Organization, Use of Estimates and Basis of Presentation - Calculation of Earnings Per Share (Details) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended
	Jul. 31, 2018	Jul. 31, 2017
Basic loss per share computation
Net income (loss) attributable to common stockholders	$ 482	$ (674)
Weighted Average common shares - basic (in shares)	11,012,281	10,982,159
Basic net income (loss) per share (in dollars per share)	$ 0.04	$ (0.06)
Income (Loss) available to common stockholders	$ 482	$ (674)
Incremental shares from assumed exercise of warrants and stock options (in shares)	1,605,740	0
Adjusted weighted average share - diluted (in shares)	12,618,021	10,982,159
Diluted net income (loss) per share (in usd per share)	$ 0.04	$ (0.06)