Income Taxes - Components of Comprehensive Provision for Income Taxes Allocation (Detail) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2019	Sep. 30, 2018	Sep. 30, 2019	Sep. 30, 2018
Comprehensive provision for income taxes (benefit) allocable to:
Net income (loss)	$ (2,286)	$ (6,158)	$ 942	$ (15,416)
Additional paid-in capital	(200)		(200)
Other comprehensive income (loss):
Currency translation	(1,200)	300	(700)	(600)
Total	(3,500)	(5,600)	600	(15,300)
OPEB
Other comprehensive income (loss):
Defined benefit plans	(100)	(100)	(100)	(100)
Defined Benefit Pension Plans
Other comprehensive income (loss):
Defined benefit plans	$ 300	$ 300	$ 700	$ 800