| Stockholders' Equity (Schedule of Warrants) (Details) (Warrant [Member], USD $) | 3 Months Ended | 
|---|---|
| Jul. 31, 2013 | |
| Warrant [Member] | |
| Share-based Compensation Arrangement by Share-based Payment Award [Line Items] | |
| Beginning Balance | 9,090,292 | 
| Granted | 1,115,026 | 
| Exercised | |
| Forfeited | (40,000) | 
| Expired | |
| Ending Balance | 10,165,318 | 
| Weighted average exercise price, beginning | $ 0.46 | 
| Weighted average exercise price, granted | $ 0.33 | 
| Weighted average exercise price, forfeited | $ 0.50 | 
| Weighted average exercise price, ending | $ 0.45 | 
| Weighted Average Remaining Contractual Term, Outstanding | 4 years 1 month 6 days | 
| Aggregate Intrinsic Value, Outstanding | $ 51,862 | 
| Exercisable | 10,165,318 | 
| Weighted Average Exercise Price, Exercisable | $ 0.45 | 
| Weighted Average Remaining Contractual Term, Exercisable | 4 years 1 month 6 days | 
| Aggregate Intrinsic Value, Exercisable | $ 51,862 | 
| X | ||||||||||
| 
- Definition The number of exercisable warrants (fully vested and expected to vest) that may be converted as of the balance sheet date. No definition available. 
 | 
| X | ||||||||||
| 
- Definition Weighted average price at which grantees can acquire the shares upon exercise of the warrants. No definition available. 
 | 
| X | ||||||||||
| 
- Definition Weighted average remaining contractual term for equity-based awards excluding options, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents the reported fact of one year, five months, and thirteen days. No definition available. 
 | 
| X | ||||||||||
| 
- Definition Weighted average exercise price of warrants forfeited. No definition available. 
 | 
| X | ||||||||||
| 
- Definition Weighted average exercise price of warrants granted. No definition available. 
 | 
| X | ||||||||||
| 
- Definition Weighted average price at which grantees can acquire the shares upon exercise of the warrants. No definition available. 
 | 
| X | ||||||||||
| 
- Definition Intrinsic value of equity-based compensation awards outstanding. Excludes stock and unit options. No definition available. 
 | 
| X | ||||||||||
| 
- Definition Intrinsic value of equity-based compensation awards vested. Excludes stock and unit options. No definition available. 
 | 
| X | ||||||||||
| 
- Definition Weighted average remaining contractual term for equity-based awards excluding options, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents the reported fact of one year, five months, and thirteen days. Reference 1: http://www.xbrl.org/2003/role/presentationRef 
 | 
| X | ||||||||||
| 
- Details 
 | 
| X | ||||||||||
| 
- Definition Number of non-option equity instruments exercised by participants. Reference 1: http://www.xbrl.org/2003/role/presentationRef 
 | 
| X | ||||||||||
| 
- Definition Number of shares under non-option equity instrument agreements for which rights to exercise lapsed. Reference 1: http://www.xbrl.org/2003/role/presentationRef 
 | 
| X | ||||||||||
| 
- Definition Number of shares under non-option equity instrument agreements that were cancelled as a result of occurrence of a terminating event. Reference 1: http://www.xbrl.org/2003/role/presentationRef 
 | 
| X | ||||||||||
| 
- Definition Net number of non-option equity instruments granted to participants. Reference 1: http://www.xbrl.org/2003/role/presentationRef 
 | 
| X | ||||||||||
| 
- Definition Number of equity instruments other than options outstanding, including both vested and non-vested instruments. Reference 1: http://www.xbrl.org/2003/role/presentationRef 
 |