Stockholders' Equity - Summary of Stock Option Activity under the Company's Equity-Based Plans (Details) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended	12 Months Ended
	Mar. 31, 2016	Dec. 31, 2015
Share-based Compensation Arrangement by Share-based Payment Award, Options, Outstanding [Roll Forward]
Number of Shares, Beginning Balance	4,446,149
Number of Shares, Exercised	(190,608)
Number of Shares, Forfeited	(145,213)
Number of Shares, Ending Balance	4,110,328	4,446,149
Number of Shares, Exercisable, Ending Balance	2,331,709
Number of Shares, Vested and expected to vest, Ending Balance	3,993,724
Share-based Compensation Arrangement by Share-based Payment Award, Options, Outstanding, Weighted Average Exercise Price [Roll Forward]
Weighted-Average Exercise Price, Beginning Balance	$ 8.96
Weighted-Average Exercise Price, Exercised	2.64
Weighted-Average Exercise Price, Forfeited	24.35
Weighted-Average Exercise Price, Ending Balance	8.71	$ 8.96
Weighted-Average Exercise Price, Exercisable, Ending Balance	6.67
Weighted-Average Exercise Price, Vested and expected to vest, Ending Balance	$ 8.53
Share-based Compensation Arrangement by Share-based Payment Award, Options, Additional Disclosures [Abstract]
Weighted-Average Remaining Contractual Term (in years)	7 years 3 months 22 days	7 years 6 months 22 days
Weighted-Average Remaining Contractual Term (in years), Exercisable	6 years 11 months 19 days
Weighted-Average Remaining Contractual Term (in years), Vested and expected to vest	7 years 3 months 15 days
Aggregate Intrinsic Value, Beginning Balance	$ 52,108
Aggregate Intrinsic Value, Ending Balance	30,286	$ 52,108
Aggregate Intrinsic Value, Exercisable, Ending Balance	20,620
Aggregate Intrinsic Value, Vested and expected to vest, Ending Balance	$ 29,845