Product Warranty (Tables)

3 Months Ended

Jul. 31, 2012

Product Warranty [Abstract]

Schedule Of Warranty Liability

	Three Months Ended
	July 31,
(in thousands)	2012		2011
Beginning balance at May 1	$	1,885	$	1,738
Accrual		2,257		2,294
Settlements		(2,160)		(2,148)
Ending balance at July 31	$	1,982	$	1,884