Quarterly report pursuant to Section 13 or 15(d)

Off-Balance-Sheet Risk and Concentration of Credit Risk (Detail)

v3.5.0.2
Off-Balance-Sheet Risk and Concentration of Credit Risk (Detail)
$ in Thousands
9 Months Ended
Sep. 30, 2016
USD ($)
clearing_broker
Dec. 31, 2015
USD ($)
Risks and Uncertainties [Abstract]    
Number of clearing brokers | clearing_broker 3  
Receivables from clearing broker | $ $ 35,018 $ 44,466