9. Restructuring Charges (Details Narrative) - USD ($) $ in Thousands	6 Months Ended	12 Months Ended
	Oct. 31, 2017	Apr. 30, 2019	Apr. 30, 2018	Apr. 30, 2017
Aggregate restructuring costs		$ 0	$ 1,258	$ 0
Restructuring [Member]
Workforce reduction	We reduced our overall workforce by 57 employees
Aggregate restructuring costs	$ 1,588
Restructuring [Member] | Contract Manufacturing Services Segment [Member]
Aggregate restructuring costs	1,258
Restructuring [Member] | Research and Development Segment [Member]
Aggregate restructuring costs	$ 330