Organization, Use of Estimates and Basis of Presentation - Calculation of Earnings Per Share (Details) - USD ($)	3 Months Ended		6 Months Ended
	Oct. 31, 2017	Oct. 31, 2016	Oct. 31, 2017	Oct. 31, 2016
Basic loss per share computation
Net loss attributable to common stockholders	$ (94,318)	$ (504,000)	$ (768,475)	$ (3,051,000)
Weighted average common shares outstanding, basic (in shares)	10,988,321	10,967,491	10,984,703	9,560,088
Basic and diluted net loss per share (in dollars per share)	$ (0.01)	$ (0.05)	$ (0.07)	$ (0.32)