Quarterly report pursuant to Section 13 or 15(d)

Service Revenue (Narrative) (Details)

v3.20.4
Service Revenue (Narrative) (Details) - USD ($)
$ in Millions
6 Months Ended
Nov. 30, 2020
Nov. 30, 2019
Service Revenue [Line Items]    
Notice of termination period 30 days  
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 years to four years  
Impairment loss $ 0.0 $ 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