Restructuring - Summary of Restructuring Accrual Activity (Detail) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019
Restructuring Cost And Reserve [Line Items]
Beginning balance	$ 45	$ 77
Restructuring expenses	124	507
Payments made	(242)	(638)
Payments received	88	99
Ending balance	15	45
China Restructuring Severance [Member]
Restructuring Cost And Reserve [Line Items]
Beginning balance	12	0
Restructuring expenses	124	507
Payments made	(136)	(495)
Payments received	0	0
Ending balance	0	12
Lease Terminations [Member]
Restructuring Cost And Reserve [Line Items]
Beginning balance	33	77
Restructuring expenses	0	0
Payments made	(106)	(143)
Payments received	88	99
Ending balance	$ 15	$ 33