Operating leases - Lease costs (Q3) (Details) - USD ($) $ in Thousands |
3 Months Ended | 9 Months Ended | 12 Months Ended | |||
|---|---|---|---|---|---|---|
Sep. 30, 2020 |
Sep. 30, 2019 |
Sep. 30, 2020 |
Sep. 30, 2019 |
Dec. 31, 2019 |
Dec. 31, 2018 |
|
| Operating leases [Abstract] | ||||||
| Operating lease costs | $ 110 | $ 95 | $ 331 | $ 219 | $ 369 | $ 189 |
| Variable lease costs | 11 | 8 | 27 | 24 | 31 | 42 |
| Total operating lease costs | $ 121 | 103 | $ 358 | 243 | $ 400 | 231 |
| Weighted-average remaining operating lease term | 1 year 10 months 24 days | 1 year 10 months 24 days | 2 years 7 months 6 days | |||
| Incremental borrowing rate for operating leases | 12.50% | 12.50% | 12.50% | |||
| Short term lease costs | 100 | $ 100 | 100 | $ 100 | ||
| Rent expense | $ 200 | $ 200 | $ 400 | $ 300 | $ 41 | $ 0 |
| X | ||||||||||
- Definition Amount of lease cost recognized by lessee for lease contract. Reference 1: http://www.xbrl.org/2003/role/disclosureRef
|
| X | ||||||||||
- References No definition available.
|
| X | ||||||||||
- Definition Amount of single lease cost, calculated by allocation of remaining cost of lease over remaining lease term. Includes, but is not limited to, single lease cost, after impairment of right-of-use asset, calculated by amortization of remaining right-of-use asset and accretion of lease liability. Reference 1: http://www.xbrl.org/2003/role/exampleRef
|
| X | ||||||||||
- Definition Amount of operating lease expense. Excludes sublease income. Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef
|
| X | ||||||||||
- Definition Weighted average discount rate for operating lease calculated at point in time. Reference 1: http://www.xbrl.org/2003/role/disclosureRef
|
| X | ||||||||||
- Definition Weighted average remaining lease term for operating lease, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents reported fact of one year, five months, and thirteen days. Reference 1: http://www.xbrl.org/2003/role/exampleRef
|
| X | ||||||||||
- Definition Amount of short-term lease cost, excluding expense for lease with term of one month or less. Reference 1: http://www.xbrl.org/2003/role/disclosureRef
|
| X | ||||||||||
- Definition Amount of variable lease cost, excluded from lease liability, recognized when obligation for payment is incurred for finance and operating leases. Reference 1: http://www.xbrl.org/2003/role/disclosureRef
|