Income tax - Expense (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2025	Dec. 31, 2024	Dec. 31, 2023
Major components of tax expense (income) [abstract]
Current tax (expense) / income	$ (2,716)	$ (2,152)	$ (3,244)
Deferred tax (expense) / income	1,302	606	2,583
Total Income tax (expense) / income	$ (1,414)	$ (1,546)	$ (661)