Stockholders' equity - Schedule of Changes in Accumulated Other Comprehensive Loss (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2026	Mar. 31, 2025
Accumulated Other Comprehensive Income Loss
Balance at beginning of period	$ 358,769
Balance at end of period	359,329
Currency translation
Accumulated Other Comprehensive Income Loss
Balance at beginning of period	(177,512)	$ (185,423)
Other comprehensive income (loss)	1,015	4,185
Balance at end of period	(176,497)	(181,238)
Defined benefit pension plans | Defined benefit pension plans
Accumulated Other Comprehensive Income Loss
Balance at beginning of period	(17,359)	(36,666)
Other comprehensive income (loss)	86	317
Balance at end of period	(17,273)	(36,349)
Other | OPEB plans
Accumulated Other Comprehensive Income Loss
Balance at beginning of period	(1,196)	(1,267)
Other comprehensive income (loss)	1	(33)
Balance at end of period	(1,195)	(1,300)
Total accumulated other comprehensive loss
Accumulated Other Comprehensive Income Loss
Balance at beginning of period	(196,067)	(223,356)
Other comprehensive income (loss)	1,102	4,469
Balance at end of period	$ (194,965)	$ (218,887)