Share-Based Compensation - Summary of Status of Company's Non-Vested Employee Stock Option Shares (Detail) (Employee Stock Options [Member], USD $)	12 Months Ended
	Dec. 31, 2013	Dec. 31, 2012
Employee Stock Options [Member]
Schedule Of Non-Vested Stock Option Activity [Line Items]
Number of shares, Beginning Balance	1,233,184
Number of shares, Granted	2,304,000
Number of shares, Vested	(454,400)
Number of shares, Forfeited	(1,924,000)
Number of shares, Ending Balance	1,158,784	1,233,184
Weighted average grant date fair value, Beginning Balance	$ 0.11
Weighted average grant date fair value, Granted	$ 0.07	$ 0.91
Weighted average grant date fair value, Vested	$ 0.14
Weighted average grant date fair value, Forfeited	$ 0.07
Weighted average grant date fair value, Ending Balance	$ 0.08	$ 0.11