Funds Held for Clients and Corporate Investments (Classification of Investments on Consolidated Balance Sheets) (Details) - USD ($) $ in Millions |
Aug. 31, 2026 |
May 31, 2026 |
|---|---|---|
| Funds Held for Clients and Corporate Investments [Abstract] | ||
| Funds held for clients | $ 4,348.4 | $ 4,832.2 |
| Corporate investments | 333.3 | 36.3 |
| Total funds held for clients and corporate investments, Fair value | $ 4,681.7 | $ 4,868.5 |