XML 73 R48.htm IDEA: XBRL DOCUMENT v3.20.4
Defined Benefit Pension Plans - Pension Expenses (Detail) - USD ($)
$ in Thousands
 3 Months Ended 9 Months Ended
Jan. 31, 2021
Jan. 31, 2020
Jan. 31, 2021
Jan. 31, 2020
Retirement Benefits [Abstract]        
Service cost $ 0 $ 0 $ 0 $ 0
Interest cost 181 208 543 624
Expected return on plan assets (321) (355) (963) (1,065)
Recognition of net loss 428 260 1,285 780
Net periodic pension expense $ 288 $ 113 $ 865 $ 339