Represents the amount of potential funding to be received.

No definition available.

Name:	reemf_AmountOfPotentialFundingForProject
Namespace Prefix:	reemf_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

- Definition

Percentage of total cost of the demonstration plant funded by the grant.

+ References

No definition available.

+ Details

Name:	reemf_PercentageOfExpectedTotalCostOfDemonstrationPlantFundedByGrant
Namespace Prefix:	reemf_
Data Type:	dtr-types:percentItemType
Balance Type:	na
Period Type:	duration

- Definition

Percentage of total cost of the demonstration plant funded by the non federal entity.

+ References

No definition available.

+ Details

Name:	reemf_PercentageOfExpectedTotalCostOfDemonstrationPlantFundedByNonFederalEntity
Namespace Prefix:	reemf_
Data Type:	dtr-types:percentItemType
Balance Type:	na
Period Type:	duration

- Definition

Represents the percentage of the total estimated cost for the project covered by outside funding.

+ References

No definition available.

+ Details

Name:	reemf_PercentageOfTotalEstimatedCostForProjectCoveredByFunding
Namespace Prefix:	reemf_
Data Type:	dtr-types:percentItemType
Balance Type:	na
Period Type:	instant

- Definition

Amount of total allowable costs for planned demonstration funded on cost share basis.

+ References

No definition available.

+ Details

Name:	reemf_TotalAllowableCostsForPlannedDemonstrationFundedOnCostShareBasis
Namespace Prefix:	reemf_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

- Definition

Minimum amount of other commitment not otherwise specified in the taxonomy. Excludes commitments explicitly modeled in the taxonomy, including but not limited to, long-term and short-term purchase commitments, recorded and unrecorded purchase obligations, supply commitments, registration payment arrangements, leases, debt, product warranties, guarantees, environmental remediation obligations, and pensions.

+ References

No definition available.

+ Details

Name:	us-gaap_OtherCommitment
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
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

No definition available.

+ Details

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

- Definition

Amount of cash restricted as to withdrawal or usage, classified as current. Cash includes, but is not limited to, currency on hand, demand deposits with banks or financial institutions, and other accounts with general characteristics of demand deposits.

+ References

Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 230
-SubTopic 10
-Section 50
-Paragraph 8
-URI http://asc.fasb.org/extlink&oid=123431023&loc=SL98516268-108586

Reference 2: http://www.xbrl.org/2009/role/commonPracticeRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 210
-SubTopic 10
-Section S99
-Paragraph 1
-Subparagraph (SX 210.5-02(1))
-URI http://asc.fasb.org/extlink&oid=120391452&loc=d3e13212-122682

Reference 3: http://www.xbrl.org/2009/role/commonPracticeRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 210
-SubTopic 10
-Section 45
-Paragraph 1
-Subparagraph (a)
-URI http://asc.fasb.org/extlink&oid=124098289&loc=d3e6676-107765

+ Details

Name:	us-gaap_RestrictedCashCurrent
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

- Details

Name:	us-gaap_RelatedPartyTransactionsByRelatedPartyAxis=reemf_GeneralAtomicsMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

RELATED PARTY (Details) - USD ($) $ in Thousands	Oct. 01, 2021	Sep. 30, 2022	Dec. 31, 2021
Related Party
Amount of potential DoE funding	$ 21,900
Percentage of total estimated cost for the project covered by DoE funding	50.00%
Allowable costs for planned demonstration funded on cost share basis	$ 43,900
Percentage of total cost of the demonstration plant funded by DoE	50.00%
Percentage of total cost of the demonstration plant funded by non federal entity	50.00%
Restricted cash			$ 2,700
General Atomics
Related Party
Commitment Amount		$ 4,200