Earnings (Loss) Per Share (Schedule Of Earnings (Loss) Per Share) (Details) (USD $) In Thousands, except Per Share data, unless otherwise specified	3 Months Ended		9 Months Ended
	Jan. 31, 2013	Jan. 31, 2012	Jan. 31, 2013	Jan. 31, 2012
Earnings (Loss) Per Share [Abstract]
Net income (loss)	$ (65)	$ 53	$ 344	$ (931)
Dividends paid and payable on preferred stock	(101)	(101)	(302)	(236)
Net income (loss) available to common stockholders	$ (166)	$ (48)	$ 42	$ (1,167)
Weighted-average shares of common stock outstanding, basic	14,718	14,713	14,718	14,657
Effect of dilutive securities			8
Weighted-average shares of common stock outstanding, diluted	14,718	14,713	14,726	14,657
Basic	$ (0.01)	$ 0.00	$ 0.00	$ (0.08)
Diluted	$ (0.01)	$ 0.00	$ 0.00	$ (0.08)