Earnings Per Share - Schedule of Basic and Diluted Earnings per Share (Details) - USD ($)	12 Months Ended
	Apr. 30, 2017	Apr. 30, 2016
Earnings Per Share of Common Stock
Net income	$ 2,401,000	$ 3,086,000
Basic EPS	$ 2,401,000	$ 3,086,000
Basic EPS, shares	4,984,013	5,024,428
Basic EPS, per share	$ 0.48	$ 0.61
Effect of dilutive convertible preferred Stock
Effect of dilutive convertible preferred Stock, shares	20,500	20,500
Effect of dilutive convertible preferred Stock, per share	$ (0.0019)	$ (0.0025)
Diluted EPS	$ 2,401,000	$ 3,086,000
Diluted EPS, shares	5,004,513	5,044,928
Diluted EPS, per share	$ 0.48	$ 0.61