Quarterly report pursuant to Section 13 or 15(d)

Summary of Significant Accounting Policies (Fair Value of Financial Instruments) (Details)

v2.4.1.9
Summary of Significant Accounting Policies (Fair Value of Financial Instruments) (Details) (USD $)
In Thousands, unless otherwise specified
Mar. 31, 2015
Jun. 30, 2014
Financial assets:    
Receivables, advances receivables and secured loans $ 102,091amrk_ReceivablesAndSecuredLoansFairValueDisclosure $ 80,640amrk_ReceivablesAndSecuredLoansFairValueDisclosure
Derivative assets - future and forward contracts 18,627us-gaap_DerivativeFairValueOfDerivativeAsset 26,296us-gaap_DerivativeFairValueOfDerivativeAsset
Financial liabilities:    
Liability for borrowed metals 6,495amrk_LiabilityOnBorrowedMetals 8,709amrk_LiabilityOnBorrowedMetals
Product financing obligation 48,114amrk_ObligationUnderProductFinancingAgreement 24,610amrk_ObligationUnderProductFinancingAgreement
Derivative liabilities 17,938us-gaap_DerivativeFairValueOfDerivativeLiability 16,525us-gaap_DerivativeFairValueOfDerivativeLiability
Accrued liabilities 4,475us-gaap_AccruedLiabilitiesCurrent 6,070us-gaap_AccruedLiabilitiesCurrent
Carrying Amount    
Financial assets:    
Cash 16,201us-gaap_CashAndCashEquivalentsFairValueDisclosure
/ us-gaap_FairValueByMeasurementBasisAxis
= us-gaap_CarryingReportedAmountFairValueDisclosureMember
13,193us-gaap_CashAndCashEquivalentsFairValueDisclosure
/ us-gaap_FairValueByMeasurementBasisAxis
= us-gaap_CarryingReportedAmountFairValueDisclosureMember
Receivables, advances receivables and secured loans 102,091amrk_ReceivablesAndSecuredLoansFairValueDisclosure
/ us-gaap_FairValueByMeasurementBasisAxis
= us-gaap_CarryingReportedAmountFairValueDisclosureMember
80,640amrk_ReceivablesAndSecuredLoansFairValueDisclosure
/ us-gaap_FairValueByMeasurementBasisAxis
= us-gaap_CarryingReportedAmountFairValueDisclosureMember
Income taxes receivable from Former Parent 4,017amrk_IncomeTaxReceivableFairValueDisclosure
/ us-gaap_FairValueByMeasurementBasisAxis
= us-gaap_CarryingReportedAmountFairValueDisclosureMember
3,139amrk_IncomeTaxReceivableFairValueDisclosure
/ us-gaap_FairValueByMeasurementBasisAxis
= us-gaap_CarryingReportedAmountFairValueDisclosureMember
Financial liabilities:    
Lines of credit 132,800us-gaap_LinesOfCreditFairValueDisclosure
/ us-gaap_FairValueByMeasurementBasisAxis
= us-gaap_CarryingReportedAmountFairValueDisclosureMember
135,200us-gaap_LinesOfCreditFairValueDisclosure
/ us-gaap_FairValueByMeasurementBasisAxis
= us-gaap_CarryingReportedAmountFairValueDisclosureMember
Liability for borrowed metals 6,495amrk_LiabilityOnBorrowedMetals
/ us-gaap_FairValueByMeasurementBasisAxis
= us-gaap_CarryingReportedAmountFairValueDisclosureMember
8,709amrk_LiabilityOnBorrowedMetals
/ us-gaap_FairValueByMeasurementBasisAxis
= us-gaap_CarryingReportedAmountFairValueDisclosureMember
Product financing obligation 48,114amrk_ObligationUnderProductFinancingAgreement
/ us-gaap_FairValueByMeasurementBasisAxis
= us-gaap_CarryingReportedAmountFairValueDisclosureMember
24,610amrk_ObligationUnderProductFinancingAgreement
/ us-gaap_FairValueByMeasurementBasisAxis
= us-gaap_CarryingReportedAmountFairValueDisclosureMember
Accounts payable, margin accounts, advances and other payables 81,820us-gaap_AccountsPayableFairValueDisclosure
/ us-gaap_FairValueByMeasurementBasisAxis
= us-gaap_CarryingReportedAmountFairValueDisclosureMember
53,627us-gaap_AccountsPayableFairValueDisclosure
/ us-gaap_FairValueByMeasurementBasisAxis
= us-gaap_CarryingReportedAmountFairValueDisclosureMember
Accrued liabilities 4,475us-gaap_AccruedLiabilitiesCurrent
/ us-gaap_FairValueByMeasurementBasisAxis
= us-gaap_CarryingReportedAmountFairValueDisclosureMember
6,070us-gaap_AccruedLiabilitiesCurrent
/ us-gaap_FairValueByMeasurementBasisAxis
= us-gaap_CarryingReportedAmountFairValueDisclosureMember
Fair value    
Financial assets:    
Cash 16,201us-gaap_CashAndCashEquivalentsFairValueDisclosure
/ us-gaap_FairValueByMeasurementBasisAxis
= us-gaap_EstimateOfFairValueFairValueDisclosureMember
13,193us-gaap_CashAndCashEquivalentsFairValueDisclosure
/ us-gaap_FairValueByMeasurementBasisAxis
= us-gaap_EstimateOfFairValueFairValueDisclosureMember
Receivables, advances receivables and secured loans 102,091amrk_ReceivablesAndSecuredLoansFairValueDisclosure
/ us-gaap_FairValueByMeasurementBasisAxis
= us-gaap_EstimateOfFairValueFairValueDisclosureMember
80,640amrk_ReceivablesAndSecuredLoansFairValueDisclosure
/ us-gaap_FairValueByMeasurementBasisAxis
= us-gaap_EstimateOfFairValueFairValueDisclosureMember
Income taxes receivable from Former Parent 4,017amrk_IncomeTaxReceivableFairValueDisclosure
/ us-gaap_FairValueByMeasurementBasisAxis
= us-gaap_EstimateOfFairValueFairValueDisclosureMember
3,139amrk_IncomeTaxReceivableFairValueDisclosure
/ us-gaap_FairValueByMeasurementBasisAxis
= us-gaap_EstimateOfFairValueFairValueDisclosureMember
Financial liabilities:    
Lines of credit 132,800us-gaap_LinesOfCreditFairValueDisclosure
/ us-gaap_FairValueByMeasurementBasisAxis
= us-gaap_EstimateOfFairValueFairValueDisclosureMember
135,200us-gaap_LinesOfCreditFairValueDisclosure
/ us-gaap_FairValueByMeasurementBasisAxis
= us-gaap_EstimateOfFairValueFairValueDisclosureMember
Liability for borrowed metals 6,495amrk_LiabilityOnBorrowedMetals
/ us-gaap_FairValueByMeasurementBasisAxis
= us-gaap_EstimateOfFairValueFairValueDisclosureMember
8,709amrk_LiabilityOnBorrowedMetals
/ us-gaap_FairValueByMeasurementBasisAxis
= us-gaap_EstimateOfFairValueFairValueDisclosureMember
Product financing obligation 48,114amrk_ObligationUnderProductFinancingAgreement
/ us-gaap_FairValueByMeasurementBasisAxis
= us-gaap_EstimateOfFairValueFairValueDisclosureMember
24,610amrk_ObligationUnderProductFinancingAgreement
/ us-gaap_FairValueByMeasurementBasisAxis
= us-gaap_EstimateOfFairValueFairValueDisclosureMember
Accounts payable, margin accounts, advances and other payables 81,820us-gaap_AccountsPayableFairValueDisclosure
/ us-gaap_FairValueByMeasurementBasisAxis
= us-gaap_EstimateOfFairValueFairValueDisclosureMember
53,627us-gaap_AccountsPayableFairValueDisclosure
/ us-gaap_FairValueByMeasurementBasisAxis
= us-gaap_EstimateOfFairValueFairValueDisclosureMember
Accrued liabilities 4,475us-gaap_AccruedLiabilitiesCurrent
/ us-gaap_FairValueByMeasurementBasisAxis
= us-gaap_EstimateOfFairValueFairValueDisclosureMember
6,070us-gaap_AccruedLiabilitiesCurrent
/ us-gaap_FairValueByMeasurementBasisAxis
= us-gaap_EstimateOfFairValueFairValueDisclosureMember
Open sales and purchase commitments | Carrying Amount    
Financial liabilities:    
Derivative liabilities - open sale and purchase commitments, net, included in payables 560us-gaap_DerivativeFairValueOfDerivativeLiabilityAmountNotOffsetAgainstCollateral
/ us-gaap_FairValueByLiabilityClassAxis
= amrk_OpenPurchasesAndSalesCommitmentsMember
/ us-gaap_FairValueByMeasurementBasisAxis
= us-gaap_CarryingReportedAmountFairValueDisclosureMember
848us-gaap_DerivativeFairValueOfDerivativeLiabilityAmountNotOffsetAgainstCollateral
/ us-gaap_FairValueByLiabilityClassAxis
= amrk_OpenPurchasesAndSalesCommitmentsMember
/ us-gaap_FairValueByMeasurementBasisAxis
= us-gaap_CarryingReportedAmountFairValueDisclosureMember
Open sales and purchase commitments | Fair value    
Financial liabilities:    
Derivative liabilities - open sale and purchase commitments, net, included in payables 560us-gaap_DerivativeFairValueOfDerivativeLiabilityAmountNotOffsetAgainstCollateral
/ us-gaap_FairValueByLiabilityClassAxis
= amrk_OpenPurchasesAndSalesCommitmentsMember
/ us-gaap_FairValueByMeasurementBasisAxis
= us-gaap_EstimateOfFairValueFairValueDisclosureMember
848us-gaap_DerivativeFairValueOfDerivativeLiabilityAmountNotOffsetAgainstCollateral
/ us-gaap_FairValueByLiabilityClassAxis
= amrk_OpenPurchasesAndSalesCommitmentsMember
/ us-gaap_FairValueByMeasurementBasisAxis
= us-gaap_EstimateOfFairValueFairValueDisclosureMember
Future contracts | Carrying Amount    
Financial liabilities:    
Derivative liabilities 0us-gaap_DerivativeFairValueOfDerivativeLiability
/ us-gaap_FairValueByLiabilityClassAxis
= us-gaap_FutureMember
/ us-gaap_FairValueByMeasurementBasisAxis
= us-gaap_CarryingReportedAmountFairValueDisclosureMember
8,078us-gaap_DerivativeFairValueOfDerivativeLiability
/ us-gaap_FairValueByLiabilityClassAxis
= us-gaap_FutureMember
/ us-gaap_FairValueByMeasurementBasisAxis
= us-gaap_CarryingReportedAmountFairValueDisclosureMember
Future contracts | Fair value    
Financial liabilities:    
Derivative liabilities 0us-gaap_DerivativeFairValueOfDerivativeLiability
/ us-gaap_FairValueByLiabilityClassAxis
= us-gaap_FutureMember
/ us-gaap_FairValueByMeasurementBasisAxis
= us-gaap_EstimateOfFairValueFairValueDisclosureMember
8,078us-gaap_DerivativeFairValueOfDerivativeLiability
/ us-gaap_FairValueByLiabilityClassAxis
= us-gaap_FutureMember
/ us-gaap_FairValueByMeasurementBasisAxis
= us-gaap_EstimateOfFairValueFairValueDisclosureMember
Forward contracts | Carrying Amount    
Financial liabilities:    
Derivative liabilities 4,951us-gaap_DerivativeFairValueOfDerivativeLiability
/ us-gaap_FairValueByLiabilityClassAxis
= us-gaap_ForwardContractsMember
/ us-gaap_FairValueByMeasurementBasisAxis
= us-gaap_CarryingReportedAmountFairValueDisclosureMember
14,873us-gaap_DerivativeFairValueOfDerivativeLiability
/ us-gaap_FairValueByLiabilityClassAxis
= us-gaap_ForwardContractsMember
/ us-gaap_FairValueByMeasurementBasisAxis
= us-gaap_CarryingReportedAmountFairValueDisclosureMember
Forward contracts | Fair value    
Financial liabilities:    
Derivative liabilities 4,951us-gaap_DerivativeFairValueOfDerivativeLiability
/ us-gaap_FairValueByLiabilityClassAxis
= us-gaap_ForwardContractsMember
/ us-gaap_FairValueByMeasurementBasisAxis
= us-gaap_EstimateOfFairValueFairValueDisclosureMember
14,873us-gaap_DerivativeFairValueOfDerivativeLiability
/ us-gaap_FairValueByLiabilityClassAxis
= us-gaap_ForwardContractsMember
/ us-gaap_FairValueByMeasurementBasisAxis
= us-gaap_EstimateOfFairValueFairValueDisclosureMember
Open sales and purchase commitments | Carrying Amount    
Financial assets:    
Derivative assets - open sale and purchase commitments, net, included in receivable 4,380us-gaap_DerivativeFairValueOfDerivativeAssetAmountNotOffsetAgainstCollateral
/ us-gaap_FairValueByAssetClassAxis
= amrk_OpenPurchasesAndSalesCommitmentsMember
/ us-gaap_FairValueByMeasurementBasisAxis
= us-gaap_CarryingReportedAmountFairValueDisclosureMember
22,170us-gaap_DerivativeFairValueOfDerivativeAssetAmountNotOffsetAgainstCollateral
/ us-gaap_FairValueByAssetClassAxis
= amrk_OpenPurchasesAndSalesCommitmentsMember
/ us-gaap_FairValueByMeasurementBasisAxis
= us-gaap_CarryingReportedAmountFairValueDisclosureMember
Open sales and purchase commitments | Fair value    
Financial assets:    
Derivative assets - open sale and purchase commitments, net, included in receivable 4,380us-gaap_DerivativeFairValueOfDerivativeAssetAmountNotOffsetAgainstCollateral
/ us-gaap_FairValueByAssetClassAxis
= amrk_OpenPurchasesAndSalesCommitmentsMember
/ us-gaap_FairValueByMeasurementBasisAxis
= us-gaap_EstimateOfFairValueFairValueDisclosureMember
22,170us-gaap_DerivativeFairValueOfDerivativeAssetAmountNotOffsetAgainstCollateral
/ us-gaap_FairValueByAssetClassAxis
= amrk_OpenPurchasesAndSalesCommitmentsMember
/ us-gaap_FairValueByMeasurementBasisAxis
= us-gaap_EstimateOfFairValueFairValueDisclosureMember
Future contracts | Carrying Amount    
Financial assets:    
Derivative assets - future and forward contracts 2,010us-gaap_DerivativeFairValueOfDerivativeAsset
/ us-gaap_FairValueByAssetClassAxis
= us-gaap_FutureMember
/ us-gaap_FairValueByMeasurementBasisAxis
= us-gaap_CarryingReportedAmountFairValueDisclosureMember
0us-gaap_DerivativeFairValueOfDerivativeAsset
/ us-gaap_FairValueByAssetClassAxis
= us-gaap_FutureMember
/ us-gaap_FairValueByMeasurementBasisAxis
= us-gaap_CarryingReportedAmountFairValueDisclosureMember
Future contracts | Fair value    
Financial assets:    
Derivative assets - future and forward contracts 2,010us-gaap_DerivativeFairValueOfDerivativeAsset
/ us-gaap_FairValueByAssetClassAxis
= us-gaap_FutureMember
/ us-gaap_FairValueByMeasurementBasisAxis
= us-gaap_EstimateOfFairValueFairValueDisclosureMember
0us-gaap_DerivativeFairValueOfDerivativeAsset
/ us-gaap_FairValueByAssetClassAxis
= us-gaap_FutureMember
/ us-gaap_FairValueByMeasurementBasisAxis
= us-gaap_EstimateOfFairValueFairValueDisclosureMember
Forward contracts | Carrying Amount    
Financial assets:    
Derivative assets - future and forward contracts 0us-gaap_DerivativeFairValueOfDerivativeAsset
/ us-gaap_FairValueByAssetClassAxis
= us-gaap_ForwardContractsMember
/ us-gaap_FairValueByMeasurementBasisAxis
= us-gaap_CarryingReportedAmountFairValueDisclosureMember
14us-gaap_DerivativeFairValueOfDerivativeAsset
/ us-gaap_FairValueByAssetClassAxis
= us-gaap_ForwardContractsMember
/ us-gaap_FairValueByMeasurementBasisAxis
= us-gaap_CarryingReportedAmountFairValueDisclosureMember
Forward contracts | Fair value    
Financial assets:    
Derivative assets - future and forward contracts $ 0us-gaap_DerivativeFairValueOfDerivativeAsset
/ us-gaap_FairValueByAssetClassAxis
= us-gaap_ForwardContractsMember
/ us-gaap_FairValueByMeasurementBasisAxis
= us-gaap_EstimateOfFairValueFairValueDisclosureMember
$ 14us-gaap_DerivativeFairValueOfDerivativeAsset
/ us-gaap_FairValueByAssetClassAxis
= us-gaap_ForwardContractsMember
/ us-gaap_FairValueByMeasurementBasisAxis
= us-gaap_EstimateOfFairValueFairValueDisclosureMember