Annual report pursuant to Section 13 and 15(d)

Derivative Instruments and Hedging Transactions (Hedging of Precious Metals Inventory) (Details)

v3.7.0.1
Derivative Instruments and Hedging Transactions (Hedging of Precious Metals Inventory) (Details) - USD ($)
$ in Thousands
Jun. 30, 2017
Jun. 30, 2016
Derivatives, Fair Value [Line Items]    
Inventory $ 284,659 $ 245,057
Commemorative coin inventory, held at lower of cost or market (40) (16)
Premium on metals position (4,088) (4,627)
Inventory value not hedged (4,128) (4,643)
Subtotal 280,531 240,414
Commitments at market:    
Open inventory purchase commitments 587,687 550,810
Open inventory sales commitments (121,602) (237,325)
Margin sale commitments (7,936) (12,439)
In-transit inventory no longer subject to market risk (3,931) (7,363)
Unhedgable premiums on open commitment positions 495 400
Inventory borrowed from suppliers (5,625) (4,352)
Product financing arrangements (135,343) (59,358)
Advances on industrial metals 1,580 4,521
Inventory subject to price risk 595,856 475,308
Inventory subject to derivative financial instruments:    
Market value of derivative financial instruments 595,681 474,979
Net inventory subject to commodity price risk 175 329
Precious metals forward contracts at market values    
Inventory subject to derivative financial instruments:    
Market value of derivative financial instruments 462,231 188,530
Precious metals futures contracts at market values    
Inventory subject to derivative financial instruments:    
Market value of derivative financial instruments $ 133,450 $ 286,449