Annual report pursuant to Section 13 and 15(d)

Segments - Fee Revenue Classified by Country (Detail)

v3.20.2
Segments - Fee Revenue Classified by Country (Detail) - USD ($)
$ in Thousands
 3 Months Ended 12 Months Ended
Apr. 30, 2020
Jan. 31, 2020
Oct. 31, 2019
Jul. 31, 2019
Apr. 30, 2019
Jan. 31, 2019
Oct. 31, 2018
Jul. 31, 2018
Apr. 30, 2020
Apr. 30, 2019
Apr. 30, 2018
Segment Reporting Information [Line Items]                      
Total revenue                 $ 1,977,330 $ 1,973,862 $ 1,819,519
Fee Revenue                      
Segment Reporting Information [Line Items]                      
Total revenue $ 440,469 $ 515,325 $ 492,389 $ 484,549 $ 490,756 $ 474,504 $ 495,205 $ 465,568 1,932,732 1,926,033 1,767,217
Fee Revenue | UNITED STATES                      
Segment Reporting Information [Line Items]                      
Total revenue                 875,605 859,969 778,470
Fee Revenue | United Kingdom                      
Segment Reporting Information [Line Items]                      
Total revenue                 204,271 202,055 176,091
Fee Revenue | Other Countries                      
Segment Reporting Information [Line Items]                      
Total revenue                 $ 852,856 $ 864,009 $ 812,656