Quarterly report [Sections 13 or 15(d)]

Service Revenue (Summary of PEO Pass-Through Costs Netted in Revenue) (Details)

v3.25.2
Service Revenue (Summary of PEO Pass-Through Costs Netted in Revenue) (Details) - USD ($)
$ in Millions
3 Months Ended
Aug. 31, 2025
Aug. 31, 2024
Revenue from Contract with Customer [Abstract]    
Payroll wages and payroll taxes $ 7,356.1 $ 6,881.6
State unemployment insurance (included in payroll wages and payroll taxes) 23.7 23.0
Guaranteed cost benefit plans $ 175.5 $ 165.8