v3.26.1
Financial Instruments Owned and Financial Instruments Sold, But Not Yet Purchased (Components of Trading Securities Owned and Trading Securities Sold, But Not Yet Purchased) (Details) - USD ($)
$ in Thousands
Mar. 31, 2026
Dec. 31, 2025
Schedule Of Trading Securities And Other Trading Assets [Line Items]    
Financial instruments owned, at fair value $ 1,657,349 $ 1,427,835
Securities Sold, But Not yet Purchased [Member]    
Schedule Of Trading Securities And Other Trading Assets [Line Items]    
Other [1] 1,216 1,249
Financial instruments owned, at fair value 924,385 793,626
Securities Sold, But Not yet Purchased [Member] | Corporate Fixed Income Securities [Member]    
Schedule Of Trading Securities And Other Trading Assets [Line Items]    
Fixed income securities 155,972 145,582
Securities Sold, But Not yet Purchased [Member] | Corporate Equity Securities [Member]    
Schedule Of Trading Securities And Other Trading Assets [Line Items]    
Financial instruments owned, at fair value 9,248 16,363
Securities Sold, But Not yet Purchased [Member] | U.S. Government Securities [Member]    
Schedule Of Trading Securities And Other Trading Assets [Line Items]    
Trading securities owned 603,437 475,449
Securities Sold, But Not yet Purchased [Member] | Mortgage-Backed Securities [Member] | Agency Securities [Member]    
Schedule Of Trading Securities And Other Trading Assets [Line Items]    
Trading securities owned 154,512 154,983
Securities Owned [Member]    
Schedule Of Trading Securities And Other Trading Assets [Line Items]    
Asset-backed securities 132,752 143,723
Other [2] 81,783 63,343
Financial instruments owned, at fair value 1,657,349 1,427,835
Securities Owned [Member] | U.S. Government Agency Securities [Member]    
Schedule Of Trading Securities And Other Trading Assets [Line Items]    
Trading securities owned 321,696 174,478
Securities Owned [Member] | Corporate Fixed Income Securities [Member]    
Schedule Of Trading Securities And Other Trading Assets [Line Items]    
Fixed income securities 332,056 295,570
Securities Owned [Member] | Corporate Equity Securities [Member]    
Schedule Of Trading Securities And Other Trading Assets [Line Items]    
Financial instruments owned, at fair value 60,180 55,312
Securities Owned [Member] | State and Municipal Securities [Member]    
Schedule Of Trading Securities And Other Trading Assets [Line Items]    
State and municipal securities 222,931 174,579
Securities Owned [Member] | U.S. Government Securities [Member]    
Schedule Of Trading Securities And Other Trading Assets [Line Items]    
Trading securities owned 8,227 5,196
Securities Owned [Member] | Mortgage-Backed Securities [Member] | Agency Securities [Member]    
Schedule Of Trading Securities And Other Trading Assets [Line Items]    
Trading securities owned $ 497,724 $ 515,634
[1] Includes syndicated loans and state and municipal securities.
[2] Includes syndicated loans, non-agency mortgage-backed securities, and sovereign debt.