XML 36 R87.htm IDEA: XBRL DOCUMENT v2.4.1.9
Stockholders' (Deficit) Equity - Schedule of Fair Value of Stock Options Weighted Average Assumptions (Detail)
8 Months Ended 12 Months Ended
Dec. 31, 2014
Apr. 30, 2014
Apr. 30, 2013
Apr. 30, 2012
Disclosure of Compensation Related Costs, Share-based Payments [Abstract]        
Expected life 7 years 6 years 9 months 15 days 6 years 9 months 26 days 5 years 6 months
Risk-free interest rate 2.15%us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardFairValueAssumptionsRiskFreeInterestRate 2.22%us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardFairValueAssumptionsRiskFreeInterestRate 1.14%us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardFairValueAssumptionsRiskFreeInterestRate 0.82%us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardFairValueAssumptionsRiskFreeInterestRate
Expected volatility 82.76%us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardFairValueAssumptionsExpectedVolatilityRate 83.96%us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardFairValueAssumptionsExpectedVolatilityRate 84.40%us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardFairValueAssumptionsExpectedVolatilityRate 91.54%us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardFairValueAssumptionsExpectedVolatilityRate