Net Loss Per Share Attributable to Common Stockholders- Excluded From Calculation (Details) - shares	3 Months Ended
	Mar. 31, 2020	Mar. 31, 2019
Outstanding common stock equivalents have been excluded from diluted net loss per common share
Outstanding common stock equivalents have been excluded from diluted net loss per common share (in shares)	28,464,913	33,281,448
Options issued and outstanding
Outstanding common stock equivalents have been excluded from diluted net loss per common share
Outstanding common stock equivalents have been excluded from diluted net loss per common share (in shares)	4,508,021	40,625
Inducement options issued and outstanding
Outstanding common stock equivalents have been excluded from diluted net loss per common share
Outstanding common stock equivalents have been excluded from diluted net loss per common share (in shares)	74	2,984
Restricted stock units issued and outstanding
Outstanding common stock equivalents have been excluded from diluted net loss per common share
Outstanding common stock equivalents have been excluded from diluted net loss per common share (in shares)	5,613	5,613
Warrants issued and outstanding
Outstanding common stock equivalents have been excluded from diluted net loss per common share
Outstanding common stock equivalents have been excluded from diluted net loss per common share (in shares)	17,622,930	71,821
Series A convertible preferred stock
Outstanding common stock equivalents have been excluded from diluted net loss per common share
Outstanding common stock equivalents have been excluded from diluted net loss per common share (in shares)	473,565	33,149,556
Series B convertible preferred stock
Outstanding common stock equivalents have been excluded from diluted net loss per common share
Outstanding common stock equivalents have been excluded from diluted net loss per common share (in shares)	4,423,250
Series B-2 convertible preferred stock
Outstanding common stock equivalents have been excluded from diluted net loss per common share
Outstanding common stock equivalents have been excluded from diluted net loss per common share (in shares)	1,431,460
Convertible Debt
Outstanding common stock equivalents have been excluded from diluted net loss per common share
Outstanding common stock equivalents have been excluded from diluted net loss per common share (in shares)		10,849