Quarterly report pursuant to Section 13 or 15(d)

Fair Value Measurement - Assumptions (Details)

v3.19.3
Fair Value Measurement - Assumptions (Details) - Black-Scholes-Merton option pricing model [Member] - Warrant - Level 3 [Member]
Sep. 30, 2019
Exercise Price [Member]  
Fair Value Measurement Inputs and Valuation Techniques [Line Items]  
Value of input 7.63
Expected dividend yield [Member]  
Fair Value Measurement Inputs and Valuation Techniques [Line Items]  
Value of input 0.0
Minimum | Stock price [Member]  
Fair Value Measurement Inputs and Valuation Techniques [Line Items]  
Value of input 4.93
Minimum | Time until expiration (years) [Member]  
Fair Value Measurement Inputs and Valuation Techniques [Line Items]  
Value of input 4.5
Minimum | Expected volatility [Member]  
Fair Value Measurement Inputs and Valuation Techniques [Line Items]  
Value of input 54
Minimum | Risk-free interest rate [Member]  
Fair Value Measurement Inputs and Valuation Techniques [Line Items]  
Value of input 1.5
Maximum | Stock price [Member]  
Fair Value Measurement Inputs and Valuation Techniques [Line Items]  
Value of input 8.13
Maximum | Time until expiration (years) [Member]  
Fair Value Measurement Inputs and Valuation Techniques [Line Items]  
Value of input 5.0
Maximum | Expected volatility [Member]  
Fair Value Measurement Inputs and Valuation Techniques [Line Items]  
Value of input 65
Maximum | Risk-free interest rate [Member]  
Fair Value Measurement Inputs and Valuation Techniques [Line Items]  
Value of input 2.4