Stockholders’ Equity and Stock-Based Compensation - Follow-on Public Offering Narrative (Details) - USD ($)	1 Months Ended
	Apr. 30, 2020	Sep. 30, 2020	Aug. 31, 2020	Dec. 31, 2019
Class of Stock [Line Items]
Warrants exercise price (in USD per share)		$ 1.54		$ 1.76
Gross proceeds	$ 18,000,000.0
Underwriting discounts and commissions and other offering expenses	$ 1,600,000
Authorized amount of stock to be issued			$ 125,000,000.0
Pre-Funded Warrant
Class of Stock [Line Items]
Number of securities called by each warrant (in shares)	1
Price per share (in USD per share)	$ 0.329
Warrants exercise price (in USD per share)	$ 0.001
Common Warrants
Class of Stock [Line Items]
Number of securities called by each warrant (in shares)	1
Price per share (in USD per share)	$ 0.33
Warrants exercise price (in USD per share)	$ 0.33
Class of warrant or right, expiration period	5 years
Common Stock
Class of Stock [Line Items]
Number of shares issued (in shares)	16,896,000
Authorized amount of stock to be issued			$ 40,000,000.0
Common Stock | Pre-Funded Warrant
Class of Stock [Line Items]
Warrants to purchase shares (in shares)	37,650,000
Common Stock | Common Warrants
Class of Stock [Line Items]
Warrants to purchase shares (in shares)	54,546,000