| Inventories - Summary of Components of Inventory (Details) - USD ($) $ in Thousands | Mar. 31, 2025 | Jun. 30, 2024 | 
|---|---|---|
| Inventory [Line Items] | ||
| Inventories | $ 759,581 | $ 579,400 | 
| Restricted inventories | 556,828 | 517,744 | 
| Restricted and non-restricted inventory, net | 1,316,409 | 1,097,144 | 
| Inventory held for Sale | ||
| Inventory [Line Items] | ||
| Inventories | 532,631 | 342,196 | 
| Repurchase Arrangements with Customers | ||
| Inventory [Line Items] | ||
| Inventories | 122,238 | 199,559 | 
| Consignment Arrangements with Customers | ||
| Inventory [Line Items] | ||
| Inventories | 1,719 | 2,416 | 
| Collectible Coins, Held at Lower of Cost or Net Realizable Value | ||
| Inventory [Line Items] | ||
| Inventories | 58,769 | 3,236 | 
| Borrowed Precious Metals | ||
| Inventory [Line Items] | ||
| Inventories | 44,224 | 31,993 | 
| Product Financing Arrangements | ||
| Inventory [Line Items] | ||
| Restricted inventories | $ 556,828 | $ 517,744 | 
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- Definition Restricted and Non-Restricted Inventory, Net No definition available. 
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- Definition Restricted Inventory No definition available. 
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- Definition Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table. No definition available. 
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- Definition Amount after valuation and LIFO reserves of inventory expected to be sold, or consumed within one year or operating cycle, if longer. Reference 1: http://www.xbrl.org/2003/role/exampleRef 
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