Income taxes - Components of Comprehensive Provision for Income Taxes Allocation (Detail) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2022	Sep. 30, 2021	Sep. 30, 2022	Sep. 30, 2021
Comprehensive provision for income taxes allocable to:
Net income	$ (5,576)	$ 1,054	$ 3,564	$ 5,460
Additional paid-in capital			100
Other comprehensive income:
Currency translation	(1,700)	(500)	(3,600)	(200)
Total	(7,000)	900	800	6,200
Defined Benefit Pension Plans
Other comprehensive income:
Defined benefit plans	$ 200	$ 300	$ 700	$ 900