Net Loss per Share - Anti-Dilutive Common Share Equivalents (Details) - shares	3 Months Ended
	Mar. 31, 2022	Mar. 31, 2021
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Anti-dilutive common share equivalents (in shares)	50,024,185	52,175,241
Warrants
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Anti-dilutive common share equivalents (in shares)	7,833,332	256,605
Common stock options issued and outstanding
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Anti-dilutive common share equivalents (in shares)	28,389,111	31,143,641
Unvested restricted stock units
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Anti-dilutive common share equivalents (in shares)	13,801,742	0
Conversion of convertible notes
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Anti-dilutive common share equivalents (in shares)	0	20,774,995