Income Taxes (Deferred Tax Asset Valuation Allowance Rollforward) (Details) - USD ($)	12 Months Ended
Apr. 30, 2019	Apr. 30, 2018
Income Tax Disclosure [Abstract]
Valuation allowance, beginning of year	$ (7,837,755)	$ (9,471,662)
Decrease (increase) during period	(2,213,279)	1,633,907
Valuation allowance, ending balance	$ (10,051,034)	$ (7,837,755)

Amount of deferred tax assets for which it is more likely than not that a tax benefit will not be realized.

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 740
-SubTopic 10
-Section 50
-Paragraph 2
-Subparagraph (c)
-URI http://asc.fasb.org/extlink&oid=84230637&loc=d3e32537-109319

Name:	us-gaap_DeferredTaxAssetsValuationAllowance
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant