FAIR VALUE MEASUREMENT (Details 2) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended		12 Months Ended
	Sep. 30, 2021	Sep. 30, 2020	Sep. 30, 2021	Sep. 30, 2020	Dec. 31, 2020
Fair Value Disclosures [Abstract]
Balance at January 1			$ 56,780	$ 17,111	$ 17,111
Issuance of warrants			0		1,221
Reclassification of warrant to common stocks to equity			0		(3,057)
Reclassification of warrant to common stocks to mezzanine equity			(1,149)		0
Change in fair value of warrants	$ 16,822	$ 0	15,046	$ 10,034	41,505
Conversion of warrants to common stock upon initial public offering	(70,677)		(70,677)
Balance at the end of the period	$ 0		$ 0		$ 56,780