Changes In Restructuring Liability (Detail) (USD $) In Thousands, unless otherwise specified	3 Months Ended
	Jul. 31, 2014	Jul. 31, 2013
Restructuring Cost and Reserve [Line Items]
Liability, Beginning period	$ 2,813
Restructuring charges, net	9,886	3,682
Reductions for cash payments	(4,004)
Exchange rate fluctuations	(51)
Liability, Ending period	8,644
Severance
Restructuring Cost and Reserve [Line Items]
Restructuring charges, net	9,571
Reductions for cash payments	(3,332)
Exchange rate fluctuations	(57)
Liability, Ending period	6,182
Facilities
Restructuring Cost and Reserve [Line Items]
Liability, Beginning period	2,813
Restructuring charges, net	315
Reductions for cash payments	(672)
Exchange rate fluctuations	6
Liability, Ending period	$ 2,462