Net Loss Per Share - Summary of Antidilutive Securities Excluded From Computation Diluted Weighted Average Shares Outstanding (Detail) - shares	3 Months Ended
	Mar. 31, 2016	Mar. 31, 2015
Schedule Of Calculation Of Numerator And Denominator In Earnings Per Share [Line Items]
Antidilutive securities excluded from computation of earnings per share amount	6,459,862	20,589,577
Restricted Stock [Member]
Schedule Of Calculation Of Numerator And Denominator In Earnings Per Share [Line Items]
Antidilutive securities excluded from computation of earnings per share amount	1,062,568
Restricted Stock Units (RSUs) [Member]
Schedule Of Calculation Of Numerator And Denominator In Earnings Per Share [Line Items]
Antidilutive securities excluded from computation of earnings per share amount	498,300
Warrants to Purchase Common Stock [Member]
Schedule Of Calculation Of Numerator And Denominator In Earnings Per Share [Line Items]
Antidilutive securities excluded from computation of earnings per share amount		200,000
Employee Stock Purchase Plan [Member]
Schedule Of Calculation Of Numerator And Denominator In Earnings Per Share [Line Items]
Antidilutive securities excluded from computation of earnings per share amount	17,639
Redeemable Convertible Preferred Stock [Member]
Schedule Of Calculation Of Numerator And Denominator In Earnings Per Share [Line Items]
Antidilutive securities excluded from computation of earnings per share amount		16,382,615
Options to Purchase Common Stock [Member]
Schedule Of Calculation Of Numerator And Denominator In Earnings Per Share [Line Items]
Antidilutive securities excluded from computation of earnings per share amount	4,881,355	4,006,962