Net Loss Per Share - Excluded From Calculation (Details) - shares	9 Months Ended
	Sep. 30, 2021	Sep. 30, 2020
Outstanding common stock equivalents have been excluded from diluted net loss per common share
Total (in shares)	3,023,039	4,428,858
Options issued and outstanding
Outstanding common stock equivalents have been excluded from diluted net loss per common share
Total (in shares)	2,301,513	1,494,369
Inducement options issued and outstanding
Outstanding common stock equivalents have been excluded from diluted net loss per common share
Total (in shares)	156,204	11,131
Restricted stock unit awards issued and outstanding
Outstanding common stock equivalents have been excluded from diluted net loss per common share
Total (in shares)	1,871	1,871
Warrants issued and outstanding
Outstanding common stock equivalents have been excluded from diluted net loss per common share
Total (in shares)	563,451	2,446,845
Series B-2 Convertible Preferred Stock
Outstanding common stock equivalents have been excluded from diluted net loss per common share
Total (in shares)		474,642