Leases (Details) - USD ($) $ in Thousands	3 Months Ended
	Jul. 31, 2020	Jul. 31, 2019
Leases
Option to extend	true
Finance lease cost:
Amortization of right-of-use assets	$ 6,139	$ 6,059
Interest on lease liabilities	3,062	3,422
Operating lease cost	10,620	10,420
Variable lease cost	2,999	3,199
Total lease cost	$ 22,820	$ 23,100
Minimum
Leases
Lease term (in years)	1 year
Renewal lease term (in years)	1 year
Maximum
Leases
Lease term (in years)	11 years
Renewal lease term (in years)	5 years