ACCOUNTS RECEIVABLE AND NOTES RECEIVABLE, NET OF ALLOWANCE - Notes Receivable, Net of Allowance for Credit Loss (Details) - USD ($) $ in Thousands	Jun. 30, 2021	Dec. 31, 2020
Receivables [Abstract]
Notes receivable, current	$ 630	$ 710
Allowance for credit losses	(215)	(244)
Net current	415	466
Notes receivable, long-term	921	816
Allowance for credit losses	(327)	(295)
Net long-term	$ 594	$ 521

Amount of allowance for credit loss on financing receivable, classified as current.

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