Leases - Additional Information (Details) $ in Thousands	3 Months Ended	9 Months Ended
	Jan. 31, 2020 USD ($)	Jan. 31, 2020 USD ($)
Lessee, Lease, Description [Line Items]
Cash paid included in measurement of operating lease liabilities		$ 900
Lease income	$ 70	$ 200
Minimum
Lessee, Lease, Description [Line Items]
Lease term	3 years	3 years
Maximum
Lessee, Lease, Description [Line Items]
Lease term	5 years	5 years