Leases - Additional Information (Details) - USD ($)	3 Months Ended
	Jul. 31, 2021	Jul. 31, 2020
Leases [Abstract]
Operating lease cost	$ 901,000	$ 335,000
Short-term operating lease costs	$ 51,000	133,000
Operating lease, weighted average lease term	16 years 6 months
Operating lease, weighted average discount rate	5.40%
Cash paid for amounts included in measurement of liabilities and operating cash flows	$ 443,000	$ 322,000