 31, In millions 2022 2021 Balance, beginning of period $ 40.2 $ 42.6 Deferral of revenue 35.0 23.5 Recognition of unearned revenue ( 26.3 ) ( 25.9 ) Balance, end of period $ 48.9 $ 40.2 Deferred revenue related to material rights is reported in the deferred revenue and other long-term liabilities line items on the Company’s Consolidated Balance Sheets. As of May 31, 2022 , the Company expects to recognize $ 22.1 million of deferred revenue related to material rights during its fiscal year ending May 31, 2023 and $ 26.8 million of deferred revenue thereafter . Assets Recognized from the Costs to Obtain and Fulfill Contracts The Company recognizes an asset for the incremental costs of obtaining a contract with a client if it is expected that the economic benefit and amortization period will be longer than one year. The Company also recognizes an asset for the costs to fulfill a contract with a client if the costs are specifically identifiable, generate or enhance resources used to satisfy future performance obligations, and are expected to be recovered. Deferred costs to obtain and fulfill contracts are reported in the prepaid expenses and other current assets and long-term deferred costs line items on the Company’s Consolidated Balance Sheets. Amortization expense related to costs to obtain and fulfill a contract are included in cost of service revenue and selling, general and administrative expenses in the Company’s Consolidated Statements of Income and Comprehensive Income. Refer to Note A of this Item 8 for additional disclosures on our policies for assets recognized from the costs to obtain and fulfill contracts. The Company regularly reviews its deferred costs for potential impairment and did no t recognize an impairment loss during fiscal 2022, 2021, or 2020. Changes in deferred costs to obtain and fulfill contracts were as follows: Costs to fulfill contracts: Year ended May 31, In millions 2022 2021 Balance, beginning of period $ 69.3 $ 67.3 Capitalization of costs 28.0 26.2 Amortization ( 25.0 ) ( 24.2 ) Balance, end of period $ 72.3 $ 69.3 Costs to obtain contracts: Year ended May 31, In millions 2022 2021 Balance, beginning of period $ 488.2 $ 473.6 Capitalization of costs 239.1 181.8 Amortization ( 177.1 ) ( 167.2 ) Balance, end of period $ 550.2 $ 488.2

Basic and Diluted Earnings Per

Basic and Diluted Earnings Per Share	12 Months Ended
	May 31, 2022
Earnings Per Share [Abstract]
Basic and Diluted Earnings Per Share	Note C — Basic and Diluted Earnings Per Share Basic and diluted earnings per share were calculated as follows: Year ended May 31, In millions, except per share amounts 2022 2021 2020 Basic earnings per share: Net income $ 1,392.8 $ 1,097.5 $ 1,098.1 Weighted-average common shares outstanding 360.6 359.9 358.5 Basic earnings per share $ 3.86 $ 3.05 $ 3.06 Diluted earnings per share: Net income $ 1,392.8 $ 1,097.5 $ 1,098.1 Weighted-average common shares outstanding 360.6 359.9 358.5 Dilutive effect of common share equivalents 2.5 2.2 2.5 Weighted-average common shares outstanding, assuming dilution 363.1 362.1 361.0 Diluted earnings per share $ 3.84 $ 3.03 $ 3.04 Weighted-average anti-dilutive common share equivalents 0.2 0.6 0.7 Weighted-average common share equivalents that had an anti-dilutive impact are excluded from the computation of diluted earnings per share.

Other Expense, Net

Other Expense, Net	12 Months Ended
	May 31, 2022
Other Income and Expenses [Abstract]
Other Expense, Net	Note D — Other Expense, Net Other expense, net, consisted of the following items: Year ended May 31, In millions 2022 2021 2020 Interest income on corporate investments $ 2.9 $ 2.3 $ 12.3 Interest expense ( 36.6 ) ( 35.8 ) ( 38.8 ) Other 18.3 7.0 3.1 Other expense, net $ ( 15.4 ) $ ( 26.5 ) $ ( 23.4 )

Stock-Based Compensation Plans

Stock-Based Compensation Plans	12 Months Ended
	May 31, 2022
Share-based Payment Arrangement [Abstract]
Stock-Based Compensation Plans	Note E — Stock-Based Compensation Plans The Paychex, Inc. 2002 Stock Incentive Plan, as last amended and restated effective October 15, 2020 (the “2002 Plan”), authorizes grants of up to 44.1 million shares of the Company’s common stock. As of May 31, 2022, there were 15.6 million shares available for future grants under the 2002 Plan. All stock-based awards to employees are recognized as compensation costs in the consolidated financial statements based on their fair values measured as of the date of grant. These costs are recognized as an expense in the Consolidated Statements of Income and Comprehensive Income on a straight-line basis over the requisite service period and an increase in additional paid-in capital. Stock-based compensation expense was $ 52.8 million , $ 52.5 million , and $ 47.4 million for fiscal years 2022, 2021, and 2020, respectively. Related income tax benefits recognized were $ 9.8 million , $ 8.6 million , and $ 9.0 million for the respective fiscal years. As of May 31, 2022, the total unrecognized compensation cost related to all unvested stock-based awards was $ 80.5 million and is expected to be recognized over a weighted-average period of 2.8 years. Black-Scholes fair value assumptions: The fair value of stock option grants was estimated at the date of grant using a Black-Scholes option pricing model. The weighted-average assumptions used for valuation under the Black-Scholes option pricing model are as follows: Year ended May 31, 2022 2021 2020 Risk-free interest rate 1.2 % 0.5 % 2.0 % Dividend yield 2.9 % 3.2 % 3.3 % Volatility factor 0.23 0.29 0.18 Expected option life in years 6.6 6.1 6.2 Weighted-average grant-date $ 17.47 $ 13.52 $ 9.86 Risk-free interest rates are yields for zero coupon U.S. Treasury notes maturing approximately at the end of the expected option life. The estimated volatility factor is based on a combination of historical volatility, using stock prices over a period equal to the expected option life, and implied market volatility. The expected option life is based on historical exercise behavior. Stock options: Stock options entitle the holder to purchase, at the end of the vesting term, a specified number of shares of Paychex common stock at an exercise price per share equal to the closing market price of the common stock on the date of grant. All stock options have a contractual life of ten years from the date of the grant and a vesting schedule as established by the Board of Directors (the “Board”). The Company issues new shares of common stock to satisfy stock option exercises. Stock option grants to executives and outside directors are typically approved by the Board in July. Grants of stock options to executives vest one -third per annum. Grants to members of the Board vest after one year . Vesting is generally achieved on these dates with active employment or participation as a member of the Board on the date of vesting. The following table summarizes stock option activity for fiscal 2022: Weighted- Weighted- average Shares average remaining Aggregate subject exercise price contractual intrinsic In millions, except per share amounts to options per share term (years) value (1) Outstanding as of May 31, 2021 3.6 $ 62.89 Granted 0.4 $ 109.71 Exercised ( 0.7 ) $ 52.50 Forfeited — $ 88.13 Expired — $ 35.37 Outstanding as of May 31, 2022 3.3 $ 70.68 6.0 $ 174.9 Exercisable as of May 31, 2022 2.3 $ 62.11 5.0 $ 144.0 (1) Total shares valued at the market price of the underlying stock as of May 31, 2022 less the exercise price. Other information pertaining to stock option grants is as follows: Year ended May 31, In millions 2022 2021 2020 Total intrinsic value of stock options exercised $ 44.3 $ 58.5 $ 22.0 Total grant-date fair value of stock options vested $ 6.4 $ 6.0 $ 5.0 Restricted Stock Units (“RSUs”): The Board grants RSUs to certain executive and non-executive employees. An RSU is an agreement to issue shares at the time of vesting with no associated exercise cost for the employee. For each unit granted, the holder will receive one share of Paychex common stock at the time of vesting. If the recipient does not vest in the shares due to leaving Paychex, all shares or units of RSUs, and any dividends accrued thereon, when applicable, will be forfeited and returned to the Company. Time-based RSUs: Time-based RSUs granted to non-executives vest one -fifth per annum over five years , while those granted to executives vest one -third per annum over three years . Vesting is generally achieved on these dates with active employment. The fair value of time-based RSUs is equal to the closing market price of the underlying common stock as of the date of grant, adjusted for the present value of expected dividends over the vesting period. Time-based RSUs may, or may not, earn dividend equivalents depending on the terms of the specific grant. Performance-based RSUs: Performance-based RSUs primarily have a two year performance period, after which the number of underlying RSUs earned will be determined based on achievement against pre-established performance targets. The RSUs earned are then subject to a one year service period. Performance-based RSUs do not earn dividend equivalents during the performance period. The fair value of the RSUs is equal to the closing market price of the underlying common stock as of the date of grant, adjusted for the present value of expected dividends over the performance period. The following table summarizes RSU activity for fiscal 2022: Weighted- Weighted- average average Time- grant-date Performance- grant-date Based fair value based fair value In millions, except per share amounts RSUs per share RSUs per share Nonvested as of May 31, 2021 1.5 $ 65.64 0.1 $ 80.59 Granted (1) 0.5 $ 109.81 — $ 103.59 Vested ( 0.5 ) $ 63.08 — $ — Forfeited ( 0.2 ) $ 77.90 — $ 80.59 Nonvested as of May 31, 2022 1.3 $ 80.60 0.1 $ 92.33 (1) For performance-based RSUs, granted number assumes achievement of performance goals at target. Actual number of shares to be earned may differ from this amount. Other information pertaining to RSUs is as follows: Year ended May 31, In millions, except per share amounts 2022 2021 2020 Time-based RSUs: Weighted-average grant-date fair value per share of RSUs granted $ 109.81 $ 67.92 $ 73.28 Weighted-average remaining vesting period (years) 2.8 3.0 2.9 Total intrinsic value of RSUs vested $ 54.7 $ 32.6 $ 40.0 Aggregate intrinsic value of nonvested RSUs (1) $ 165.2 $ 152.7 $ 99.9 Total grant-date fair value of RSUs vested $ 30.0 $ 25.6 $ 23.6 Performance-based RSUs (2) : Weighted-average grant-date fair value per share of RSUs granted $ 103.59 $ — $ 80.59 Weighted-average remaining vesting period (years) 1.0 1.1 2.1 Total intrinsic value of RSUs vested $ — $ — $ — Aggregate intrinsic value of nonvested RSUs (1) $ 14.7 $ 6.2 $ 4.4 Total grant-date fair value of RSUs vested $ — $ — $ — (1) Based on the market price of the underlying common stock as of May 31, 2022, 2021 and 2020 . (2) No performance-based RSUs were granted during fiscal 2021. Restricted stock awards: The Board approves grants of restricted stock awards to the Company’s executives and outside directors. All shares underlying awards of restricted stock are restricted in that they are not transferable until they vest. Recipients of the restricted stock earn dividends, which are paid to the recipient at the time the awards vest. If the recipient does not vest in the shares due to leaving Paychex, all shares of restricted stock, and the dividends accrued thereon, when applicable, will be forfeited and returned to the Company. Time-based restricted stock awards: Time-based restricted stock awards granted to executives vest one -third per annum. Time-based restricted stock awards granted to outside directors vest on the one year anniversary of the grant date. Vesting is generally achieved on these dates with active employment or participation as a member of the Board on the date of vesting. The fair value of time-based restricted stock awards is equal to the closing market price of the underlying common stock as of the date of grant. Performance-based restricted stock awards: Performance-based restricted stock awards primarily have a two year performance period, after which the number of shares earned will be determined based on achievement against pre-established performance targets. The restricted shares earned are then subject to a one year service period. Performance-based shares do not earn dividend equivalents during the performance period. The fair value of performance-based shares is equal to the closing market price of the underlying common stock as of the date of grant, adjusted for the present value of expected dividends over the performance period. The following table summarizes time-based and performance-based restricted stock award activity for fiscal 2022: Weighted- Weighted- average average grant-date Performance- grant-date Time-based fair value based fair value In millions, except per share amounts shares per share shares per share Nonvested as of May 31, 2021 0.1 $ 74.60 0.1 $ 69.28 Granted (1) 0.1 $ 114.21 0.1 $ 103.97 Vested ( 0.1 ) $ 74.20 ( 0.1 ) $ 65.17 Forfeited — $ 98.11 — $ 107.40 Nonvested as of May 31, 2022 0.1 $ 93.15 0.1 $ 92.45 (1) For performance-based shares, granted number assumes achievement of performance goals at target. Actual number of shares to be earned may differ from this amount. Other information pertaining to time-based and performance-based restricted stock awards is as follows: Year ended May 31, In millions, except per share amounts 2022 2021 2020 Weighted-average grant-date fair value per share of time-based shares granted $ 114.21 $ 73.93 $ 84.46 Total grant-date fair value of time-based restricted stock vested $ 3.8 $ 3.0 $ 3.2 Weighted-average grant-date fair value per share of performance-based shares $ 103.97 $ 65.17 $ 80.59 Total grant-date fair value of performance-based restricted stock vested $ 7.2 $ 8.4 $ 5.8 Long-term Incentive Plan (“LTIP”): The Company has two long-term incentive performance-based stock awards under its LTIP. In July 2011, the Board approved a special award of performance-based non-qualified stock options. Although the performance period was completed in fiscal 2016 and the stock options were earned and vested, some stock options remained outstanding as of May 31, 2020; there were no stock options outstanding as of May 31, 2021 or 2022. In July 2016, the Board approved an LTIP award comprised of both performance-based non-qualified stock options and performance-based restricted stock awards. This award was granted to executives down to the vice president level with vesting dependent on achievement against long-term strategic and financial objectives. Total stock options and restricted shares earned were based on achievement against pre-established targets for fiscal 2020. The following table summarizes LTIP performance-based stock option activity for fiscal 2022: Weighted- Weighted- average Shares average remaining Aggregate subject exercise price contractual intrinsic In millions, except per share amounts to options per share term (years) value (1) Outstanding as of May 31, 2021 0.7 $ 60.71 Exercised ( 0.3 ) $ 61.06 Outstanding as of May 31, 2022 0.4 $ 60.52 4.0 $ 28.3 Exercisable as of May 31, 2022 0.4 $ 60.52 4.0 $ 28.3 (1) Shares valued at the market price of the underlying stock as of May 31, 2022 less the exercise price. Other information pertaining to LTIP performance-based stock options is as follows: Year ended May 31, In millions 2022 2021 2020 Total intrinsic value of stock options exercised $ 16.0 $ 26.3 $ 23.0 Total grant-date fair value of stock options vested $ — $ 8.0 $ — No performance-based stock options vested in fiscal years 2022 or 2020. There were no performance-based restricted stock awards outstanding as of May 31, 2022 or 2021. Non-compensatory employee benefit plan: The Company offers a qualified Employee Stock Purchase Plan (“ESPP”) to all employees. The Company’s common stock can be purchased through a payroll deduction at a discount to the market price. The qualified ESPP allows for a discount of up to 15 % based on the sole discretion of the committee established to administer the plan. For offering periods during fiscal years 2022, 2021, and 2020 the discount was set at 5 % of the market price. Transactions under the non-qualified ESPP occurred directly through the Company’s transfer agent and no brokerage fees were charged to employees. Transactions under the qualified ESPP occur through the Company’s third-party stock plan administrator. The plans have been deemed non-compensatory and therefore, no stock-based compensation costs have been recognized for fiscal years 2022, 2021, or 2020 related to the plan.

Funds Held for Clients and Corp

Funds Held for Clients and Corporate Investments	12 Months Ended
	May 31, 2022
Funds Held for Clients and Corporate Investments [Abstract]
Funds Held for Clients and Corporate Investments	Note F — Funds Held for Clients and Corporate Investments Funds held for clients and corporate investments are as follows: May 31, 2022 Gross Gross Amortized unrealized unrealized Fair In millions cost gains losses value Type of issue: Funds held for clients' money market securities and other $ 482.6 $ — $ — $ 482.6 AFS securities: Asset-backed securities 68.5 0.0 ( 1.3 ) 67.2 Corporate bonds 699.3 1.8 ( 19.0 ) 682.1 Municipal bonds 1,577.6 0.6 ( 92.4 ) 1,485.8 U.S. government agency and treasury securities 574.5 0.3 ( 26.3 ) 548.5 Variable rate demand notes 1,245.6 — — 1,245.6 Total AFS securities 4,165.5 2.7 ( 139.0 ) 4,029.2 Other 30.4 1.8 ( 2.2 ) 30.0 Total funds held for clients and corporate investments $ 4,678.5 $ 4.5 $ ( 141.2 ) $ 4,541.8 May 31, 2021 Gross Gross Amortized unrealized unrealized Fair In millions cost gains losses value Type of issue: Funds held for clients' money market securities and other $ 739.6 $ — $ — $ 739.6 AFS securities: Asset-backed securities 86.5 1.4 — 87.9 Corporate bonds 635.8 28.8 ( 0.2 ) 664.4 Municipal bonds 1,669.0 33.0 ( 2.3 ) 1,699.7 U.S. government agency and treasury securities 549.6 20.1 ( 1.5 ) 568.2 Variable rate demand notes — — — — Total AFS securities 2,940.9 83.3 ( 4.0 ) 3,020.2 Other 26.4 7.7 ( 0.1 ) 34.0 Total funds held for clients and corporate investments $ 3,706.9 $ 91.0 $ ( 4.1 ) $ 3,793.8 Included in funds held for clients’ money market securities and other restricted cash equivalents as of May 31, 2022 were bank demand deposit accounts, money market funds, time deposits, commercial paper and variable rate demand notes (“VRDNs”) with maturities of 90 days or less at acquisition. Included in asset-backed securities as of May 31, 2022 were investment-grade securities primarily collateralized by fixed-rate auto loans and credit card receivables and all have credit ratings of AAA. The primary risk associated with these securities is the collection of the underlying receivables. Collateral on these asset-backed securities has performed as expected through May 31, 2022. Included in corporate bonds as of May 31, 2022 were investment-grade securities covering a wide range of issuers, industries, and sectors and primarily carry credit ratings of A or better and having maturities ranging from June 9, 2022 through December 13, 2028 . Included in municipal bonds as of May 31, 2022 were general obligation bonds and revenue bonds primarily carrying credit ratings of AA or better and have maturities ranging from June 1, 2022 through April 1, 2029 . A substantial portion of our portfolios are invested in high credit quality securities with ratings of AA or higher, and A-1/P-1 ratings on short-term securities. The classification of funds held for clients and corporate investments on the Consolidated Balance Sheets is as follows: May 31, In millions 2022 2021 Funds held for clients $ 3,682.9 $ 3,750.0 Corporate investments 853.9 36.7 Long-term corporate investments 5.0 7.1 Total funds held for clients and corporate investments $ 4,541.8 $ 3,793.8 Funds held for clients’ money market securities and other restricted cash equivalents is collected from clients before due dates for payroll tax administration services and employee payment services and is invested until remitted to the applicable tax or regulatory agencies or client employees. Based upon the Company’s intent and its contractual obligation to clients, these funds are considered restricted until they are remitted to fund these client obligations. The Company’s AFS securities reflected a net unrealized loss of $ 136.3 million and a net unrealized gain of $ 79.3 million as of May 31, 2022 and May 31, 2021 respectively. Included in the net unrealized losses and gains as of May 31, 2022 and May 31, 2021 were 817 and 137 AFS securities in an unrealized loss position, representing approximately 64 % and 11 % of the total securities held, respectively. AFS securities in an unrealized loss position for which a credit loss has not been recognized were as follows: May 31, 2022 Securities in an unrealized Securities in an unrealized Total Gross Gross Gross unrealized Fair unrealized Fair unrealized Fair In millions losses value losses value losses value Type of issue: Asset-backed securities $ ( 0.9 ) $ 48.5 $ ( 0.3 ) $ 5.7 $ ( 1.2 ) $ 54.2 Corporate bonds ( 17.5 ) 425.4 ( 1.5 ) 16.7 ( 19.0 ) 442.1 Municipal bonds ( 81.9 ) 1,171.5 ( 10.6 ) 86.6 ( 92.5 ) 1,258.1 U.S. government agency and treasury securities ( 15.9 ) 414.2 ( 10.4 ) 91.7 ( 26.3 ) 505.9 Total $ ( 116.2 ) $ 2,059.6 $ ( 22.8 ) $ 200.7 $ ( 139.0 ) $ 2,260.3 May 31, 2021 Securities in an unrealized Securities in an unrealized Total Gross Gross Gross unrealized Fair unrealized Fair unrealized Fair In millions losses value losses value losses value Type of issue: Asset-backed securities $ — $ 7.1 $ — $ — $ — $ 7.1 Corporate bonds ( 0.2 ) 22.0 — — ( 0.2 ) 22.0 Municipal bonds ( 2.3 ) 288.2 — — ( 2.3 ) 288.2 U.S. government agency and treasury securities ( 1.5 ) 102.6 — — ( 1.5 ) 102.6 Total $ ( 4.0 ) $ 419.9 $ — $ — $ ( 4.0 ) $ 419.9 The Company regularly reviews its investment portfolios to determine if any investment is impaired due to changes in credit risk or other potential valuation concerns. The Company believes the investments held as of May 31, 2022 that had gross unrealized losses of $ 139.0 million were not impaired due to credit risk or other valuation concerns and was not required to record a credit loss or an allowance for credit losses on its AFS securities. The Company believes it is probable that the principal and interest will be collected in accordance with contractual terms and that the unrealized losses on these securities were due to changes in interest rates and were not due to increased credit risk or other valuation concerns. A substantial portion of the securities in an unrealized loss position as of May 31, 2022 and 2021 held an AA rating or better. The Company does not intend to sell these investments until the recovery of their amortized cost basis or maturity and further believes that it is not more-likely-than-not that it will be required to sell these investments prior to that time. The Company’s assessment that an investment is not impaired due to credit risk or other valuation concerns could change in the future due to new developments or changes in the Company’s strategies or assumptions related to any particular investment. Realized gains and losses from the sale of AFS securities were as follows: Year ended May 31, In millions 2022 2021 2020 Gross realized gains $ 0.2 $ 1.2 $ 11.6 Gross realized losses 0.0 — ( 0.3 ) Net realized gains $ 0.2 $ 1.2 $ 11.3 The amortized cost and fair value of AFS securities that had stated maturities as of May 31, 2022 are shown below by expected maturity. May 31, 2022 Amortized Fair In millions cost value Maturity date: Due in one year or less $ 295.6 $ 296.3 Due after one year through three years 743.2 737.1 Due after three years through five years 1,304.4 1,235.4 Due after five years 1,822.3 1,760.4 Total $ 4,165.5 $ 4,029.2 VRDNs are primarily categorized as due after five years in the table above as the contractual maturities on these securities are typically 20 to 30 years . Although these securities are issued as long-term securities, they are priced and traded as short-term instruments because of the liquidity provided through the tender feature.

Fair Value Measurements

Fair Value Measurements	12 Months Ended
	May 31, 2022
Fair Value Disclosures [Abstract]
Fair Value Measurements	Note G — Fair Value Measurements Fair value is defined as the price that would be received to sell an asset or paid to transfer a liability (an exit price) in an orderly transaction between market participants at the measurement date. The accounting standards related to fair value measurements include a hierarchy for information and valuations used in measuring fair value that is broken down into three levels based on reliability, as follows: • Level 1 valuations are based on quoted prices in active markets for identical instruments that the Company can access at the measurement date. • Level 2 valuations are based on inputs other than quoted prices included in Level 1 that are observable for the instrument, either directly or indirectly, for substantially the full term of the asset or liability including the following: o quoted prices for similar, but not identical, instruments in active markets; o quoted prices for identical or similar instruments in markets that are not active; o inputs other than quoted prices that are observable for the instrument; or o inputs that are derived principally from or corroborated by observable market data by correlation or other means. • Level 3 valuations are based on information that is unobservable and significant to the overall fair value measurement. The carrying values of cash and cash equivalents, restricted cash and restricted cash equivalents, accounts receivable, net of allowance for credit losses, PEO unbilled receivables, net of advance collections, accounts payable and short-term borrowings, when used by the Company, approximate fair value due to the short maturities of these instruments. Marketable securities included in funds held for clients and corporate investments consist primarily of securities classified as AFS and are recorded at fair value on a recurring basis. The Company’s financial assets and liabilities measured at fair value on a recurring basis were as follows: May 31, 2022 Quoted Significant prices in other Significant Carrying active observable unobservable value markets inputs inputs In millions (Fair value) (Level 1) (Level 2) (Level 3) Assets: Restricted and unrestricted cash equivalents: Commercial paper $ 5.2 $ — $ 5.2 $ — Time deposits 187.9 — 187.9 — VRDNs 10.0 — 10.0 — Money market securities 16.1 16.1 — — Total restricted and unrestricted cash equivalents $ 219.2 $ 16.1 $ 203.1 $ — AFS securities: Asset-backed securities $ 67.2 $ — $ 67.2 $ — Corporate bonds 682.1 — 682.1 — Municipal bonds 1,485.8 — 1,485.8 — U.S. government agency and treasury securities 548.5 — 548.5 — VRDNs 1,245.6 — 1,245.6 — Total AFS securities $ 4,029.2 $ — $ 4,029.2 $ — Other $ 30.0 $ 30.0 $ — $ — Liabilities: Other long-term liabilities $ 29.9 $ 29.9 $ — $ — May 31, 2021 Quoted Significant prices in other Significant Carrying active observable unobservable value markets inputs inputs In millions (Fair value) (Level 1) (Level 2) (Level 3) Assets: Restricted and unrestricted cash equivalents: Money market securities $ 2.9 $ 2.9 $ — $ — Total restricted and unrestricted cash equivalents $ 2.9 $ 2.9 $ — $ — AFS securities: Asset-backed securities $ 87.9 $ — $ 87.9 $ — Corporate bonds 664.4 — 664.4 — Municipal bonds 1,699.7 — 1,699.7 — U.S. government agency and treasury securities 568.2 — 568.2 — VRDNs — — — — Total AFS securities $ 3,020.2 $ — $ 3,020.2 $ — Other $ 34.0 $ 34.0 $ — $ — Liabilities: Other long-term liabilities $ 32.6 $ 32.6 $ — $ — In determining the fair value of its assets and liabilities, the Company predominately uses the market approach. Money market securities, which are cash equivalents, are considered Level 1 investments as they are valued based on quoted market prices in active markets. Cash equivalents also include commercial paper, time deposits, and VRDNs which are considered Level 2 investments as they are valued based on similar, but not identical, instruments in active markets. AFS securities, including asset-backed securities, corporate bonds, municipal bonds, U.S. government agency securities, and VRDNs, when held by the Company, are included in Level 2 and are valued utilizing inputs obtained from an independent pricing service. To determine the fair value of the Company’s Level 2 AFS securities, the independent pricing service uses a variety of inputs, including benchmark yields, reported trades, non-binding broker/dealer quotes, issuer spreads, two-sided markets, benchmark securities, bids, offers, reference data, new issue data, and monthly payment information. The Company has not adjusted the prices obtained from the independent pricing service because it believes that they are appropriately valued. Assets included as other are mutual fund investments, consisting of participants’ eligible deferral contributions under the Company’s non-qualified and unfunded deferred compensation plans. The related liability is reported as other long-term liabilities. The mutual funds are considered Level 1 investments as they are valued based on quoted market prices in active markets. The Company’s long-term borrowings are accounted for on a historical cost basis. As of May 31, 2022 and May 31, 2021, the fair value of long-term borrowings, net of debt issuance costs was $ 404.1 million and $ 450.2 million for the Senior Notes, Series A, respectively, and $ 402.5 million and $ 457.7 million for the Senior Notes, Series B, respectively. The Company’s long-term borrowings are not traded in active markets, and as a result, its fair values were estimated using a market approach employing Level 2 valuation inputs, including borrowing rates the Company believes are currently available based on loans with similar terms and maturities. The preceding methods described may produce a fair value calculation that may not be indicative of net realizable value or reflective of future fair values. Furthermore, although the Company believes its valuation methods are appropriate and consistent with other market participants, the use of different methodologies or assumptions to determine the fair value of certain financial instruments could result in a different fair value measurement at the reporting date.

Leases

Leases	12 Months Ended
	May 31, 2022
Leases [Abstract]
Leases	Note H — Leases The Company’s lease portfolio consists primarily of operating leases for office space and has remaining terms from less than one year up to ten years , with contractual terms expiring from 2022 to 2032 . Lease contracts may include one or more renewal options that allow the Company to extend the lease term, typically from one year to five years per renewal option. The exercise of lease options is generally at the discretion of the Company. None of the Company’s leases contain residual value guarantees, substantial restrictions, or covenants. Supplemental balance sheet information related to the Company’s leases were as follows: May 31, $ in millions 2022 2021 Operating lease right-of-use assets, net of accumulated amortization $ 78.7 $ 103.0 Operating lease liabilities, current (1) 25.1 28.9 Operating lease liabilities, non-current 74.8 92.4 Weighted average remaining lease term (in years) 5.1 5.2 Weighted average discount rate 1.94 % 1.81 % (1) The current portion of operating lease liabilities is reported in the other current liabilities line item on the Company’s Consolidated Balance Sheets. The components of lease expense were as follows: Year ended May 31, In millions 2022 2021 2020 Fixed payment operating lease expense $ 27.2 $ 34.6 $ 38.2 Variable payment operating lease expense 6.9 8.3 8.6 Short-term lease expense - 0.1 0.2 During the three months ended August 31, 2020, the Company ceased the use of certain leased property and accelerated the amortization of operating lease ROU assets, resulting in an additional $ 24.4 million of expense. The accelerated amortization expense recognized subsequent to August 31, 2020 is immaterial. This expense was included in selling, general and administrative expenses on the Consolidated Statements of Income and Comprehensive Income. The related lease liabilities will be satisfied under the original terms of the lease arrangements, unless buy-outs can be negotiated. Supplemental cash flow information related to the Company’s leases were as follows: Year ended May 31, In millions 2022 2021 2020 Cash paid for amounts included in the measurement of lease liabilities $ 32.4 $ 32.2 $ 41.6 Amortization of ROU assets 22.7 29.2 34.4 ROU assets obtained in exchange for new operating lease liabilities 15.8 26.8 21.5 Lease incentives received in the form of tenant allowances and free rent 9.1 0.8 6.1 Future lease payments are as follows: May 31, In millions 2022 2023 $ 27.0 2024 20.9 2025 18.9 2026 13.4 2027 9.5 Thereafter 15.5 Total future lease payments 105.2 Less: imputed interest 5.3 Total operating lease liabilities $ 99.9 Current portion $ 25.1 Non-current portion $ 74.8 As of May 31, 2022 , the Company has entered into one lease agreement that has not yet commenced for a term of ten years . This lease will require lease payments over the term of approximately $ 1.8 million.

Property and Equipment, Net of

Property and Equipment, Net of Accumulated Depreciation	12 Months Ended
	May 31, 2022
Property, Plant and Equipment [Abstract]
Property and Equipment, Net of Accumulated Depreciation	Note I — Property and Equipment, Net of Accumulated Depreciation The components of property and equipment, at cost, consisted of the following: May 31, In millions 2022 2021 Land and improvements $ 10.3 $ 10.3 Buildings and improvements 157.1 158.3 Data processing equipment 217.4 211.4 Software (1) 832.1 748.3 Furniture, fixtures, and equipment 97.7 99.8 Leasehold improvements 91.7 83.5 Construction in progress (1) 50.7 50.3 Total property and equipment, gross 1,457.0 1,361.9 Less: Accumulated depreciation 1,055.7 966.1 Property and equipment, net of accumulated depreciation $ 401.3 $ 395.8 (1) Software includes both purchased software and costs capitalized related to internally developed software placed in service. Capitalized costs related to internally developed software that has not yet been placed in service is included in construction in progress. Depreciation expense was $ 133.7 million , $ 123.4 million , and $ 127.8 million for fiscal 2022, 2021, and 2020 , respectively.

Goodwill and Intangible Assets,

Goodwill and Intangible Assets, Net of Accumulated Amortization	12 Months Ended
	May 31, 2022
Goodwill and Intangible Assets Disclosure [Abstract]
Goodwill and Intangible Assets, Net of Accumulated Amortization	Note J — Goodwill and Intangible Assets, Net of Accumulated Amortization Goodwill and changes in goodwill as of and for the years ended May 31, 2022 and May 31, 2021 were as follows: May 31, In millions 2022 2021 Balance, beginning of fiscal year $ 1,820.7 $ 1,791.1 Changes during the period: Goodwill acquired 27.7 19.6 Currency translation adjustment ( 16.9 ) 10.0 Balance, end of fiscal year $ 1,831.5 $ 1,820.7 The Company had certain intangible assets on its Consolidated Balance Sheets. The components of intangible assets, at cost, consisted of the following: May 31, In millions 2022 2021 Client lists $ 637.4 $ 632.3 Other intangible assets 23.0 24.1 Total intangible assets, gross 660.4 656.4 Less: Accumulated amortization 435.8 380.6 Intangible assets, net of accumulated amortization $ 224.6 $ 275.8 During fiscal 2022, the Company acquired customer lists with a weighted-average amortization period of 8.0 years. Amortization expense relating to intangible assets was $ 58.1 million, $ 68.6 million, and $ 81.9 million for fiscal 2022, 2021, and 2020, respectively. The Company did no t recognize an impairment loss as it relates to its goodwill or intangible assets during fiscal 2022, 2021, or 2020. The estimated amortization expense for the next five fiscal years relating to intangible asset balances is as follows: In millions Estimated Year ending May 31, expense 2023 $ 59.4 2024 56.5 2025 53.5 2026 37.8 2027 4.5

Income Taxes

Income Taxes	12 Months Ended
	May 31, 2022
Income Tax Disclosure [Abstract]
Income Taxes	Note K — Income Taxes The components of deferred tax assets and liabilities are as follows: May 31, In millions 2022 2021 Deferred tax assets: Compensation and employee benefit liabilities $ 56.8 $ 53.0 Other current liabilities 21.3 19.8 Tax credit carry forward 0.2 0.2 Stock-based compensation 12.9 12.0 Unrealized losses on available-for-sale securities 33.6 — Leases 20.5 29.0 Net operating loss (“NOL”) carry forwards 5.6 7.6 Tax benefit of uncertain tax positions 9.9 5.3 Gross deferred tax assets 160.8 126.9 Deferred tax liabilities: Deferred contract costs 141.9 127.5 Capitalized software 50.8 49.0 Depreciation 8.1 8.9 Goodwill and intangible assets 103.5 111.3 Operating lease right-of-use assets 17.7 26.1 Revenue not subject to current taxes — 1.9 Unrealized gains on available-for-sale securities — 20.2 Other 4.3 — Gross deferred tax liabilities 326.3 344.9 Net deferred tax liability $ ( 165.5 ) $ ( 218.0 ) The deferred tax asset related to NOL carry forwards is comprised of $ 0.8 million of federal NOL carry forwards, $ 4.4 million of state NOL carry forwards, and $ 0.4 million of foreign NOL carry forwards. The federal NOL carry forwards were acquired through various acquisitions and expire between the fiscal years ending May 31, 2025 and May 31, 2037 . The state NOL carry forwards expire between the fiscal years ending May 31, 2023 through May 31, 2041 . The components of the provision for income taxes are as follows: Year ended May 31, In millions 2022 2021 2020 Current: Federal $ 326.0 $ 271.5 $ 264.8 State 104.5 85.9 77.5 Non-U.S. ( 1.0 ) 0.3 0.7 Total current 429.5 357.7 343.0 Deferred: Federal 0.9 ( 12.9 ) ( 0.8 ) State 0.9 ( 7.6 ) ( 3.5 ) Non-U.S. 0.5 ( 0.5 ) 0.3 Total deferred 2.3 ( 21.0 ) ( 4.0 ) Income taxes $ 431.8 $ 336.7 $ 339.0 A reconciliation of the U.S. federal statutory tax rate to the Company’s effective income tax rate is as follows: Year ended May 31, 2022 2021 2020 Federal statutory tax rate 21.0 % 21.0 % 21.0 % Increase/(decrease) resulting from: State income taxes, net of federal tax benefit 4.6 % 4.3 % 4.0 % Tax-exempt municipal bond interest ( 0.2 ) % ( 0.3 ) % ( 0.4 ) % Stock option windfall benefit ( 0.9 ) % ( 1.2 ) % ( 0.9 ) % Tax credits ( 1.1 ) % ( 0.6 ) % ( 0.5 ) % Other items 0.3 % 0.3 % 0.4 % Effective income tax rate 23.7 % 23.5 % 23.6 % The effective income tax rates in all periods were impacted by recognition of net discrete tax benefits related to employee stock-based compensation payments. Uncertain income tax positions: The Company is subject to U.S. federal income tax, numerous local and state tax jurisdictions within the U.S., and taxes in Europe. The Company maintains a reserve for uncertain tax positions. As of May 31, 2022 and 2021, the total reserve for uncertain tax positions, including interest and net of federal benefits, was $ 48.2 million and $ 20.4 million , respectively, and was included in long-term liabilities on the Consolidated Balance Sheets. A reconciliation of the beginning and ending amounts of the Company’s gross unrecognized tax benefits, not including interest or other potential offsetting effec ts, is as follows: Year ended May 31, In millions 2022 2021 2020 Balance as of beginning of fiscal year $ 22.4 $ 26.2 $ 22.1 Additions for tax positions of the current year 11.1 5.5 4.1 Additions for tax positions of prior years 20.6 9.2 1.2 Reductions for tax positions of prior years ( 1.8 ) — ( 0.6 ) Settlements with tax authorities ( 0.4 ) ( 15.2 ) — Expiration of the statute of limitations ( 1.7 ) ( 3.3 ) ( 0.6 ) Balance as of end of fiscal year $ 50.2 $ 22.4 $ 26.2 The reserve as of May 31, 2022 substantially relates to the Company’s uncertain tax positions for certain U.S. federal and state income tax matters. The Company believes the reserve for uncertain tax positions, including interest and net of federal benefits, of $ 48.2 million as of May 31, 2022 adequately covers open tax years and uncertain tax positions up to and including fiscal 2022 for major taxing jurisdictions. As of May 31, 2022 and 2021, the entire $ 48.2 million and $ 20.4 million , respectively, of unrecognized tax benefits, including interest and net of federal benefit, if recognized, would impact the Company’s effective income tax rate. The Company has concluded all U.S. federal income tax matters through fiscal 2017. With limited exception, state income tax audits by taxing authorities are closed through fiscal 2014, primarily due to expiration of the statute of limitations. The Company continues to follow its policy of recognizing interest and penalties accrued on tax positions as a component of income taxes on the Consolidated Statements of Income and Comprehensive Income. The amount of accrued interest and penalties associated with the Company’s tax positions is immaterial to the Consolidated Balance Sheets. The amount of interest and penalties recognized for fiscal years 2022, 2021, and 2020 was immaterial to the Company’s results of operations.

Short-term Financing

Short-term Financing	12 Months Ended
	May 31, 2022
Debt Disclosure [Abstract]
Short-term Financing	Note L — Short-term Financing The Company maintains committed and unsecured credit facilities and irrevocable letters of credit as part of its normal and recurring business operations. The purpose of these credit facilities is to meet short-term funding requirements, finance working capital needs, and for general corporate purposes. The Company typically borrows on an overnight or short-term basis on its credit facilities. Details of the Company’s credit facilities as of May 31, 2022 are as follows: Maximum Amount Outstanding Amount May 31, $ in millions Expiration Date Available 2022 2021 Credit facilities: JP Morgan Chase Bank, N.A. (“JPM”) (1) July 31, 2024 $ 1,000.0 $ — $ — JPM (1) September 17, 2026 $ 750.0 — — PNC Bank, National Association (“PNC”) (weighted-average interest 2.34 % at May 31, 2022 and 1.16 % at May 31, 2021) February 6, 2023 $ 250.0 8.7 7.4 Outstanding short-term financing (2) $ 8.7 $ 7.4 (1) JPM acts as the administrative agent for this syndicated credit facility. (2) The total amount available under these credit facilities as of May 31, 2022 was approximately $ 2.0 billion. Amounts under the PNC credit facility remain outstanding as of the date of this report. Upon the expiration date of any credit facility, any borrowings outstanding under that facility will mature and be payable. Interest rates on each of the Company’s credit facilities can be based upon (1) an alternate base rate that is established by the lending institution at the highest of several publicly available interest rates, plus an applicable interest rate margin, or (2) at our election, London Interbank Offered Rate (“LIBOR”) or an alternate interest rate as determined by the administrative agent, plus an applicable interest rate margin. The Company is also required to pay a commitment fee, ranging from 0.05 % to 0.15 %, related to the unutilized portion of each credit facility. The commitment fee is determined on a sliding-scale basis based upon the Company’s consolidated leverage ratio. On September 17, 2021, the Company amended its $ 500.0 million credit facility with JPM to increase the credit facility’s maximum borrowing capacity to $ 750.0 million, extend the term through September 17, 2026 with the option to extend for two additional one-year periods, and amend interest rate provisions to phase out the use of LIBOR. In addition, the Company amended its $ 1.0 billion credit facility with JPM. The amendment phases out the use of LIBOR and adopts other administrative changes to maintain consistency with the Company’s other credit facilities. Obligations under the credit facilities are guaranteed by the Company and certain of its subsidiaries. The credit facilities contain financial and operational covenants with which the Company must maintain compliance. The Company’s ability to borrow under the credit facilities may be restricted in the event of certain covenant breaches or events of default. In addition, the terms of the credit facilities could restrict the Company’s ability to engage in certain business transactions. The Company was in compliance with all these covenants as of May 31, 2022. Certain lenders under these credit facilities, and their respective affiliates, have performed, and may in the future perform for the Company, various commercial banking, investment banking, underwriting, and other financial advisory services, for which they have received, and will continue to receive in the future, customary fees and expenses. Letters of credit: The Company had irrevocable standby letters of credit outstanding totaling $ 140.2 million and $ 180.4 million as of May 31, 2022 and May 31, 2021 , respectively, required to secure commitments for certain insurance policies. The letters of credit expire at various dates between June 8, 2022 and May 26, 2023 . No amounts were outstanding on these letters of credit during fiscal 2022 or fiscal 2021, or as of May 31, 2022 and May 31, 2021, respectively. Subsequent to May 31, 2022 , letters of credit expiring on June 8, 2022 , June 15, 2022 , June 26, 2022 , and July 15, 2022 were renewed for one year terms.

Long-Term Financing

Long-Term Financing	12 Months Ended
	May 31, 2022
Debt Disclosure [Abstract]
Long-Term Financing	Note M — Long-term Financing Long-term debt, at amortized cost, consisted of the following as of: May 31, In millions 2022 2021 Senior Notes, Series A $ 400.0 $ 400.0 Senior Notes, Series B 400.0 400.0 Total long-term borrowings 800.0 800.0 Less: Debt issuance costs, net of accumulated amortization ( 2.3 ) ( 2.7 ) Long-term borrowings, net of debt issuance costs $ 797.7 $ 797.3 Certain information related to the Senior Notes, Series A and Senior Notes, Series B (collectively the “Notes”) issued pursuant to the Note Purchase and Guarantee Agreement (the “Agreement”) for fiscal 2022 and fiscal 2021 are as follows: Senior Notes Senior Notes Series A Series B Stated interest rate 4.07 % 4.25 % Effective interest rate 4.15 % 4.31 % Interest rate type Fixed Fixed Interest payment dates Semi-annual, in arrears Semi-annual, in arrears Principal payment dates March 13, 2026 March 13, 2029 Note type Unsecured Unsecured The effective interest rates for each note series includes the interest on the note and amortization of debt issuance costs. Payment of all amounts due with respect to the Notes and performance under the Agreement is guaranteed by the Company, Paychex of New York LLC, and certain other subsidiaries of the Company. The Company may, at its option, prepay at any time all, or any part of, the Notes, subject to certain conditions as described in the Agreement. The Agreement contains customary representations, warranties, affirmative and negative covenants, including financial covenants that are usual and customary for such arrangements. The Company was in compliance with all these covenants as of May 31, 2022 .

Supplemental Cash Flow Informat

Supplemental Cash Flow Information	12 Months Ended
	May 31, 2022
Supplemental Cash Flow Elements [Abstract]
Supplemental Cash Flow Information	Note N — Supplemental Cash Flow Information Income taxes paid were $ 397.7 million, $ 421.4 million, and $ 298.8 million for fiscal 2022, 2021, and 2020, respectively. Interest expense paid was $ 35.5 million, $ 34.9 million, and $ 38.0 million for fiscal 2022, 2021, and 2020, respectively. Refer to Note H for supplemental cash flow information pertaining to the Company's leasing activities.

Employee Benefit Plans

Employee Benefit Plans	12 Months Ended
	May 31, 2022
Retirement Benefits [Abstract]
Employee Benefit Plans	Note O — Employee Benefit Plans 401(k) plan: The Company maintains a contributory savings plan that qualifies under section 401(k) of the Internal Revenue Code. The Paychex, Inc. 401(k) Incentive Retirement Plan (the “Plan”) allows all employees to immediately participate in the salary deferral portion of the Plan, contributing up to a maximum of 50 % of their salary, subject to Internal Revenue Service limitations. Employees who have completed one year of service and a minimum of 1,000 hours worked are eligible to receive a Company matching contribution, when such contribution is in effect. The Company provides a matching contribution of 100 % of the first 3 % and 50 % on the next 2 % of eligible pay for a total matching contribution of 4 %. The Company temporarily suspended its matching contribution effective July 31, 2020 through Dec ember 31, 2020. The Company’s matching contribution was reinstated on January 1, 2021 at the percentages in effect at the time of the temporary suspension. Company contributions to the Plan for fiscal 2022, 2021, and 2020 were $ 35.6 million , $ 19.2 million , and $ 30.1 million , respectively. The Plan is 100 % participant directed. Plan participants can fully diversify their portfolios by choosing from any or all investment fund choices in the Plan. Transfers in and out of investment funds, including the Paychex, Inc. Employee Stock Ownership Plan Stock Fund, are not restricted, except for certain restricted trading periods for individuals designated as insiders as specified in the Company’s Insider Trading Policy. The Company matching contribution, when in effect, follows the same fund elections as the employee compensation deferrals. Deferred compensation plans: The Company and certain subsidiaries offer non-qualified and unfunded deferred compensation plans to a select group of key employees, executive officers, and outside directors. Eligible employees are provided with the opportunity to defer up to 50 % of their annual base salary and bonus and outside directors may defer 100 % of their Board cash compensation. Gains and losses are credited based on the participant’s election of a variety of investment choices. The Company does not match any participant deferral or guarantee its return. Distributions are paid at one of the following dates selected by the participant: the participant’s termination date, the date the part icipant retires from any active employment, or a designated specific date. The amounts accrued under these plans were $ 29.9 million and $ 32.6 million as of May 31, 2022 and 2021, respectively, and are reflected in other long-term liabilities on the accompanying Consolidated Balance Sheets.

Commitments and Contingencies

Commitments and Contingencies	12 Months Ended
	May 31, 2022
Commitments and Contingencies Disclosure [Abstract]
Commitments and Contingencies	Note P — Commitments and Contingencies Contingencies: The Company is subject to various claims and legal matters that arise in the normal course of its business. These include disputes or potential disputes related to breach of contract, tort, employment-related claims, tax claims, statutory, and other matters. The Company’s management currently believes that resolution of any outstanding legal matters will not have a material adverse effect on the Company’s financial position or results of operations. However, legal matters are subject to inherent uncertainties and there exists the possibility that the ultimate resolution of these matters could have a material adverse impact on the Company’s financial position and the results of operations in the period in which any such effect is recorded. Other commitments: As of May 31, 2022, the Company had outstanding commitments under existing workers’ compensation insurance agreements and legally binding contractual arrangements with minimum future payment obligations of approximately $ 379.1 million. The Company also enters into various purchase commitments with vendors in the ordinary course of business and had outstanding commitments to purchase approximately $ 7.6 million of capital assets. These minimum future payment obligations relate to the following fiscal years: Payments due by period In millions 2023 2024 2025 2026 2027 Thereafter Workers' compensation estimated obligations $ 64.1 $ 36.8 $ 22.4 $ 14.8 $ 10.9 $ 40.7 Purchase obligations 149.8 28.9 9.7 0.5 0.3 0.2 In the normal course of business, the Company makes representations and warranties that guarantee the performance of services under service arrangements with clients. Historically, there have been no material losses related to such guarantees. The Company has also entered into indemnification agreements with its officers and directors, which require the Company to defend and, if necessary, indemnify these individuals for certain pending or future claims as they relate to their services provided to the Company. The Company currently self-insures the deductible portion of various insured exposures under certain corporate employee and PEO employee health and medical benefit plans. The Company’s estimated loss exposure under these insurance arrangements is recorded in other current liabilities on the Consolidated Balance Sheets. Historically, the amounts accrued have not been material and were not material as of May 31, 2022 . The Company also maintains insurance coverage in addition to its purchased primary insurance policies for gap coverage for employment practices liability, errors and omissions, warranty liability, theft and embezzlement, cyber threats, and acts of terrorism; and capacity for deductibles and self-insured retentions through its captive insurance company.

Valuation and Qualifying Accoun

Valuation and Qualifying Accounts	12 Months Ended
	May 31, 2022
SEC Schedule, 12-09, Valuation and Qualifying Accounts [Abstract]
Valuation and Qualifying Accounts	Schedule II — Valuation and Qualifying Accounts PAYCHEX, INC. CONSOLIDATED FINANCIAL STATEMENT SCHEDULE FOR THE YEAR ENDED MAY 31, (In millions) Additions to/ Balance as of Additions (deductions Balance as beginning charged to from) other Costs and of end Description of fiscal year expenses accounts deductions (1) of fiscal year 2022 Allowance for credit losses $ 16.0 $ 10.5 $ — $ 8.3 $ 18.2 2021 Allowance for credit losses $ 12.5 $ 11.5 $ — $ 8.0 $ 16.0 2020 Allowance for doubtful accounts $ 10.2 $ 13.0 $ — $ 10.7 $ 12.5 (1) Uncollectible amounts written off, net of recoveries, and other adjustments.

Description of Business, Basi_2

Description of Business, Basis of Presentation, and Significant Accounting Policies (Policy)	12 Months Ended
	May 31, 2022
Accounting Policies [Abstract]
Description of Business	Description of business: Paychex, Inc. and its wholly owned subsidiaries (collectively, the “Company” or “Paychex”) is a leading human resource (“HR”) software and services company, offering integrated human capital management (“HCM”) solutions for HR, payroll, benefits, and insurance services for small- to medium-sized businesses in the United States (“U.S.”). The Company also has operations in parts of Europe and India. Paychex, a Delaware corporation formed i n 1979, reports as one segment. Substantially all of the Company’s revenue is generated within the U.S. Approximately one percent of the Company’s total revenue was generated within Europe for each of the fiscal years ended May 31, 2022 (“fiscal 2022”), May 31, 2021 (“fiscal 2021”), and May 31, 2020 (“fiscal 2020 ”). Long-lived assets in Europe were approximately 6 % and 7 % of total long-lived assets of the Company as of May 31, 2022 and 2021 , respectively. Long-lived assets in India were less than 1 % of total long-lived assets of the Company as of May 31, 2022 and 2021. Within Paychex’s HCM solutions, Paychex offers a comprehensive portfolio of services and products that allow its clients to meet their diverse HR and payroll needs. Clients can select services on an á la carte basis or as part of various product bundles. Paychex’s offerings often leverage the information gathered in its base payroll processing service, allowing the Company to provide comprehensive outsourcing services covering the HCM spectrum. Paychex supports its small business clients utilizing its proprietary, robust, software as a service (“SaaS”) Paychex Flex ® platform and the Company’s SurePayroll ® SaaS-based products. Both products allow users to process payroll when they want, how they want, and on any type of device (desktop, tablet, and mobile phone). Paychex’s medium-sized clients generally have more complex payroll and employee benefit needs and can opt for an integrated suite of HCM solutions, which allows them to choose the services and software that will meet the needs of their businesses. Total revenue is comprised of service revenue and interest on funds held for clients. Service revenue is comprised primarily of the fees earned on the portfolio of HCM services, which include payroll processing, complementary HR management and administration services, professional employer organization (“PEO”) solutions, and insurance agency commissions. Refer to Note B of this Item 8 for further discussion of the Company’s service revenue.
Basis of Presentation	Basis of presentation: The consolidated financial statements include the accounts of Paychex, Inc., and its wholly owned subsidiaries. All intercompany accounts and transactions have been eliminated in consolidation. Certain disclosures are reported as zero balances due to rounding.
Reclassifications	Reclassifications: Certain prior year amounts have been reclassified to conform to the current period presentation. These reclassifications had no effect on reported consolidated earnings.
Cash and Cash Equivalents	Cash and cash equivalents: Cash and cash equivalents consist of available cash, money market securities, and other investments with a maturity of 90 days or less at acquisition. Cash and cash equivalents include funds collected from the Company’s PEO clients for the payment of worksite employee payrolls and associated payroll taxes. Funds of $ 89.7 million and $ 150.5 million collected from PEO clients are included in cash and cash equivalents on the Company’s Consolidated Balance Sheets as of May 31, 2022 and 2021 , respectively.
Restricted Cash and Restricted Cash Equivalents	Restricted cash and restricted cash equivalents: Restricted cash and restricted cash equivalents are recorded at fair value, and consist of cash and cash equivalents, primarily money market securities, included in funds held for clients and cash that is restricted in use for payment of workers’ compensation claims.
Accounts Receivable, Net of Allowance for Credit Losses	Accounts receivable, net of allowance for credit losses: Accounts receivable balances are shown on the Consolidated Balance Sheets net of the allowance for credit losses of $ 18.2 million and $ 16.0 million as of May 31, 2022 and 2021, respectively. These balances include trade receivables for services provided to clients and purchased receivables related to payroll funding arrangements with clients in the temporary staffing industry. Trade receivables were $ 123.2 million and $ 98.4 million as of May 31, 2022 and 2021, respectively. Purchased receivables were $ 618.8 million and $ 495.9 million as of May 31, 2022 and 2021, respectively. The Company is exposed to credit losses through the sale of services, payment of client obligations, and collection of purchased receivables. To mitigate this credit risk, the Company has multiple programs in place to assess and continuously monitor each client’s ability to pay for these products and services. Credit monitoring programs include, but are not limited to, new client credit reviews, establishing appropriate credit limits, monitoring of credit distressed clients, and early electronic wire and collection procedures. The Company also considers contract terms and conditions, client business type or strategy and may require collateralized asset support or prepayment to mitigate credit risk. Accounts receivable are written off and charged against the allowance for credit losses when the Company has exhausted all collection efforts without success. The Company estimates its allowance for credit losses based on historical loss activity adjusted for current economic conditions and reasonable and supportable forecast factors, when applicable. The provision for the allowance for credit losses and accounts written off were no t material for the fiscal years ended May 31, 2022, 2021 and 2020 , respectively. No single client had a material impact on total accounts receivable as of May 31, 2022 or 2021 . No single client had a material impact on service revenue or results of operations for the fiscal years ended May 31, 2022, 2021 and 2020 .
PEO Unbilled Receivables, Net of Advance Collections	PEO unbilled receivables, net of advance collections: The Company recognizes a liability for worksite employee gross wages and related payroll tax liabilities at the end of the period in which the worksite employee performs work, and where it assumes, under applicable state regulations, the obligation for the payment of payroll and payroll tax liabilities. The estimated payroll and payroll tax liabilities are recorded in accrued worksite employee compensation and related items on the Company’s Consolidated Balance Sheets. The associated unbilled receivables, including estimated revenues, offset by advance collections from clients, are recorded as PEO unbilled receivables, net of advance collections on the Company’s Consolidated Balance Sheets. As of May 31, 2022 and 2021, advance collections included in PEO unbilled receivables, net of advance collections were $ 2.6 million and $ 2.5 million , respectively.
Funds Held for Clients and Corporate Investments	Funds held for clients and corporate investments: Marketable securities included in funds held for clients and corporate investments consist primarily of securities classified as AFS and are recorded at fair value obtained from an independent pricing service. The funds held for clients portfolio also includes cash and cash equivalents such as money market securities. Unrealized gains and losses, net of applicable income taxes, are reported as other comprehensive income in the Consolidated Statements of Income and Comprehensive Income. Realized gains and losses on the sale of AFS securities are determined by specific identification of the cost basis of each security. On the Consolidated Statements of Income and Comprehensive Income, realized gains and losses from the funds held for clients portfolio and corporate investments portfolio are included in interest on funds held for clients and other expense, net, respectively.
Concentrations	Concentrations: Substantially all the Company’s deposited cash is maintained at large well-capitalized (as defined by their regulators) financial institutions. These deposits may exceed the amount of any insurance provided. All the Company’s deliverable securities, primarily municipal bond securities, are held in custody with certain of the aforementioned financial institutions, for which that institution bears the risk of custodial loss. Non-deliverable securities are primarily time deposits and money market funds.
Property and Equipment, Net of Accumulated Depreciation	Property and equipment, net of accumulated depreciation: Property and equipment is stated at cost, less accumulated depreciation. Depreciation is based on the estimated useful lives of property and equipment using the straight-line method. The estimated useful lives of depreciable assets are generally as follows: Category Depreciable life Buildings and improvements 10 to 35 years or the remaining life, whichever is shorter Data processing equipment 3 to 4 years Furniture, fixtures, and equipment 2 to 7 years Leasehold improvements 10 years or the life of the lease, whichever is shorter Software 3 to 12 years Normal and recurring repairs and maintenance costs are charged to expense as incurred. The Company reviews the carrying value of property and equipment for impairment when events or changes in circumstances indicate that the carrying value of such assets may not be recoverable.
Software Development and Enhancements	Software development and enhancements: Expenditures for software purchases and software developed for internal use are capitalized and depreciated on a straight-line basis over the estimated useful lives, which are generally 3 to 5 years. Software developed as part of the Company’s main processing platform is depreciated over 12 years. For software developed for internal use, certain costs are capitalized, including external direct costs of materials and services associated with developing or obtaining the software, and payroll and payroll-related costs for employees who are directly associated with internal-use software projects. Capitalization of these costs ceases no later than the point at which the project is substantially complete and ready for its intended use. Costs associated with preliminary project stage activities, training, maintenance, and other post-implementation stage activities are expensed as incurred. The carrying value of software and development costs is reviewed for impairment when events or changes in circumstances indicate that the carrying value of such assets may not be recoverable.
Goodwill and Other Intangible Assets, Net of Accumulated Amortization	Goodwill and other intangible assets, net of accumulated amortization: Goodwill is not amortized, but instead is tested for impairment on an annual basis and between annual tests if an event occurs or circumstances change in a way to indicate that there has been a potential decline in the fair value of a reporting unit. The Company performs its annual impairment testing in its fiscal fourth quarter. During fiscal 2022, a qualitative assessment was performed for our Paychex, Inc., excluding Purchased Receivables, reporting unit, and a quantitative assessment was performed on the Purchased Receivable reporting unit to determine if it is more-likely-than-not that the fair value of the reporting units had declined below their carrying value. A qualitative analysis was performed for all reporting units in fiscal 2021 and 2020 . The qualitative assessment considered various financial, macroeconomic, industry, and reporting unit specific qualitative factors. Based on the results of the Company’s testing, no impairment loss was recognized in the results of operations for fiscal 2022, 2021, or 2020. Subsequent to the latest review, there have been no events or circumstances that indicate any potential impairment of the Company’s goodwill balance. Intangible assets are comprised primarily of client list acquisitions and are reported net of accumulated amortization on the Consolidated Balance Sheets. Intangible assets are amortized over periods generally ranging from 3 to 12 years. Certain client lists use an accelerated method, while other intangible assets use the straight-line method of amortization. In addition, the Company has intangible assets with indefinite useful lives, which are tested for impairment on an annual basis and between annual tests if an event occurs or circumstances change in a way to indicate that the carrying value may not be recoverable. The Company has determined, using qualitative assessments, there is no impairment of intangible assets with indefinite useful lives for fiscal 2022, 2021, or 2020 .
Impairment of Long-Lived Assets	Impairment of Long-Lived Assets: Long-lived assets, including intangible assets with finite lives and operating lease right-of-use (“ROU”) assets, are reviewed for impairment when events or changes in circumstances indicate that the carrying amount of an asset may not be recoverable. Recoverability of assets to be held and used is measured by a comparison of the carrying amount of an asset to estimated undiscounted future cash flows expected to be generated by the asset. If the carrying amount of an asset exceeds its estimated future cash flows, an impairment charge is recognized for the amount by which the carrying amount of the asset exceeds the estimated fair value of the asset. The Company has determined that there was no impairment of long-lived assets for fiscal 2022, 2021, or 2020 .
Foreign Currency	Foreign Currency: The financial statements of the Company’s foreign subsidiaries have been translated into U.S. dollars. Assets and liabilities are translated into U.S. dollars at period-end exchange rates. Income and expenses are translated at the average exchange rate for the reporting period. The resulting non-cash foreign currency translation adjustments, representing unrealized gains or losses, are included in Consolidated Statements of Stockholders’ Equity as a component of accumulated other comprehensive (loss)/income, net of tax. The Company did no t have any material realized gains or losses resulting from foreign exchange transactions during fiscal 2022, 2021, or 2020 .
Revenue Recognition	Revenue recognition: Revenues are primarily attributable to fees for providing services as well as investment income earned on funds held for clients. Fees associated with services are recognized in the period services are rendered and earned under service arrangements with clients where service fees are fixed or determinable and collectability is reasonably assured. The Company’s service revenue is largely attributable to processing services where the fee is based on a fixed amount per processing period or a fixed amount per processing period plus a fee per employee or transaction processed. Insurance Solutions revenues are recognized when commissions are earned on premiums billed and collected. Fees earned for funding payrolls of our clients in the temporary staffing agency via the purchase of accounts receivable are based on a percentage of funding amounts as specified in the client contract. These fees are then recognized over the average collection period of 46 to 48 days. The revenue earned from delivery service for the distribution of certain client payroll checks and reports is included in service revenue, and the costs for the delivery are included in cost of service revenue on the Consolidated Statements of Income and Comprehensive Income. The Company receives advance payments for set-up fees from its clients. Advance payments received for certain of the Company’s service offerings for set-up fees are considered a material right. Therefore, the Company defers the revenue associated with these advance payments, recognizing the revenue and related expenses over the expected period to which the material right exists. PEO Solutions revenue is included in service revenue and is reported net of certain pass-through costs billed and incurred, which include payroll wages, payroll taxes, including federal and state unemployment insurance, and certain health insurance benefit premiums, primarily costs related to the Company’s guaranteed cost benefit plans. Direct costs related to workers’ compensation and certain benefit plans where the Company retains risk are recognized as cost of service revenue rather than as a reduction in service revenue. Refer to Note B of this Item 8 for further discussion of the PEO pass-through costs. Interest on funds held for clients is earned primarily on funds that are collected from clients before due dates for payroll tax administration services and for employee payment services and invested until remittance to the applicable tax or regulatory agencies or client employees. The interest earned on these funds is included in total revenue on the Consolidated Statements of Income and Comprehensive Income because the collecting, holding, and remitting of these funds are components of providing these services.
Assets Recognized from the Costs to Obtain and Fulfill Contracts	Assets Recognized from the Costs to Obtain and Fulfill Contracts: The Company recognizes an asset for the incremental costs of obtaining a contract with a client if it is expected that the economic benefit and amortization period will be longer than one year. Incremental costs of obtaining a contract include only those costs that are directly related to the acquisition of new contracts and that would not have been incurred if the contract had not been obtained. The Company does not incur incremental costs to obtain a contract renewal. The Company determined that certain sales commissions and bonuses, including related fringe benefits, meet the capitalization criteria under Accounting Standards Codification (“ASC”) Subtopic 340-40, “Other Assets and Deferred Costs: Contracts with Customers” (“ASC 340-40”). The Company also recognizes an asset for the costs to fulfill a contract with a client if the costs are specifically identifiable, generate or enhance resources used to satisfy future performance obligations, and are expected to be recovered. The Company determined that substantially all costs related to implementation activities are administrative in nature and meet the capitalization criteria under ASC 340-40. These capitalized costs to fulfill a contract principally relate to upfront direct costs that are expected to be recovered and enhance the Company’s ability to satisfy future performance obligations. The assets related to both costs to obtain and costs to fulfill contracts with clients are capitalized and amortized using an accelerated method over an eight-year life to closely align with the pattern of client attrition over the estimated life of the client relationship. The Company regularly reviews its deferred costs for potential impairment and did no t recognize an impairment loss during fiscal 2022, 2021, or 2020 .
Cost of Service Revenue	Cost of service revenue: The Company’s costs and expenses applicable to total service revenue represent direct costs associated with providing HR, payroll, benefits, and insurance services. This includes labor-related costs, direct costs related to certain PEO offerings, postage and delivery costs, facility costs, professional services, and depreciation and amortization of property and equipment, including internally developed software.
Selling, General and Administrative Expenses	Selling, general and administrative expenses: The Company’s selling, general and administrative expenses represent labor-related costs, including amortization of deferred sales commissions and bonuses, corporate asset depreciation and amortization, marketing, and other general and administrative expenses incurred by the Company.
PEO Insurance Reserves	PEO insurance reserves: As part of the PEO solution, the Company offers workers’ compensation insurance and health insurance to clients for the benefit of client employees. Workers’ compensation insurance is primarily provided under fully insured high deductible workers’ compensation insurance policies. Workers’ compensation insurance reserves are established to provide for the estimated costs of paying claims up to per occurrence liability limits. These reserves include estimates of certain expenses associated with processing and settling these claims. In establishing the PEO workers’ compensation insurance reserves, the Company uses an independent actuarial estimate of undiscounted future cash payments that would be made to settle claims. The determination of estimated ultimate losses by the Company’s independent actuary are based on accepted actuarial methods and assumptions. The estimated ultimate losses are primarily based upon loss development factors, and other factors such as the nature of employees’ job responsibilities, the historical frequency and severity of workers’ compensation claims, and an estimate of future cost trends. Each reporting period, changes in actuarial assumptions resulting from changes in actual claims experience and other trends are incorporated into our workers’ compensation claims cost estimates. For fiscal 2022 , the Company has an aggregate maximum liability of $ 2.0 million for claims exceeding $ 1.0 million, and once met, the maximum individual claims liability is $ 1.0 million. The Company’s maximum individual claims liability under its PEO workers’ compensation insurance policies was $ 1.0 million for fiscal 2021. As of May 31, 2022 and 2021, the Company had recorded current liabilities of $ 64.1 million and $ 65.3 million , respectively, and long-term liabilities of $ 125.6 million and $ 117.8 million , respectively, on its Consolidated Balance Sheets for workers’ compensation insurance reserves. The amounts were recorded in the other current liabilities and other long-term liabilities sections, respectively, of the Consolidated Balance Sheets. With respect to the PEO health insurance, the Company offers various health insurance plans that take the form of either fully insured guaranteed cost plans or fully insured insurance arrangements where the Company retains risk. A reserve for insurance arrangements where the Company retains risk is established to provide for the payment of claims in accordance with the Company’s service contract with the carrier. The claims liability includes estimates for reported losses, plus amounts for those claims incurred but not reported, and estimates of certain expenses associated with processing and settling the claims. The Company’s maximum individual claims liability was $ 0.5 million and $ 0.3 million under its policies durin g both fiscal 2022 and fiscal 2021, respectively. Amounts accrued related to the health insurance and dental and vision plan reserves were $ 46.2 million and $ 43.9 million as of May 31, 2022 and 2021, respectively. These amounts are included in current liabilities on the Consolidated Balance Sheets. Estimating the ultimate cost of future claims is an uncertain and complex process based upon historical loss experience and independent actuarial loss projections, and is subject to change due to multiple factors, including economic trends, changes in legal liability law, and damage awards, all of which could materially impact the reserves as reported in the consolidated financial statements. Accordingly, final claim settlements may vary from the present estimates, particularly with workers’ compensation insurance where those payments may not occur until well into the future. The Company regularly reviews the adequacy of its estimated insurance reserves. Adjustments to previously established reserves are reflected in the results of operations for the period in which the adjustment is identified. Such adjustments could be significant, reflecting any combination of new and adverse or favorable trends. Adjustments to previously established reserves were not material for fiscal 2022, 2021, or 2020 .
Leases	Leases: The Company adopted the requirements of Accounting Standards Updates (“ASUs”) No. 2016-02 on June 1, 2019. At contract inception, the Company determines if the new contractual arrangement is a lease or contains a leasing arrangement. If a contract contains a lease whose term is greater than one year, the Company evaluates whether it should be classified as an operating or a finance lease. Currently, all the Company’s leases have been classified as operating leases. Upon modification of a contract, the Company will reassess to determine if a contract is or contains a leasing arrangement. The Company records lease liabilities based on the future estimated cash payments discounted over the lease term, defined as the non-cancellable time period of the lease, together with all the following: • periods covered by an option to extend the lease if the Company is reasonably certain to exercise the extension option; and • periods covered by an option to terminate the lease if the Company is reasonably certain not to exercise the termination option. Leases may also include options to terminate the arrangement or options to purchase the underlying lease property. The Company does not separate lease and non-lease components of contracts. Lease components provide the Company with the right to use an identified asset, which consist of the Company’s real estate properties and office equipment. Non-lease components consist primarily of maintenance services. As an implicit discount rate is typically not readily determinable in the Company’s lease agreements, the Company uses its estimated secured incremental borrowing rate based on the information available at the lease commencement date in determining the present value of future lease payments. The incremental borrowing rate is determined using a portfolio approach utilizing publicly available information related to our unsecured borrowing rates. For certain leases with original terms of 12 months or less, the Company recognizes lease expense as incurred and does not recognize any lease liabilities. Short-term and long-term portions of operating lease liabilities are classified as other current liabilities and operating lease liabilities, respectively, in the Company’s Consolidated Balance Sheets. An ROU asset is measured as the amount of the lease liability with adjustments, if applicable, for lease incentives, initial direct costs incurred by the Company, and lease prepayments made prior to or at lease commencement. ROU assets are classified as operating lease ROU assets, net of accumulated amortization, on the Company’s Consolidated Balance Sheets. The Company evaluates the carrying value of ROU assets if there are indicators of potential impairment and performs the analysis concurrent with the review of the recoverability of the related asset group. If the carrying value of the asset group is determined to not be fully recoverable and is in excess of its estimated fair value, the Company will record an impairment loss in its Consolidated Statements of Income and Comprehensive Income. The Company did no t recognize an impairment loss during fiscal 2022, fiscal 2021 or fiscal 2020. Fixed lease expense payments are recognized on a straight-line basis over the lease term. Variable lease payments vary because of changes in facts or circumstances occurring after the commencement date, other than the passage of time, and are often due to changes in an external market rate or the value of an index (e.g. Consumer Price Index). Variable lease payments are expensed as incurred in the Company’s Consolidated Statements of Income and Comprehensive Income.
Stock-Based Compensation Costs	Stock-based compensation costs: All stock-based awards to employees are recognized as compensation costs in the consolidated financial statements based on their fair values measured as of the date of grant. The Company estimates the fair value of stock option grants using a Black-Scholes option pricing model. This model requires various assumptions as inputs including expected volatility of the Paychex stock price and expected option life. Volatility is estimated based on a combination of historical volatility, using stock prices over a period equal to the expected option life, and implied market volatility. Expected option life is estimated based on historical exercise behavior. The Company periodically reassesses its assumptions as well as its choice of valuation model. The Company will reconsider use of this model if additional information becomes available in the future indicating that another model would provide a more accurate estimate of fair value or if characteristics of future grants would warrant such a change. The fair value of stock awards is determined based on the stock price at the date of grant. For grants that do not accrue dividends or dividend equivalents, the fair value is the stock price reduced by the present value of estimated dividends over the vesting period or performance period. The Company’s policy is to estimate forfeitures and only record compensation costs for those awards that are expected to vest. The assumptions for forfeitures are determined based on type of award and historical experience. Forfeiture assumptions are adjusted at the point in time a significant change is identified, with any adjustment recorded in the period of change, and the final adjustment at the end of the requisite service period to equal actual forfeitures. The assumptions of volatility, expected option life, and forfeitures all require significant judgment and are subject to change in the future due to factors such as employee exercise behavior, stock price trends, and changes to type or provisions of stock-based awards. Any material change in one or more of these assumptions could have an impact on the estimated fair value of a future award. Refer to Note E of this Item 8 for further discussion of the Company’s stock-based compensation plans.
Income Taxes	Income taxes: The Company accounts for deferred taxes by recognizing deferred tax assets and liabilities for the expected future tax consequences of events that have been included in the consolidated financial statements or tax returns. Under this method, deferred tax assets and liabilities are determined based on the difference between the financial statement and tax basis of assets and liabilities, using enacted tax rates in effect for the fiscal year in which the differences are expected to reverse. The Company also maintains a reserve for uncertain tax positions. The Company evaluates tax positions taken or expected to be taken in a tax return for recognition in its consolidated financial statements. Prior to recording the related tax benefit in the consolidated financial statements, the Company must conclude that tax positions will be more-likely-than-not to be sustained, assuming those positions will be examined by taxing authorities with full knowledge of all relevant information. The benefit recognized in the consolidated financial statements is the amount the Company expects to realize after examination by taxing authorities. If a tax position drops below the more-likely-than-not standard, the benefit can no longer be recognized. Assumptions, judgment, and the use of estimates are required in determining if the more-likely-than-not standard has been met when developing the provision for income taxes and in determining the expected benefit. A change in the assessment of the more-likely-than-not standard could materially impact the Company’s results of operations or financial position. Refer to Note K of this Item 8 for further discussion of the Company’s reserve for uncertain tax positions.
Use of Estimates	Use of estimates: The preparation of financial statements in conformity with U.S. generally accepted accounting principles requires management to make estimates, judgments, and assumptions that affect reported amounts of assets, liabilities, revenue, and expenses during the reporting period. Actual amounts and results could differ from these estimates.
Recently Adopted and Issued Accounting Pronouncements	Recently adopted accounting pronouncements: In June 2021 , the Company adopted the following ASUs, no ne of which had a material impact on its consolidated financial statements: • ASU No. 2020-08, “Codification Improvements to Subtopic 310-20, Receivables – Nonrefundable Fees and Other Costs;” and • ASU No. 2019-12, “Income Taxes (Topic 740): Simplifying the Accounting for Income Taxes.” Recently issued accounting pronouncements: In November 2021, the Financial Accounting Standards Board (“FASB”) issued ASU No. 2021-10 “Government Assistance (Topic 832): Disclosures by Business Entities about Government Assistance.” This ASU will improve the transparency of government assistance received by most business entities by requiring the disclosure of: (1) the types of government assistance received; (2) the accounting for such assistance; and (3) the effect of the assistance on a business entity’s financial statements. ASU No. 2021-10 is effective for financial statements issued for annual periods beginning after December 15, 2021, with early application permitted. This ASU is applicable to the Company's fiscal year beginning June 1, 2022. The adoption of this guidance will not have a material impact on the Company's consolidated financial statements. In October 2021, the FASB issued ASU No. 2021-08 “Business Combinations (Topic 805): Accounting for Contract Assets and Contract Liabilities from Contracts with Customers.” This ASU clarifies that an acquirer of a business should recognize and measure contract assets and contract liabilities in a business combination in accordance with Accounting Standards Codification Topic 606, Revenue from Contracts with Customers. ASU No. 2021-08 is effective for public business entities for fiscal years, including interim periods within those fiscal years, beginning after December 15, 2022, with early application permitted. This ASU is applicable to the Company's fiscal year beginning June 1, 2023, and the impact of its adoption on the Company’s consolidated financial statements will depend on the contract assets and liabilities acquired in business combinations after that date. Other recent authoritative guidance issued by the FASB (including technical corrections to the FASB ASC), the American Institute of Certified Public Accountants, and the Securities and Exchange Commission (“SEC”) did not or is not expected to have a material impact on the Company’s consolidated financial statements.

Description of Business, Basi_3

Description of Business, Basis of Presentation, and Significant Accounting Policies (Tables)	12 Months Ended
	May 31, 2022
Accounting Policies [Abstract]
Estimated Useful Lives of Depreciable Assets	The estimated useful lives of depreciable assets are generally as follows: Category Depreciable life Buildings and improvements 10 to 35 years or the remaining life, whichever is shorter Data processing equipment 3 to 4 years Furniture, fixtures, and equipment 2 to 7 years Leasehold improvements 10 years or the life of the lease, whichever is shorter Software 3 to 12 years

Service Revenue (Tables)

Service Revenue (Tables)	12 Months Ended
	May 31, 2022
Revenue from Contract with Customer [Abstract]
Summary of PEO Pass-Through Costs Netted in Revenue	PEO pass-through costs netted within the PEO and Insurance Solutions revenue are as follows: Year ended May 31, In millions 2022 2021 2020 Payroll wages and payroll taxes $ 24,070.2 $ 20,587.1 $ 20,463.8 State unemployment insurance (included in payroll wages and $ 139.1 $ 119.0 $ 85.7 Guaranteed cost benefit plans $ 641.4 $ 586.4 $ 647.0
Summary of Changes in Deferred Revenue Related to Material Rights Performance Obligations	Changes in deferred revenue related to material rights that exceed one year were as follows: Year ended May 31, In millions 2022 2021 Balance, beginning of period $ 40.2 $ 42.6 Deferral of revenue 35.0 23.5 Recognition of unearned revenue ( 26.3 ) ( 25.9 ) Balance, end of period $ 48.9 $ 40.2
Summary of Changes in Deferred Costs to Obtain and Fulfill Contracts	Changes in deferred costs to obtain and fulfill contracts were as follows: Costs to fulfill contracts: Year ended May 31, In millions 2022 2021 Balance, beginning of period $ 69.3 $ 67.3 Capitalization of costs 28.0 26.2 Amortization ( 25.0 ) ( 24.2 ) Balance, end of period $ 72.3 $ 69.3 Costs to obtain contracts: Year ended May 31, In millions 2022 2021 Balance, beginning of period $ 488.2 $ 473.6 Capitalization of costs 239.1 181.8 Amortization ( 177.1 ) ( 167.2 ) Balance, end of period $ 550.2 $ 488.2

Basic and Diluted Earnings Pe_2

Basic and Diluted Earnings Per Share (Tables)	12 Months Ended
	May 31, 2022
Earnings Per Share [Abstract]
Basic and Diluted Earnings Per Share	Basic and diluted earnings per share were calculated as follows: Year ended May 31, In millions, except per share amounts 2022 2021 2020 Basic earnings per share: Net income $ 1,392.8 $ 1,097.5 $ 1,098.1 Weighted-average common shares outstanding 360.6 359.9 358.5 Basic earnings per share $ 3.86 $ 3.05 $ 3.06 Diluted earnings per share: Net income $ 1,392.8 $ 1,097.5 $ 1,098.1 Weighted-average common shares outstanding 360.6 359.9 358.5 Dilutive effect of common share equivalents 2.5 2.2 2.5 Weighted-average common shares outstanding, assuming dilution 363.1 362.1 361.0 Diluted earnings per share $ 3.84 $ 3.03 $ 3.04 Weighted-average anti-dilutive common share equivalents 0.2 0.6 0.7

Other Expense, Net (Tables)

Other Expense, Net (Tables)	12 Months Ended
	May 31, 2022
Other Income and Expenses [Abstract]
Schedule of Other Expense, Net	Other expense, net, consisted of the following items: Year ended May 31, In millions 2022 2021 2020 Interest income on corporate investments $ 2.9 $ 2.3 $ 12.3 Interest expense ( 36.6 ) ( 35.8 ) ( 38.8 ) Other 18.3 7.0 3.1 Other expense, net $ ( 15.4 ) $ ( 26.5 ) $ ( 23.4 )

Stock-Based Compensation Plans

Stock-Based Compensation Plans (Tables)	12 Months Ended
	May 31, 2022
Stock Options [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Weighted-Average Assumptions	Year ended May 31, 2022 2021 2020 Risk-free interest rate 1.2 % 0.5 % 2.0 % Dividend yield 2.9 % 3.2 % 3.3 % Volatility factor 0.23 0.29 0.18 Expected option life in years 6.6 6.1 6.2 Weighted-average grant-date $ 17.47 $ 13.52 $ 9.86
Stock Option Activity	Weighted- Weighted- average Shares average remaining Aggregate subject exercise price contractual intrinsic In millions, except per share amounts to options per share term (years) value (1) Outstanding as of May 31, 2021 3.6 $ 62.89 Granted 0.4 $ 109.71 Exercised ( 0.7 ) $ 52.50 Forfeited — $ 88.13 Expired — $ 35.37 Outstanding as of May 31, 2022 3.3 $ 70.68 6.0 $ 174.9 Exercisable as of May 31, 2022 2.3 $ 62.11 5.0 $ 144.0 (1) Total shares valued at the market price of the underlying stock as of May 31, 2022 less the exercise price.
Other Information Pertaining to Stock Option	Year ended May 31, In millions 2022 2021 2020 Total intrinsic value of stock options exercised $ 44.3 $ 58.5 $ 22.0 Total grant-date fair value of stock options vested $ 6.4 $ 6.0 $ 5.0
Time Based And Performance Based Restricted Stock Units [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
RSU Activity	Weighted- Weighted- average average Time- grant-date Performance- grant-date Based fair value based fair value In millions, except per share amounts RSUs per share RSUs per share Nonvested as of May 31, 2021 1.5 $ 65.64 0.1 $ 80.59 Granted (1) 0.5 $ 109.81 — $ 103.59 Vested ( 0.5 ) $ 63.08 — $ — Forfeited ( 0.2 ) $ 77.90 — $ 80.59 Nonvested as of May 31, 2022 1.3 $ 80.60 0.1 $ 92.33 (1) For performance-based RSUs, granted number assumes achievement of performance goals at target. Actual number of shares to be earned may differ from this amount.
Other Information Pertaining to RSUs	Year ended May 31, In millions, except per share amounts 2022 2021 2020 Time-based RSUs: Weighted-average grant-date fair value per share of RSUs granted $ 109.81 $ 67.92 $ 73.28 Weighted-average remaining vesting period (years) 2.8 3.0 2.9 Total intrinsic value of RSUs vested $ 54.7 $ 32.6 $ 40.0 Aggregate intrinsic value of nonvested RSUs (1) $ 165.2 $ 152.7 $ 99.9 Total grant-date fair value of RSUs vested $ 30.0 $ 25.6 $ 23.6 Performance-based RSUs (2) : Weighted-average grant-date fair value per share of RSUs granted $ 103.59 $ — $ 80.59 Weighted-average remaining vesting period (years) 1.0 1.1 2.1 Total intrinsic value of RSUs vested $ — $ — $ — Aggregate intrinsic value of nonvested RSUs (1) $ 14.7 $ 6.2 $ 4.4 Total grant-date fair value of RSUs vested $ — $ — $ — (1) Based on the market price of the underlying common stock as of May 31, 2022, 2021 and 2020 . (2) No performance-based RSUs were granted during fiscal 2021.
Time-Based And Performance-Based Restricted Stock Awards [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Restricted Stock Awards Activity	Weighted- Weighted- average average grant-date Performance- grant-date Time-based fair value based fair value In millions, except per share amounts shares per share shares per share Nonvested as of May 31, 2021 0.1 $ 74.60 0.1 $ 69.28 Granted (1) 0.1 $ 114.21 0.1 $ 103.97 Vested ( 0.1 ) $ 74.20 ( 0.1 ) $ 65.17 Forfeited — $ 98.11 — $ 107.40 Nonvested as of May 31, 2022 0.1 $ 93.15 0.1 $ 92.45 (1) For performance-based shares, granted number assumes achievement of performance goals at target. Actual number of shares to be earned may differ from this amount.
Other Information Pertaining to Restricted Stock Awards	Year ended May 31, In millions, except per share amounts 2022 2021 2020 Weighted-average grant-date fair value per share of time-based shares granted $ 114.21 $ 73.93 $ 84.46 Total grant-date fair value of time-based restricted stock vested $ 3.8 $ 3.0 $ 3.2 Weighted-average grant-date fair value per share of performance-based shares $ 103.97 $ 65.17 $ 80.59 Total grant-date fair value of performance-based restricted stock vested $ 7.2 $ 8.4 $ 5.8
LTIP Performance-Based Stock Options [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Stock Option Activity	Weighted- Weighted- average Shares average remaining Aggregate subject exercise price contractual intrinsic In millions, except per share amounts to options per share term (years) value (1) Outstanding as of May 31, 2021 0.7 $ 60.71 Exercised ( 0.3 ) $ 61.06 Outstanding as of May 31, 2022 0.4 $ 60.52 4.0 $ 28.3 Exercisable as of May 31, 2022 0.4 $ 60.52 4.0 $ 28.3 (1) Shares valued at the market price of the underlying stock as of May 31, 2022 less the exercise price.
Other Information Pertaining to Stock Option	Year ended May 31, In millions 2022 2021 2020 Total intrinsic value of stock options exercised $ 16.0 $ 26.3 $ 23.0 Total grant-date fair value of stock options vested $ — $ 8.0 $ —

Funds Held for Clients and Co_2

Funds Held for Clients and Corporate Investments (Tables)	12 Months Ended
	May 31, 2022
Funds Held for Clients and Corporate Investments [Abstract]
Funds Held for Clients and Corporate Investments	May 31, 2022 Gross Gross Amortized unrealized unrealized Fair In millions cost gains losses value Type of issue: Funds held for clients' money market securities and other $ 482.6 $ — $ — $ 482.6 AFS securities: Asset-backed securities 68.5 0.0 ( 1.3 ) 67.2 Corporate bonds 699.3 1.8 ( 19.0 ) 682.1 Municipal bonds 1,577.6 0.6 ( 92.4 ) 1,485.8 U.S. government agency and treasury securities 574.5 0.3 ( 26.3 ) 548.5 Variable rate demand notes 1,245.6 — — 1,245.6 Total AFS securities 4,165.5 2.7 ( 139.0 ) 4,029.2 Other 30.4 1.8 ( 2.2 ) 30.0 Total funds held for clients and corporate investments $ 4,678.5 $ 4.5 $ ( 141.2 ) $ 4,541.8 May 31, 2021 Gross Gross Amortized unrealized unrealized Fair In millions cost gains losses value Type of issue: Funds held for clients' money market securities and other $ 739.6 $ — $ — $ 739.6 AFS securities: Asset-backed securities 86.5 1.4 — 87.9 Corporate bonds 635.8 28.8 ( 0.2 ) 664.4 Municipal bonds 1,669.0 33.0 ( 2.3 ) 1,699.7 U.S. government agency and treasury securities 549.6 20.1 ( 1.5 ) 568.2 Variable rate demand notes — — — — Total AFS securities 2,940.9 83.3 ( 4.0 ) 3,020.2 Other 26.4 7.7 ( 0.1 ) 34.0 Total funds held for clients and corporate investments $ 3,706.9 $ 91.0 $ ( 4.1 ) $ 3,793.8
Classification of Investments on Consolidated Balance Sheets	May 31, In millions 2022 2021 Funds held for clients $ 3,682.9 $ 3,750.0 Corporate investments 853.9 36.7 Long-term corporate investments 5.0 7.1 Total funds held for clients and corporate investments $ 4,541.8 $ 3,793.8
Securities in Unrealized Loss Position	May 31, 2022 Securities in an unrealized Securities in an unrealized Total Gross Gross Gross unrealized Fair unrealized Fair unrealized Fair In millions losses value losses value losses value Type of issue: Asset-backed securities $ ( 0.9 ) $ 48.5 $ ( 0.3 ) $ 5.7 $ ( 1.2 ) $ 54.2 Corporate bonds ( 17.5 ) 425.4 ( 1.5 ) 16.7 ( 19.0 ) 442.1 Municipal bonds ( 81.9 ) 1,171.5 ( 10.6 ) 86.6 ( 92.5 ) 1,258.1 U.S. government agency and treasury securities ( 15.9 ) 414.2 ( 10.4 ) 91.7 ( 26.3 ) 505.9 Total $ ( 116.2 ) $ 2,059.6 $ ( 22.8 ) $ 200.7 $ ( 139.0 ) $ 2,260.3 May 31, 2021 Securities in an unrealized Securities in an unrealized Total Gross Gross Gross unrealized Fair unrealized Fair unrealized Fair In millions losses value losses value losses value Type of issue: Asset-backed securities $ — $ 7.1 $ — $ — $ — $ 7.1 Corporate bonds ( 0.2 ) 22.0 — — ( 0.2 ) 22.0 Municipal bonds ( 2.3 ) 288.2 — — ( 2.3 ) 288.2 U.S. government agency and treasury securities ( 1.5 ) 102.6 — — ( 1.5 ) 102.6 Total $ ( 4.0 ) $ 419.9 $ — $ — $ ( 4.0 ) $ 419.9
Realized Gains and Losses from Sale of Available-for-sale Securities	Year ended May 31, In millions 2022 2021 2020 Gross realized gains $ 0.2 $ 1.2 $ 11.6 Gross realized losses 0.0 — ( 0.3 ) Net realized gains $ 0.2 $ 1.2 $ 11.3
Amortized Cost and Fair Value of Available-for-Sale Securities by Contractual Maturity	May 31, 2022 Amortized Fair In millions cost value Maturity date: Due in one year or less $ 295.6 $ 296.3 Due after one year through three years 743.2 737.1 Due after three years through five years 1,304.4 1,235.4 Due after five years 1,822.3 1,760.4 Total $ 4,165.5 $ 4,029.2

Fair Value Measurements (Tables

Fair Value Measurements (Tables)	12 Months Ended
	May 31, 2022
Fair Value Disclosures [Abstract]
Financial Assets and Liabilities Measured at Fair Value on Recurring Basis	The Company’s financial assets and liabilities measured at fair value on a recurring basis were as follows: May 31, 2022 Quoted Significant prices in other Significant Carrying active observable unobservable value markets inputs inputs In millions (Fair value) (Level 1) (Level 2) (Level 3) Assets: Restricted and unrestricted cash equivalents: Commercial paper $ 5.2 $ — $ 5.2 $ — Time deposits 187.9 — 187.9 — VRDNs 10.0 — 10.0 — Money market securities 16.1 16.1 — — Total restricted and unrestricted cash equivalents $ 219.2 $ 16.1 $ 203.1 $ — AFS securities: Asset-backed securities $ 67.2 $ — $ 67.2 $ — Corporate bonds 682.1 — 682.1 — Municipal bonds 1,485.8 — 1,485.8 — U.S. government agency and treasury securities 548.5 — 548.5 — VRDNs 1,245.6 — 1,245.6 — Total AFS securities $ 4,029.2 $ — $ 4,029.2 $ — Other $ 30.0 $ 30.0 $ — $ — Liabilities: Other long-term liabilities $ 29.9 $ 29.9 $ — $ — May 31, 2021 Quoted Significant prices in other Significant Carrying active observable unobservable value markets inputs inputs In millions (Fair value) (Level 1) (Level 2) (Level 3) Assets: Restricted and unrestricted cash equivalents: Money market securities $ 2.9 $ 2.9 $ — $ — Total restricted and unrestricted cash equivalents $ 2.9 $ 2.9 $ — $ — AFS securities: Asset-backed securities $ 87.9 $ — $ 87.9 $ — Corporate bonds 664.4 — 664.4 — Municipal bonds 1,699.7 — 1,699.7 — U.S. government agency and treasury securities 568.2 — 568.2 — VRDNs — — — — Total AFS securities $ 3,020.2 $ — $ 3,020.2 $ — Other $ 34.0 $ 34.0 $ — $ — Liabilities: Other long-term liabilities $ 32.6 $ 32.6 $ — $ —

Leases (Tables)

Leases (Tables)	12 Months Ended
	May 31, 2022
Leases [Abstract]
Supplemental Balance Sheet Information Related to Leases	Supplemental balance sheet information related to the Company’s leases were as follows: May 31, $ in millions 2022 2021 Operating lease right-of-use assets, net of accumulated amortization $ 78.7 $ 103.0 Operating lease liabilities, current (1) 25.1 28.9 Operating lease liabilities, non-current 74.8 92.4 Weighted average remaining lease term (in years) 5.1 5.2 Weighted average discount rate 1.94 % 1.81 % (1) The current portion of operating lease liabilities is reported in the other current liabilities line item on the Company’s Consolidated Balance Sheets.
Components of Lease Expense	The components of lease expense were as follows: Year ended May 31, In millions 2022 2021 2020 Fixed payment operating lease expense $ 27.2 $ 34.6 $ 38.2 Variable payment operating lease expense 6.9 8.3 8.6 Short-term lease expense - 0.1 0.2
Supplemental Cash Flow Information Related to Leases	Supplemental cash flow information related to the Company’s leases were as follows: Year ended May 31, In millions 2022 2021 2020 Cash paid for amounts included in the measurement of lease liabilities $ 32.4 $ 32.2 $ 41.6 Amortization of ROU assets 22.7 29.2 34.4 ROU assets obtained in exchange for new operating lease liabilities 15.8 26.8 21.5 Lease incentives received in the form of tenant allowances and free rent 9.1 0.8 6.1
Future Lease Payments	Future lease payments are as follows: May 31, In millions 2022 2023 $ 27.0 2024 20.9 2025 18.9 2026 13.4 2027 9.5 Thereafter 15.5 Total future lease payments 105.2 Less: imputed interest 5.3 Total operating lease liabilities $ 99.9 Current portion $ 25.1 Non-current portion $ 74.8

Property and Equipment, Net o_2

Property and Equipment, Net of Accumulated Depreciation (Tables)	12 Months Ended
	May 31, 2022
Property, Plant and Equipment [Abstract]
Components of Property and Equipment, at Cost	The components of property and equipment, at cost, consisted of the following: May 31, In millions 2022 2021 Land and improvements $ 10.3 $ 10.3 Buildings and improvements 157.1 158.3 Data processing equipment 217.4 211.4 Software (1) 832.1 748.3 Furniture, fixtures, and equipment 97.7 99.8 Leasehold improvements 91.7 83.5 Construction in progress (1) 50.7 50.3 Total property and equipment, gross 1,457.0 1,361.9 Less: Accumulated depreciation 1,055.7 966.1 Property and equipment, net of accumulated depreciation $ 401.3 $ 395.8 (1) Software includes both purchased software and costs capitalized related to internally developed software placed in service. Capitalized costs related to internally developed software that has not yet been placed in service is included in construction in progress.

Goodwill and Intangible Asset_2

Goodwill and Intangible Assets, Net of Accumulated Amortization (Tables)	12 Months Ended
	May 31, 2022
Goodwill and Intangible Assets Disclosure [Abstract]
Change in Goodwill	Goodwill and changes in goodwill as of and for the years ended May 31, 2022 and May 31, 2021 were as follows: May 31, In millions 2022 2021 Balance, beginning of fiscal year $ 1,820.7 $ 1,791.1 Changes during the period: Goodwill acquired 27.7 19.6 Currency translation adjustment ( 16.9 ) 10.0 Balance, end of fiscal year $ 1,831.5 $ 1,820.7
Components of Intangible Assets, at Cost	The Company had certain intangible assets on its Consolidated Balance Sheets. The components of intangible assets, at cost, consisted of the following: May 31, In millions 2022 2021 Client lists $ 637.4 $ 632.3 Other intangible assets 23.0 24.1 Total intangible assets, gross 660.4 656.4 Less: Accumulated amortization 435.8 380.6 Intangible assets, net of accumulated amortization $ 224.6 $ 275.8
Estimated Amortization Expense	The estimated amortization expense for the next five fiscal years relating to intangible asset balances is as follows: In millions Estimated Year ending May 31, expense 2023 $ 59.4 2024 56.5 2025 53.5 2026 37.8 2027 4.5

Income Taxes (Tables)

Income Taxes (Tables)	12 Months Ended
	May 31, 2022
Income Tax Disclosure [Abstract]
Components of Deferred Tax Assets and Liabilities	The components of deferred tax assets and liabilities are as follows: May 31, In millions 2022 2021 Deferred tax assets: Compensation and employee benefit liabilities $ 56.8 $ 53.0 Other current liabilities 21.3 19.8 Tax credit carry forward 0.2 0.2 Stock-based compensation 12.9 12.0 Unrealized losses on available-for-sale securities 33.6 — Leases 20.5 29.0 Net operating loss (“NOL”) carry forwards 5.6 7.6 Tax benefit of uncertain tax positions 9.9 5.3 Gross deferred tax assets 160.8 126.9 Deferred tax liabilities: Deferred contract costs 141.9 127.5 Capitalized software 50.8 49.0 Depreciation 8.1 8.9 Goodwill and intangible assets 103.5 111.3 Operating lease right-of-use assets 17.7 26.1 Revenue not subject to current taxes — 1.9 Unrealized gains on available-for-sale securities — 20.2 Other 4.3 — Gross deferred tax liabilities 326.3 344.9 Net deferred tax liability $ ( 165.5 ) $ ( 218.0 )
Components of Provision for Income Taxes	The components of the provision for income taxes are as follows: Year ended May 31, In millions 2022 2021 2020 Current: Federal $ 326.0 $ 271.5 $ 264.8 State 104.5 85.9 77.5 Non-U.S. ( 1.0 ) 0.3 0.7 Total current 429.5 357.7 343.0 Deferred: Federal 0.9 ( 12.9 ) ( 0.8 ) State 0.9 ( 7.6 ) ( 3.5 ) Non-U.S. 0.5 ( 0.5 ) 0.3 Total deferred 2.3 ( 21.0 ) ( 4.0 ) Income taxes $ 431.8 $ 336.7 $ 339.0
Reconciliation of U.S. Federal Statutory Tax Rate	A reconciliation of the U.S. federal statutory tax rate to the Company’s effective income tax rate is as follows: Year ended May 31, 2022 2021 2020 Federal statutory tax rate 21.0 % 21.0 % 21.0 % Increase/(decrease) resulting from: State income taxes, net of federal tax benefit 4.6 % 4.3 % 4.0 % Tax-exempt municipal bond interest ( 0.2 ) % ( 0.3 ) % ( 0.4 ) % Stock option windfall benefit ( 0.9 ) % ( 1.2 ) % ( 0.9 ) % Tax credits ( 1.1 ) % ( 0.6 ) % ( 0.5 ) % Other items 0.3 % 0.3 % 0.4 % Effective income tax rate 23.7 % 23.5 % 23.6 %
Reconciliation of Gross Unrecognized Tax Benefits, Not Including Interest or Other Potential Offsetting Effects	A reconciliation of the beginning and ending amounts of the Company’s gross unrecognized tax benefits, not including interest or other potential offsetting effec ts, is as follows: Year ended May 31, In millions 2022 2021 2020 Balance as of beginning of fiscal year $ 22.4 $ 26.2 $ 22.1 Additions for tax positions of the current year 11.1 5.5 4.1 Additions for tax positions of prior years 20.6 9.2 1.2 Reductions for tax positions of prior years ( 1.8 ) — ( 0.6 ) Settlements with tax authorities ( 0.4 ) ( 15.2 ) — Expiration of the statute of limitations ( 1.7 ) ( 3.3 ) ( 0.6 ) Balance as of end of fiscal year $ 50.2 $ 22.4 $ 26.2

Short-term Financing (Tables)

Short-term Financing (Tables)	12 Months Ended
	May 31, 2022
Revolving Credit Facility [Member]
Line of Credit Facility [Line Items]
Description of Credit Facilities	Details of the Company’s credit facilities as of May 31, 2022 are as follows: Maximum Amount Outstanding Amount May 31, $ in millions Expiration Date Available 2022 2021 Credit facilities: JP Morgan Chase Bank, N.A. (“JPM”) (1) July 31, 2024 $ 1,000.0 $ — $ — JPM (1) September 17, 2026 $ 750.0 — — PNC Bank, National Association (“PNC”) (weighted-average interest 2.34 % at May 31, 2022 and 1.16 % at May 31, 2021) February 6, 2023 $ 250.0 8.7 7.4 Outstanding short-term financing (2) $ 8.7 $ 7.4 (1) JPM acts as the administrative agent for this syndicated credit facility. (2) The total amount available under these credit facilities as of May 31, 2022 was approximately $ 2.0 billion. Amounts under the PNC credit facility remain outstanding as of the date of this report.

Long-Term Financing (Tables)

Long-Term Financing (Tables)	12 Months Ended
	May 31, 2022
Debt Disclosure [Abstract]
Schedule of Long-Term Debt	Long-term debt, at amortized cost, consisted of the following as of: May 31, In millions 2022 2021 Senior Notes, Series A $ 400.0 $ 400.0 Senior Notes, Series B 400.0 400.0 Total long-term borrowings 800.0 800.0 Less: Debt issuance costs, net of accumulated amortization ( 2.3 ) ( 2.7 ) Long-term borrowings, net of debt issuance costs $ 797.7 $ 797.3 Certain information related to the Senior Notes, Series A and Senior Notes, Series B (collectively the “Notes”) issued pursuant to the Note Purchase and Guarantee Agreement (the “Agreement”) for fiscal 2022 and fiscal 2021 are as follows: Senior Notes Senior Notes Series A Series B Stated interest rate 4.07 % 4.25 % Effective interest rate 4.15 % 4.31 % Interest rate type Fixed Fixed Interest payment dates Semi-annual, in arrears Semi-annual, in arrears Principal payment dates March 13, 2026 March 13, 2029 Note type Unsecured Unsecured

Commitments and Contingencies (

Commitments and Contingencies (Tables)	12 Months Ended
	May 31, 2022
Commitments and Contingencies Disclosure [Abstract]
Minimum Future Payment Obligations	These minimum future payment obligations relate to the following fiscal years: Payments due by period In millions 2023 2024 2025 2026 2027 Thereafter Workers' compensation estimated obligations $ 64.1 $ 36.8 $ 22.4 $ 14.8 $ 10.9 $ 40.7 Purchase obligations 149.8 28.9 9.7 0.5 0.3 0.2

Description of Business, Basi_4

Description of Business, Basis of Presentation, and Significant Accounting Policies (Narrative) (Details)	12 Months Ended
	May 31, 2022 USD ($) Item Segment	May 31, 2021 USD ($) Item	May 31, 2020 USD ($) Item
Accounting Policies [Line Items]
Number of reportable segments | Segment	1
Cash and cash equivalents	$ 370,000,000	$ 995,200,000	$ 905,200,000
Allowance for credit losses	18,200,000	16,000,000
Advance collections	2,600,000	2,500,000
Goodwill	1,831,500,000	1,820,700,000	1,791,100,000
Goodwill, impairment loss	0	0	0
Impairment of intangible assets with indefinite useful lives	0	0	0
Impairment of long-lived assets	0	0	0
Realized gains or losses from foreign exchange transactions	0	0	0
Impairment loss, assets recognized from the costs to obtain and fufill contracts	0	0	0
Workers' compensation insurance costs in current liabilities	64,100,000	65,300,000
Workers' compensation insurance costs in long-term liabilities	125,600,000	117,800,000
Maximum individual health insurance claims liability	500,000	300,000
PEO accrued health insurance and dental and vision plan reserves in current liabilities	46,200,000	43,900,000
Operating lease, impairment loss	$ 0	0	$ 0
Accounting Standards Update 2020-08 [Member]
Accounting Policies [Line Items]
Change in accounting principle, accounting standards update, adoption date	Jun. 30, 2021
Change in accounting principle, accounting standards update, adopted [true false]	true
Change in accounting principle, accounting standards update, immaterial effect [true false]	true
Accounting Standards Update 2019-12 [Member]
Accounting Policies [Line Items]
Change in accounting principle, accounting standards update, adoption date	Jun. 30, 2021
Change in accounting principle, accounting standards update, adopted [true false]	true
Change in accounting principle, accounting standards update, immaterial effect [true false]	true
Trade Receivables [Member]
Accounting Policies [Line Items]
Receivables	$ 123,200,000	98,400,000
Purchased Receivables [Member]
Accounting Policies [Line Items]
Receivables	$ 618,800,000	$ 495,900,000
Minimum [Member]
Accounting Policies [Line Items]
Payroll funding fees average collection period	46 days
Minimum [Member] | Finite Lived Assets [Member]
Accounting Policies [Line Items]
Amortization period	3 years
Minimum [Member] | Software [Member]
Accounting Policies [Line Items]
Estimated useful lives	3 years
Minimum [Member] | Software Development [Member]
Accounting Policies [Line Items]
Estimated useful lives	12 years
Maximum [Member]
Accounting Policies [Line Items]
Payroll funding fees average collection period	48 days
Maximum [Member] | Finite Lived Assets [Member]
Accounting Policies [Line Items]
Amortization period	12 years
Maximum [Member] | Software [Member]
Accounting Policies [Line Items]
Estimated useful lives	5 years
Revenue [Member]
Accounting Policies [Line Items]
Number of clients creating a credit concentration | Item	0	0	0
Accounts And Unbilled Receivables [Member]
Accounting Policies [Line Items]
Number of clients creating a credit concentration | Item	0	0
INDIA [Member] | Long Lived Assets [Member] | Geographic Concentration Risk [Member] | Maximum [Member]
Accounting Policies [Line Items]
Concentration percentage	1%	1%
Europe [Member] | Revenue [Member] | Geographic Concentration Risk [Member]
Accounting Policies [Line Items]
Concentration percentage	1%	1%	1%
Europe [Member] | Long Lived Assets [Member] | Geographic Concentration Risk [Member]
Accounting Policies [Line Items]
Concentration percentage	6%	7%
PEO Aggregate Claims Exceeding $1.0M [Member] | Minimum [Member]
Accounting Policies [Line Items]
Individual Claims Liability Workers Compensation Insurance	$ 1,000,000
PEO Aggregate Claims Exceeding $1.0M [Member] | Maximum [Member]
Accounting Policies [Line Items]
Maximum individual workers' compensation claims liability	2,000,000
PEO And Insurance Solutions [Member]
Accounting Policies [Line Items]
Cash and cash equivalents	89,700,000	$ 150,500,000
PEO [Member]
Accounting Policies [Line Items]
Maximum individual workers' compensation claims liability		$ 1,000,000
Individual Claims Liability Workers Compensation Insurance	$ 1,000,000

Description of Business, Basi_5

Description of Business, Basis of Presentation, and Significant Accounting Policies (Estimated Useful Lives of Depreciable Assets) (Details)	12 Months Ended
	May 31, 2022
Buildings and Improvements [Member] | Minimum [Member]
Property, Plant and Equipment [Line Items]
Estimated useful lives	10 years
Buildings and Improvements [Member] | Maximum [Member]
Property, Plant and Equipment [Line Items]
Estimated useful lives	35 years
Data Processing Equipment [Member] | Minimum [Member]
Property, Plant and Equipment [Line Items]
Estimated useful lives	3 years
Data Processing Equipment [Member] | Maximum [Member]
Property, Plant and Equipment [Line Items]
Estimated useful lives	4 years
Furniture, Fixtures, and Equipment [Member] | Minimum [Member]
Property, Plant and Equipment [Line Items]
Estimated useful lives	2 years
Furniture, Fixtures, and Equipment [Member] | Maximum [Member]
Property, Plant and Equipment [Line Items]
Estimated useful lives	7 years
Leasehold Improvements [Member]
Property, Plant and Equipment [Line Items]
Estimated useful lives	10 years
Software [Member] | Minimum [Member]
Property, Plant and Equipment [Line Items]
Estimated useful lives	3 years
Software [Member] | Maximum [Member]
Property, Plant and Equipment [Line Items]
Estimated useful lives	12 years

Service Revenue (Narrative) (De

Service Revenue (Narrative) (Details) - USD ($)	12 Months Ended
	May 31, 2022	May 31, 2021	May 31, 2020
Service Revenue [Line Items]
Notice of termination period	30 days
Revenue performance obligations timing	the Company defers revenue associated with these performance obligations, which exceed one year, and subsequently recognizes them as future services are provided, over approximately three years to four years.
Impairment loss	$ 0	$ 0	$ 0
Minimum [Member]
Service Revenue [Line Items]
Revenue performance obligations timing, years	3 years
Maximum [Member]
Service Revenue [Line Items]
Revenue performance obligations timing, years	4 years

Service Revenue (Narrative) (Pe

Service Revenue (Narrative) (Performance Obligation) (Details) $ in Millions	May 31, 2022 USD ($)
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2022-06-01
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items]
Deferred revenue, performance obligations	$ 22.1
Deferred revenue, timing of satisfaction	1 year
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2023-06-01
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items]
Deferred revenue, performance obligations	$ 26.8
Deferred revenue, timing of satisfaction

Service Revenue (Summary of PEO

Service Revenue (Summary of PEO Pass-Through Costs Netted in Revenue) (Details) - USD ($) $ in Millions	12 Months Ended
	May 31, 2022	May 31, 2021	May 31, 2020
Revenue from Contract with Customer [Abstract]
Payroll wages and payroll taxes	$ 24,070.2	$ 20,587.1	$ 20,463.8
State unemployment insurance (included in payroll wages and payroll taxes)	139.1	119	85.7
Guaranteed cost benefit plans	$ 641.4	$ 586.4	$ 647

Service Revenue (Summary of Cha

Service Revenue (Summary of Changes in Deferred Revenue Related to Material Rights Performance Obligations) (Details) - USD ($) $ in Millions	12 Months Ended
	May 31, 2022	May 31, 2021
Revenue from Contract with Customer [Abstract]
Balance, beginning of period	$ 40.2	$ 42.6
Deferral of revenue	35	23.5
Recognition of unearned revenue	(26.3)	(25.9)
Balance, end of period	$ 48.9	$ 40.2

Service Revenue (Summary of C_2

Service Revenue (Summary of Changes in Deferred Costs to Obtain and Fulfill Contracts) (Details) - USD ($) $ in Millions	12 Months Ended
	May 31, 2022	May 31, 2021	May 31, 2020
Capitalized Contract Cost [Line Items]
Amortization	$ 202.1	$ 191.4	$ 186.1
Costs To Fulfill Contracts [Member]
Capitalized Contract Cost [Line Items]
Balance, beginning of period	69.3	67.3
Capitalization of costs	28	26.2
Amortization	(25)	(24.2)
Balance, end of period	72.3	69.3	67.3
Costs To Obtain Contracts [Member]
Capitalized Contract Cost [Line Items]
Balance, beginning of period	488.2	473.6
Capitalization of costs	239.1	181.8
Amortization	(177.1)	(167.2)
Balance, end of period	$ 550.2	$ 488.2	$ 473.6

Basic and Diluted Earnings Pe_3

Basic and Diluted Earnings Per Share (Basic and Diluted Earnings Per Share) (Details) - USD ($) $ / shares in Units, shares in Millions, $ in Millions	12 Months Ended
	May 31, 2022	May 31, 2021	May 31, 2020
Basic earnings per share:
Net income	$ 1,392.8	$ 1,097.5	$ 1,098.1
Weighted-average common shares outstanding	360.6	359.9	358.5
Basic earnings per share	$ 3.86	$ 3.05	$ 3.06
Diluted earnings per share:
Net income	$ 1,392.8	$ 1,097.5	$ 1,098.1
Weighted-average common shares outstanding	360.6	359.9	358.5
Dilutive effect of common share equivalents	2.5	2.2	2.5
Weighted-average common shares outstanding, assuming dilution	363.1	362.1	361
Diluted earnings per share	$ 3.84	$ 3.03	$ 3.04
Weighted-average anti-dilutive common share equivalents	0.2	0.6	0.7

Other Expense, Net (Schedule of

Other Expense, Net (Schedule of Other Expense, Net) (Details) - USD ($) $ in Millions	12 Months Ended
	May 31, 2022	May 31, 2021	May 31, 2020
Other Income and Expenses [Abstract]
Interest income on corporate investments	$ 2.9	$ 2.3	$ 12.3
Interest expense	(36.6)	(35.8)	(38.8)
Other	18.3	7	3.1
Other expense, net	$ (15.4)	$ (26.5)	$ (23.4)

Stock-Based Compensation Plan_2

Stock-Based Compensation Plans (Narrative) (Details) - USD ($) $ in Millions	12 Months Ended
	May 31, 2022	May 31, 2021	May 31, 2020
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Shares authorized for grant	44,100,000
Shares available for future grants	15,600,000
Stock-based compensation expense	$ 52.8	$ 52.5	$ 47.4
Income tax benefits related to stock-based compensation	9.8	$ 8.6	9
Total unrecognized compensation cost related to all unvested stock-based awards	$ 80.5
Weighted-average period in years of all unvested stock-based awards	2 years 9 months 18 days
Stock Options [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Stock options granted	400,000
Contractual life	10 years
Time-Based RSUs [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Outstanding balance	1,300,000	1,500,000
Performance-Based RSUs [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Performance period	2 years
Service period	1 year
Outstanding balance	100,000	100,000
Time-Based Restricted Stock Awards [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Vesting period	1 year
Outstanding balance	100,000	100,000
Performance-Based Restricted Stock Awards [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Performance period	2 years
Service period	1 year
Outstanding balance	100,000	100,000
LTIP Performance-Based Restricted Stock [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Outstanding balance	0	0
Director [Member] | Stock Options [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Vesting period	1 year
Non-Executive [Member] | Time-Based RSUs [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Vesting period	5 years
Executive [Member] | Time-Based RSUs [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Vesting period	3 years
Tranche One [Member] | Time-Based Restricted Stock Awards [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Vesting percentage	33.30%
Tranche One [Member] | Officer [Member] | Stock Options [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Vesting percentage	33.30%
Tranche One [Member] | Non-Executive [Member] | Time-Based RSUs [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Vesting percentage	20%
Tranche One [Member] | Executive [Member] | Time-Based RSUs [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Vesting percentage	33.30%
Employee Stock Purchase Plan [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Stock-based compensation expense	$ 0	$ 0	$ 0
Discount to the market price	5%	5%	5%
Maximum [Member] | Employee Stock Purchase Plan [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Discount to the market price	15%

Stock-Based Compensation Plan_3

Stock-Based Compensation Plans (Weighted-Average Assumptions) (Details) - Stock Options [Member] - $ / shares	12 Months Ended
	May 31, 2022	May 31, 2021	May 31, 2020
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Risk-free interest rate	1.20%	0.50%	2%
Dividend yield	2.90%	3.20%	3.30%
Volatility factor	0.23%	0.29%	0.18%
Expected option life in years	6 years 7 months 6 days	6 years 1 month 6 days	6 years 2 months 12 days
Weighted-average grant-date fair value of stock options granted (per share)	$ 17.47	$ 13.52	$ 9.86

Stock-Based Compensation Plan_4

Stock-Based Compensation Plans (Stock Option Activity) (Details) - Stock Options [Member] $ / shares in Units, shares in Millions, $ in Millions	12 Months Ended
	May 31, 2022 USD ($) $ / shares shares
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Outstanding, Beginning balance, Shares subject to options | shares	3.6
Granted, Shares subject to options | shares	0.4
Exercised, Shares subject to options | shares	(0.7)
Outstanding, Ending balance, Shares subject to options | shares	3.3
Exercisable, Shares subject to options | shares	2.3
Outstanding, Beginning balance, Weighted-average exercise price per share	$ 62.89
Granted, Weighted-average exercise price per share	109.71
Exercised, Weighted-average exercise price per share	52.50
Forfeited, Weighted-average exercise price per share	88.13
Expired, Weighted-average exercise price per share	35.37
Outstanding, Ending balance, Weighted-average exercise price per share	70.68
Exercisable, Weighted-average exercise price per share	$ 62.11
Outstanding, Weighted-average remaining contractual term (years)	6 years
Exercisable, Weighted-average remaining contractual term (years)	5 years
Outstanding, Aggregate intrinsic value | $	$ 174.9	[1]
Exercisable, Aggregate intrinsic value | $	$ 144	[1]
[1] Total shares valued at the market price of the underlying stock as of May 31, 2022 less the exercise price.

Stock-Based Compensation Plan_5

Stock-Based Compensation Plans (Other Information Pertaining to Stock Option) (Details) - Stock Options [Member] - USD ($) $ in Millions	12 Months Ended
	May 31, 2022	May 31, 2021	May 31, 2020
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Total intrinsic value of stock options exercised	$ 44.3	$ 58.5	$ 22
Total grant-date fair value of stock options vested	$ 6.4	$ 6	$ 5

Stock-Based Compensation Plan_6

Stock-Based Compensation Plans (RSU Activity) (Details) - $ / shares		12 Months Ended
		May 31, 2022		May 31, 2021	May 31, 2020
Time-Based RSUs [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Nonvested, Beginning balance		1,500,000
Granted	[1]	500,000
Vested		(500,000)
Forfeited		(200,000)
Nonvested, Ending balance		1,300,000		1,500,000
Nonvested, Beginning balance, Weighted-average grant-date fair value per share		$ 65.64
Granted, Weighted-average grant-date fair value per share		109.81	[1]	$ 67.92	$ 73.28
Vested, Weighted-average grant-date fair value per share		63.08
Forfeited, Weighted-average grant-date fair value per share		77.90
Nonvested, Ending balance, Weighted-average grant-date fair value per share		$ 80.60		$ 65.64
Performance-Based RSUs [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Nonvested, Beginning balance		100,000
Granted	[1]	0
Vested
Forfeited		0
Nonvested, Ending balance		100,000		100,000
Nonvested, Beginning balance, Weighted-average grant-date fair value per share		$ 80.59
Granted, Weighted-average grant-date fair value per share	[2]	103.59	[1]	$ 0	$ 80.59
Vested, Weighted-average grant-date fair value per share
Forfeited, Weighted-average grant-date fair value per share		80.59
Nonvested, Ending balance, Weighted-average grant-date fair value per share		$ 92.33		$ 80.59
[1] For performance-based RSUs, granted number assumes achievement of performance goals at target. Actual number of shares to be earned may differ from this amount. No performance-based RSUs were granted during fiscal 2021.

Stock-Based Compensation Plan_7

Stock-Based Compensation Plans (Other Information Pertaining to RSUs) (Details) - USD ($) $ / shares in Units, $ in Millions		12 Months Ended
		May 31, 2022		May 31, 2021	May 31, 2020
Time-Based RSUs [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Weighted-average grant-date fair value per share		$ 109.81	[1]	$ 67.92	$ 73.28
Weighted-average remaining vesting period (years)		2 years 9 months 18 days		3 years	2 years 10 months 24 days
Total intrinsic value of RSUs vested		$ 54.7		$ 32.6	$ 40
Aggregate intrinsic value of nonvested RSUs	[2]	165.2		152.7	99.9
Total grant-date fair value of RSUs vested		$ 30		$ 25.6	$ 23.6
Performance-Based RSUs [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Weighted-average grant-date fair value per share	[3]	$ 103.59	[1]	$ 0	$ 80.59
Weighted-average remaining vesting period (years)	[3]	1 year		1 year 1 month 6 days	2 years 1 month 6 days
Total intrinsic value of RSUs vested	[3]
Aggregate intrinsic value of nonvested RSUs	[2],[3]	14.7		6.2	4.4
Total grant-date fair value of RSUs vested	[3]
[1] For performance-based RSUs, granted number assumes achievement of performance goals at target. Actual number of shares to be earned may differ from this amount. Based on the market price of the underlying common stock as of May 31, 2022, 2021 and 2020 . No performance-based RSUs were granted during fiscal 2021.

Stock-Based Compensation Plan_8

Stock-Based Compensation Plans (Restricted Stock Awards Activity) (Details) - $ / shares shares in Millions		12 Months Ended
		May 31, 2022		May 31, 2021	May 31, 2020
Time-Based Restricted Stock Awards [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Nonvested, Beginning balance		0.1
Granted	[1]	0.1
Vested		(0.1)
Forfeited		0
Nonvested, Ending balance		0.1		0.1
Nonvested, Beginning balance, Weighted-average grant-date fair value per share		$ 74.60
Granted, Weighted-average grant-date fair value per share		114.21	[1]	$ 73.93	$ 84.46
Vested, Weighted-average grant-date fair value per share		74.20
Forfeited, Weighted-average grant-date fair value per share		98.11
Nonvested, Ending balance, Weighted-average grant-date fair value per share		$ 93.15		$ 74.60
Performance-Based Restricted Stock Awards [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Nonvested, Beginning balance		0.1
Granted	[1]	0.1
Vested		(0.1)
Forfeited		0
Nonvested, Ending balance		0.1		0.1
Nonvested, Beginning balance, Weighted-average grant-date fair value per share		$ 69.28
Granted, Weighted-average grant-date fair value per share		103.97	[1]	$ 65.17	$ 80.59
Vested, Weighted-average grant-date fair value per share		65.17
Forfeited, Weighted-average grant-date fair value per share		107.40
Nonvested, Ending balance, Weighted-average grant-date fair value per share		$ 92.45		$ 69.28
[1] For performance-based shares, granted number assumes achievement of performance goals at target. Actual number of shares to be earned may differ from this amount.

Stock-Based Compensation Plan_9

Stock-Based Compensation Plans (Other Information Pertaining to Restricted Stock Awards) (Details) - USD ($) $ / shares in Units, $ in Millions	12 Months Ended
	May 31, 2022		May 31, 2021	May 31, 2020
Time-Based Restricted Stock Awards [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Weighted-average grant-date fair value per share	$ 114.21	[1]	$ 73.93	$ 84.46
Total grant-date fair value of shares vested	$ 3.8		$ 3	$ 3.2
Performance-Based Restricted Stock Awards [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Weighted-average grant-date fair value per share	$ 103.97	[1]	$ 65.17	$ 80.59
Total grant-date fair value of shares vested	$ 7.2		$ 8.4	$ 5.8
[1] For performance-based shares, granted number assumes achievement of performance goals at target. Actual number of shares to be earned may differ from this amount.

Stock-Based Compensation Pla_10

Stock-Based Compensation Plans (LTIP Performance-Based Stock Option Activity) (Details) - LTIP Performance-Based Stock Options [Member] $ / shares in Units, shares in Millions, $ in Millions	12 Months Ended
	May 31, 2022 USD ($) $ / shares shares
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Outstanding, Beginning balance, Shares subject to options | shares	0.7
Exercised, Shares subject to options | shares	(0.3)
Outstanding, Ending balance, Shares subject to options | shares	0.4
Exercisable, Shares subject to options | shares	0.4
Outstanding, Beginning balance, Weighted-average exercise price per share | $ / shares	$ 60.71
Exercised, Weighted-average exercise price per share | $ / shares	61.06
Outstanding, Ending balance, Weighted-average exercise price per share | $ / shares	60.52
Exercisable, Weighted-average exercise price per share | $ / shares	$ 60.52
Outstanding, Weighted-average remaining contractual term (years)	4 years
Exercisable, Weighted-average remaining contractual term (years)	4 years
Outstanding, Aggregate intrinsic value | $	$ 28.3	[1]
Exercisable, Aggregate intrinsic value | $	$ 28.3	[1]
[1] Shares valued at the market price of the underlying stock as of May 31, 2022 less the exercise price.

Stock-Based Compensation Pla_11

Stock-Based Compensation Plans (Other Information Pertaining to LTIP Performance-Based Stock Options) (Details) - LTIP Performance-Based Stock Options [Member] - USD ($) $ in Millions	12 Months Ended
	May 31, 2022	May 31, 2021	May 31, 2020
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Total intrinsic value of stock options exercised	$ 16	$ 26.3	$ 23
Total grant-date fair value of stock options vested		$ 8

Funds Held for Clients and Co_3

Funds Held for Clients and Corporate Investments (Funds Held for Clients and Corporate Investments) (Details) - USD ($) $ in Millions	May 31, 2022	May 31, 2021
Schedule of Available-for-sale Securities [Line Items]
Funds held for clients' money market securities and other restricted cash equivalents, Amortized cost	$ 482.6	$ 739.6
Funds held for clients' money market securities and other restricted cash equivalents, Fair value	482.6	739.6
AFS securities, Amortized cost	4,165.5	2,940.9
AFS securities, Gross unrealized gains	2.7	83.3
AFS securities, Gross unrealized losses	(139)	(4)
AFS securities, Fair value	4,029.2	3,020.2
Other, Amortized cost	30.4	26.4
Other, Gross unrealized gains	1.8	7.7
Other, Gross unrealized losses	(2.2)	(0.1)
Other, Fair value	30	34
Total funds held for clients and corporate investments, Amortized cost	4,678.5	3,706.9
Total funds held for clients and corporate investments, Gross unrealized gains	4.5	91
Total funds held for clients and corporate investments, Gross unrealized losses	(141.2)	(4.1)
Total funds held for clients and corporate investments, Fair value	4,541.8	3,793.8
Asset-Backed Securities [Member]
Schedule of Available-for-sale Securities [Line Items]
AFS securities, Amortized cost	68.5	86.5
AFS securities, Gross unrealized gains	0	1.4
AFS securities, Gross unrealized losses	(1.3)
AFS securities, Fair value	67.2	87.9
Corporate Bonds [Member]
Schedule of Available-for-sale Securities [Line Items]
AFS securities, Amortized cost	699.3	635.8
AFS securities, Gross unrealized gains	1.8	28.8
AFS securities, Gross unrealized losses	(19)	(0.2)
AFS securities, Fair value	682.1	664.4
Municipal Bonds [Member]
Schedule of Available-for-sale Securities [Line Items]
AFS securities, Amortized cost	1,577.6	1,669
AFS securities, Gross unrealized gains	0.6	33
AFS securities, Gross unrealized losses	(92.4)	(2.3)
AFS securities, Fair value	1,485.8	1,699.7
U.S. Government Agency And Treasury Securities [Member]
Schedule of Available-for-sale Securities [Line Items]
AFS securities, Amortized cost	574.5	549.6
AFS securities, Gross unrealized gains	0.3	20.1
AFS securities, Gross unrealized losses	(26.3)	(1.5)
AFS securities, Fair value	548.5	$ 568.2
Variable Rate Demand Notes [Member]
Schedule of Available-for-sale Securities [Line Items]
AFS securities, Amortized cost	1,245.6
AFS securities, Fair value	$ 1,245.6

Funds Held for Clients and Co_4

Funds Held for Clients and Corporate Investments (Narrative) (Details) $ in Millions	12 Months Ended
	May 31, 2022 USD ($) Security	May 31, 2021 USD ($) Security
Schedule of Available-for-sale Securities [Line Items]
Gross unrealized losses on available-for-sale securities	$ 139	$ 4
Net unrealized gain (loss) on available-for-sale securities	$ (136.3)	$ 79.3
Number of available-for-sale securities in an unrealized loss position | Security	817	137
Percentage of available-for-sale securities in an unrealized loss position	64%	11%
Corporate Bonds [Member]
Schedule of Available-for-sale Securities [Line Items]
Gross unrealized losses on available-for-sale securities	$ 19	$ 0.2
Corporate Bonds [Member] | Minimum [Member]
Schedule of Available-for-sale Securities [Line Items]
Available-for-sale securities maturity date	Jun. 09, 2022
Corporate Bonds [Member] | Maximum [Member]
Schedule of Available-for-sale Securities [Line Items]
Available-for-sale securities maturity date	Dec. 13, 2028
Municipal Bonds [Member]
Schedule of Available-for-sale Securities [Line Items]
Gross unrealized losses on available-for-sale securities	$ 92.5	$ 2.3
Municipal Bonds [Member] | Minimum [Member]
Schedule of Available-for-sale Securities [Line Items]
Available-for-sale securities maturity date	Jun. 01, 2022
Municipal Bonds [Member] | Maximum [Member]
Schedule of Available-for-sale Securities [Line Items]
Available-for-sale securities maturity date	Apr. 01, 2029
Variable Rate Demand Notes [Member] | Minimum [Member]
Schedule of Available-for-sale Securities [Line Items]
Available-for-sale securities contractual maturities	20 years
Variable Rate Demand Notes [Member] | Maximum [Member]
Schedule of Available-for-sale Securities [Line Items]
Available-for-sale securities contractual maturities	30 years

Funds Held for Clients and Co_5

Funds Held for Clients and Corporate Investments (Classification of Investments on Consolidated Balance Sheets) (Details) - USD ($) $ in Millions	May 31, 2022	May 31, 2021
Funds Held for Clients and Corporate Investments [Abstract]
Funds held for clients	$ 3,682.9	$ 3,750
Corporate investments	853.9	36.7
Long-term corporate investments	5	7.1
Total funds held for clients and corporate investments, Fair value	$ 4,541.8	$ 3,793.8

Funds Held for Clients and Co_6

Funds Held for Clients and Corporate Investments (Securities in Unrealized Loss Position) (Details) - USD ($) $ in Millions	May 31, 2022	May 31, 2021
Schedule of Available-for-sale Securities [Line Items]
Securities in an unrealized loss position for less than twelve months, Gross unrealized losses	$ (116.2)	$ (4)
Securities in an unrealized loss position for less than twelve months, Fair value	2,059.6	419.9
Securities in an unrealized loss position for more than twelve months, Gross unrealized losses	(22.8)
Securities in an unrealized loss position for more than twelve months, Fair value	200.7
Total, Gross unrealized losses	(139)	(4)
Total, Fair value	2,260.3	419.9
Asset-Backed Securities [Member]
Schedule of Available-for-sale Securities [Line Items]
Securities in an unrealized loss position for less than twelve months, Gross unrealized losses	(0.9)
Securities in an unrealized loss position for less than twelve months, Fair value	48.5	7.1
Securities in an unrealized loss position for more than twelve months, Gross unrealized losses	(0.3)
Securities in an unrealized loss position for more than twelve months, Fair value	5.7
Total, Gross unrealized losses	(1.2)
Total, Fair value	54.2	7.1
Corporate Bonds [Member]
Schedule of Available-for-sale Securities [Line Items]
Securities in an unrealized loss position for less than twelve months, Gross unrealized losses	(17.5)	(0.2)
Securities in an unrealized loss position for less than twelve months, Fair value	425.4	22
Securities in an unrealized loss position for more than twelve months, Gross unrealized losses	(1.5)
Securities in an unrealized loss position for more than twelve months, Fair value	16.7
Total, Gross unrealized losses	(19)	(0.2)
Total, Fair value	442.1	22
Municipal Bonds [Member]
Schedule of Available-for-sale Securities [Line Items]
Securities in an unrealized loss position for less than twelve months, Gross unrealized losses	(81.9)	(2.3)
Securities in an unrealized loss position for less than twelve months, Fair value	1,171.5	288.2
Securities in an unrealized loss position for more than twelve months, Gross unrealized losses	(10.6)
Securities in an unrealized loss position for more than twelve months, Fair value	86.6
Total, Gross unrealized losses	(92.5)	(2.3)
Total, Fair value	1,258.1	288.2
U.S. Government Agency And Treasury Securities [Member]
Schedule of Available-for-sale Securities [Line Items]
Securities in an unrealized loss position for less than twelve months, Gross unrealized losses	(15.9)	(1.5)
Securities in an unrealized loss position for less than twelve months, Fair value	414.2	102.6
Securities in an unrealized loss position for more than twelve months, Gross unrealized losses	(10.4)
Securities in an unrealized loss position for more than twelve months, Fair value	91.7
Total, Gross unrealized losses	(26.3)	(1.5)
Total, Fair value	$ 505.9	$ 102.6

Funds Held for Clients and Co_7

Funds Held for Clients and Corporate Investments (Realized Gains and Losses from Sale of Available-for-sale Securities) (Details) - USD ($) $ in Millions	12 Months Ended
	May 31, 2022	May 31, 2021	May 31, 2020
Funds Held for Clients and Corporate Investments [Abstract]
Gross realized gains	$ 0.2	$ 1.2	$ 11.6
Gross realized losses	0		(0.3)
Net realized gains on available-for-sale securities	$ 0.2	$ 1.2	$ 11.3

Funds Held for Clients and Co_8

Funds Held for Clients and Corporate Investments (Amortized Cost and Fair Value of Available-for-Sale Securities by Contractual Maturity) (Details) - USD ($) $ in Millions	May 31, 2022	May 31, 2021
Funds Held for Clients and Corporate Investments [Abstract]
Due in one year or less, Amortized cost	$ 295.6
Due after one year through three years, Amortized cost	743.2
Due after three years through five years, Amortized cost	1,304.4
Due after five years, Amortized cost	1,822.3
AFS securities, Amortized cost	4,165.5	$ 2,940.9
Due in one year or less, Fair value	296.3
Due after one year through three years, Fair value	737.1
Due after three years through five years, Fair value	1,235.4
Due after five years, Fair value	1,760.4
AFS securities, Fair value	$ 4,029.2	$ 3,020.2

Fair Value Measurements (Narrat

Fair Value Measurements (Narrative) (Details) - USD ($) $ in Millions	May 31, 2022	May 31, 2021
Senior Notes, Series A [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair value of long-term borrowings	$ 404.1	$ 450.2
Senior Notes, Series B [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair value of long-term borrowings	$ 402.5	$ 457.7

Fair Value Measurements (Financ

Fair Value Measurements (Financial Assets and Liabilities Measured at Fair Value on Recurring Basis) (Details) - USD ($) $ in Millions	May 31, 2022	May 31, 2021
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Restricted and unrestricted cash equivalents	$ 219.2	$ 2.9
Available-for-sale securities	4,029.2	3,020.2
Other	30	34
Other long-term liabilities	29.9	32.6
Commercial Paper [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Restricted and unrestricted cash equivalents	5.2
Time Deposits [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Restricted and unrestricted cash equivalents	187.9
VRDNs [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Restricted and unrestricted cash equivalents	10
Available-for-sale securities	1,245.6
Money Market Securities [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Restricted and unrestricted cash equivalents	16.1	2.9
Asset-Backed Securities [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale securities	67.2	87.9
Corporate Bonds [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale securities	682.1	664.4
Municipal Bonds [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale securities	1,485.8	1,699.7
U.S. Government Agency And Treasury Securities [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale securities	548.5	568.2
Quoted Prices in Active Markets (Level 1) [Member] | Recurring [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Restricted and unrestricted cash equivalents	16.1	2.9
Other	30	34
Other long-term liabilities	29.9	32.6
Quoted Prices in Active Markets (Level 1) [Member] | Money Market Securities [Member] | Recurring [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Restricted and unrestricted cash equivalents	16.1	2.9
Significant Other Observable Inputs (Level 2) [Member] | Recurring [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Restricted and unrestricted cash equivalents	203.1
Available-for-sale securities	4,029.2	3,020.2
Significant Other Observable Inputs (Level 2) [Member] | Commercial Paper [Member] | Recurring [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Restricted and unrestricted cash equivalents	5.2
Significant Other Observable Inputs (Level 2) [Member] | Time Deposits [Member] | Recurring [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Restricted and unrestricted cash equivalents	187.9
Significant Other Observable Inputs (Level 2) [Member] | VRDNs [Member] | Recurring [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Restricted and unrestricted cash equivalents	10
Available-for-sale securities	1,245.6
Significant Other Observable Inputs (Level 2) [Member] | Asset-Backed Securities [Member] | Recurring [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale securities	67.2	87.9
Significant Other Observable Inputs (Level 2) [Member] | Corporate Bonds [Member] | Recurring [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale securities	682.1	664.4
Significant Other Observable Inputs (Level 2) [Member] | Municipal Bonds [Member] | Recurring [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale securities	1,485.8	1,699.7
Significant Other Observable Inputs (Level 2) [Member] | U.S. Government Agency And Treasury Securities [Member] | Recurring [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale securities	$ 548.5	$ 568.2

Leases (Narrative) (Details)

Leases (Narrative) (Details) $ in Millions	3 Months Ended	12 Months Ended
	Aug. 31, 2020 USD ($)	May 31, 2022 USD ($) Agreement	May 31, 2021 USD ($)	May 31, 2020 USD ($)
Lessee, Lease, Description [Line Items]
Amortization of operating lease ROU assets	$ 24.4	$ 22.7	$ 29.2	$ 34.4
Number of lease agreements, not yet commenced | Agreement		1
Lease not yet commenced, term of contract		10 years
Lease payments, not yet commenced		$ 1.8
Minimum [Member]
Lessee, Lease, Description [Line Items]
Operating leases, term of contract		1 year
Operating leases, contractual term		2022
Operating leases, renewal term		1 year
Maximum [Member]
Lessee, Lease, Description [Line Items]
Operating leases, term of contract		10 years
Operating leases, contractual term		2032
Operating leases, renewal term		5 years

Leases (Supplemental Balance Sh

Leases (Supplemental Balance Sheet Information Related to Leases) (Details) - USD ($) $ in Millions		May 31, 2022	May 31, 2021
Leases [Abstract]
Operating lease right-of-use assets, net of accumulated amortization		$ 78.7	$ 103
Operating lease liabilities, current	[1]	$ 25.1	$ 28.9
Operating Lease, Liability, Current, Statement of Financial Position [Extensible Enumeration]		Other Liabilities, Current	Other Liabilities, Current
Operating lease, liabilities, noncurrent		$ 74.8	$ 92.4
Weighted average remaining lease term (in years)		5 years 1 month 6 days	5 years 2 months 12 days
Weighted average discount rate		1.94%	1.81%
[1] The current portion of operating lease liabilities is reported in the other current liabilities line item on the Company’s Consolidated Balance Sheets.

Leases (Components of Lease Exp

Leases (Components of Lease Expense) (Details) - USD ($) $ in Millions	12 Months Ended
	May 31, 2022	May 31, 2021	May 31, 2020
Leases [Abstract]
Fixed payment operating lease expense	$ 27.2	$ 34.6	$ 38.2
Variable payment operating lease expense	$ 6.9	8.3	8.6
Short-term lease expense		$ 0.1	$ 0.2

Leases (Supplemental Cash Flow

Leases (Supplemental Cash Flow Information Related to Leases) (Details) - USD ($) $ in Millions	3 Months Ended	12 Months Ended
	Aug. 31, 2020	May 31, 2022	May 31, 2021	May 31, 2020
Leases [Abstract]
Cash paid for amounts included in the measurement of lease liabilities		$ 32.4	$ 32.2	$ 41.6
Amortization of ROU assets	$ 24.4	22.7	29.2	34.4
ROU assets obtained in exchange for new operating lease liabilities		15.8	26.8	21.5
Lease incentives received in the form of tenant allowances and free rent		$ 9.1	$ 0.8	$ 6.1

Leases - (Future Lease Payments

Leases - (Future Lease Payments) (Details) - USD ($) $ in Millions		May 31, 2022	May 31, 2021
Leases [Abstract]
2023		$ 27
2024		20.9
2025		18.9
2026		13.4
2027		9.5
Thereafter		15.5
Total future lease payments		105.2
Less: imputed interest		5.3
Total operating lease liabilities		99.9
Current portion	[1]	25.1	$ 28.9
Non-current portion		$ 74.8	$ 92.4
[1] The current portion of operating lease liabilities is reported in the other current liabilities line item on the Company’s Consolidated Balance Sheets.

Property and Equipment, Net o_3

Property and Equipment, Net of Accumulated Depreciation (Components of Property and Equipment, at Cost) (Details) - USD ($) $ in Millions		May 31, 2022	May 31, 2021
Property, Plant and Equipment [Line Items]
Total property and equipment, gross		$ 1,457	$ 1,361.9
Less: Accumulated depreciation		1,055.7	966.1
Property and equipment, net of accumulated depreciation		401.3	395.8
Land and Improvements [Member]
Property, Plant and Equipment [Line Items]
Total property and equipment, gross		10.3	10.3
Buildings and Improvements [Member]
Property, Plant and Equipment [Line Items]
Total property and equipment, gross		157.1	158.3
Data Processing Equipment [Member]
Property, Plant and Equipment [Line Items]
Total property and equipment, gross		217.4	211.4
Software [Member]
Property, Plant and Equipment [Line Items]
Total property and equipment, gross	[1]	832.1	748.3
Furniture, Fixtures, and Equipment [Member]
Property, Plant and Equipment [Line Items]
Total property and equipment, gross		97.7	99.8
Leasehold Improvements [Member]
Property, Plant and Equipment [Line Items]
Total property and equipment, gross		91.7	83.5
Construction in Progress [Member]
Property, Plant and Equipment [Line Items]
Total property and equipment, gross	[1]	$ 50.7	$ 50.3
[1] Software includes both purchased software and costs capitalized related to internally developed software placed in service. Capitalized costs related to internally developed software that has not yet been placed in service is included in construction in progress.

Property and Equipment, Net o_4

Property and Equipment, Net of Accumulated Depreciation (Narrative) (Details) - USD ($) $ in Millions	12 Months Ended
	May 31, 2022	May 31, 2021	May 31, 2020
Property, Plant and Equipment [Abstract]
Depreciation expense	$ 133.7	$ 123.4	$ 127.8

Goodwill and Intangible Asset_3

Goodwill and Intangible Assets, Net of Accumulated Amortization (Narrative) (Details) - USD ($)	12 Months Ended
	May 31, 2022	May 31, 2021	May 31, 2020
Goodwill and Intangible Assets [Line Items]
Amortization expense	$ 58,100,000	$ 68,600,000	$ 81,900,000
Impairment loss relates to goodwill or intangible assets	$ 0	$ 0	$ 0
Client Lists [Member]
Goodwill and Intangible Assets [Line Items]
Acquired intangible assets with weighted-average amortization period	8 years

Goodwill and Intangible Asset_4

Goodwill and Intangible Assets, Net of Accumulated Amortization (Change in Goodwill) (Details) - USD ($) $ in Millions	12 Months Ended
	May 31, 2022	May 31, 2021
Goodwill and Intangible Assets Disclosure [Abstract]
Goodwill Balance, beginning of fiscal year	$ 1,820.7	$ 1,791.1
Changes during the period:
Goodwill acquired	27.7	19.6
Currency translation adjustment	(16.9)	10
Goodwill Balance, end of fiscal year	$ 1,831.5	$ 1,820.7

Goodwill and Intangible Asset_5

Goodwill and Intangible Assets, Net of Accumulated Amortization (Components of Intangible Assets, at Cost) (Details) - USD ($) $ in Millions	May 31, 2022	May 31, 2021
Intangible Assets [Line Items]
Total intangible assets, gross	$ 660.4	$ 656.4
Less: Accumulated amortization	435.8	380.6
Intangible assets, net of accumulated amortization	224.6	275.8
Other Intangible Assets [Member]
Intangible Assets [Line Items]
Total intangible assets, gross	23	24.1
Client Lists [Member]
Intangible Assets [Line Items]
Total intangible assets, gross	$ 637.4	$ 632.3

Goodwill and Intangible Asset_6

Goodwill and Intangible Assets, Net of Accumulated Amortization (Estimated Amortization Expense) (Details) $ in Millions	May 31, 2022 USD ($)
Year ending May 31
2023	$ 59.4
2024	56.5
2025	53.5
2026	37.8
2027	$ 4.5

Income Taxes (Narrative) (Detai

Income Taxes (Narrative) (Details) - USD ($) $ in Millions	12 Months Ended
	May 31, 2022	May 31, 2021
Income Tax Contingency [Line Items]
NOL carry forwards	$ 5.6	$ 7.6
Reserve for uncertain tax positions	48.2	20.4
Impact uncertain tax benefits, if recognized, on effective income tax rate	48.2	$ 20.4
Federal [Member]
Income Tax Contingency [Line Items]
NOL carry forwards	$ 0.8
Federal [Member] | Minimum [Member]
Income Tax Contingency [Line Items]
NOL carry forwards, Expiration date	May 31, 2025
Federal [Member] | Maximum [Member]
Income Tax Contingency [Line Items]
NOL carry forwards, Expiration date	May 31, 2037
State [Member]
Income Tax Contingency [Line Items]
NOL carry forwards	$ 4.4
State [Member] | Minimum [Member]
Income Tax Contingency [Line Items]
NOL carry forwards, Expiration date	May 31, 2023
State [Member] | Maximum [Member]
Income Tax Contingency [Line Items]
NOL carry forwards, Expiration date	May 31, 2041
Foreign [Member]
Income Tax Contingency [Line Items]
NOL carry forwards	$ 0.4

Income Taxes (Components of Def

Income Taxes (Components of Deferred Tax Assets and Liabilities) (Details) - USD ($) $ in Millions	May 31, 2022	May 31, 2021
Income Tax Disclosure [Abstract]
Compensation and employee benefit liabilities	$ 56.8	$ 53
Other current liabilities	21.3	19.8
Tax credit carry forward	0.2	0.2
Stock-based compensation	12.9	12
Unrealized losses on available-for-sale securities	33.6
Leases	20.5	29
Net operating loss ("NOL") carry forwards	5.6	7.6
Tax benefit of uncertain tax positions	9.9	5.3
Gross deferred tax assets	160.8	126.9
Deferred contract costs	141.9	127.5
Capitalized software	50.8	49
Depreciation	8.1	8.9
Goodwill and Intangible assets	103.5	111.3
Operating lease right-of-use assets	17.7	26.1
Revenue not subject to current taxes		1.9
Unrealized gains on available-for-sale securities		20.2
Other	4.3
Gross deferred tax liabilities	326.3	344.9
Net deferred tax liability	$ (165.5)	$ (218)

Income Taxes (Components of Pro

Income Taxes (Components of Provision for Income Taxes) (Details) - USD ($) $ in Millions	12 Months Ended
	May 31, 2022	May 31, 2021	May 31, 2020
Income Tax Disclosure [Abstract]
Federal	$ 326	$ 271.5	$ 264.8
State	104.5	85.9	77.5
Non-U.S.	(1)	0.3	0.7
Total current	429.5	357.7	343
Federal	0.9	(12.9)	(0.8)
State	0.9	(7.6)	(3.5)
Non-U.S.	0.5	(0.5)	0.3
Total deferred	2.3	(21)	(4)
Income taxes	$ 431.8	$ 336.7	$ 339

Income Taxes (Reconciliation of

Income Taxes (Reconciliation of U.S. Federal Statutory Tax Rate) (Details)	12 Months Ended
	May 31, 2022	May 31, 2021	May 31, 2020
Income Tax Disclosure [Abstract]
Federal statutory tax rate	21%	21%	21%
Increase/(decrease) resulting from:
State income taxes, net of federal tax benefit	4.60%	4.30%	4%
Tax-exempt municipal bond interest	(0.20%)	(0.30%)	(0.40%)
Stock option windfall benefit	(0.90%)	(1.20%)	(0.90%)
Tax credits	(1.10%)	(0.60%)	(0.50%)
Other items	0.30%	0.30%	0.40%
Effective income tax rate	23.70%	23.50%	23.60%

Income Taxes (Reconciliation _2

Income Taxes (Reconciliation of Gross Unrecognized Tax Benefits, Not Including Interest or Other Potential Offsetting Effects) (Details) - USD ($) $ in Millions	12 Months Ended
	May 31, 2022	May 31, 2021	May 31, 2020
Income Tax Disclosure [Abstract]
Balance as of beginning of fiscal year	$ 22.4	$ 26.2	$ 22.1
Additions for tax positions of the current year	11.1	5.5	4.1
Additions for tax positions of prior years	20.6	9.2	1.2
Reductions for tax positions of prior years	(1.8)		(0.6)
Settlements with tax authorities	(0.4)	(15.2)
Expiration of the statute of limitations	(1.7)	(3.3)	(0.6)
Balance as of end of fiscal year	$ 50.2	$ 22.4	$ 26.2

Short-term Financing (Narrative

Short-term Financing (Narrative) (Details) - USD ($) $ in Millions								12 Months Ended
		Jul. 15, 2022	Jun. 26, 2022	Jun. 15, 2022	Jun. 08, 2022	Jun. 01, 2022	Sep. 17, 2021	May 31, 2022		May 31, 2021
Revolving Credit Facility [Member]
Financing [Line Items]
Maximum borrowing capacity								$ 2,000
Revolving Credit Facility [Member] | JPM $1 Billion Credit Facility [Member] | JP Morgan Chase Bank, N.A. [Member]
Financing [Line Items]
Maximum borrowing capacity							$ 1,000	$ 1,000	[1]
Expiration date	[1]							Jul. 31, 2024
Revolving Credit Facility [Member] | JPM $500 Million Credit Facility [Member] | JP Morgan Chase Bank, N.A. [Member]
Financing [Line Items]
Maximum borrowing capacity							500
Revolving Credit Facility [Member] | JPM $750 Million Credit Facility [Member] | JP Morgan Chase Bank, N.A. [Member]
Financing [Line Items]
Maximum borrowing capacity							$ 750	$ 750	[1]
Expiration date							Sep. 17, 2026	Sep. 17, 2026	[1]
Revolving Credit Facility [Member] | PNC $250 Million Credit Facility [Member] | PNC Bank, National Association [Member]
Financing [Line Items]
Maximum borrowing capacity								$ 250
Expiration date								Feb. 06, 2023
Weighted-average interest rate								2.34%		1.16%
Standby Letters of Credit [Member]
Financing [Line Items]
Maximum borrowing capacity								$ 140.2		$ 180.4
Amounts outstanding								$ 0		$ 0
Standby Letters of Credit [Member] | Subsequent Event [Member]
Financing [Line Items]
Expiration date		Jul. 15, 2022	Jun. 26, 2022	Jun. 15, 2022	Jun. 08, 2022
Renewal term						1 year
Minimum [Member] | Revolving Credit Facility [Member]
Financing [Line Items]
Commitment fee, percentage								0.05%
Minimum [Member] | Standby Letters of Credit [Member]
Financing [Line Items]
Expiration date								Jun. 08, 2022
Maximum [Member] | Revolving Credit Facility [Member]
Financing [Line Items]
Commitment fee, percentage								0.15%
Maximum [Member] | Standby Letters of Credit [Member]
Financing [Line Items]
Expiration date								May 26, 2023
[1] JPM acts as the administrative agent for this syndicated credit facility.

Short-term Financing (Descripti

Short-term Financing (Description of Credit Facilities) (Details) - Revolving Credit Facility [Member] - USD ($) $ in Millions			12 Months Ended
		Sep. 17, 2021	May 31, 2022		May 31, 2021
Line of Credit Facility [Line Items]
Maximum Amount Available			$ 2,000
Amount Outstanding	[1]		$ 8.7		$ 7.4
JP Morgan Chase Bank, N.A. [Member] | JPM $1 Billion Credit Facility [Member]
Line of Credit Facility [Line Items]
Expiration Date	[2]		Jul. 31, 2024
Maximum Amount Available		$ 1,000	$ 1,000	[2]
JP Morgan Chase Bank, N.A. [Member] | JPM $750 Million Credit Facility [Member]
Line of Credit Facility [Line Items]
Expiration Date		Sep. 17, 2026	Sep. 17, 2026	[2]
Maximum Amount Available		$ 750	$ 750	[2]
JP Morgan Chase Bank, N.A. [Member] | JPM $500 Million Credit Facility [Member]
Line of Credit Facility [Line Items]
Maximum Amount Available		$ 500
PNC Bank, National Association [Member] | PNC $250 Million Credit Facility [Member]
Line of Credit Facility [Line Items]
Expiration Date			Feb. 06, 2023
Maximum Amount Available			$ 250
Amount Outstanding			$ 8.7		$ 7.4
Weighted-average interest rate			2.34%		1.16%
[1] The total amount available under these credit facilities as of May 31, 2022 was approximately $ 2.0 billion. Amounts under the PNC credit facility remain outstanding as of the date of this report. JPM acts as the administrative agent for this syndicated credit facility.

Long-Term Financing (Schedule o

Long-Term Financing (Schedule of Long-Term Debt, at Amortized Cost) (Details) - USD ($) $ in Millions	May 31, 2022	May 31, 2021
Debt Instrument [Line Items]
Total long-term borrowings	$ 800	$ 800
Less: Debt issuance costs, net of accumulated amortization	(2.3)	(2.7)
Long-term borrowings, net of debt issuance costs	797.7	797.3
Senior Notes, Series A [Member] | Senior Notes [Member]
Debt Instrument [Line Items]
Total long-term borrowings	400	400
Senior Notes, Series B [Member] | Senior Notes [Member]
Debt Instrument [Line Items]
Total long-term borrowings	$ 400	$ 400

Long-Term Financing (Informatio

Long-Term Financing (Information Related to Senior Notes) (Details) - Senior Notes [Member]	12 Months Ended
	May 31, 2022	May 31, 2021
Senior Notes, Series A [Member]
Debt Instrument [Line Items]
Stated interest rate	4.07%	4.07%
Effective interest rate	4.15%	4.15%
Interest rate type	Fixed	Fixed
Interest payment dates	Semi-annual, in arrears	Semi-annual, in arrears
Principal payment dates	Mar. 13, 2026	Mar. 13, 2026
Note type	Unsecured	Unsecured
Senior Notes, Series B [Member]
Debt Instrument [Line Items]
Stated interest rate	4.25%	4.25%
Effective interest rate	4.31%	4.31%
Interest rate type	Fixed	Fixed
Interest payment dates	Semi-annual, in arrears	Semi-annual, in arrears
Principal payment dates	Mar. 13, 2029	Mar. 13, 2029
Note type	Unsecured	Unsecured

Supplemental Cash Flow Inform_2

Supplemental Cash Flow Information (Narrative) (Details) - USD ($) $ in Millions	12 Months Ended
	May 31, 2022	May 31, 2021	May 31, 2020
Supplemental Cash Flow Elements [Abstract]
Income taxes paid	$ 397.7	$ 421.4	$ 298.8
Interest expense paid	$ 35.5	$ 34.9	$ 38

Employee Benefit Plans (Narrati

Employee Benefit Plans (Narrative) (Details) - USD ($) $ in Millions	12 Months Ended
	May 31, 2022	May 31, 2021	May 31, 2020
Deferred Compensation Plans [Member]
Defined Contribution Plan Disclosure [Line Items]
Percentage of annual base salary and bonus that eligible employees may defer	50%
Percentage of Board cash compensation that eligible outside directors may defer	100%
Amounts accrued under deferred compensation plans	$ 29.9	$ 32.6
401(K) Plan [Member]
Defined Contribution Plan Disclosure [Line Items]
Maximum percentage of salary deferral	50%
Years of service to be eligible for matching contribution	1 year
Minimum number of hours worked for eligibility	1,000
Employer's matching contribution as a percent of the first 3% of employees' salary contributed	100%
Percentage of employees' salary contributed matched 100% by employer	3%
Employer's matching contribution as a percent of the next 2% of employees' salary contributed	50%
Percentage of employees' salary contributed matched 50% by employer	2%
Total percentage of employees' salary contributed matched by employer	4%
Company contributions to the plan	$ 35.6	$ 19.2	$ 30.1
Percentage participant directed	100%

Commitments and Contingencies_2

Commitments and Contingencies (Narrative) (Details) $ in Millions	May 31, 2022 USD ($)
Commitments and Contingencies Disclosure [Abstract]
Minimum future payment obligations under purchase orders, legally binding contractual arrangements, and under existing workers' compensation insurance agreements	$ 379.1
Commitments to purchase capital assets	$ 7.6

Commitments and Contingencies_3

Commitments and Contingencies (Minimum Future Payment Obligations) (Details) $ in Millions	May 31, 2022 USD ($)
Workers' Compensation Estimated Obligations [Member]
2023	$ 64.1
2024	36.8
2025	22.4
2026	14.8
2027	10.9
Thereafter	40.7
Purchase Obligations [Member]
2023	149.8
2024	28.9
2025	9.7
2026	0.5
2027	0.3
Thereafter	$ 0.2

Valuation and Qualifying Acco_2

Valuation and Qualifying Accounts (Details) - Allowance for Credit Losses [Member] - USD ($)		12 Months Ended
		May 31, 2022	May 31, 2021	May 31, 2020
Valuation and Qualifying Accounts Disclosure [Line Items]
Balance as of beginning of fiscal year		$ 16	$ 12.5	$ 10.2
Additions charged to expenses		10.5	11.5	13
Costs and deductions	[1]	8.3	8	10.7
Balance as of end of fiscal year		$ 18.2	$ 16	$ 12.5
[1] Uncollectible amounts written off, net of recoveries, and other adjustments.