Quarterly report pursuant to Section 13 or 15(d)

Funds Held for Clients and Corporate Investments (Narrative) (Details)

v3.22.2.2
Funds Held for Clients and Corporate Investments (Narrative) (Details)
$ in Millions
3 Months Ended 12 Months Ended
Aug. 31, 2022
USD ($)
Security
May 31, 2022
USD ($)
Security
Schedule of Available-for-sale Securities [Line Items]    
Net unrealized losses on available-for-sale securities $ 175.6 $ 136.3
Number of available-for-sale securities in an unrealized loss position | Security 1,111 817
Percentage of available-for-sale securities in an unrealized loss position 95.00% 64.00%
Gross unrealized losses on available-for-sale securities $ 175.6 $ 139.0
Corporate Bonds [Member]    
Schedule of Available-for-sale Securities [Line Items]    
Gross unrealized losses on available-for-sale securities $ 28.3 19.0
Corporate Bonds [Member] | Minimum [Member]    
Schedule of Available-for-sale Securities [Line Items]    
Available-for-sale securities maturity date Sep. 01, 2022  
Corporate Bonds [Member] | Maximum [Member]    
Schedule of Available-for-sale Securities [Line Items]    
Available-for-sale securities maturity date Dec. 13, 2028  
Municipal Bonds [Member]    
Schedule of Available-for-sale Securities [Line Items]    
Gross unrealized losses on available-for-sale securities $ 108.3 $ 92.5
Municipal Bonds [Member] | Minimum [Member]    
Schedule of Available-for-sale Securities [Line Items]    
Available-for-sale securities maturity date Sep. 01, 2022  
Municipal Bonds [Member] | Maximum [Member]    
Schedule of Available-for-sale Securities [Line Items]    
Available-for-sale securities maturity date Apr. 01, 2030  
Variable Rate Demand Notes [Member] | Minimum [Member]    
Schedule of Available-for-sale Securities [Line Items]    
Available-for-sale securities contractual maturities 20 years  
Variable Rate Demand Notes [Member] | Maximum [Member]    
Schedule of Available-for-sale Securities [Line Items]    
Available-for-sale securities contractual maturities 30 years