Income Taxes - Deferred Tax Assets and Deferred Tax Liabilities (Detail) - USD ($) $ in Thousands	Dec. 31, 2020	Dec. 31, 2019
Deferred tax assets:
Net operating losses	$ 22,658	$ 17,881
Intangible assets	29,145	33,743
Research and development credits	10,773	9,752
Depreciation	7,426	7,223
Valuation reserves and accrued liabilities	7,131	7,196
Stock compensation	4,200	3,485
Defined benefit obligation	1,974	2,027
Inventory	1,571	1,284
Other credits	12,068	11,753
Unrealized foreign currency exchange loss	1,431
Other	64	113
Total deferred tax asset	98,441	94,457
Valuation allowance	(17,197)	(17,316)
Deferred tax liabilities:
Unrealized foreign currency exchange gains		(674)
Undistributed profits of subsidiary	(5,727)	(4,629)
Property and equipment	(2,758)	(3,366)
Other	(572)	(733)
Total deferred tax liability	(9,057)	(9,402)
Net deferred tax asset	$ 72,187	$ 67,739