Quarterly report pursuant to Section 13 or 15(d)

Funds Held for Clients and Corporate Investments (Details 2)

v3.3.0.814
Funds Held for Clients and Corporate Investments (Details 2)
$ in Millions
 3 Months Ended
Aug. 31, 2015
USD ($)
Security
Aug. 31, 2014
USD ($)
May. 31, 2015
USD ($)
Security
Maturity Date:      
Due in one year or less, Amortized cost $ 369.7    
Due in one year or less, Fair value 372.5    
Due after one year through three years, Amortized cost 697.9    
Due after one year through three years, Fair value 705.8    
Due after three years through five years, Amortized cost 851.3    
Due after three years through five years, Fair value 858.7    
Due after five years, Amortized cost 959.9    
Due after five years, Fair value 965.3    
Total, Amortized cost 2,878.8    
Fair value 2,902.3   $ 3,595.6
Funds Held for Clients and Corporate Investments (Textual)      
Net unrealized gain on available-for-sale securities $ 23.5   $ 13.6
Number of available-for-sale securities in an unrealized loss position | Security 196   280
Gross realized gains $ 0.0 $ 0.1  
Gross realized losses $ 0.0 $ 0.0  
Minimum maturity period for VRDNs primarily categorized as due after five years (in years) 20 years    
Maximum maturity period for VRDNs, primarily categorized as due after five years (in years) 30 years