Quarterly report pursuant to Section 13 or 15(d)

Inventories - Additional Information (Details)

v3.20.2
Inventories - Additional Information (Details) - USD ($)
 3 Months Ended 12 Months Ended
Sep. 30, 2020
Jun. 30, 2020
Jun. 30, 2019
Inventory [Line Items]      
Inventory held for sale [1] $ 311,582,000 $ 246,603,000  
Precious metals inventory subject to repurchase arrangements 80,800,000 71,000,000  
Consignment arrangements with customers 700,000 2,800,000  
Commemorative coin inventory, held at lower of cost or net realizable value 9,000 17,000 $ 17,000
Product financing arrangement, restricted 101,600,000 74,700,000  
Unrealized (losses) gains included in inventory balance (8,400,000) 6,500,000  
Premium on metals position 6,770,000 3,684,000  
Inventories      
Inventory [Line Items]      
Borrowed precious metals from suppliers 18,800,000 19,300,000  
Inventory held for Sale      
Inventory [Line Items]      
Inventory held for sale $ 211,194,000 $ 153,412,000  
[1] Includes amounts of the consolidated variable interest entity, which is presented separately in the table below.