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FAIR VALUE MEASUREMENTS - EQUITY INVESTMENT (Details) - Sienna - Equity Investment - USD ($)		3 Months Ended	6 Months Ended
	Aug. 03, 2017	Jun. 30, 2018	Jun. 30, 2018	Jan. 01, 2018	Dec. 31, 2017	Dec. 31, 2007
Equity Investments [Line Item]
Number of shares owned						13,842,625
Cost method investment, original cost					$ 0	$ 0
Trading restriction period	24 months
Fair value of equity investment		$ 676,000	$ 676,000
Change in fair value of equity investment		388,000	513,000
Loss related to foreign currency translation		$ 38,000	$ 38,000
Accounting Standards Update 2016-01 and 2018-03
Equity Investments [Line Item]
Cumulative effect adjustment				$ 1,189,000

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