Leases - Future Minimum Lease Payments Under ASC Topic 840 (Details) $ in Thousands	Apr. 30, 2019 USD ($)
Operating Leases Under Topic 840
2020	$ 17,943
2021	17,649
2022	12,435
2023	10,636
2024	9,854
2025 (and thereafter)	38,871
Operating leases, future minimum payments due	107,388
Capital Leases Under Topic ASC 840
2020	2,456
2021	1,953
2022	1,013
2023	705
2024	701
2025 (and thereafter)	166
Capital leases, future minimum payments due	6,994
Less amounts representing interest (2% - 6.5%)	(349)
Total obligations under capital leases	$ 6,645
Minimum
Lessee, Lease, Description [Line Items]
Capital leases, interest percentage	2.00%
Maximum
Lessee, Lease, Description [Line Items]
Capital leases, interest percentage	6.50%