Quarterly report pursuant to Section 13 or 15(d)

Receivables (Narrative) (Details)

v2.4.0.8
Receivables (Narrative) (Details) (USD $)
 3 Months Ended 6 Months Ended 12 Months Ended 1 Months Ended 0 Months Ended 3 Months Ended 1 Months Ended
Dec. 31, 2013
class
Sep. 30, 2013
Dec. 31, 2013
Dec. 31, 2012
Jun. 30, 2013
Sep. 27, 2013
Dec. 31, 2013
Maximum
Jun. 30, 2013
Maximum
Dec. 31, 2011
A-Mark
Dec. 30, 2012
A-Mark
Oct. 31, 2011
A-Mark
Sep. 27, 2013
Collateral Finance Corporation
Dec. 31, 2012
Due From M.F. Global, Inc. Trustee
A-Mark
Jul. 31, 2012
Due From M.F. Global, Inc. Trustee
A-Mark
Dec. 31, 2011
Due From M.F. Global, Inc. Trustee
A-Mark
Jul. 31, 2012
Receivables and Secured Loans, Gross - Trading Operations
A-Mark
Accounts, Notes, Loans and Financing Receivable [Line Items]                                
Loans receivable average effective rate of interest (percentage)     7.90%   8.00%                      
Commodities Account Segregated Balance Amount Held By Broker At Bankruptcy                     $ 20,300,000          
Commodities Amount Segregated Amount Returned Subsequent To Broker Bankruptcy                 14,600,000              
Commodities Account Segregated Percentage Returned Subsequent To Broker Bankruptcy                 72.00%              
Receivables and Secured Loans Gross - Trading Operations 83,356,000   83,356,000   94,613,000                 4,100,000 5,700,000  
Proceeds from Bankruptcy Claims                               1,600,000
Proceeds from Sale of Other Receivables                         3,800,000      
Allowance for Doubtful Other Receivables, Current                   (1,000,000)            
Allowance for Doubtful Accounts Receivable, Recoveries       700,000                        
Payments to Acquire Loans Receivable                       350,000        
Loans and Leases Receivable, Gross           12,800,000                    
Option to extend maturity   180 days                            
Repayments of Debt 2,300,000                              
Amortization of debt discount 100,000                              
Classes of Receivables 2                              
Impaired Financing Receivable, Recorded Investment $ 0   $ 0   $ 70,000                      
Loans Receivable Payment Terms For Interest     30 days                          
Loans Receivable Delinquent Period, Provision For Default 30 days   30 days                          
Loan Receivable Liquidation Period Post Default 90 days   90 days                          
Credit Quality Indicator Loan-to-value Threshold Percentage 75.00%                              
Secured Loans-to-Value Percentage             100.00% 100.00%