Quarterly report pursuant to Section 13 or 15(d)

Goodwill and Intangible Assets, Net of Accumulated Amortization (Components of Intangible Assets, at Cost) (Details)

v3.10.0.1
Goodwill and Intangible Assets, Net of Accumulated Amortization (Components of Intangible Assets, at Cost) (Details) - USD ($)
$ in Millions
Nov. 30, 2018
May 31, 2018
Intangible Assets [Line Items]    
Total intangible assets, gross $ 318.5 $ 321.8
Less: Accumulated amortization 190.5 180.4
Intangible assets, net of accumulated amortization 128.0 141.4 [1]
Client Lists [Member]    
Intangible Assets [Line Items]    
Total intangible assets, gross 305.7 308.5
Other Intangible Assets [Member]    
Intangible Assets [Line Items]    
Total intangible assets, gross $ 12.8 $ 13.3
[1] Amounts have been adjusted to reflect the adoption of ASC Topic 606.