Property and Equipment - Narrative (Details) - USD ($) $ in Thousands	1 Months Ended	3 Months Ended		6 Months Ended
	Nov. 30, 2014	Oct. 31, 2016	Oct. 31, 2015	Oct. 31, 2016	Oct. 31, 2015	Apr. 30, 2016
Property, Plant and Equipment [Line Items]
Depreciation		$ 34	$ 31	$ 74	$ 64
Capital leased assets, gross		$ 124		$ 124		$ 124
Capital leases monthly payments	$ 3
Capital leases of lessee, contingent rentals, basis spread on variable rate		5.00%		5.00%
Assets Held under Capital Leases [Member]
Property, Plant and Equipment [Line Items]
Depreciation		$ 6	$ 6	$ 12	$ 12
Equipment Leased to Other Party [Member]
Property, Plant and Equipment [Line Items]
Capital lease asset	$ 149