Equipment, Furniture and Fixtures (Details) (USD $) In Thousands, unless otherwise specified	Jan. 31, 2014	Apr. 30, 2013
Property, Plant and Equipment [Line Items]
Gross equipment, furniture and fixtures	$ 2,686	$ 2,741
Accumulated depreciation and amortization	(2,145)	(2,168)
Net equipment, furniture and fixtures	541	573	[1]
Plant and Machinery [Member]
Property, Plant and Equipment [Line Items]
Gross equipment, furniture and fixtures	661	757
Computer Equipment [Member]
Property, Plant and Equipment [Line Items]
Gross equipment, furniture and fixtures	1,728	1,662
Leasehold Improvement [Member]
Property, Plant and Equipment [Line Items]
Gross equipment, furniture and fixtures	201	201
Furniture, Fixtures and Equipment [Member]
Property, Plant and Equipment [Line Items]
Gross equipment, furniture and fixtures	96	96
Construction in Progress [Member]
Property, Plant and Equipment [Line Items]
Gross equipment, furniture and fixtures	$ 0	$ 25

[1] Derived from the consolidated audited financial statements included in the Company's Annual Report on Form 10-K for the fiscal year ended April 30, 2013 filed with the SEC.