Leases - Supplemental Balance Sheet Information (Details) - USD ($) $ in Thousands	Jul. 31, 2019	Apr. 30, 2019	Feb. 01, 2019
Assets
Operating lease right-of-use assets	$ 2,738	$ 3,014	$ 2,710
Liabilities
Total operating lease liabilities	2,738	3,014	2,710
Current liabilities	720	853
Non-current liabilities	2,018	2,161
Total Operating lease liabilities	$ 2,738	$ 3,014	$ 2,710
Weighted average remaining lease term (years)
Operating leases	2 years 2 months 1 day
Weighted average discount rate:
Operating leases	10.02%