Quarterly report pursuant to Section 13 or 15(d)

Funds Held for Clients and Corporate Investments (Classification of Investments on Consolidated Balance Sheets) (Details)

v3.7.0.1
Funds Held for Clients and Corporate Investments (Classification of Investments on Consolidated Balance Sheets) (Details) - USD ($)
$ in Millions
Feb. 28, 2017
May 31, 2016
Funds Held for Clients and Corporate Investments [Abstract]    
Funds held for clients $ 4,784.6 $ 3,997.5
Corporate investments 214.0 220.6
Long-term corporate investments 440.2 441.1
Total funds held for clients and corporate investments, Fair value $ 5,438.8 $ 4,659.2