Discount rate on asset retirement obligations.

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Discount rate on environmental trust liability during current period.

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Emissions expense .

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Environmental trust liability.

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Number of digital assets.

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Percentage of annual emission expense and credit in the following year.

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Revenue term period .

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Voluntary carbon offset credits amount.

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Amount of direct write-downs of accounts receivable charged against the allowance.

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The carrying amount of a liability for an asset retirement obligation. An asset retirement obligation is a legal obligation associated with the disposal or retirement of a tangible long-lived asset that results from the acquisition, construction or development, or the normal operations of a long-lived asset, except for certain obligations of lessees.

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Amount of accretion expense recognized during the period that is associated with an asset retirement obligation. Accretion expense measures and incorporates changes due to the passage of time into the carrying amount of the liability.

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The carrying amount of the asset transferred to a third party to serve as a deposit, which typically serves as security against failure by the transferor to perform under terms of an agreement.

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Carrying amount of assets as of the balance sheet date pertaining to amounts paid by the insured (including a ceding company) under insurance or reinsurance contracts for which insurance risk is not transferred.

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The aggregate amount of write-downs for impairments recognized during the period for long-lived assets held for abandonment, exchange or sale.

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Amount of current income tax expense (benefit) and deferred income tax expense (benefit) pertaining to continuing operations.

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The carrying value as of the balance sheet date of the current and noncurrent portions of long-term obligations drawn from a line of credit, which is a bank's commitment to make loans up to a specific amount. Examples of items that might be included in the application of this element may consist of letters of credit, standby letters of credit, and revolving credit arrangements, under which borrowings can be made up to a maximum amount as of any point in time conditional on satisfaction of specified terms before, as of and after the date of drawdowns on the line. Includes short-term obligations that would normally be classified as current liabilities but for which (a) postbalance sheet date issuance of a long term obligation to refinance the short term obligation on a long term basis, or (b) the enterprise has entered into a financing agreement that clearly permits the enterprise to refinance the short-term obligation on a long term basis and the following conditions are met (1) the agreement does not expire within 1 year and is not cancelable by the lender except for violation of an objectively determinable provision, (2) no violation exists at the BS date, and (3) the lender has entered into the financing agreement is expected to be financially capable of honoring the agreement.

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The total expense recognized in the period for promotion, public relations, and brand or product advertising.

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Period over which grantee's right to exercise award under share-based payment arrangement is no longer contingent on satisfaction of service or performance condition, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents reported fact of one year, five months, and thirteen days. Includes, but is not limited to, combination of market, performance or service condition.

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Period from grant date that an equity-based award expires, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents the reported fact of one year, five months, and thirteen days.

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Number of shares of stock issued during the period pursuant to acquisitions.

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Number of shares issued during the period as a result of a stock split.

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Description of the stock split arrangement. Also provide the retroactive effect given by a stock split that occurs after the balance date but before the release of financial statements.

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SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES - Additional Information (Detail) $ in Thousands		1 Months Ended		3 Months Ended		6 Months Ended		12 Months Ended
	Jan. 29, 2021 shares	Mar. 31, 2021 shares	Jan. 31, 2021 shares	Jun. 30, 2021 USD ($)	Jun. 30, 2020 USD ($)	Jun. 30, 2021 USD ($)	Jun. 30, 2020 USD ($)	Dec. 31, 2020 USD ($) Bitcoins	Dec. 31, 2019 USD ($) Bitcoins	Dec. 31, 2018 USD ($)
Accounts receivable write off as uncollectible								$ 0	$ 0
Impairment Loss									100
Cash deposit								100
Deposit Contracts, Assets								$ 74	510
Percentage of annual emission expense and credit in the following year				50.00%		50.00%		50.00%
Asset retirement obligation				$ 2,345		$ 2,345		$ 2,277	2,135	$ 0
Discount rate on asset retirement obligations				5.00%		5.00%		5.00%
Discount rate on environmental trust liability during current period				4.50%		4.50%		4.50%
Environmental trust liability				$ 4,994		$ 4,994		$ 4,927	4,697
Provision for income taxes				1,397		2,129		0	0
Advertising and promotional costs								117	$ 0
Asset retirement obligation expense						$ 68	$ 74	$ 142
Share based compensation arrangement,expiration period						10 years
Vesting period						3 years
Stockholders equity note stock split	4-for-1	4-for-1
Number of digital assets \| Bitcoins								26.1	38.9
Impairment Of Long Lived Assets
Impairment Loss								$ 0	$ 0
Digital Assets
Impairment Loss								$ 100
New York [Member]
Purchase of voluntary carbon offset credits				684
Greenidge Common Stock [Member]
Shares issued in exchange for acquisition of ownership interests \| shares	7,000,000		7,000,000
Hash Rate Revenue [Member] \| Maximum [Member]
Revenue term period								180 days
Hash Rate Revenue [Member] \| Minimum [Member]
Revenue term period								30 days
Letter of Credit [Member]
Long-term Line of Credit				4,994		$ 4,994		$ 4,938	4,938
Cost of Sales [Member]
Emissions expense				402	$ 309	815	473	$ 1,738	$ 206
Other Income And Expense [Member]
Asset retirement obligation expense				$ 35	$ 32	$ 68	$ 74
GGHI Class B Common Stock [Member]
Number of shares after split \| shares	28,000,000	28,000,000