Furniture, Equipment and Purchased Software (Detail) (USD $) In Thousands, unless otherwise specified	Apr. 30, 2014	Apr. 30, 2013
Property, Plant and Equipment [Line Items]
Gross property plant and equipment	$ 34,226	$ 33,971
Accumulated depreciation and amortization	(30,545)	(29,489)
Net property plant and equipment	3,681	4,482
Buildings and leasehold improvements
Property, Plant and Equipment [Line Items]
Gross property plant and equipment	20,011	19,993
Computer equipment and purchased software
Property, Plant and Equipment [Line Items]
Gross property plant and equipment	9,842	9,611
Office furniture and equipment
Property, Plant and Equipment [Line Items]
Gross property plant and equipment	$ 4,373	$ 4,367