Quarterly report pursuant to Section 13 or 15(d)

Fair Value of Assets and Liabilities (Narrative) (Details)

v3.7.0.1
Fair Value of Assets and Liabilities (Narrative) (Details) - USD ($)
$ in Thousands
Jun. 30, 2017
Dec. 31, 2016
Schedule of Trading Securities and Other Trading Assets [Line Items]    
Securities owned deposited with the Company's subsidiaries clearing broker $ 3,428 $ 3,161
Securities owned, at fair value 4,267 3,543
Common Stock and Warrants | Warrants to purchase common stock | Level 2    
Schedule of Trading Securities and Other Trading Assets [Line Items]    
Securities owned, at fair value $ 692 $ 252