Intangible assets - Rollforward (Details) - USD ($) $ in Thousands |
12 Months Ended | |
|---|---|---|
Dec. 31, 2023 |
Dec. 31, 2022 |
|
| Reconciliation of Changes in Intangible assets [Roll Forward] | ||
| Beginning balance | $ 5,214 | $ 20,788 |
| Additions to intangible assets | 154 | 550 |
| Amortization expense | (1,696) | (3,107) |
| Impairment charges on intangible assets | (2,266) | (13,017) |
| Ending balance | 1,406 | 5,214 |
| Cost | ||
| Reconciliation of Changes in Intangible assets [Roll Forward] | ||
| Beginning balance | 79,227 | 78,677 |
| Additions to intangible assets | 154 | 550 |
| Amortization expense | 0 | 0 |
| Impairment charges on intangible assets | 0 | 0 |
| Ending balance | 79,381 | 79,227 |
| Accumulated amortization | ||
| Reconciliation of Changes in Intangible assets [Roll Forward] | ||
| Beginning balance | (74,013) | (57,889) |
| Additions to intangible assets | 0 | 0 |
| Amortization expense | 1,696 | 3,107 |
| Impairment charges on intangible assets | (2,266) | (13,017) |
| Ending balance | $ (77,975) | $ (74,013) |