Basis of Presentation and Summary of Significant Accounting Policies - Antidilutive Shares Excluded From Computation of Net Loss Per Share (Details) - shares	3 Months Ended
	Mar. 31, 2020	Mar. 31, 2019
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Securites excluded from computation of net loss per common share	12,382,114	9,690,359
Stock options
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Securites excluded from computation of net loss per common share	8,373,040	7,777,367
Restricted Stock Units (RSUs)
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Securites excluded from computation of net loss per common share	1,287,986	0
Common stock warrants
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Securites excluded from computation of net loss per common share	2,677,188	1,866,831
Employee stock purchase plan
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Securites excluded from computation of net loss per common share	43,900	46,161