A-Mark Precious Metals, Inc. Annual report pursuant to Section 13 and 15(d)

Commitments and Contingencies (Operational Contengencies) (Details)

v3.19.2

Commitments and Contingencies (Operational Contengencies) (Details) - ounce		1 Months Ended
	Aug. 31, 2016	Apr. 30, 2017
Long-term Purchase Commitment [Line Items]
Purchase commitment, period	3 years
Purchase commitment, renewal term	2 years
Minimum quantity required (in ounces)	300,000
Price subject to adjustment, period	6 months
Supply commitment, term	3 years
Supply commitment, renewal term	2 years
Price subject to adjustment, period	6 months
Agreement to lease (in ounces)	100,000
Lease fees, subject to adjustment	6 months
Asahi Refining USA, Inc
Long-term Purchase Commitment [Line Items]
Term of lease (in years)	1 year
Operating leases, renewal term	1 year
Silver Products \| AM&ST Associates, LLC
Long-term Purchase Commitment [Line Items]
Purchase commitment, period	3 years
Purchase commitment, renewal term	2 years
Minimum quantity required (in ounces)		175,000
Supply Commitment \| Asahi Refining USA, Inc
Long-term Purchase Commitment [Line Items]
Supply commitment, renewal term	2 years

- Definition

Commitment and Contingencies, Agreement to Lease

+ References

No definition available.

+ Details

Name:	amrk_CommitmentandContingenciesAgreementtoLeaseSilverProducts
Namespace Prefix:	amrk_
Data Type:	xbrli:integerItemType
Balance Type:	na
Period Type:	duration

- Definition

Lessor Leasing Arrangements, Operating Leases, Lease Fees, Subject to Adjust, Duration

+ References

No definition available.

+ Details

Name:	amrk_LessorLeasingArrangementsOperatingLeasesLeaseFeesSubjecttoAdjustDuration
Namespace Prefix:	amrk_
Data Type:	xbrli:durationItemType
Balance Type:	na
Period Type:	duration

- Definition

Long-term Purchase Commitment, Price Adjustment, Period

+ References

No definition available.

+ Details

Name:	amrk_LongtermPurchaseCommitmentPriceAdjustmentPeriod
Namespace Prefix:	amrk_
Data Type:	xbrli:durationItemType
Balance Type:	na
Period Type:	duration

- Definition

Long-term Purchase Commitment, Renewal Term

+ References

No definition available.

+ Details

Name:	amrk_LongtermPurchaseCommitmentRenewalTerm
Namespace Prefix:	amrk_
Data Type:	xbrli:durationItemType
Balance Type:	na
Period Type:	duration

- Definition

Supply Commitment, Duration

+ References

No definition available.

+ Details

Name:	amrk_SupplyCommitmentDuration
Namespace Prefix:	amrk_
Data Type:	xbrli:durationItemType
Balance Type:	na
Period Type:	duration

- Definition

Supply Commitment, Price Adjustment, Period

+ References

No definition available.

+ Details

Name:	amrk_SupplyCommitmentPriceAdjustmentPeriod
Namespace Prefix:	amrk_
Data Type:	xbrli:durationItemType
Balance Type:	na
Period Type:	duration

- Definition

Supply Commitment, Renewal Term

+ References

No definition available.

+ Details

Name:	amrk_SupplyCommitmentRenewalTerm
Namespace Prefix:	amrk_
Data Type:	xbrli:durationItemType
Balance Type:	na
Period Type:	duration

- Definition

Term of lessee's operating lease, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents reported fact of one year, five months, and thirteen days.

+ References

Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 842
-SubTopic 20
-Section 50
-Paragraph 3
-Subparagraph (a)(3)
-URI http://asc.fasb.org/extlink&oid=77888426&loc=SL77918673-209980

+ Details

Name:	us-gaap_LesseeOperatingLeaseTermOfContract
Namespace Prefix:	us-gaap_
Data Type:	xbrli:durationItemType
Balance Type:	na
Period Type:	instant

- Definition

Term of lessor's operating lease renewal, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents reported fact of one year, five months, and thirteen days.

+ References

Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 842
-SubTopic 30
-Section 50
-Paragraph 3
-Subparagraph (a)(3)
-URI http://asc.fasb.org/extlink&oid=119202524&loc=SL77919359-209981

+ Details

Name:	us-gaap_LessorOperatingLeaseRenewalTerm
Namespace Prefix:	us-gaap_
Data Type:	xbrli:durationItemType
Balance Type:	na
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_LongTermPurchaseCommitmentLineItems
Namespace Prefix:	us-gaap_
Data Type:	xbrli:stringItemType
Balance Type:	na
Period Type:	duration

- Definition

Number of units of goods that must be purchased within the specified time period of the agreement to avoid penalties or unfavorable effects on pricing, among other adverse consequences.

+ References

No definition available.

+ Details

Name:	us-gaap_LongTermPurchaseCommitmentMinimumQuantityRequired
Namespace Prefix:	us-gaap_
Data Type:	xbrli:integerItemType
Balance Type:	na
Period Type:	duration

- Definition

Period covered by the long-term purchase commitment, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents the reported fact of one year, five months, and thirteen days.

+ References

No definition available.

+ Details

Name:	us-gaap_LongtermPurchaseCommitmentPeriod
Namespace Prefix:	us-gaap_
Data Type:	xbrli:durationItemType
Balance Type:	na
Period Type:	duration

- Details

Name:	srt_CounterpartyNameAxis=amrk_AsahiRefiningUSAIncandAMSTMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_LongTermPurchaseCommitmentByCategoryOfItemPurchasedAxis=amrk_SilverProductsMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	srt_CounterpartyNameAxis=amrk_AMSTAssociatesLLCMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_SupplyCommitmentAxis=us-gaap_SupplyCommitmentMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type: