Consolidated Statements Of Stockholders Equity (USD $) In Thousands, except Share data	Preferred Stock [Member]	Common Stock [Member]	Additional Paid-in Capital [Member]	Accumulated Other Comprehensive Income (Loss) [Member]	Retained Earnings [Member]	Total
Balance at Apr. 30, 2011		$ 15	$ 95,111	$ 443	$ (77,536)	$ 18,034
Common Stock, Shares, Balance at Apr. 30, 2011		14,578,277
Net income (loss)					(16,662)	(16,662)
Translation adjustments				(102)		(102)
Comprehensive income (loss)						(16,764)
Issuance of common stock, value	2		3,970			3,972
Issuance of common stock, shares	1,666,667
Exercise of stock options, value			192			192
Exercise of stock options, shares		139,500
Preferred stock dividends			(334)			(334)
Stock-based compensation			921			921
Balance at Apr. 30, 2012	2	15	99,860	341	(94,198)	6,021
Common Stock, Shares, Balance at Apr. 30, 2012		14,717,777
Preferred Stock, Shares, Balance at Apr. 30, 2012	1,666,667
Net income (loss)					532	532
Translation adjustments				(61)		(61)
Comprehensive income (loss)						471
Preferred stock dividends			(400)			(400)
Stock-based compensation			593			593
Balance at Apr. 30, 2013	2	15	100,053	280	(93,666)	6,684
Common Stock, Shares, Balance at Apr. 30, 2013		14,717,777				14,717,777
Preferred Stock, Shares, Balance at Apr. 30, 2013	1,666,667					1,666,667
Net income (loss)					(1,558)	(1,558)
Comprehensive income (loss)						(1,558)
Exercise of stock options, shares
Preferred stock dividends			(66)			(66)
Stock-based compensation			165			165
Conversion of preferred stock to common stock, value	(2)	2
Conversion of preferred stock to common stock, shares	(1,666,667)	1,666,667
Balance at Apr. 30, 2014		$ 17	$ 100,152	$ 280	$ (95,224)	$ 5,225
Common Stock, Shares, Balance at Apr. 30, 2014		16,384,444				16,384,444
Preferred Stock, Shares, Balance at Apr. 30, 2014						0