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

Hedging Transactions (Narrative) (Details) (USD $)	3 Months Ended		6 Months Ended
Hedging Transactions (Narrative) (Details) (USD $)	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2014	Dec. 31, 2013	Jun. 30, 2014
Derivative [Line Items]
Realized loss on future commodity contracts, net	$ (28,166,000)	$ 7,567,000	$ (34,522,000)	$ (10,022,000)
Derivative usual settlement period			2 days
Derivative open positions expected settlement period			30 days
Unrealized gains (losses) on foreign exchange	(75,000)	24,000	(84,000)	60,000
Foreign Exchange
Derivative [Line Items]
Open inventory sale commitments	800,000		800,000		2,700,000
Forward contracts
Derivative [Line Items]
Open inventory sale commitments	$ 2,400,000		$ 2,400,000		$ 3,800,000