Organization, Use of Estimates and Basis of Presentation - Calculation of Earnings Per Share (Details) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended		6 Months Ended
	Oct. 31, 2016	Oct. 31, 2015	Oct. 31, 2016	Oct. 31, 2015
Basic loss per share computation
Net loss attributable to common stockholders	$ (504)	$ (2,548)	$ (3,051)	$ (5,461)
Weighted average common shares outstanding, basic (in shares)	10,967,491	8,702,237	9,560,088	8,702,237
Basic and diluted net loss per share (in dollars per share)	$ (0.05)	$ (0.29)	$ (0.32)	$ (0.63)