Annual report pursuant to Section 13 and 15(d)

Goodwill and Intangible Assets, Net of Accumulated Amortization (Details Textuals)

 v2.3.0.11
Goodwill and Intangible Assets, Net of Accumulated Amortization (Details Textuals) (USD $)
In Millions
12 Months Ended
May 31, 2011
May 31, 2010
May 31, 2009
Goodwill and Intangible Assets, Net of Accumulated Amortization (Textuals) [Abstract]      
Goodwill $ 513.7 $ 421.6  
Amortization of intangible assets 20.3 21.1 21.0
Sure Payroll [Member]
     
Goodwill [Line Items]      
Effect of changes in goodwill due to acquisition 84.6    
E Plan Member
     
Goodwill [Line Items]      
Effect of changes in goodwill due to acquisition $ 7.5