Quarterly report pursuant to Section 13 or 15(d)

Fair Value Measurements - Additional Information (Details)

v3.20.2
Fair Value Measurements - Additional Information (Details) - Level 3
Jun. 30, 2020
Dec. 31, 2019
Fair Value Balance Sheet Grouping Financial Statement Captions [Line Items]    
Warrant liabilities, maturity date Jun. 12, 2023  
Stock Price Volatility    
Fair Value Balance Sheet Grouping Financial Statement Captions [Line Items]    
Derivative liabilities, unobservable inputs rate 55.4  
Stock Price Volatility | Minimum [Member]    
Fair Value Balance Sheet Grouping Financial Statement Captions [Line Items]    
Warrant liabilities, stock price volatility rate 69.1  
Stock Price Volatility | Maximum    
Fair Value Balance Sheet Grouping Financial Statement Captions [Line Items]    
Warrant liabilities, stock price volatility rate 76.4  
Stock Price Volatility | Weighted Average    
Fair Value Balance Sheet Grouping Financial Statement Captions [Line Items]    
Warrant liabilities, stock price volatility rate 74.0  
Weighted Average Expected Term    
Fair Value Balance Sheet Grouping Financial Statement Captions [Line Items]    
Warrant liabilities, expected term 1 year 10 months 24 days  
Weighted Average Expected Term | Minimum [Member]    
Fair Value Balance Sheet Grouping Financial Statement Captions [Line Items]    
Warrant liabilities, expected term   1 year 4 months 24 days
Weighted Average Expected Term | Maximum    
Fair Value Balance Sheet Grouping Financial Statement Captions [Line Items]    
Warrant liabilities, expected term   3 years
Market Credit Spread    
Fair Value Balance Sheet Grouping Financial Statement Captions [Line Items]    
Derivative liabilities, unobservable inputs rate 1,864  
Estimated Yield    
Fair Value Balance Sheet Grouping Financial Statement Captions [Line Items]    
Derivative liabilities, unobservable inputs rate 19.0  
Discounts for Lack of Marketability | March 2019 Notes    
Fair Value Balance Sheet Grouping Financial Statement Captions [Line Items]    
Senior convertible notes, unobservable inputs rate 6.13