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

Quarterly report pursuant to Section 13 or 15(d)

Related Party Transactions (Details)

Related Party Transactions (Details) (USD $)	3 Months Ended		6 Months Ended		0 Months Ended
Related Party Transactions (Details) (USD $)	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2014	Dec. 31, 2013	Jul. 02, 2013	Jul. 02, 2014	Jun. 30, 2014	Jun. 18, 2014	Jun. 05, 2014	Oct. 09, 2014
Related Party Transaction [Line Items]
Sales	$ 1,530,000amrk_SaleofInventoryofRelatedParty	$ 4,571,000amrk_SaleofInventoryofRelatedParty	$ 3,082,000amrk_SaleofInventoryofRelatedParty	$ 8,437,000amrk_SaleofInventoryofRelatedParty
Purchases	3,617,000amrk_PurchasesOfInventoryRelatedParty	4,298,000amrk_PurchasesOfInventoryRelatedParty	6,538,000amrk_PurchasesOfInventoryRelatedParty	6,749,000amrk_PurchasesOfInventoryRelatedParty
Receivable	8,539,000us-gaap_DueFromRelatedParties		8,539,000us-gaap_DueFromRelatedParties				5,852,000us-gaap_DueFromRelatedParties
Payables	17,000		17,000				272,000
Short term loan receivable						3,700,000		2,600,000	3,800,000
Income taxes receivable from Former Parent	3,139,000us-gaap_DueFromRelatedPartiesCurrent		3,139,000us-gaap_DueFromRelatedPartiesCurrent				3,139,000us-gaap_DueFromRelatedPartiesCurrent
Calzona
Related Party Transaction [Line Items]
Sales	0	1,481,000	157,000	2,349,000
Purchases	0	354,000	0	354,000
Receivable	0		0				0
Payables	0		0				67,000
SNI
Related Party Transaction [Line Items]
Sales	386,000	1,616,000	610,000	3,787,000
Purchases	2,145,000	1,794,000	3,793,000	2,260,000
Receivable	0		0				0
Payables	10,000		10,000				72,000
Stack Bowers Galleries
Related Party Transaction [Line Items]
Sales	722,000	856,000	1,300,000	1,202,000
Purchases	569,000	1,529,000	1,467,000	2,650,000
Receivable	5,325,000		5,325,000				2,563,000
Payables	0		0				0
Short term loan receivable	0		0				2,600,000	2,600,000
Rate of interest (percentage)								5.50%
Teletrade (now doing business as Stack's Bowers)
Related Party Transaction [Line Items]
Sales	422,000	618,000	1,015,000	1,099,000
Purchases	903,000	621,000	1,278,000	1,485,000
Receivable	0		0				0
Payables	7,000		7,000				133,000
SGI (Former Parent)
Related Party Transaction [Line Items]
Receivable	3,214,000		3,214,000				3,289,000
Payables	0		0				0
Corporate overhead charges payable to SNI			0	400,000
Dividends paid to SGI			0	5,000,000	5,000,000
Former owner
Related Party Transaction [Line Items]
Payment related to royalty agreement with former owner	130,000	110,000
Royalty expense	130,000		130,000				200,000
Line of Credit [Member] \| Stack Bowers Galleries
Related Party Transaction [Line Items]
Short term loan receivable	5,300,000		5,300,000
Line of credit, maximum borrowing capacity										$ 16,000,000.0