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

Quarterly report pursuant to Section 13 or 15(d)

Financing Agreements (Narrative) (Details)

Financing Agreements (Narrative) (Details) (USD $)	3 Months Ended		6 Months Ended		0 Months Ended
Financing Agreements (Narrative) (Details) (USD $)	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2014	Dec. 31, 2013	Sep. 12, 2014	Jun. 30, 2014	Mar. 31, 2014
Schedule Of Financing Arrangements [Line Items]
Interest expense, notes payable	$ 800,000us-gaap_InterestExpenseDebt	$ 800,000us-gaap_InterestExpenseDebt
Percentage of total expense recognized	84.60%	89.40%	86.30%	85.80%
Effective rate of interest	2.84%	3.22%	2.95%	3.19%
Liability on borrowed metals	5,684,000amrk_LiabilityOnBorrowedMetals		5,684,000amrk_LiabilityOnBorrowedMetals			8,709,000amrk_LiabilityOnBorrowedMetals
Product financing obligation	80,660,000		80,660,000			24,610,000
Sixth Participant \| Line of credit
Schedule Of Financing Arrangements [Line Items]
Line of credit, maximum borrowing capacity					50,000,000.0
Trading credit facility \| Line of credit
Schedule Of Financing Arrangements [Line Items]
Interest expense, notes payable			1,800,000	1,600,000
Trading credit facility \| A-Mark \| Line of credit
Schedule Of Financing Arrangements [Line Items]
Line of credit, maximum borrowing capacity	220,000,000		220,000,000
Variable rate basis			one-month LIBOR
Credit facility, interest rate at period end	0.17%		0.17%			0.15%
Borrowings due on demand	151,000,000		151,000,000			135,200,000
Credit facility, remaining borrowing capacity	19,500,000		19,500,000			14,400,000
Credit facility, minimum required tangible net worth	25,000,000				35,000,000
Trading credit facility \| Certain lender common to SNI and A-Mark \| A-Mark \| Line of credit
Schedule Of Financing Arrangements [Line Items]
Line of credit, maximum borrowing capacity	20,000,000		20,000,000
Trading credit facility \| Certain lender common to SNI and A-Mark \| SNI and A-Mark \| Line of credit
Schedule Of Financing Arrangements [Line Items]
Line of credit, maximum borrowing capacity							23,000,000
Trading credit facility \| Certain lender common to SNI and A-Mark \| SNI \| Line of credit
Schedule Of Financing Arrangements [Line Items]
Line of credit, maximum borrowing capacity							5,000,000
Collectibles credit facility \| Certain lender common to SNI and A-Mark \| SNI \| Line of credit
Schedule Of Financing Arrangements [Line Items]
Credit facility, remaining borrowing capacity	$ 0		$ 0			$ 3,300,000