Note 16 - Gain on Sale of Operating Facility (Details Textual)		3 Months Ended	12 Months Ended
	Jul. 29, 2016 USD ($) ft²	Jul. 31, 2016 USD ($)	Apr. 30, 2018 USD ($)	Apr. 30, 2017 USD ($)	Apr. 30, 2016 USD ($)	Feb. 29, 2016 ft²
Proceeds from Sale of Property, Plant, and Equipment, Total				$ 11,555,000
Seagis Property Group LP (the "Landlord") [Member]
Area of Real Estate Property | ft²						24,110
Fulfillment and Warehouse Facility [Member]
Area of Real Estate Property | ft²	85,000
Proceeds from Sale of Property, Plant, and Equipment, Total	$ 11,555,000
Gain Loss on Disposition of Assets, Net of Tax		$ 5,280,000