Net Loss Per Share - Potential Dilutive Shares Excluded from Computation of Diluted Net Loss Per Share (Details) - shares	9 Months Ended
	Sep. 30, 2022	Sep. 30, 2021
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Antidilutive securities excluded from computation of earnings per share, amount	34,485,557	35,386,620
Warrants
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Antidilutive securities excluded from computation of earnings per share, amount	22,922,342	22,705,571
Common Stock Options
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Antidilutive securities excluded from computation of earnings per share, amount	10,623,215	11,072,894
Inducement Stock Options | Two Thousand Twelve Stock Option Plan [Member]
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Antidilutive securities excluded from computation of earnings per share, amount	0	97,500
Unvested Restricted Stock
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Antidilutive securities excluded from computation of earnings per share, amount	940,000	1,510,655