EARNINGS (LOSS) PER SHARE - Schedule of EPS (Details) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended						9 Months Ended
	Sep. 30, 2021	Jun. 30, 2021	Mar. 31, 2021	Sep. 30, 2020	Jun. 30, 2020	Mar. 31, 2020	Sep. 30, 2021	Sep. 30, 2020
Numerator:
Net income (loss)	$ 71,674	$ (25,442)	$ (55,512)	$ (22,608)	$ (26,344)	$ 41,564	$ (9,280)	$ (7,388)
Less: Deemed Dividend	0			0			0	(147)
Less: Income attributable to participating securities - basic	(52)			0			0	0
Net Income (Loss) Available to Common Stockholders, Basic, Total	$ 71,622			$ (22,608)			$ (9,280)	$ (7,535)
Denominator:
Weighted-average common shares outstanding - basic (in shares)	196,778,000			117,886,000			176,547,000	113,437,000
Net (loss) per common share - basic (in dollars per share)	$ 0.36			$ (0.19)			$ (0.05)	$ (0.07)
Dilutive Earnings (Loss) Per Share:
Less: Income attributable to participating securities - diluted	$ (51)			$ 0			$ 0	$ 0
Net income (loss) attributable to common stockholders - diluted	$ 71,623			$ (22,608)			$ (9,280)	$ (7,535)
Denominator:
Stock options and employee stock purchase plan (in shares)	4,239,000			0			0	0
Weighted-average common shares outstanding for diluted (in shares)	201,017,000			117,886,000			176,547,000	113,437,000
Net (loss) income per common share - diluted (in dollars per share)	$ 0.36			$ (0.19)			$ (0.05)	$ (0.07)
Potentially dilutive securities outstanding
Common stock equivalents excluded from calculation of diluted net (loss) income per share (in shares)	11,328,000			12,712,000			15,710,000	12,712,000
Warrants
Potentially dilutive securities outstanding
Common stock equivalents excluded from calculation of diluted net (loss) income per share (in shares)	55,000			2,485,000			199,000	2,485,000
Stock options
Potentially dilutive securities outstanding
Common stock equivalents excluded from calculation of diluted net (loss) income per share (in shares)	11,273,000			10,227,000			15,511,000	10,227,000