Fair Value of Financial Instruments - Quantitative Information About Significant Unobservable Inputs (Parenthetical) (Detail) (Other assets, Equity warrant assets)	Sep. 30, 2013
Other assets | Equity warrant assets
Fair Value Inputs, Assets, Quantitative Information [Line Items]
Weighted average contractual remaining term	6 years 6 months
Estimated remaining life	2 years 11 months 2 days