Warrant derivative liability - Fair value of warrant derivative liability (Q3) (Details) - USD ($) $ in Thousands |
3 Months Ended | 9 Months Ended | 12 Months Ended | ||||
|---|---|---|---|---|---|---|---|
Sep. 30, 2020 |
Jun. 30, 2020 |
Mar. 31, 2020 |
Sep. 30, 2020 |
Sep. 30, 2019 |
Dec. 31, 2019 |
Dec. 31, 2018 |
|
| Warrant Liability [Roll Forward] | |||||||
| Balance, beginning of period | $ 4,315 | $ 841 | $ 2,220 | $ 2,220 | $ 0 | $ 0 | |
| Change in fair value of derivative liability | (4,213) | 3,474 | (1,379) | (2,118) | $ (886) | 90 | $ 0 |
| Balance as of period end | $ 102 | $ 4,315 | $ 841 | $ 102 | $ 2,220 | $ 0 | |
| X | ||||||||||
- Definition Warrant Liability No definition available.
|
| X | ||||||||||
- Definition Fair value, after the effects of master netting arrangements, of a financial liability or contract with one or more underlyings, notional amount or payment provision or both, and the contract can be net settled by means outside the contract or delivery of an asset, expected to be settled within one year or normal operating cycle, if longer. Includes assets not subject to a master netting arrangement and not elected to be offset. Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
|
| X | ||||||||||
- Definition Amount of expense (income) related to adjustment to fair value of warrant liability. Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
|