Deferred Tax Assets and Deferred Tax Liabilities (Detail) - USD ($) $ in Thousands	Dec. 31, 2015	Dec. 31, 2014
Deferred tax assets:
Derivative financial instruments	$ 267	$ 2,461
Net operating losses	5,525	7,075
Research and development credits	21,494	26,204
Depreciation	3,886	3,456
Valuation reserves and accrued liabilities	5,553	4,788
Foreign tax credit	1,654	823
Stock compensation	3,129	2,006
Inventory	1,622	1,443
Patents	156	138
Defined benefit obligation	2,011	1,479
Other credits	639	593
Other	10	144
Deferred tax assets, gross	45,946	50,610
Valuation allowance	(13,418)	(18,037)
Deferred tax liabilities:
Intangible assets	(10,161)	(14,593)
Unrealized foreign currency exchange gains	(3,797)	(2,855)
Undistributed profits of subsidiary	(3,254)	(293)
Property and equipment	(696)	(162)
Other	(342)	(384)
Deferred tax liabilities, gross	(18,250)	(18,287)
Net deferred tax asset (liability)	$ 14,278	$ 14,286