Stock Options (Details 1)	9 Months Ended
	Jan. 31, 2016 USD ($) $ / shares shares
Options Outstanding | shares	710,019
Options Exercisable | shares	393,823
Options Outstanding - Aggregate Intrinsic Value | $
Options Exercisable - Aggregate Intrinsic Value | $
Exercise Price Range One [Member]
Exercise Price	$ 44.00
Options Outstanding | shares	2,326
Options Outstanding, Weighted Avg. Life Remaining	4 days
Options Outstanding, Weighted Avg. Exercise Price	$ 44.00
Options Exercisable | shares	2,326
Options Exercisable, Weighted Avg. Exercise Price	$ 44.00
Exercise Price Range Two [Member]
Exercise Price	$ 12.00
Options Outstanding | shares	132,987
Options Outstanding, Weighted Avg. Life Remaining	7 years 11 months 5 days
Options Outstanding, Weighted Avg. Exercise Price	$ 12.00
Options Exercisable | shares	54,654
Options Exercisable, Weighted Avg. Exercise Price	$ 12.00
Exercise Price Range Three [Member]
Exercise Price	$ 6.00
Options Outstanding | shares	10,000
Options Outstanding, Weighted Avg. Life Remaining	9 years
Options Outstanding, Weighted Avg. Exercise Price	$ 6.00
Options Exercisable | shares	10,000
Options Exercisable, Weighted Avg. Exercise Price	$ 6.00
Exercise Price Range Four [Member]
Exercise Price	$ 2.00
Options Outstanding | shares	483,039
Options Outstanding, Weighted Avg. Life Remaining	9 years 3 months
Options Outstanding, Weighted Avg. Exercise Price	$ 2.00
Options Exercisable | shares	320,037
Options Exercisable, Weighted Avg. Exercise Price	$ 2.00
Exercise Price Range Five [Member]
Exercise Price	$ 3.00
Options Outstanding | shares	81,667
Options Outstanding, Weighted Avg. Life Remaining	9 years 10 months 28 days
Options Outstanding, Weighted Avg. Exercise Price	$ 2.00
Options Exercisable | shares	6,806
Options Exercisable, Weighted Avg. Exercise Price	$ 3.00