Fair Value of Financial Instruments - Additional Information (Detail) - $ / shares	May. 07, 2015	May. 07, 2014	Dec. 31, 2015	Dec. 31, 2014	Sep. 24, 2014
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis Valuation Techniques [Line Items]
Number of warrants issued to purchase of common stock		200,000			9,000,000
Warrants Vested	100,000	100,000
Warrants issued		200,000	0	12,991,000
Black-Scholes-Merton Valuation Model [Member]
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis Valuation Techniques [Line Items]
Fair value assumption, expected volatility	88.50%	97.60%
Fair value assumption, risk free interest rate	0.63%	0.90%
Fair value assumption, expected term	2 years	3 years
Fair value assumption, expected dividend yield	0.00%	0.00%
Grant date fair value of the initial warrant valuation	$ 0.35	$ 1.61
Warrants issued	100,000