| Income Taxes (Narrative) (Details) - USD ($) | 12 Months Ended | |
|---|---|---|
| Apr. 30, 2019 | Apr. 30, 2018 | |
| Operating Loss Carryforwards [Line Items] | Ìý | Ìý | 
| Net change in the valuation allowance | $ 2,213,279 | $ (1,633,907) | 
| Net operating loss carryforwards | $ 37,500,000 | Ìý | 
| Earliest Tax Year [Member] | Ìý | Ìý | 
| Operating Loss Carryforwards [Line Items] | Ìý | Ìý | 
| Net operating loss carryforwards, expiration | Dec. 31, 2033 | Ìý | 
| Years under examination | 2015 | Ìý | 
| Latest Tax Year [Member] | Ìý | Ìý | 
| Operating Loss Carryforwards [Line Items] | Ìý | Ìý | 
| Net operating loss carryforwards, expiration | Dec. 31, 2038 | Ìý | 
| Years under examination | 2018 | Ìý | 
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- Definition Tax year being audited in the income tax examination, in CCYY format. No definition available. 
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- Definition Amount of operating loss carryforward, before tax effects, available to reduce future taxable income under enacted tax laws. Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef 
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- Definition Expiration date of each operating loss carryforward included in operating loss carryforward, in CCYY-MM-DD format. Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef 
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- Definition Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table. No definition available. 
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- Definition Amount of increase (decrease) in the valuation allowance for a specified deferred tax asset. Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef 
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