Note 7 - Debt - Revolving Credit Facility (Details) - Revolving loans under the new facility - USD ($) $ in Millions	Feb. 15, 2023	Dec. 31, 2023
Debt
Initial aggregate revolving commitment	$ 125.0	$ 91.1
Amount borrowed under accordian feature	$ 50.0
Outstanding borrowings		42.5
Fixed charge coverage ratio	1.10
Average daily cash balance	$ 5.0
Line of Credit Facility, Remaining Borrowing Capacity		$ 48.6
Additional amount to be maintained in a separate dedicated account	$ 1.0
Secured overnight financing rate
Debt
Interest rate, basis spread	2.00%
Base Rate
Debt
Interest rate, basis spread	1.50%
Debt instrument, interest rate during period	3.00%
Federal funds
Debt
Interest rate, basis spread	0.50%

Amount of average additional daily cash balance to be maintained.

No definition available.

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Balance Type:	debit
Period Type:	duration

- Definition

Amount of average daily cash balance to be maintained.

+ References

No definition available.

+ Details

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Namespace Prefix:	metc_
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Balance Type:	debit
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- Definition

Fixed charge coverage ratio .

+ References

No definition available.

+ Details

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- Definition

Amount borrowed as accodian feature under line of credit facility.

+ References

No definition available.

+ Details

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Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- Definition

Amount of borrowings base of initial aggregate revolving commitment under line of credit facility.

+ References

No definition available.

+ Details

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Period Type:	instant

- Definition

Percentage points added to the reference rate to compute the variable rate on the debt instrument.

+ References

No definition available.

+ Details

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- Definition

The average effective interest rate during the reporting period.

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Topic 470
-SubTopic 20
-Name Accounting Standards Codification
-Section 50
-Paragraph 1F
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-Publisher FASB
-URI https://asc.fasb.org//1943274/2147481139/470-20-50-1F

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-Name Accounting Standards Codification
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-Section 45
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Reference 3: http://fasb.org/us-gaap/role/ref/legacyRef
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- Definition

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.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Name Accounting Standards Codification
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Reference 2: http://www.xbrl.org/2009/role/commonPracticeRef
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+ Details

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Balance Type:	credit
Period Type:	instant

- Definition

Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table.

+ References

Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef
-Topic 235
-SubTopic 10
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-Publisher FASB
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+ Details

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- Definition

Amount of borrowing capacity currently available under the credit facility (current borrowing capacity less the amount of borrowings outstanding).

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Name Accounting Standards Codification
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