Service Revenue (Summary of PEO Pass-Through Costs Netted in Revenue) (Details) - USD ($) $ in Millions |
3 Months Ended | 9 Months Ended | ||
|---|---|---|---|---|
Feb. 28, 2026 |
Feb. 28, 2025 |
Feb. 28, 2026 |
Feb. 28, 2025 |
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| Revenue from Contract with Customer [Abstract] | ||||
| Payroll wages and payroll taxes | $ 8,587.8 | $ 7,783.0 | $ 23,638.5 | $ 21,836.6 |
| State unemployment insurance (included in payroll wages and payroll taxes) | 88.6 | 81.5 | 134.7 | 127.9 |
| Guaranteed cost benefit plans | $ 193.8 | $ 172.6 | $ 547.2 | $ 505.9 |
| X | ||||||||||
- Definition Direct Pass Through Cost Guaranteed Cost Benefit Plans No definition available.
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| X | ||||||||||
- Definition Direct Pass Through Cost Payroll Wages And Taxes Including Federal And State Unemployment Insurance No definition available.
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| X | ||||||||||
- Definition Direct Pass Through Cost State Unemployment Insurance No definition available.
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| X | ||||||||||
- References No definition available.
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