Stockholders' Equity - Summary of Stock Options Outstanding (Detail) (USD $)			9 Months Ended
	Sep. 30, 2014	Dec. 31, 2013	Sep. 30, 2014 $1.00 - 5.00 [Member]	Sep. 30, 2014 $5.01 - 10.00 [Member]	Sep. 30, 2014 $ 10.01 - 15.00 [Member]	Sep. 30, 2014 $15.01 - 20.00 [Member]
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range [Line Items]
Range of Exercise Prices, minimum			$ 1.00	$ 5.01	$ 10.01	$ 15.01
Range of Exercise Prices, maximum			$ 5.00	$ 10.00	$ 15.00	$ 20.00
Number Outstanding	3,007,314		2,059,390	905,344	23,744	18,836
Weighted Average Remaining Contractual Life (Years)			5 years 3 months	4 years 4 days	9 years 9 months 26 days	9 years 11 months 27 days
Weighted Average Exercise Price			$ 3.10	$ 6.44	$ 12.44	$ 15.95
Aggregate Intrinsic Value	$ 38,598,170