Long-lived Assets (Property And Equipment, net) by Geographic Area (Detail) - USD ($) $ in Thousands	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
Revenues from External Customers and Long-Lived Assets [Line Items]
Property and equipment, net	$ 124,478	$ 105,496	$ 98,488
Taiwan
Revenues from External Customers and Long-Lived Assets [Line Items]
Property and equipment, net	111,341	102,420	94,996
China
Revenues from External Customers and Long-Lived Assets [Line Items]
Property and equipment, net	12,518	2,770	3,117
Others
Revenues from External Customers and Long-Lived Assets [Line Items]
Property and equipment, net	$ 619	$ 306	$ 375

Amount after accumulated depreciation, depletion and amortization of physical assets used in the normal conduct of business to produce goods and services and not intended for resale. Examples include, but are not limited to, land, buildings, machinery and equipment, office equipment, and furniture and fixtures.

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Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
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