Fair Value Measurements - Assumptions Used in Valuing Derivative Liabilities (Detail) |
12 Months Ended | ||
---|---|---|---|
Sep. 30, 2016 |
Sep. 30, 2015 |
Sep. 30, 2014 |
|
2012 Warrants | |||
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis Valuation Techniques [Line Items] | |||
Risk-free interest rate | 0.68% | 0.60% | 1.07% |
Expected life | 1 year 2 months 12 days | 2 years 2 months 12 days | 3 years 2 months 12 days |
Volatility | 89.00% | 75.00% | 69.00% |
2013 Warrants | |||
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis Valuation Techniques [Line Items] | |||
Risk-free interest rate | 0.68% | 0.60% | 1.07% |
Expected life | 1 year 3 months 18 days | 2 years 3 months 18 days | 3 years 3 months 18 days |
Volatility | 89.00% | 75.00% | 69.00% |
Exchange rights | |||
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis Valuation Techniques [Line Items] | |||
Risk-free interest rate | 0.68% | 1.00% | 1.07% |
Expected life | 1 year 6 months | 2 years 6 months | 3 years 3 months 18 days |
Volatility | 89.00% | 75.00% | 100.00% |