Accounts Payable and Other Current Liabilities - Additional Information (Details) - USD ($) $ in Millions	Dec. 31, 2025	Jun. 30, 2025
Accounts Payable And Other Current Liabilities [Abstract]
Advances related to precious metals leases	$ 280.5	$ 246.5

Accounts payable advance to precious metals leases.

No definition available.

Name:	gold_AccountsPayableAdvanceToPreciousMetalsLeases
Namespace Prefix:	gold_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant