SUPPLEMENTAL BALANCE SHEET AND CASH FLOW INFORMATION - Summary of noncash investing and financing activities (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020
Disclosure Text Block Supplement [Abstract]
Shares issued to Support.com shareholders upon Merger (Notes 3 and 9)	$ 93,885	$ 0
Stock issued to purchase miners	991	0
Contribution of Preferred Units, Senior Priority Units, and Notes Payable to Related Party for Greenidge Class B common stock	72,048	0
Issuance of shares for investor fee associated with successful completion of Merger (Notes 4 and 9)	17,826	0
Issuance of warrants to advisor in connection with completion of Merger (Note 4 and 9)	8,779	0
Property and equipment purchases financed with accounts payable	0	4,910
Property and equipment purchases in accounts payable	2,769	1,120
Property and equipment purchased with digital assets	0	787
Notes payable principal and interest converted to members	0	13,926
Deemed distribution of GC preferred units	0	1,276
Contribution of GC preferred units	$ 0	$ 15,000