Net Loss Per Share - Dilutive Securities Excluded from Calculation of Diluted Earnings Per Share (Details) - shares	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
Options to purchase common stock
Antidilutive Securities Excluded From Computation Of Earnings Per Share [Line Items]
Dilutive securities excluded from calculation of diluted earnings per share	7,195,398	8,142,348	11,165,846
Warrants to purchase common stock - liability classified
Antidilutive Securities Excluded From Computation Of Earnings Per Share [Line Items]
Dilutive securities excluded from calculation of diluted earnings per share	2,036,733	2,156,153	2,156,153
Warrants to purchase common stock - equity classified
Antidilutive Securities Excluded From Computation Of Earnings Per Share [Line Items]
Dilutive securities excluded from calculation of diluted earnings per share	1,418,116	1,418,116	1,457,866
Unvested restricted stock units
Antidilutive Securities Excluded From Computation Of Earnings Per Share [Line Items]
Dilutive securities excluded from calculation of diluted earnings per share	6,244,013	8,046,399	4,379,777