| Document and Entity Information | Oct. 08, 2021 |
| Cover [Abstract] | |
| Amendment Flag | false |
| Entity Central Index Key | 0001844971 |
| Document Type | 8-K |
| Document Period End Date | Oct. 8, 2021 |
| Entity Registrant Name | GREENIDGE GENERATION HOLDINGS INC. |
| Entity Incorporation State Country Code | DE |
| Entity File Number | 001-40808 |
| Entity Tax Identification Number | 86-1746728 |
| Entity Address, Address Line One | 590 Plant Road |
| Entity Address, City or Town | Dresden |
| Entity Address, State or Province | NY |
| Entity Address, Postal Zip Code | 14441 |
| City Area Code | (315) |
| Local Phone Number | 536-2359 |
| Written Communications | false |
| Soliciting Material | false |
| Pre Commencement Tender Offer | false |
| Pre Commencement Issuer Tender Offer | false |
| Security 12b Title | Class A Common Stock, par value $0.0001 per share |
| Trading Symbol | GREE |
| Security Exchange Name | NASDAQ |
| Entity Emerging Growth Company | true |
| Entity Ex Transition Period | false |
