Quarterly report pursuant to Section 13 or 15(d)

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

v3.20.2
Funds Held for Clients and Corporate Investments (Funds Held for Clients and Corporate Investments) (Details) - USD ($)
$ in Millions
Aug. 31, 2020
May 31, 2020
Schedule of Available-for-sale Securities [Line Items]    
Funds held for clients' money market securities and other cash equivalents, Amortized cost $ 344.4 $ 683.5
Funds held for clients' money market securities and other cash equivalents, Fair value 344.4 683.5
Available-for-sale securities, Amortized cost 2,863.2 2,657.2
Available-for-sale securities, Gross unrealized gains 117.1 101.7
Available-for-sale securities, Gross unrealized losses (0.2) (1.7)
Available-for-sale securities, Fair value 2,980.1 2,757.2
Other, Amortized cost 26.3 25.4
Other, Gross unrealized gains 4.4 2.2
Other, Gross unrealized losses (0.1) (0.4)
Other, Fair value 30.6 27.2
Total funds held for clients and corporate investments, Amortized cost 3,233.9 3,366.1
Total funds held for clients and corporate investments, Gross unrealized gains 121.5 103.9
Total funds held for clients and corporate investments, Gross unrealized losses (0.3) (2.1)
Total funds held for clients and corporate investments, Fair value 3,355.1 3,467.9
Asset-Backed Securities [Member]    
Schedule of Available-for-sale Securities [Line Items]    
Available-for-sale securities, Amortized cost 75.9 68.0
Available-for-sale securities, Gross unrealized gains 2.1 1.7
Available-for-sale securities, Fair value 78.0 69.7
Corporate Bonds [Member]    
Schedule of Available-for-sale Securities [Line Items]    
Available-for-sale securities, Amortized cost 648.8 649.6
Available-for-sale securities, Gross unrealized gains 38.6 34.1
Available-for-sale securities, Gross unrealized losses   (0.1)
Available-for-sale securities, Fair value 687.4 683.6
Municipal Bonds [Member]    
Schedule of Available-for-sale Securities [Line Items]    
Available-for-sale securities, Amortized cost 1,616.2 1,373.8
Available-for-sale securities, Gross unrealized gains 46.3 37.4
Available-for-sale securities, Gross unrealized losses (0.2) (1.6)
Available-for-sale securities, Fair value 1,662.3 1,409.6
U.S. Government Agency And Treasury Securities [Member]    
Schedule of Available-for-sale Securities [Line Items]    
Available-for-sale securities, Amortized cost 522.3 565.8
Available-for-sale securities, Gross unrealized gains 30.1 28.5
Available-for-sale securities, Fair value $ 552.4 $ 594.3