Goodwill and Intangible Assets - Goodwill (Details) - USD ($) $ in Thousands	Dec. 31, 2023	Dec. 31, 2022
Goodwill [Line Items]
Goodwill	$ 1,148,926	$ 1,148,926
Operating Segments | Market Making
Goodwill [Line Items]
Goodwill	755,292	755,292
Operating Segments | Execution Services
Goodwill [Line Items]
Goodwill	393,634	393,634
Corporate
Goodwill [Line Items]
Goodwill	$ 0	$ 0