Quarterly report [Sections 13 or 15(d)]

Funds Held for Clients and Corporate Investments (Amortized Cost and Fair Value of Available-for-Sale Securities by Contractual Maturity) (Details)

v3.25.1
Funds Held for Clients and Corporate Investments (Amortized Cost and Fair Value of Available-for-Sale Securities by Contractual Maturity) (Details) - USD ($)
$ in Millions
Feb. 28, 2025
May 31, 2024
Funds Held for Clients and Corporate Investments [Abstract]    
Due in one year or less, Amortized cost $ 460.1  
Due after one year through three years, Amortized cost 1,921.7  
Due after three years through five years, Amortized cost 879.5  
Due after five years, Amortized cost 211.7  
AFS securities, Amortized cost 3,473.0 $ 3,492.1
Due in one year or less, Fair value 455.4  
Due after one year through three years, Fair value 1,868.4  
Due after three years through five years, Fair value 867.9  
Due after five years, Fair value 213.4  
AFS securities, Fair value $ 3,405.1 $ 3,329.6