Income taxes - Valuation allowance (Details) - USD ($) |
12 Months Ended | |
|---|---|---|
Dec. 31, 2020 |
Dec. 31, 2019 |
|
| Valuation Allowance [Abstract] | ||
| Valuation allowance, at beginning of year | $ 7,913,000 | $ 0 |
| Increase in valuation allowance | 8,811,000 | 7,892,000 |
| Halo Acquisition | 0 | 21,000 |
| Valuation allowance, at end of year | 16,724,000 | 7,913,000 |
| Accrued interest and penalties | $ 0 | $ 0 |
| X | ||||||||||
- Definition Amount of increase in valuation allowance for deferred tax assets arising from acquisition. No definition available.
|
| X | ||||||||||
- Definition Amount of deferred tax assets for which it is more likely than not that a tax benefit will not be realized. Reference 1: http://www.xbrl.org/2003/role/disclosureRef
|
| X | ||||||||||
- Definition Amount accrued for interest on an underpayment of income taxes and penalties related to a tax position claimed or expected to be claimed in the tax return. Reference 1: http://www.xbrl.org/2003/role/disclosureRef
|
| X | ||||||||||
- References No definition available.
|
| X | ||||||||||
- Definition Amount of increase (decrease) in the valuation allowance for a specified deferred tax asset. Reference 1: http://www.xbrl.org/2003/role/disclosureRef
|