Refers to the average fixed sales price per ton.

No definition available.

Name:	metc_ContractsWithFixedSalesPricesAverage
Namespace Prefix:	metc_
Data Type:	srt-types:perUnitItemType
Balance Type:	na
Period Type:	duration

- Definition

Represents the number of major customers accounting for 10% or more of the specified concentration risk benchmark, which includes, but not limited to, sales revenue, accounts receivable, etc.

+ References

No definition available.

+ Details

Name:	metc_NumberOfMajorCustomers
Namespace Prefix:	metc_
Data Type:	xbrli:integerItemType
Balance Type:	na
Period Type:	duration

- Definition

Represents the percentage of committed tons.

+ References

No definition available.

+ Details

Name:	metc_PercentageOfCommittedTons
Namespace Prefix:	metc_
Data Type:	dtr-types:percentItemType
Balance Type:	na
Period Type:	duration

- Definition

Refers to the term of sales contract.

+ References

No definition available.

+ Details

Name:	metc_RevenueContractTerm
Namespace Prefix:	metc_
Data Type:	xbrli:durationItemType
Balance Type:	na
Period Type:	duration

- Definition

Mass of product allocated to performance obligation.

+ References

No definition available.

+ Details

Name:	metc_RevenueRemainingPerformanceObligationMass
Namespace Prefix:	metc_
Data Type:	dtr-types:massItemType
Balance Type:	na
Period Type:	instant

- Definition

For an entity that discloses a concentration risk in relation to quantitative amount, which serves as the "benchmark" (or denominator) in the equation, this concept represents the concentration percentage derived from the division.

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Topic 280
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 42
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147482810/280-10-50-42

Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef
-Name Accounting Standards Codification
-Topic 825
-SubTopic 10
-Section 50
-Paragraph 21
-Subparagraph (a)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147482907/825-10-50-21

Reference 3: http://fasb.org/us-gaap/role/ref/legacyRef
-Name Accounting Standards Codification
-Topic 825
-SubTopic 10
-Section 50
-Paragraph 20
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147482907/825-10-50-20

Reference 4: http://fasb.org/us-gaap/role/ref/legacyRef
-Name Accounting Standards Codification
-Topic 275
-SubTopic 10
-Section 50
-Paragraph 18
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147482861/275-10-50-18

Reference 5: http://fasb.org/us-gaap/role/ref/legacyRef
-Name Accounting Standards Codification
-Topic 275
-SubTopic 10
-Section 50
-Paragraph 20
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147482861/275-10-50-20

+ Details

Name:	us-gaap_ConcentrationRiskPercentage1
Namespace Prefix:	us-gaap_
Data Type:	dtr-types:percentItemType
Balance Type:	na
Period Type:	duration

- Definition

Amount of revenue recognized from performance obligation satisfied or partially satisfied in previous reporting periods. Includes, but is not limited to, change in transaction price.

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Topic 606
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 12A
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147479806/606-10-50-12A

+ Details

Name:	us-gaap_ContractWithCustomerPerformanceObligationSatisfiedInPreviousPeriod
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration

- 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

No definition available.

+ Details

Name:	us-gaap_RevenueRemainingPerformanceObligationExpectedTimingOfSatisfactionLineItems
Namespace Prefix:	us-gaap_
Data Type:	xbrli:stringItemType
Balance Type:	na
Period Type:	duration

- Details

Name:	us-gaap_RevenueRemainingPerformanceObligationExpectedTimingOfSatisfactionStartDateAxis=2025-07-01
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_RevenueRemainingPerformanceObligationExpectedTimingOfSatisfactionStartDateAxis=2026-01-01
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_ConcentrationRiskByTypeAxis=us-gaap_CustomerConcentrationRiskMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_ConcentrationRiskByBenchmarkAxis=us-gaap_SalesRevenueNetMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	srt_MajorCustomersAxis=metc_TopCustomersMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	srt_RangeAxis=srt_MinimumMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	srt_MajorCustomersAxis=metc_CustomerMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	srt_MajorCustomersAxis=metc_CustomerBMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	srt_MajorCustomersAxis=metc_TotalCustomerMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_ConcentrationRiskByBenchmarkAxis=us-gaap_AccountsReceivableMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	srt_MajorCustomersAxis=metc_CustomerCMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	srt_ProductOrServiceAxis=metc_FixedPricedContractsMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	srt_ProductOrServiceAxis=metc_ContractsWithIndexedBasedPricingMechanismsMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

Note 8 - Revenue (Details) T in Millions, $ in Millions	3 Months Ended		6 Months Ended
Note 8 - Revenue (Details) T in Millions, $ in Millions	Jun. 30, 2025 USD ($) customer T	Jun. 30, 2024 customer	Jun. 30, 2025 USD ($) customer T $ / T	Jun. 30, 2024 customer
REVENUES
Term of domestic sales contracts			1 year
Increase to revenue \| $	$ 0.5		$ 0.4
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2025-07-01
REVENUES
Percentage of committed tons			60.00%
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2026-01-01
REVENUES
Percentage of committed tons			40.00%
Customer Concentration Risk \| Revenue Benchmark
REVENUES
Number of major customers \| customer	1	3	2	3
Customer Concentration Risk \| Revenue Benchmark \| Top Customers \| Minimum
REVENUES
Concentration risk percentage	10.00%	10.00%	10.00%	10.00%
Customer Concentration Risk \| Revenue Benchmark \| Customer A
REVENUES
Concentration risk percentage			16.00%
Customer Concentration Risk \| Revenue Benchmark \| Customer B
REVENUES
Concentration risk percentage			11.00%
Customer Concentration Risk \| Revenue Benchmark \| Total Customer Base
REVENUES
Concentration risk percentage	16.00%	31.00%		33.00%
Customer Concentration Risk \| Accounts Receivable
REVENUES
Number of major customers \| customer			3
Customer Concentration Risk \| Accounts Receivable \| Top Customers \| Minimum
REVENUES
Concentration risk percentage			10.00%
Customer Concentration Risk \| Accounts Receivable \| Customer A
REVENUES
Concentration risk percentage			20.00%
Customer Concentration Risk \| Accounts Receivable \| Customer B
REVENUES
Concentration risk percentage			18.00%
Customer Concentration Risk \| Accounts Receivable \| Customer C
REVENUES
Concentration risk percentage			12.00%
Customer Concentration Risk \| Accounts Receivable \| Total Customer Base
REVENUES
Concentration risk percentage			50.00%
Fixed Priced Contracts
REVENUES
Outstanding performance obligation, mass \| T	1.0		1.0
Average per ton \| $ / T			15
Contracts with Indexed Based Pricing Mechanisms
REVENUES
Outstanding performance obligation, mass \| T	2.0		2.0