MERGER WITH SUPPORT - Summary of Supplemental Pro Forma Financial Information (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended		9 Months Ended
	Sep. 30, 2021	Sep. 30, 2020	Jun. 30, 2021	Jun. 30, 2020	Sep. 30, 2021	Sep. 30, 2020
Business Acquisition [Line Items]
Net (loss) income	$ (7,896)	$ (289)	$ 4,797	$ (2,177)	$ (3,099)	$ (2,466)
Greenidge Generation Holdings Inc [Member]
Business Acquisition [Line Items]
Revenues	42,448	16,461			87,830	47,258
Net (loss) income	$ (11,783)	$ (1,646)			$ (12,602)	$ (6,274)