8. EQUITY COMPENSATION PLANS (Details Narrative)
$ in Thousands
3 Months Ended
Jul. 31, 2018
USD ($)
shares
Stock Incentive Plans [Member]  
Shares available for grant 5,005,142
Options and restricted stock rights [Member]  
Shares available for grant 3,088,084
Future grants of share-based awards [Member]  
Shares available for grant 1,917,058
ESPP [Member]  
Shares authorized under plan 2,142,857
Shares available for grant 1,271,409
Common stock purchased under plan 0
Non-Vested Employee Stock Options [Member]  
Unrecognized compensation cost | $ $ 2,370
Unrecognized cost amortization period 2 years 9 months 22 days
Non-Vested Restricted Stock Rights [Member]  
Unrecognized compensation cost | $ $ 449
Unrecognized cost amortization period 3 years 10 months 14 days
Restricted Stock Rights [Member]  
RSR's granted 128,050
Aggregate grant date fair value | $ $ 464