Description of the Business and Liquidity (Details) - USD ($) $ in Thousands	1 Months Ended	3 Months Ended
	Jun. 30, 2020	Jun. 30, 2020	Dec. 31, 2019
Liquidity
Accumulated deficit	$ 278,801	$ 278,801	$ 235,574
Net proceeds from issuance of common stock and preferred stock			65,700
2017 Equity Distribution Agreement
Liquidity
Net proceeds from issuance of common stock			$ 2,100
Issuance of shares under equity distribution agreement (in shares)			1,692,289
Series A Convertible Preferred Stock | Private placement
Liquidity
Issuance of stock (in shares)			30,000
Common Stock
Liquidity
Issuance of stock (in shares)		18,400,000
Issuance of shares under equity distribution agreement (in shares)		315,229
Common Stock | Public Offering
Liquidity
Issuance of stock (in shares)	18,400,000		32,200,000
Net proceeds from issuance of common stock	$ 42,900