Accrued Restructuring Charges (Schedule Of Accrued Liability Associated With Realignment) (Details) (USD $) In Thousands, unless otherwise specified	9 Months Ended
	Jan. 31, 2014
Restructuring Cost and Reserve [Line Items]
Charges	$ 829
Payments	(300)
Accrued liability at January 31, 2014	529
Severance [Member]
Restructuring Cost and Reserve [Line Items]
Charges	347
Payments	(170)
Accrued liability at January 31, 2014	177
Lease Abandonment [Member]
Restructuring Cost and Reserve [Line Items]
Charges	482
Payments	(130)
Accrued liability at January 31, 2014	$ 352