Net Income (Loss) Per Share - Summary of Potentially Dilutive Securities (Details) - shares	3 Months Ended
	Mar. 31, 2019	Mar. 31, 2018
Antidilutive Securities Excluded From Computation Of Earnings Per Share [Line Items]
Potentially dilutive securities not included in the calculation of diluted net loss per share	519,107	1,210,065
Employee Stock Options
Antidilutive Securities Excluded From Computation Of Earnings Per Share [Line Items]
Potentially dilutive securities not included in the calculation of diluted net loss per share	468,104	1,159,062
Warrants outstanding
Antidilutive Securities Excluded From Computation Of Earnings Per Share [Line Items]
Potentially dilutive securities not included in the calculation of diluted net loss per share	51,003	51,003