Segment Reporting - Schedule of Total Revenue, Net Income and Significant Expenses Used by the CODM (Details) - USD ($) $ in Millions |
12 Months Ended | ||||||||
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May 31, 2025 |
May 31, 2024 |
May 31, 2023 |
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| Segment Reporting Information [Line Items] | |||||||||
| Total revenue | $ 5,571.7 | $ 5,278.3 | $ 5,007.1 | ||||||
| Core business operations: | |||||||||
| Depreciation and amortization | 209.5 | 176.5 | 176.6 | ||||||
| Non-core business operations: | |||||||||
| Total expenses | 3,364.0 | 3,104.2 | 2,974.0 | ||||||
| Interest expense, excluding Paycor acquisition-related costs | (71.4) | (37.3) | (36.7) | ||||||
| Acquisition-related costs | [1] | (34.0) | |||||||
| Other income, net | 73.6 | 81.2 | 51.8 | ||||||
| Income before income taxes | 2,175.9 | 2,218.0 | 2,048.2 | ||||||
| Income tax expense | 518.6 | 527.6 | 490.9 | ||||||
| Net income | 1,657.3 | 1,690.4 | 1,557.3 | ||||||
| Core [Member] | |||||||||
| Core business operations: | |||||||||
| Compensation-related expenses | 1,853.0 | 1,810.4 | 1,782.6 | ||||||
| PEO direct insurance costs | 520.1 | 471.3 | 416.8 | ||||||
| Depreciation and amortization | 168.8 | 176.5 | 176.6 | ||||||
| Other segment items | [2] | 659.8 | 606.5 | $ 598.0 | |||||
| Noncore [Member] | |||||||||
| Non-core business operations: | |||||||||
| Acquisition-related costs | [1] | $ 162.3 | |||||||
| Cost optimization initiatives | [3] | $ 39.5 | |||||||
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- Definition Acquisition related costs included in interest expense. No definition available.
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- Definition Core business operations. No definition available.
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- Definition Cost optimization initiatives. No definition available.
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- Definition Interest expense excluding acquisition related costs. No definition available.
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- Definition Non-core business operations. No definition available.
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- Definition PEO direct insurance costs. No definition available.
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- Definition This element represents acquisition-related costs incurred to effect a business combination which costs have been expensed during the period. Such costs include finder's fees; advisory, legal, accounting, valuation, and other professional or consulting fees; general administrative costs, including the costs of maintaining an internal acquisitions department; and may include costs of registering and issuing debt and equity securities. Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
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- Definition Amount of expense for salary, wage, profit sharing; incentive and equity-based compensation; and other employee benefit. Other employee benefit expense includes, but is not limited to, service component of net periodic benefit cost for defined benefit plan. Excludes compensation cost in cost of good and service sold. Reference 1: http://www.xbrl.org/2003/role/exampleRef
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- Definition Total costs of sales and operating expenses for the period. Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
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- Definition The aggregate expense recognized in the current period that allocates the cost of tangible assets, intangible assets, or depleting assets to periods that benefit from use of the assets. Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
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- Definition Amount of income (loss) from continuing operations, including income (loss) from equity method investments, before deduction of income tax expense (benefit), and income (loss) attributable to noncontrolling interest. Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef
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- Definition Amount of current income tax expense (benefit) and deferred income tax expense (benefit) pertaining to continuing operations. Reference 1: http://www.xbrl.org/2003/role/disclosureRef
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- Definition Amount, after deduction of tax, noncontrolling interests, dividends on preferred stock and participating securities; of income (loss) available to common shareholders. Reference 1: http://www.xbrl.org/2003/role/disclosureRef
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- Definition The aggregate amount of income or expense from ancillary business-related activities (that is to say, excluding major activities considered part of the normal operations of the business). Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
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- Definition Amount of revenue recognized from goods sold, services rendered, insurance premiums, or other activities that constitute an earning process. Includes, but is not limited to, investment and interest income before deduction of interest expense when recognized as a component of revenue, and sales and trading gain (loss). Reference 1: http://www.xbrl.org/2003/role/exampleRef
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- Definition Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table. No definition available.
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- Definition Amount of other expense (income) and loss (gain) calculated as difference between segment revenue and separately disclosed expense category to arrive at segment profit (loss). Reference 1: http://www.xbrl.org/2003/role/exampleRef
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