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Pension Benefits - Additional Information (Detail)	12 Months Ended
	Dec. 31, 2019 USD ($)	Dec. 31, 2019 TWD ($)	Dec. 31, 2019 HKD ($)	Dec. 31, 2018 USD ($)	Dec. 31, 2017 USD ($)
Defined Benefit Plan Disclosure [Line Items]
Accumulated benefit obligation	$ 238,000			$ 233,000
Prepaid pension	85,000			56,000
Fair value of plan assets	411,000			376,000
Accumulated other comprehensive loss	(66,000)			(86,000)
Net periodic benefit cost	2,000			1,000	$ 0
Defined benefit plan, expected contribution in 2020	8,000
Expected future benefit payments from 2020 to 2024	1,000
Expected future benefit payments from 2025 to 2029	$ 14,000
Hong Kong
Defined Benefit Plan Disclosure [Line Items]
Percentage of salaries and wages contributed	5.00%	5.00%	5.00%
Pension Plan | Operating Expenses
Defined Benefit Plan Disclosure [Line Items]
Total amount of defined contribution pension expenses	$ 187,000			$ 210,000	$ 190,000
Pension Plan | Taiwan
Defined Benefit Plan Disclosure [Line Items]
Percentage of salaries and wages contributed	2.00%	2.00%	2.00%
Maximum
Defined Benefit Plan Disclosure [Line Items]
Lump sum retirement benefit, equivalent months of pensionable salary	45 months	45 months	45 months
Maximum | Taiwan | Monthly Payment
Defined Benefit Plan Disclosure [Line Items]
Maximum monthly contribution for each employee	$ 300	$ 9,000
Maximum | Hong Kong | Monthly Payment
Defined Benefit Plan Disclosure [Line Items]
Maximum monthly contribution for each employee	$ 193		$ 1,500
Minimum | Pension Plan | Taiwan
Defined Benefit Plan Disclosure [Line Items]
Percentage of salaries and wages contributed	6.00%	6.00%	6.00%
For each of first 15 years of service
Defined Benefit Plan Disclosure [Line Items]
Lump sum retirement benefit, equivalent months of pensionable salary	2 months	2 months	2 months
For each year of service thereafter
Defined Benefit Plan Disclosure [Line Items]
Lump sum retirement benefit, equivalent months of pensionable salary	1 month	1 month	1 month

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