Note 10 - Industry Segmentation and Sales by Major Customer - Schedule of Revenue by Major Customers by Reporting Segments (Details) - Customer Concentration Risk [Member] - Sales Revenue, Net [Member]		12 Months Ended
		Apr. 30, 2017	Apr. 30, 2016
Top Customer [Member]
Concentration risk percentage		10.50%
Aerospace Products [Member] | Top Customer [Member]
Concentration risk percentage		10.50%		[1]
Professional Services [Member]
Concentration risk percentage	[1]

[1] Revenue represented less than 10% of consolidated revenue.