CONDENSED CONSOLIDATED STATEMENT OF CHANGES IN STOCKHOLDERS' EQUITY - USD ($) $ in Thousands	Total	Common Stock	Treasury Stock	Additional Paid-in Capital	Accumulated Deficit
Beginning balance (shares) at Apr. 30, 2018		11,003,228	269,685
Beginning balance at Apr. 30, 2018	$ 3	$ 11	$ (1,252)	$ 72,070	$ (70,826)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Stock-based compensation	75			75
Issuance of common stock for services (in shares)		4,762
Issuance of common stock on exercise of stock options and warrants (in shares)		20,000
Issuance of common stock on exercise of stock options and warrants				42
Net income	483				483
Ending balance (shares) at Jul. 31, 2018		11,027,990	269,685
Ending balance at Jul. 31, 2018	603	$ 11	$ (1,252)	72,187	(70,343)
Beginning balance (shares) at Apr. 30, 2018		11,003,228	269,685
Beginning balance at Apr. 30, 2018	3	$ 11	$ (1,252)	72,070	(70,826)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income	750
Ending balance (shares) at Oct. 31, 2018		11,474,805	0
Ending balance at Oct. 31, 2018	1,992	$ 11	$ 0	72,057	(70,076)
Beginning balance (shares) at Jul. 31, 2018		11,027,990	269,685
Beginning balance at Jul. 31, 2018	603	$ 11	$ (1,252)	72,187	(70,343)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Stock-based compensation	88			88
Issuance of common stock on exercise of stock options and warrants (in shares)		446,815	269,685
Issuance of common stock on exercise of stock options and warrants	1,034		$ 1,252	(218)
Net income	267				267
Ending balance (shares) at Oct. 31, 2018		11,474,805	0
Ending balance at Oct. 31, 2018	$ 1,992	$ 11	$ 0	$ 72,057	$ (70,076)