Income taxes - Components of Comprehensive Provision (Benefit) for Income Taxes Allocation (Detail) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2024	Jun. 30, 2023	Jun. 30, 2024	Jun. 30, 2023
Comprehensive provision (benefit) for income taxes allocable to:
Net income (loss)	$ 1,302	$ (7,300)	$ 2,290	$ (5,879)
Additional paid-in capital	8	110	8	18
Other comprehensive income (loss):
Currency translation	124	(371)	(1,196)	(814)
Other	(11)	(50)	(19)	(84)
Total	1,524	(7,316)	1,285	(6,360)
Defined Benefit Pension Plans
Other comprehensive income (loss):
Pension plans	$ 101	$ 295	$ 202	$ 399