v3.10.0.1
Collateralized Transactions (Concentration Risk) (Details) - U.S. Government and Agency Securities and Other Sovereign Government Obligations
12 Months Ended
Dec. 31, 2018
Dec. 31, 2017
Trading Assets    
Concentration Risk    
Concentration Risk, Percentage 12.00% 9.00%
Off Balance Sheet - Collateral Received    
Concentration Risk    
Concentration Risk, Percentage 17.00% 14.00%