Quarterly report pursuant to Section 13 or 15(d)

Service Revenue (Narrative) (Details)

v3.10.0.1
Service Revenue (Narrative) (Details) - USD ($)
$ in Millions
3 Months Ended 6 Months Ended
Nov. 30, 2018
Nov. 30, 2018
Service Revenue [Line Items]    
Percentage of client worksite employees participation in benefit plans not retained risk   60.00%
Percentage of client worksite employees participation in benefit plans retained risk   40.00%
Revenue performance obligations timing   the Company defers revenue associated with these performance obligations, which exceed one year, and subsequently recognizes these as future services are provided, over approximately three to four years
Deferral of revenue $ 6.8 $ 13.6
Impairment loss   $ 0.0
Minimum [Member]    
Service Revenue [Line Items]    
Revenue performance obligations timing, years   3 years
Maximum [Member]    
Service Revenue [Line Items]    
Revenue performance obligations timing, years   4 years
Remainder Of Fiscal 2019 [Member]    
Service Revenue [Line Items]    
Deferral of revenue   $ 12.8
Fiscal Year Ended May 31, 2020 [Member]    
Service Revenue [Line Items]    
Deferral of revenue   18.5
Thereafter [Member]    
Service Revenue [Line Items]    
Deferral of revenue   $ 14.7