FAIR VALUE MEASUREMENTS - EQUITY INVESTMENT (Details) - Equity Investment - USD ($)	3 Months Ended
Mar. 31, 2019	Mar. 31, 2018	Dec. 31, 2007
Equity Investments [Line Item]
Number of shares owned			13,842,625
Cost method investments cost basis			$ 0
Fair value of equity investment	$ 688,000
Increase (decrease) in fair value of equity investment	98,000	$ (108,000)
Gain (loss) related to foreign currency translation	$ 5,000	$ (17,000)

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Amount of increase (decrease) of investment in equity security measured at fair value with change in fair value recognized in net income (FV-NI).

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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.

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