Earnings (Loss) Per Share (Schedule Of Earnings (Loss) Per Share) (Details) (USD $) In Thousands, except Per Share data, unless otherwise specified	3 Months Ended		6 Months Ended
	Oct. 31, 2012	Oct. 31, 2011	Oct. 31, 2012	Oct. 31, 2011
Earnings (Loss) Per Share [Abstract]
Net income (loss)	$ 252	$ 795	$ 409	$ (983)
Dividends paid and payable on preferred stock	(101)	(101)	(202)	(135)
Net income (loss) available to common stockholders	$ 151	$ 694	$ 207	$ (1,118)
Weighted-average shares of common stock outstanding, basic	14,718	14,657	14,718	14,629
Effect of dilutive securities	11	152	5
Weighted-average shares of common stock outstanding, diluted	14,729	14,809	14,723	14,629
Basic	$ 0.01	$ 0.05	$ 0.01	$ (0.08)
Diluted	$ 0.01	$ 0.05	$ 0.01	$ (0.08)