Annual report pursuant to Section 13 and 15(d)

Share-Based Compensation - Summary of Employee Stock Option Activity (Detail)

Share-Based Compensation - Summary of Employee Stock Option Activity (Detail) - USD ($)	12 Months Ended
	Dec. 31, 2013	Dec. 31, 2012
Non Employee Stock Options [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Number of shares, Outstanding, Beginning balance	416,000
Number of shares, Granted		416,000
Number of shares, Exercised
Number of shares, Forfeited
Number of shares, Outstanding, Ending Balance	416,000	416,000
Number of shares, Vested or expected to vest	416,000
Number of shares, Exercisable	128,000	24,000
Weighted average exercise price, Outstanding	$ 0.52
Weighted average exercise price, Forfeited
Weighted average exercise price, Outstanding	$ 0.52	$ 0.52
Weighted average exercise price, Outstanding, Vested or expected to vest	0.52
Weighted Average Exercise Price, Outstanding, Exercisable	$ 0.48	$ 0.31
Weighted-average remaining life (years), Outstanding	5 years 10 months 24 days
Weighted-average remaining life (years), Vested or expected to vest	5 years 10 months 24 days
Weighted-average remaining life (years), Exercisable	4 years 4 months 17 days	4 years 8 months 23 days
Aggregate intrinsic value, Vested or expected to vest	$ 49
Aggregate intrinsic value, Exercisable	$ 49	$ 0
Employee Stock Option [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Number of shares, Outstanding, Beginning balance	4,985,480	4,068,024
Number of shares, Granted	2,304,000	960,000
Number of shares, Exercised	(55,379)	(19,535)
Number of shares, Forfeited	(2,011,671)	(23,009)
Number of shares, Outstanding, Ending Balance	5,222,430	4,985,480
Number of shares, Vested or expected to vest	5,222,430
Number of shares, Exercisable	4,063,646	3,752,296
Weighted average exercise price, Outstanding	$ 0.42	$ 0.31
Weighted average exercise price, Granted	1.22	0.91
Weighted average exercise price, Exercised	0.04	0.04
Weighted average exercise price, Forfeited	1.22	2.04
Weighted average exercise price, Outstanding	0.47	0.42
Weighted average exercise price, Outstanding, Vested or expected to vest	0.47
Weighted Average Exercise Price, Outstanding, Exercisable	$ 0.30	$ 0.29
Weighted-average remaining life (years), Outstanding	4 years 8 months 5 days
Weighted-average remaining life (years), Vested or expected to vest	4 years 8 months 5 days
Weighted-average remaining life (years), Exercisable	3 years 8 months 19 days	4 years 3 months 11 days
Aggregate intrinsic value, Exercised	$ 10,663	$ 8,726
Aggregate intrinsic value, Outstanding	432,392
Aggregate intrinsic value, Vested or expected to vest	432,392
Aggregate intrinsic value, Exercisable	$ 432,392	$ 423,487
Stock Option [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Number of shares, Forfeited	(2,000,000)
Joint Share Ownership Plan Awards [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Weighted average exercise price, Granted		$ 0.17