Summary of significant accounting policies (Details) - USD ($) $ in Thousands |
12 Months Ended | |
|---|---|---|
Dec. 31, 2024 |
Dec. 31, 2023 |
|
| Summary of significant accounting policies | ||
| Contract revenue on uncompleted contracts as beginning balance | $ 4,022 | $ 523 |
| New contract awards during the year | 5,621 | 9,044 |
| Contract adjustment | 30 | 252 |
| Contract revenue recognized for the year | (5,834) | (5,797) |
| Backlog as ending balance | $ 3,839 | $ 4,022 |