v3.26.1
Commitments and Contingencies (Legal) (Details)
$ in Millions
Jun. 30, 2026
USD ($)
Financial Instruments Owned and Pledged as Collateral [Line Items]  
Collateral securities $ 837.3
Collateral security (Fair value) 1,200.0
Amount pledged with client-owned securities 526.6
Remaining collateral securities that can be re-pledged, loaned, or sold 645.6
Options Clearing Corporation [Member]  
Financial Instruments Owned and Pledged as Collateral [Line Items]  
Marketable Securities 15.0
National Securities Clearing Corporation [Member]  
Financial Instruments Owned and Pledged as Collateral [Line Items]  
Marketable Securities $ 25.0