Share-Based Payments - Narrative (Details) - USD ($)			3 Months Ended			6 Months Ended
	Jul. 21, 2016	Jul. 19, 2016	Oct. 31, 2016	Jul. 31, 2016	Oct. 31, 2015	Oct. 31, 2016	Oct. 31, 2015
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Stock-based compensation expense (in usd)			$ 535,000		$ 748,000	$ 1,664,000	$ 1,523,000
Weighted-average grant date fair value (in usd per share)			$ 1.16		$ 5.47	$ 1.73	$ 4.99
Shares granted		1,568,191				2,320,681
Shares exchanged during period		1,793,781
Grants in period, weighted average exercise price (in usd per share)		$ 2.10				$ 1.98
Warrants outstanding			2,109,840			2,109,840
Chief Executive Officer and President [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Shares granted						203,043
Shares granted, net of forfeitures						203,043
Minimum [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Exchanges, weighted average exercise price (in usd per share)		4.55
Maximum [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Exchanges, weighted average exercise price (in usd per share)		$ 6.96
Employee Stock Option [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Modification expense (in usd)	$ 414,756		$ 38,590	$ 330,945
Modification expense for future period (in usd)	$ 45,221