Quarterly report pursuant to Section 13 or 15(d)

STOCKHOLDERS' EQUITY - Stock option activity (Details)

v3.20.2
STOCKHOLDERS' EQUITY - Stock option activity (Details) - USD ($)
$ / shares in Units, $ in Thousands
3 Months Ended 9 Months Ended
Nov. 30, 2019
May 31, 2020
Feb. 29, 2020
Stock Options      
Beginning, balance outstanding 14,761 14,761  
Granted   3,667  
Exercised   (9)  
Forfeited   (7,051)  
Ending, balance outstanding   11,368  
Vested and expected to vest   10,187  
Exercisable   5,998  
Weighted Average Exercise Price      
Beginning, balance outstanding $ 4.89 $ 4.89  
Granted   2.24  
Exercised   2.06  
Forfeited   4.74  
Ending, balance outstanding   4.10  
Vested and expected to vest   $ 4.13  
Exercisable     $ 4.40
SharebasedCompensationArrangementBySharebasedPaymentAwardOptionsOutstandingWeightedAverageRemainingContractualTerm2 9 years 8 years 4 months 24 days  
SharebasedCompensationArrangementBySharebasedPaymentAwardOptionsOutstandingWeightedAverageRemainingContractualTerm2 9 years 8 years 4 months 24 days  
Vested and expected to vest   8 years 3 months 18 days  
Weighted Average Remaining Contractual Term Exercisable   7 years 10 months 24 days  
Aggregate intrinsic value, beginning balance outstanding $ 3,192 $ 3,192  
Aggregate Intrinsic Value Granted    
Aggregate Intrinsic Value, Exercised   14  
Aggregate Intrinsic Value, Forfeited    
Aggregate intrinsic value, ending balance outstanding   358  
Aggregate Intrinsic Value, Vested and expected to vest   285  
Aggregate Intrinsic Value Exercisable   $ 26