Note 5 - SBA Paycheck Protection Program (Details) - USD ($) $ in Thousands	Apr. 20, 2020	Jun. 30, 2020
Deferred income		$ 1,139
PPP Loan
Proceeds from loan	$ 8,400
Debt Instrument, Interest Rate, Stated Percentage	1.00%
Anticipated amount of loan to be forgiven		7,300
Deferred income		$ 1,100

Refers to the anticipated amount of debt to be forgiven.

No definition available.

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Namespace Prefix:	metc_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- Definition

Contractual interest rate for funds borrowed, under the debt agreement.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 210
-SubTopic 10
-Section S99
-Paragraph 1
-Subparagraph (SX 210.5-02.22(a)(1))
-URI http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682

+ Details

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Period Type:	instant

- Definition

Amount of deferred income excluding obligation to transfer product and service to customer for which consideration has been received or is receivable.

+ References

Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 470
-SubTopic 10
-Section 25
-Paragraph 2
-URI http://asc.fasb.org/extlink&oid=28183603&loc=d3e692-112598

+ Details

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Data Type:	xbrli:monetaryItemType
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Period Type:	instant

- Definition

The cash inflow from a debt initially having maturity due after one year or beyond the operating cycle, if longer.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 230
-SubTopic 10
-Section 45
-Paragraph 14
-Subparagraph (b)
-URI http://asc.fasb.org/extlink&oid=118932676&loc=d3e3255-108585

+ Details

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Balance Type:	debit
Period Type:	duration

- Details

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Balance Type:
Period Type: