Quarterly report pursuant to Section 13 or 15(d)

Fair value measurements (Schedule of Weighted Average Unobservable Inputs) (Details)

v3.19.2
Fair value measurements (Schedule of Weighted Average Unobservable Inputs) (Details) - Fair Value, Inputs, Level 3 [Member]
1 Months Ended 3 Months Ended
Jan. 28, 2019
Jun. 30, 2019
Dividend yield [Member] | Warrant [Member]    
Fair Value Measurement Inputs and Valuation Techniques [Line Items]    
Weighted Average Unobservable Inputs 0% 0%
Expected Price volatility [Member] | Warrant [Member]    
Fair Value Measurement Inputs and Valuation Techniques [Line Items]    
Weighted Average Unobservable Inputs 111.6% 119.9%-120.5%
Risk free interest rate [Member] | Warrant [Member]    
Fair Value Measurement Inputs and Valuation Techniques [Line Items]    
Weighted Average Unobservable Inputs 2.58% 2.23%-2.58%
Expected term [Member] | Warrant [Member]    
Fair Value Measurement Inputs and Valuation Techniques [Line Items]    
Weighted Average Unobservable Inputs 5 years 4 years, 10 months
Senior Secured Convertible Promissory Notes [Member] | Dividend yield [Member]    
Fair Value Measurement Inputs and Valuation Techniques [Line Items]    
Weighted Average Unobservable Inputs 0% 0.00
Senior Secured Convertible Promissory Notes [Member] | Expected Price volatility [Member]    
Fair Value Measurement Inputs and Valuation Techniques [Line Items]    
Weighted Average Unobservable Inputs 119.5% 122.2%-127.1%
Senior Secured Convertible Promissory Notes [Member] | Risk free interest rate [Member]    
Fair Value Measurement Inputs and Valuation Techniques [Line Items]    
Weighted Average Unobservable Inputs 2.60% 2.07%-2.44%
Senior Secured Convertible Promissory Notes [Member] | Expected term [Member]    
Fair Value Measurement Inputs and Valuation Techniques [Line Items]    
Weighted Average Unobservable Inputs 1 year