Annual report pursuant to Section 13 and 15(d)

Fee Revenue - Additional Information (Details 1)

v3.19.2
Fee Revenue - Additional Information (Details 1)
$ in Millions
 12 Months Ended
Apr. 30, 2019
USD ($)
Revenue Remaining Performance Obligation Expected Timing Of Satisfaction [Line Items]  
Revenue recognized, remaining performance obligation $ 539.5
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date: 2019-05-01  
Revenue Remaining Performance Obligation Expected Timing Of Satisfaction [Line Items]  
Revenue recognized, remaining performance obligation $ 307.7
Revenue, remaining performance obligation, expected timing of satisfaction, period 1 year
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date: 2020-05-01  
Revenue Remaining Performance Obligation Expected Timing Of Satisfaction [Line Items]  
Revenue recognized, remaining performance obligation $ 132.2
Revenue, remaining performance obligation, expected timing of satisfaction, period 1 year
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date: 2021-05-01  
Revenue Remaining Performance Obligation Expected Timing Of Satisfaction [Line Items]  
Revenue recognized, remaining performance obligation $ 77.4
Revenue, remaining performance obligation, expected timing of satisfaction, period 1 year
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date: 2022-05-01  
Revenue Remaining Performance Obligation Expected Timing Of Satisfaction [Line Items]  
Revenue recognized, remaining performance obligation $ 22.2
Revenue, remaining performance obligation, expected timing of satisfaction, period
Revenue, remaining performance obligation, expected timing of satisfaction, explanation 2023 and thereafter