Stock-Based Compensation - Summarizes Information with Respect to Stock Options Outstanding (Detail) (USD $)	9 Months Ended
	Sep. 30, 2014	Dec. 17, 2013
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range [Line Items]
Exercise Price Per Share	$ 2.00	$ 2.66
Outstanding Options, Shares	2,267,918
Outstanding Options, Weighted- Average Remaining Contractual Term	9 years 3 months 25 days
Weighted Average- Exercise Price	$ 2.71
Exercisable Options, Shares	309,982
Exercisable Options, Weighted- Average Exercise Price	$ 2.98
Range of Exercise Prices - Range 1 [Member]
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range [Line Items]
Exercise Price Per Share	$ 2.05
Outstanding Options, Shares	56,900
Outstanding Options, Weighted- Average Remaining Contractual Term	9 years 10 months 2 days
Weighted Average- Exercise Price	$ 2.05
Exercisable Options, Shares	0
Exercisable Options, Weighted- Average Exercise Price	$ 0
Range of Exercise Prices - Range 2 [Member]
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range [Line Items]
Exercise Price Per Share	$ 2.27
Outstanding Options, Shares	1,293,720
Outstanding Options, Weighted- Average Remaining Contractual Term	9 years 2 months 12 days
Weighted Average- Exercise Price	$ 2.27
Exercisable Options, Shares	241,960
Exercisable Options, Weighted- Average Exercise Price	$ 2.27
Range of Exercise Prices - Range 3 [Member]
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range [Line Items]
Exercise Price Per Share	$ 3.04
Outstanding Options, Shares	742,298
Outstanding Options, Weighted- Average Remaining Contractual Term	9 years 6 months 29 days
Weighted Average- Exercise Price	$ 3.04
Exercisable Options, Shares	53,022
Exercisable Options, Weighted- Average Exercise Price	$ 3.04
Range of Exercise Prices - Range 4 [Member]
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range [Line Items]
Exercise Price Per Share	$ 3.85
Outstanding Options, Shares	160,000
Outstanding Options, Weighted- Average Remaining Contractual Term	9 years 8 months 12 days
Weighted Average- Exercise Price	$ 3.85
Exercisable Options, Shares	0
Exercisable Options, Weighted- Average Exercise Price	$ 0
Range of Exercise Prices - Range 5 [Member]
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range [Line Items]
Exercise Price Per Share	$ 14.30
Outstanding Options, Shares	15,000
Outstanding Options, Weighted- Average Remaining Contractual Term	1 year 8 months 16 days
Weighted Average- Exercise Price	$ 14.30
Exercisable Options, Shares	15,000
Exercisable Options, Weighted- Average Exercise Price	$ 14.30