| SEGMENT INFORMATION - Long-live Assets by Geographic Area (Details) - USD ($) $ in Thousands | Dec. 31, 2019 | Dec. 31, 2018 | 
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| Segment Reporting Information [Line Items] | ||
| Total long-lived assets | $ 735 | $ 934 | 
| United States | ||
| Segment Reporting Information [Line Items] | ||
| Total long-lived assets | 379 | 521 | 
| Hong Kong | ||
| Segment Reporting Information [Line Items] | ||
| Total long-lived assets | 135 | 145 | 
| China | ||
| Segment Reporting Information [Line Items] | ||
| Total long-lived assets | 57 | 61 | 
| Other foreign countries | ||
| Segment Reporting Information [Line Items] | ||
| Total long-lived assets | $ 164 | $ 207 | 
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- Definition Long-lived assets other than financial instruments, long-term customer relationships of a financial institution, mortgage and other servicing rights, deferred policy acquisition costs, and deferred tax assets. Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef 
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- Definition Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table. No definition available. 
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