v3.26.1
Financial Instruments Owned and Financial Instruments Sold, But Not Yet Purchased (Narrative) (Details) - USD ($)
$ in Millions
Jun. 30, 2026
Dec. 31, 2025
Schedule Of Trading Securities And Other Trading Assets [Line Items]    
Financial instruments pledged as collateral $ 1,200.0 $ 880.5
Securities Owned [Member]    
Schedule Of Trading Securities And Other Trading Assets [Line Items]    
Financial instruments pledged as collateral $ 870.1 $ 523.4