Annual report pursuant to Section 13 and 15(d)

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

v3.23.2
Funds Held for Clients and Corporate Investments (Funds Held for Clients and Corporate Investments) (Details) - USD ($)
$ in Millions
May 31, 2023
May 31, 2022
Schedule of Available-for-sale Securities [Line Items]    
Funds held for clients' money market securities and other restricted cash equivalents, Amortized cost $ 863.1 $ 482.6
Funds held for clients' money market securities and other restricted cash equivalents, Fair value 863.1 482.6
AFS securities, Amortized cost 3,779.9 4,165.5
AFS securities, Gross unrealized gains 4.1 2.7
AFS securities, Gross unrealized losses (179.4) (139.0)
AFS securities, Fair value 3,604.6 4,029.2
Other, Amortized cost 30.1 30.4
Other, Gross unrealized gains 1.1 1.8
Other, Gross unrealized losses (2.9) (2.2)
Other, Fair value 28.3 30.0
Total funds held for clients and corporate investments, Amortized cost 4,673.1 4,678.5
Total funds held for clients and corporate investments, Gross unrealized gains 5.2 4.5
Total funds held for clients and corporate investments, Gross unrealized losses (182.3) (141.2)
Total funds held for clients and corporate investments, Fair value 4,496.0 4,541.8
Asset-Backed Securities [Member]    
Schedule of Available-for-sale Securities [Line Items]    
AFS securities, Amortized cost 88.1 68.5
AFS securities, Gross unrealized gains   0.0
AFS securities, Gross unrealized losses (1.4) (1.3)
AFS securities, Fair value 86.7 67.2
Corporate Bonds [Member]    
Schedule of Available-for-sale Securities [Line Items]    
AFS securities, Amortized cost 1,468.3 699.3
AFS securities, Gross unrealized gains 3.7 1.8
AFS securities, Gross unrealized losses (31.1) (19.0)
AFS securities, Fair value 1,440.9 682.1
Municipal Bonds [Member]    
Schedule of Available-for-sale Securities [Line Items]    
AFS securities, Amortized cost 1,091.3 1,577.6
AFS securities, Gross unrealized gains 0.1 0.6
AFS securities, Gross unrealized losses (105.3) (92.4)
AFS securities, Fair value 986.1 1,485.8
U.S. Government Agency And Treasury Securities [Member]    
Schedule of Available-for-sale Securities [Line Items]    
AFS securities, Amortized cost 788.1 574.5
AFS securities, Gross unrealized gains 0.3 0.3
AFS securities, Gross unrealized losses (41.6) (26.3)
AFS securities, Fair value 746.8 548.5
Variable Rate Demand Notes [Member]    
Schedule of Available-for-sale Securities [Line Items]    
AFS securities, Amortized cost 344.1 1,245.6
AFS securities, Fair value $ 344.1 $ 1,245.6