Accrued Restructuring Charges (Narrative) (Details) - USD ($) $ in Thousands	12 Months Ended
	Apr. 30, 2015	Apr. 30, 2014
Restructuring Cost and Reserve [Line Items]
Restructuring costs incurred	$ 171	$ 1,000
Lease Abandonment [Member]
Restructuring Cost and Reserve [Line Items]
Restructuring costs incurred	150	700
Other Costs [Member]
Restructuring Cost and Reserve [Line Items]
Restructuring costs incurred	$ 21	$ 300