Accrued Restructuring Charge (Summary Of Restructuring And Other Costs) (Details) (USD $) In Thousands, unless otherwise specified	3 Months Ended
	Jul. 31, 2014
Restructuring Cost and Reserve [Line Items]
Amounts incurred and expected to be incurred	$ 1,212
Amounts incurred for the three months ended July 31, 2014	171
Severance [Member]
Restructuring Cost and Reserve [Line Items]
Amounts incurred and expected to be incurred	420
Lease Abandonment [Member]
Restructuring Cost and Reserve [Line Items]
Amounts incurred and expected to be incurred	933
Amounts incurred for the three months ended July 31, 2014	150
Asset Impairment [Member]
Restructuring Cost and Reserve [Line Items]
Amounts incurred and expected to be incurred	127
Deferred Rent Liability [Member]
Restructuring Cost and Reserve [Line Items]
Amounts incurred and expected to be incurred	(356)
Other Costs [Member]
Restructuring Cost and Reserve [Line Items]
Amounts incurred and expected to be incurred	88
Amounts incurred for the three months ended July 31, 2014	$ 21