Name:	gmo_AdditionalOwnershipInterestGrantedToMinorityPartyUponFailureToReturnRequiredCapital
Namespace Prefix:	gmo_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	instant

The amount of reduction limit on capital contributions made by POS-Minerals without reduction in ownership percentage.

No definition available.

Name:	gmo_CapitalContributionsReductionLimitWithoutReductionInOwnershipPercentage
Namespace Prefix:	gmo_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

The period of time during which failure to follow standard mining industry practices results in a change of control.

No definition available.

Name:	gmo_ConsecutiveMonthsFailureToFollowStandardMiningPractices
Namespace Prefix:	gmo_
Data Type:	xbrli:durationItemType
Balance Type:	na
Period Type:	duration

The return of contributions required as the result of not commencing production at the specified date.

No definition available.

Name:	gmo_ContingentPaymentsToMinorityShareholders
Namespace Prefix:	gmo_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

Represents the contribution percentage in all other costs incurred by the LLC.

No definition available.

Name:	gmo_ContributionPercentageInAllOtherCosts
Namespace Prefix:	gmo_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	duration

Represents the percentage of costs of the co-venturer for management of the LLC which the entity assumed.

No definition available.

Name:	gmo_ContributionPercentageInCostsRelatedToCompensationAndReimbursement
Namespace Prefix:	gmo_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	duration

Contributions made by EMLLC to its members.

No definition available.

Name:	gmo_ContributionsMadeByEMLLCToMembers
Namespace Prefix:	gmo_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

The multiple of the unpaid contributions over the deemed capital contributions by which the reporting entity's interest in the LLC is subject to dilution if the co-venturer elects to receive an additional ownership interest.

No definition available.

Name:	gmo_DilutionFormulaFactor
Namespace Prefix:	gmo_
Data Type:	xbrli:decimalItemType
Balance Type:	na
Period Type:	instant

The remaining reserve balance from the initial fund from members.

No definition available.

Name:	gmo_InitialFundFromMembersReserveAccountBalance
Namespace Prefix:	gmo_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

The percentage interest to be used in the calculation of the required purchase of the co-venturer's interest in a project, in the event of specified conditions.

No definition available.

Name:	gmo_InterestRateOnUnreimbursedCapitalContributions
Namespace Prefix:	gmo_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	instant

The amount which the reporting entity's subsidiary is required to fund the return of capital contributions previously made. The return of contributions is required because the project did not achieve the specified date for commencement of commercial production.

No definition available.

Name:	gmo_ObligationToFundReturnOfContributions
Namespace Prefix:	gmo_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration

Ownership interest in project.

No definition available.

Name:	gmo_ProjectOwnershipPercentage
Namespace Prefix:	gmo_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	instant

The percentage of total contributions to the LLC by the co-venturer which the entity will payment in the even of specified conditions.

No definition available.

Name:	gmo_PuttablePercentageOfCashContributionsFollowingFailureToUseStandardMiningIndustryPractice
Namespace Prefix:	gmo_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	instant

Represents the percentage of reduction of the Return of Contribution owed by Nevada Moly to POS-Minerals on principal payments made for equipment.

No definition available.

Name:	gmo_ReductionOfContributionsPercentageOnPrincipalPaymentsForEquipment
Namespace Prefix:	gmo_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	duration

The amount of capital contributions previously made by POS-Minerals which the reporting entity's subsidiary is required. The return of contributions is required because the project did not achieve the specified date for commencement of commercial production.

No definition available.

Name:	gmo_ReductionOnObligationToFundForCapitalContributions
Namespace Prefix:	gmo_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

Represents the amount of remaining capital contributions due to POS-Minerals.

No definition available.

Name:	gmo_RemainingAmountOfCapitalContributionsDueToRelatedParty
Namespace Prefix:	gmo_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration

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

No definition available.

Name:	us-gaap_DebtInstrumentBasisSpreadOnVariableRate1
Namespace Prefix:	us-gaap_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	duration

The reference rate for the variable rate of the debt instrument, such as LIBOR or the US Treasury rate and the maturity of the reference rate used, such as three months or six months LIBOR.

No definition available.

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

The equity interest of noncontrolling shareholders, partners or other equity holders in consolidated entity.

No definition available.

Name:	us-gaap_MinorityInterestOwnershipPercentageByNoncontrollingOwners
Namespace Prefix:	us-gaap_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	instant

The parent entity's interest in net assets of the subsidiary, expressed as a percentage.

No definition available.

Name:	us-gaap_MinorityInterestOwnershipPercentageByParent
Namespace Prefix:	us-gaap_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	instant

Total contributions made by each class of partners (i.e., general, limited and preferred partners).

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 505
-SubTopic 10
-Section S99
-Paragraph 1
-Subparagraph (SX 210.3-04)
-URI http://asc.fasb.org/extlink&oid=27012166&loc=d3e187085-122770

Reference 2: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 505
-SubTopic 10
-Section S99
-Paragraph 1
-Subparagraph (SAB Topic 4.F)
-URI http://asc.fasb.org/extlink&oid=27012166&loc=d3e187085-122770

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

The cash outflow for acquisition of machinery and equipment.

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 230
-SubTopic 10
-Section 45
-Paragraph 13
-Subparagraph (c)
-URI http://asc.fasb.org/extlink&oid=66902209&loc=d3e3213-108585

Reference 2: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Glossary Investing Activities
-URI http://asc.fasb.org/extlink&oid=6516133

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

Amount of cash inflow from a noncontrolling interest. Includes, but is not limited to, purchase of additional shares or other increase in noncontrolling interest ownership.

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Glossary Financing Activities
-URI http://asc.fasb.org/extlink&oid=6513228

Reference 2: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 230
-SubTopic 10
-Section 45
-Paragraph 14
-URI http://asc.fasb.org/extlink&oid=66902209&loc=d3e3255-108585

Name:	us-gaap_ProceedsFromMinorityShareholders
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

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.

No definition available.

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

Name:	us-gaap_CapitalizedCostsOfUnprovedPropertiesExcludedFromAmortizationByPropertyOrProjectAxis=gmo_MountHopeProjectMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

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

Name:	dei_LegalEntityAxis=gmo_EurekaMolyLlcMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

Name:	dei_LegalEntityAxis=gmo_NevadaMolyLlcMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

Name:	us-gaap_VariableRateAxis=us-gaap_LondonInterbankOfferedRateLIBORMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

Name:	us-gaap_PropertyPlantAndEquipmentByTypeAxis=gmo_MillingProcessEquipmentMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type: