Income Taxes - Components of Comprehensive Provision for Income Taxes Allocation (Detail) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2021	Sep. 30, 2020	Sep. 30, 2021	Sep. 30, 2020
Comprehensive provision (benefit) for income taxes allocable to:
Net income (loss)	$ 1,054	$ 1,163	$ 5,460	$ (3,616)
Additional paid-in capital				(100)
Other comprehensive income (loss):
Currency translation	(500)	600	(200)	(900)
Total	900	2,000	6,200	(3,800)
Defined Benefit Pension Plans
Other comprehensive income (loss):
Defined benefit plans	$ 300	$ 200	$ 900	$ 800