Quarterly report pursuant to Section 13 or 15(d)

Fair Value Measurements - Summary of changes in fair value of the Company's derivative liability measured at fair value using significant unobservable inputs (Level 3) (Details)

v3.19.3
Fair Value Measurements - Summary of changes in fair value of the Company's derivative liability measured at fair value using significant unobservable inputs (Level 3) (Details) - Derivative [Member] - USD ($)
$ in Thousands
3 Months Ended 9 Months Ended
Sep. 30, 2019
Sep. 30, 2018
Sep. 30, 2019
Sep. 30, 2018
Beginning balance $ 387 $ 25,776 $ 0 $ 20,832
Additions 0 6,328 216 7,886
Change in fair value 0 10,908 171 14,294
Reclassification to equity at initial public offering 0 (43,012) 0 (43,012)
Ending balance $ 387 $ 0 $ 387 $ 0