Quarterly report pursuant to Section 13 or 15(d)

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

v3.24.3
Funds Held for Clients and Corporate Investments (Funds Held for Clients and Corporate Investments) (Details) - USD ($)
$ in Millions
Aug. 31, 2024
May 31, 2024
Schedule of Available-for-sale Securities [Line Items]    
Funds held for clients' money market securities and other restricted cash equivalents, Amortized cost $ 333.6 $ 380.3
Funds held for clients' money market securities and other restricted cash equivalents, Fair value 333.6 380.3
AFS securities, Amortized cost 3,511.7 3,492.1
AFS securities, Gross unrealized gains 17.6 1.7
AFS securities, Gross unrealized losses (98.0) (164.2)
AFS securities, Fair value 3,431.3 3,329.6
Other, Amortized cost 33.9 32.3
Other, Gross unrealized gains 4.0 3.2
Other, Gross unrealized losses (1.2) (1.6)
Other, Fair value 36.7 33.9
Total funds held for clients and corporate investments, Amortized cost 3,879.2 3,904.7
Total funds held for clients and corporate investments, Gross unrealized gains 21.6 4.9
Total funds held for clients and corporate investments, Gross unrealized losses (99.2) (165.8)
Total funds held for clients and corporate investments, Fair value 3,801.6 3,743.8
Asset-Backed Securities [Member]    
Schedule of Available-for-sale Securities [Line Items]    
AFS securities, Amortized cost 132.5 135.7
AFS securities, Gross unrealized gains 0.9 0.1
AFS securities, Gross unrealized losses (0.3) (1.1)
AFS securities, Fair value 133.1 134.7
Corporate Bonds [Member]    
Schedule of Available-for-sale Securities [Line Items]    
AFS securities, Amortized cost 1,422.0 1,400.3
AFS securities, Gross unrealized gains 11.5 1.3
AFS securities, Gross unrealized losses (12.4) (32.8)
AFS securities, Fair value 1,421.1 1,368.8
Municipal Bonds [Member]    
Schedule of Available-for-sale Securities [Line Items]    
AFS securities, Amortized cost 1,059.5 1,060.1
AFS securities, Gross unrealized gains 0.8 0.2
AFS securities, Gross unrealized losses (61.4) (86.9)
AFS securities, Fair value 998.9 973.4
U.S. Government Agency And Treasury Securities [Member]    
Schedule of Available-for-sale Securities [Line Items]    
AFS securities, Amortized cost 897.7 896.0
AFS securities, Gross unrealized gains 4.4 0.1
AFS securities, Gross unrealized losses (23.9) (43.4)
AFS securities, Fair value $ 878.2 $ 852.7