Annual report [Section 13 and 15(d), not S-K Item 405]

Long-Term Investments - Schedule of Carrying Value and Ownership Percentage of Investment (Parenthetical) (Details)

v3.25.2
Long-Term Investments - Schedule of Carrying Value and Ownership Percentage of Investment (Parenthetical) (Details)
Jun. 30, 2025
Apr. 30, 2025
Feb. 28, 2025
Jun. 30, 2024
AMS Holding, LLC        
Schedule Of Equity And Cost Method Investments [Line Items]        
Ownership percentage   90.00%    
AMS Holding, LLC | APS Investment, LLC        
Schedule Of Equity And Cost Method Investments [Line Items]        
Ownership percentage       10.00%
APS Investment, LLC        
Schedule Of Equity And Cost Method Investments [Line Items]        
Ownership percentage [1] 0.00%     33.30%
APS Investment, LLC | Spectrum Group International, Inc. and Pinehurst Coin Exchange, Inc.        
Schedule Of Equity And Cost Method Investments [Line Items]        
Ownership percentage     100.00%  
APS Investment, LLC | Pinehurst Coin Exchange, Inc.        
Schedule Of Equity And Cost Method Investments [Line Items]        
Ownership percentage       33.30%
APS Investment, LLC | Stack's Bowers Numismatics, LLC        
Schedule Of Equity And Cost Method Investments [Line Items]        
Ownership percentage       33.30%
[1] APS Investment, LLC is a holding company that as of June 30, 2024 owned a 10% equity interest in AMS Holding, LLC. A-Mark, Pinehurst Coin Exchange, Inc. and Stack's Bowers Galleries each own a one-third equity interest in APS Investment, LLC. In February 2025, the Company acquired both SGI, the parent of Stack's Bowers Galleries, and Pinehurst; as a result, the Company owned 100% of APS Investment, LLC. In April 2025, the Company acquired the remaining 90% of AMS Holding, LLC it did not previously own.