Name:	metc_CarbonOreRareEarthRevenueFromContractWithCustomerIncludingAssessedTax
Namespace Prefix:	metc_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration

Amount of cash available for dividend from financial performance of carbon ore rare earth assets.

No definition available.

Name:	metc_CashAvailableForDividend
Namespace Prefix:	metc_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

The price per ton of infrastructure fee income from coal processed at preparation plants.

No definition available.

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

The price per ton of infrastructure fee income from coal loaded at rail load out facilities.

No definition available.

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

The price per ton of infrastructure revenue.

No definition available.

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

Amount, including tax collected from customer, of infrastructure revenue from satisfaction of performance obligation by transferring promised good or service to customer. Tax collected from customer is tax assessed by governmental authority that is both imposed on and concurrent with specific revenue-producing transaction, including, but not limited to, sales, use, value-added and excise.

No definition available.

Name:	metc_RevenueInfrastructureFromContractWithCustomerIncludingAssessedTax
Namespace Prefix:	metc_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration

Amount, including tax collected from customer, of royalty revenue from satisfaction of performance obligation by transferring promised good or service to customer. Tax collected from customer is tax assessed by governmental authority that is both imposed on and concurrent with specific revenue-producing transaction, including, but not limited to, sales, use, value-added and excise.

No definition available.

Name:	metc_RevenueRoyaltyFromContractWithCustomerIncludingAssessedTax
Namespace Prefix:	metc_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration

Amount of cash available for dividend from financial performance of carbon ore rare earth assets.

No definition available.

Name:	metc_TrackingStockDividendFromFinancialPerformanceOfCarbonOreRareEarthAssets
Namespace Prefix:	metc_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

The percent of dividend on tracking stock from financial performance of carbon ore rare earth assets.

No definition available.

Name:	metc_TrackingStockDividendFromFinancialPerformanceOfCarbonOreRareEarthAssetsPercent
Namespace Prefix:	metc_
Data Type:	xbrli:pureItemType
Balance Type:	na
Period Type:	duration

Name:	us-gaap_StatementClassOfStockAxis=us-gaap_CommonClassBMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

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

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

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