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
Aug. 31, 2018
May 31, 2018
Intangible Assets [Line Items]    
Total intangible assets, gross $ 320.7 $ 321.8
Less: Accumulated amortization 185.2 180.4
Intangible assets, net of accumulated amortization 135.5 141.4 [1]
Client Lists [Member]    
Intangible Assets [Line Items]    
Total intangible assets, gross 307.4 308.5
Other Intangible Assets [Member]    
Intangible Assets [Line Items]    
Total intangible assets, gross $ 13.3 $ 13.3
[1] Amounts have been adjusted to reflect the adoption of ASC Topic 606.