Assumptions Used In Binomial and Monte Carlo Valuation Model (Detail)	Dec. 31, 2009 Y	Sep. 30, 2013 Binomial/Monte Carlo Option Pricing Model Y	Sep. 30, 2012 Binomial/Monte Carlo Option Pricing Model Y	Sep. 30, 2013 Binomial/Monte Carlo Option Pricing Model Minimum Y	Sep. 30, 2012 Binomial/Monte Carlo Option Pricing Model Minimum Y
Class of Warrant or Right [Line Items]
Risk-free interest rate	2.14%	0.10%	0.23%
Expected volatility	105.00%	75.00%	70.00%
Expected dividend yield	0.00%	0.00%	0.00%
Expected life in years	5	13	12	1.19	2.19