Quarterly report pursuant to Section 13 or 15(d)

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

v3.19.1
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
Mar. 31, 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% 113.7%
Risk free interest rate [Member] | Warrant [Member]    
Fair Value Measurement Inputs and Valuation Techniques [Line Items]    
Weighted Average Unobservable Inputs 2.58% 2.23%
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%
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% 118.0%
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% 2.41%
Senior Secured Convertible Promissory Notes [Member] | Expected term [Member]    
Fair Value Measurement Inputs and Valuation Techniques [Line Items]    
Weighted Average Unobservable Inputs 1 year 10 months