Net Loss Per Share - Additional Information (Details) - shares	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Anti-dilutive securities excluded from computation of diluted net loss per share attributable to common stockholders	10,247,413	8,209,246	6,682,618
Potential common shares that would have been included in diluted income per share were not anti-dilutive effect caused by the net loss, computed by converting these securities using the treasury stock method	1,100,000	1,000,000	1,000,000
Options to Purchase Common Stock [Member]
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Anti-dilutive securities excluded from computation of diluted net loss per share attributable to common stockholders	7,128,247	5,378,008	3,977,160
Warrants to Purchase Common Stock [Member]
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Anti-dilutive securities excluded from computation of diluted net loss per share attributable to common stockholders	2,172,899	2,172,899	2,172,899
Restricted Stock Units (RSUs) [Member]
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Anti-dilutive securities excluded from computation of diluted net loss per share attributable to common stockholders		199,135	323,819
Performance-Based Restricted Stock Units (PRSUs) [Member]
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Anti-dilutive securities excluded from computation of diluted net loss per share attributable to common stockholders	867,506	395,791	148,216
Employee Stock Purchase Plan [Member]
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Anti-dilutive securities excluded from computation of diluted net loss per share attributable to common stockholders	78,761	63,413	60,524