Income taxes - Components of Comprehensive Provision (Benefit) for Income Taxes Allocation (Details) - USD ($) $ in Thousands	3 Months Ended	6 Months Ended
Jun. 30, 2026	Jun. 30, 2025	Jun. 30, 2026	Jun. 30, 2025
Comprehensive provision for income taxes allocable to:
Income tax expense	$ 2,462	$ (43)	$ 3,934	$ (66)
Additional paid-in capital	21	8	21	8
Other comprehensive income (loss):
Currency translation	(277)	914	(7)	2,026
Other	1	(9)	1	(18)
Comprehensive income tax expense	2,230	955	3,995	2,120
Pension Plan
Other comprehensive income (loss):
Defined benefit pension plans	$ 23	$ 85	$ 46	$ 170

Amount of current income tax expense (benefit) and deferred income tax expense (benefit) pertaining to continuing operations.

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