4. Leases (Details - Operating leases assets and liabilities) - USD ($) $ in Thousands	Jan. 31, 2021	Apr. 30, 2020
Lessee Disclosure [Abstract]
Operating lease right-of-use assets	$ 19,053	$ 20,100
Current portion of operating lease liabilities	1,334	1,228
Operating lease liabilities, less current portion	20,233	21,244
Total operating lease liabilities	$ 21,567	$ 22,472
Weighted average lease term	9 years 9 months 18 days	10 years 6 months
Weighted average discount rate	7.40%	8.00%