Annual report pursuant to Section 13 and 15(d)

Income Taxes (Deferred Tax Asset Valuation Allowance Rollforward) (Details)

v3.10.0.1
Income Taxes (Deferred Tax Asset Valuation Allowance Rollforward) (Details) - USD ($)
12 Months Ended
Apr. 30, 2018
Apr. 30, 2017
Income Tax Disclosure [Abstract]    
Valuation allowance, beginning of year $ (9,471,662) $ (9,068,774)
Decrease (increase) during period 1,633,907 (402,888)
Valuation allowance, ending balance $ (7,837,755) $ (9,471,662)