FAIR VALUE OF FINANCIAL INSTRUMENTS - NARRATIVE (Details) $ in Thousands	3 Months Ended	9 Months Ended
	Sep. 30, 2021 USD ($)	Sep. 30, 2021 USD ($)	Feb. 28, 2021 tranche
Convertible notes
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Total loss due to changes in fair value | $	$ (27,800)	$ (1,918,565)
Warrants
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Total loss due to changes in fair value | $	$ 2,500	$ (127,092)
Convertible notes
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Number of tranches issued | tranche			2
Convertible notes | Investor
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Number of tranches issued | tranche			2