Quarterly report pursuant to Section 13 or 15(d)

Subsequent Events (Narrative) (Details)

v3.19.3.a.u2
Subsequent Events (Narrative) (Details) - Trading Credit Facility - Trading Credit Facility - Line of Credit - A-Mark - USD ($)
Jan. 13, 2020
Dec. 31, 2019
Subsequent Event [Line Items]    
Line of credit, current borrowing capacity   $ 210,000,000
Line of credit, accordion option   50,000,000
Line of credit facility, maximum borrowing capacity   $ 260,000,000
Subsequent Event    
Subsequent Event [Line Items]    
Line of credit, current borrowing capacity $ 220,000,000  
Line of credit, accordion option 50,000,000  
Line of credit facility, maximum borrowing capacity $ 270,000,000