Leases - Summary of Supplemental Balance Sheet Information Related to Leases (Detail) - USD ($) $ in Thousands	Jan. 31, 2022	Apr. 30, 2021
Finance Leases:
Property and equipment, at cost	$ 5,051	$ 4,801
Accumulated depreciation	(2,738)	(2,590)
Property and equipment, net	$ 2,313	$ 2,211
Finance Lease, Right-of-Use Asset, Statement of Financial Position [Extensible Enumeration]	us-gaap:OtherAssets	us-gaap:OtherAssets
Other accrued liabilities	$ 935	$ 1,010
Finance Lease, Liability, Current, Statement of Financial Position [Extensible Enumeration]	us-gaap:OtherLiabilitiesCurrent	us-gaap:OtherLiabilitiesCurrent
Other liabilities	$ 1,393	$ 1,301
Finance Lease, Liability, Noncurrent, Statement of Financial Position [Extensible Enumeration]	Other liabilities	Other liabilities
Total finance lease liabilities	$ 2,328	$ 2,311
Weighted average remaining lease terms:
Operating leases	5 years	5 years
Finance leases	3 years 2 months 12 days	2 years 8 months 12 days
Weighted average discount rate:
Operating leases	4.50%	4.80%
Finance leases	3.40%	4.20%