3.7.0.1 html 178 291 1 false 53 0 false 11 false false R1.htm 00090 - Document - Document and Entity Information Sheet http://www.generalmoly.com/role/DocumentDocumentAndEntityInformation Document and Entity Information Cover 1 false false R2.htm 00100 - Statement - CONSOLIDATED BALANCE SHEETS Sheet http://www.generalmoly.com/role/StatementConsolidatedBalanceSheets CONSOLIDATED BALANCE SHEETS Statements 2 false false R3.htm 00105 - Statement - CONSOLIDATED BALANCE SHEETS (Parenthetical) Sheet http://www.generalmoly.com/role/StatementConsolidatedBalanceSheetsParenthetical CONSOLIDATED BALANCE SHEETS (Parenthetical) Statements 3 false false R4.htm 00200 - Statement - CONSOLIDATED STATEMENTS OF OPERATIONS AND COMPREHENSIVE LOSS Sheet http://www.generalmoly.com/role/StatementConsolidatedStatementsOfOperationsAndComprehensiveLoss CONSOLIDATED STATEMENTS OF OPERATIONS AND COMPREHENSIVE LOSS Statements 4 false false R5.htm 00300 - Statement - CONSOLIDATED STATEMENTS OF CASH FLOWS Sheet http://www.generalmoly.com/role/StatementConsolidatedStatementsOfCashFlows CONSOLIDATED STATEMENTS OF CASH FLOWS Statements 5 false false R6.htm 10101 - Disclosure - DESCRIPTION OF BUSINESS Sheet http://www.generalmoly.com/role/DisclosureDescriptionOfBusiness DESCRIPTION OF BUSINESS Notes 6 false false R7.htm 10201 - Disclosure - LIQUIDITY Sheet http://www.generalmoly.com/role/DisclosureLiquidity LIQUIDITY Notes 7 false false R8.htm 10301 - Disclosure - SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES Sheet http://www.generalmoly.com/role/DisclosureSummaryOfSignificantAccountingPolicies SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES Notes 8 false false R9.htm 10401 - Disclosure - MINING PROPERTIES, LAND AND WATER RIGHTS Sheet http://www.generalmoly.com/role/DisclosureMiningPropertiesLandAndWaterRights MINING PROPERTIES, LAND AND WATER RIGHTS Notes 9 false false R10.htm 10501 - Disclosure - ASSET RETIREMENT OBLIGATIONS Sheet http://www.generalmoly.com/role/DisclosureAssetRetirementObligations ASSET RETIREMENT OBLIGATIONS Notes 10 false false R11.htm 10601 - Disclosure - SENIOR CONVERTIBLE PROMISSORY NOTES Notes http://www.generalmoly.com/role/DisclosureSeniorConvertiblePromissoryNotes SENIOR CONVERTIBLE PROMISSORY NOTES Notes 11 false false R12.htm 10701 - Disclosure - COMMON STOCK UNITS, COMMON STOCK AND COMMON STOCK WARRANTS Sheet http://www.generalmoly.com/role/DisclosureCommonStockUnitsCommonStockAndCommonStockWarrants COMMON STOCK UNITS, COMMON STOCK AND COMMON STOCK WARRANTS Notes 12 false false R13.htm 10801 - Disclosure - PREFERRED STOCK Sheet http://www.generalmoly.com/role/DisclosurePreferredStock PREFERRED STOCK Notes 13 false false R14.htm 10901 - Disclosure - EQUITY INCENTIVES Sheet http://www.generalmoly.com/role/DisclosureEquityIncentives EQUITY INCENTIVES Notes 14 false false R15.htm 11001 - Disclosure - CHANGES IN CONTINGENTLY REDEEMABLE NONCONTROLLING INTEREST AND EQUITY Sheet http://www.generalmoly.com/role/DisclosureChangesInContingentlyRedeemableNoncontrollingInterestAndEquity CHANGES IN CONTINGENTLY REDEEMABLE NONCONTROLLING INTEREST AND EQUITY Notes 15 false false R16.htm 11101 - Disclosure - INCOME TAXES Sheet http://www.generalmoly.com/role/DisclosureIncomeTaxes INCOME TAXES Notes 16 false false R17.htm 11201 - Disclosure - COMMITMENTS AND CONTINGENCIES Sheet http://www.generalmoly.com/role/DisclosureCommitmentsAndContingencies COMMITMENTS AND CONTINGENCIES Notes 17 false false R18.htm 11301 - Disclosure - SUBSEQUENT EVENTS Sheet http://www.generalmoly.com/role/DisclosureSubsequentEvents SUBSEQUENT EVENTS Notes 18 false false R19.htm 20302 - Disclosure - SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES (Policies) Sheet http://www.generalmoly.com/role/DisclosureSummaryOfSignificantAccountingPoliciesPolicies SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES (Policies) Policies 19 false false R20.htm 30203 - Disclosure - LIQUIDITY (Tables) Sheet http://www.generalmoly.com/role/DisclosureLiquidityTables LIQUIDITY (Tables) Tables http://www.generalmoly.com/role/DisclosureLiquidity 20 false false R21.htm 30303 - Disclosure - SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES (Tables) Sheet http://www.generalmoly.com/role/DisclosureSummaryOfSignificantAccountingPoliciesTables SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES (Tables) Tables http://www.generalmoly.com/role/DisclosureSummaryOfSignificantAccountingPolicies 21 false false R22.htm 30403 - Disclosure - MINING PROPERTIES, LAND AND WATER RIGHTS (Tables) Sheet http://www.generalmoly.com/role/DisclosureMiningPropertiesLandAndWaterRightsTables MINING PROPERTIES, LAND AND WATER RIGHTS (Tables) Tables http://www.generalmoly.com/role/DisclosureMiningPropertiesLandAndWaterRights 22 false false R23.htm 30503 - Disclosure - ASSET RETIREMENT OBLIGATIONS (Tables) Sheet http://www.generalmoly.com/role/DisclosureAssetRetirementObligationsTables ASSET RETIREMENT OBLIGATIONS (Tables) Tables http://www.generalmoly.com/role/DisclosureAssetRetirementObligations 23 false false R24.htm 30603 - Disclosure - SENIOR CONVERTIBLE PROMISSORY NOTES (Tables) Notes http://www.generalmoly.com/role/DisclosureSeniorConvertiblePromissoryNotesTables SENIOR CONVERTIBLE PROMISSORY NOTES (Tables) Tables http://www.generalmoly.com/role/DisclosureSeniorConvertiblePromissoryNotes 24 false false R25.htm 30903 - Disclosure - EQUITY INCENTIVES (Tables) Sheet http://www.generalmoly.com/role/DisclosureEquityIncentivesTables EQUITY INCENTIVES (Tables) Tables http://www.generalmoly.com/role/DisclosureEquityIncentives 25 false false R26.htm 31003 - Disclosure - CHANGES IN CONTINGENTLY REDEEMABLE NONCONTROLLING INTEREST AND EQUITY (Tables) Sheet http://www.generalmoly.com/role/DisclosureChangesInContingentlyRedeemableNoncontrollingInterestAndEquityTables CHANGES IN CONTINGENTLY REDEEMABLE NONCONTROLLING INTEREST AND EQUITY (Tables) Tables http://www.generalmoly.com/role/DisclosureChangesInContingentlyRedeemableNoncontrollingInterestAndEquity 26 false false R27.htm 40101 - Disclosure - DESCRIPTION OF BUSINESS - Related Parties (Details) Sheet http://www.generalmoly.com/role/DisclosureDescriptionOfBusinessRelatedPartiesDetails DESCRIPTION OF BUSINESS - Related Parties (Details) Details 27 false false R28.htm 40102 - Disclosure - DESCRIPTION OF BUSINESS - Capital Requirements and Restructuring (Details) Sheet http://www.generalmoly.com/role/DisclosureDescriptionOfBusinessCapitalRequirementsAndRestructuringDetails DESCRIPTION OF BUSINESS - Capital Requirements and Restructuring (Details) Details 28 false false R29.htm 40201 - Disclosure - LIQUIDITY - Schedule of Liquidity (Details) Sheet http://www.generalmoly.com/role/DisclosureLiquidityScheduleOfLiquidityDetails LIQUIDITY - Schedule of Liquidity (Details) Details 29 false false R30.htm 40202 - Disclosure - LIQUIDITY - Restructuring Costs and Reserves (Details) Sheet http://www.generalmoly.com/role/DisclosureLiquidityRestructuringCostsAndReservesDetails LIQUIDITY - Restructuring Costs and Reserves (Details) Details 30 false false R31.htm 40203 - Disclosure - LIQUIDITY - Cash Commitments (Details) Sheet http://www.generalmoly.com/role/DisclosureLiquidityCashCommitmentsDetails LIQUIDITY - Cash Commitments (Details) Details 31 false false R32.htm 40204 - Disclosure - LIQUIDITY - Purchase Commitment excluding Long-term Commitment (Details) Sheet http://www.generalmoly.com/role/DisclosureLiquidityPurchaseCommitmentExcludingLongTermCommitmentDetails LIQUIDITY - Purchase Commitment excluding Long-term Commitment (Details) Details 32 false false R33.htm 40301 - Disclosure - SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES - Accounting Method (Details) Sheet http://www.generalmoly.com/role/DisclosureSummaryOfSignificantAccountingPoliciesAccountingMethodDetails SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES - Accounting Method (Details) Details 33 false false R34.htm 40302 - Disclosure - SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES - Contingently Redeemable Noncontrolling Interest ("CRNCI") (Details) Sheet http://www.generalmoly.com/role/DisclosureSummaryOfSignificantAccountingPoliciesContingentlyRedeemableNoncontrollingInterestcrnciDetails SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES - Contingently Redeemable Noncontrolling Interest ("CRNCI") (Details) Details 34 false false R35.htm 40303 - Disclosure - SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES - Basic and Diluted Net Loss Per Share (Details) Sheet http://www.generalmoly.com/role/DisclosureSummaryOfSignificantAccountingPoliciesBasicAndDilutedNetLossPerShareDetails SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES - Basic and Diluted Net Loss Per Share (Details) Details 35 false false R36.htm 40304 - Disclosure - SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES - Depreciation and Amortization (Details) Sheet http://www.generalmoly.com/role/DisclosureSummaryOfSignificantAccountingPoliciesDepreciationAndAmortizationDetails SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES - Depreciation and Amortization (Details) Details 36 false false R37.htm 40305 - Disclosure - SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES - Senior Convertible Promissory Notes and other Long-Term Debt (Details) Notes http://www.generalmoly.com/role/DisclosureSummaryOfSignificantAccountingPoliciesSeniorConvertiblePromissoryNotesAndOtherLongTermDebtDetails SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES - Senior Convertible Promissory Notes and other Long-Term Debt (Details) Details 37 false false R38.htm 40306 - Disclosure - SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES - Stock-based Compensation (Details) Sheet http://www.generalmoly.com/role/DisclosureSummaryOfSignificantAccountingPoliciesStockBasedCompensationDetails SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES - Stock-based Compensation (Details) Details 38 false false R39.htm 40401 - Disclosure - MINING PROPERTIES, LAND AND WATER RIGHTS (Details) Sheet http://www.generalmoly.com/role/DisclosureMiningPropertiesLandAndWaterRightsDetails MINING PROPERTIES, LAND AND WATER RIGHTS (Details) Details http://www.generalmoly.com/role/DisclosureMiningPropertiesLandAndWaterRightsTables 39 false false R40.htm 40501 - Disclosure - ASSET RETIREMENT OBLIGATIONS (Details) Sheet http://www.generalmoly.com/role/DisclosureAssetRetirementObligationsDetails ASSET RETIREMENT OBLIGATIONS (Details) Details http://www.generalmoly.com/role/DisclosureAssetRetirementObligationsTables 40 false false R41.htm 40601 - Disclosure - SENIOR CONVERTIBLE PROMISSORY NOTES - Convertible Debt (Details) Notes http://www.generalmoly.com/role/DisclosureSeniorConvertiblePromissoryNotesConvertibleDebtDetails SENIOR CONVERTIBLE PROMISSORY NOTES - Convertible Debt (Details) Details 41 false false R42.htm 40602 - Disclosure - SENIOR CONVERTIBLE PROMISSORY NOTES - Embedded Derivatives (Details) Notes http://www.generalmoly.com/role/DisclosureSeniorConvertiblePromissoryNotesEmbeddedDerivativesDetails SENIOR CONVERTIBLE PROMISSORY NOTES - Embedded Derivatives (Details) Details 42 false false R43.htm 40701 - Disclosure - COMMON STOCK UNITS, COMMON STOCK AND COMMON STOCK WARRANTS (Details) Sheet http://www.generalmoly.com/role/DisclosureCommonStockUnitsCommonStockAndCommonStockWarrantsDetails COMMON STOCK UNITS, COMMON STOCK AND COMMON STOCK WARRANTS (Details) Details http://www.generalmoly.com/role/DisclosureCommonStockUnitsCommonStockAndCommonStockWarrants 43 false false R44.htm 40801 - Disclosure - PREFERRED STOCK (Details) Sheet http://www.generalmoly.com/role/DisclosurePreferredStockDetails PREFERRED STOCK (Details) Details http://www.generalmoly.com/role/DisclosurePreferredStock 44 false false R45.htm 40901 - Disclosure - EQUITY INCENTIVES - Stock Options and Stock Appreciation Rights (Details) Sheet http://www.generalmoly.com/role/DisclosureEquityIncentivesStockOptionsAndStockAppreciationRightsDetails EQUITY INCENTIVES - Stock Options and Stock Appreciation Rights (Details) Details 45 false false R46.htm 40903 - Disclosure - EQUITY INCENTIVES - Summary of Equity Incentive Awards Activity (Details) Sheet http://www.generalmoly.com/role/DisclosureEquityIncentivesSummaryOfEquityIncentiveAwardsActivityDetails EQUITY INCENTIVES - Summary of Equity Incentive Awards Activity (Details) Details 46 false false R47.htm 40904 - Disclosure - EQUITY INCENTIVES - Restricted Stock Units and Stock Awards Activity, Non-vested Awards (Details) Sheet http://www.generalmoly.com/role/DisclosureEquityIncentivesRestrictedStockUnitsAndStockAwardsActivityNonVestedAwardsDetails EQUITY INCENTIVES - Restricted Stock Units and Stock Awards Activity, Non-vested Awards (Details) Details 47 false false R48.htm 41001 - Disclosure - CHANGES IN CONTINGENTLY REDEEMABLE NONCONTROLLING INTEREST AND EQUITY - Changes CRNCI (Details) Sheet http://www.generalmoly.com/role/DisclosureChangesInContingentlyRedeemableNoncontrollingInterestAndEquityChangesCrnciDetails CHANGES IN CONTINGENTLY REDEEMABLE NONCONTROLLING INTEREST AND EQUITY - Changes CRNCI (Details) Details http://www.generalmoly.com/role/DisclosureChangesInContingentlyRedeemableNoncontrollingInterestAndEquityTables 48 false false R49.htm 41002 - Disclosure - CHANGES IN CONTINGENTLY REDEEMABLE NONCONTROLLING INTEREST (CRNCI) - Changes in Equity (Details) Sheet http://www.generalmoly.com/role/DisclosureChangesInContingentlyRedeemableNoncontrollingInterestCrnciChangesInEquityDetails CHANGES IN CONTINGENTLY REDEEMABLE NONCONTROLLING INTEREST (CRNCI) - Changes in Equity (Details) Details http://www.generalmoly.com/role/DisclosureChangesInContingentlyRedeemableNoncontrollingInterestAndEquityTables 49 false false R50.htm 41101 - Disclosure - INCOME TAXES (Details) Sheet http://www.generalmoly.com/role/DisclosureIncomeTaxesDetails INCOME TAXES (Details) Details http://www.generalmoly.com/role/DisclosureIncomeTaxes 50 false false R51.htm 41201 - Disclosure - COMMITMENTS AND CONTINGENCIES - Operating Leases (Details) Sheet http://www.generalmoly.com/role/DisclosureCommitmentsAndContingenciesOperatingLeasesDetails COMMITMENTS AND CONTINGENCIES - Operating Leases (Details) Details 51 false false R52.htm 41202 - Disclosure - COMMITMENTS AND CONTINGENCIES - Equipment and Supply Procurement (Details) Sheet http://www.generalmoly.com/role/DisclosureCommitmentsAndContingenciesEquipmentAndSupplyProcurementDetails COMMITMENTS AND CONTINGENCIES - Equipment and Supply Procurement (Details) Details 52 false false R53.htm 41203 - Disclosure - COMMITMENTS AND CONTINGENCIES - Obligations Under Capital and Operating Leases (Details) Sheet http://www.generalmoly.com/role/DisclosureCommitmentsAndContingenciesObligationsUnderCapitalAndOperatingLeasesDetails COMMITMENTS AND CONTINGENCIES - Obligations Under Capital and Operating Leases (Details) Details 53 false false R54.htm 41204 - Disclosure - COMMITMENTS AND CONTINGENCIES - Loss Contingencies (Details) Sheet http://www.generalmoly.com/role/DisclosureCommitmentsAndContingenciesLossContingenciesDetails COMMITMENTS AND CONTINGENCIES - Loss Contingencies (Details) Details 54 false false All Reports Book All Reports gmo-20170331.xml gmo-20170331.xsd gmo-20170331_cal.xml gmo-20170331_def.xml gmo-20170331_lab.xml gmo-20170331_pre.xml true true