Income Taxes (Provision (Benefit) For Income Taxes After Applying The Statutory U.S. Federal Income Tax Rate) (Details) (USD $) In Thousands, unless otherwise specified	12 Months Ended
	Apr. 30, 2014	Apr. 30, 2013	Apr. 30, 2012
Income Taxes [Abstract]
Computed tax expense (benefit) at statutory rate	$ (420)	$ 277	$ (5,613)
Net operating loss carryforward limitation	219	(235)	7,352
State income taxes, net of federal tax benefit	100	74	102
Capital loss carryforward limitation	84
Change in valuation allowance for deferred tax assets	190	(88)	(1,752)
Stock-based compensation	56	182	297
Change in fair value of warrants	24	(124)	(358)
Foreign taxes	104	125	(377)
Foreign tax credits	(60)	(70)	(39)
Other	36	141	541
Provision for income taxes	$ 333	$ 282	$ 153