FAIR VALUE CONVERTIBLE PROMISSORY NOTES (Details) - USD ($) $ in Thousands	Sep. 30, 2021	Dec. 31, 2020
PREPAID EXPENSES AND OTHER ASSETS
Series A subordinated convertible note at fair value	$ 3,109	$ 7,010
Series B subordinated convertible note at fair value	11,583	11,674
Total convertible promissory notes	14,692	18,684
Less: Investor Note offset - Series B Note	(5,000)	(5,000)
Carrying value of convertible promissory notes at fair value	9,692	13,684
Less: current portion of convertible promissory notes at fair value	(6,583)	(6,674)
Convertible promissory notes, less current portion	$ 3,109	$ 7,010