Basis of Presentation and Summary of Significant Accounting Policies - Net loss per share - Anti-dilutive securities (Details) - shares	3 Months Ended
	Jul. 31, 2016	Jul. 31, 2015
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Anti-dilutive securities	489,995	1,850,244
Common Stock Equivalent of Convertible Notes
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Anti-dilutive securities	0	100,000
Common Stock Equivalent of Convertible Notes - Related Parties
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Anti-dilutive securities	9,070	9,070
Series A Preferred Shares
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Anti-dilutive securities	0	522,167
Series B Preferred Shares
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Anti-dilutive securities	344,480	0
Warrant
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Anti-dilutive securities	133,667	1,119,425
Stock Options
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Anti-dilutive securities	2,778	99,582