Basis of presentation, principles of consolidation and significant accounting policies - Fair Value of Warrant Liability (Details) - Recurring - USD ($) $ in Thousands |
Sep. 30, 2019 |
Dec. 31, 2018 |
---|---|---|
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis | ||
Fair value of derivative liability | $ 6,820 | $ 1,508 |
Quoted Pricesin ActiveMarkets forIdenticalAssets (Level 1) | ||
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis | ||
Fair value of derivative liability | 0 | 0 |
Significant OtherObservable Inputs(Level 2) | ||
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis | ||
Fair value of derivative liability | 0 | 0 |
Significant OtherUnobservable Inputs(Level 3) | ||
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis | ||
Fair value of derivative liability | $ 6,820 | $ 1,508 |