Receivables from and Payables to Broker-dealers, Clearing Organizations and Customers - Schedule of Receivables from and Payables to Broker-dealers, Clearing Organizations and Customers (Detail) - USD ($) $ in Thousands	Dec. 31, 2023	Dec. 31, 2022
Receivables from broker-dealers, clearing organizations and customers:
Securities failed-to-deliver - broker-dealers and clearing organizations	$ 282,125	$ 144,523
Securities failed-to-deliver - customers	284,322	235,056
Deposits with clearing organizations and broker-dealers	115,151	88,923
Other	6,338	7,833
Total	687,936	476,335
Payables to broker-dealers, clearing organizations and customers:
Securities failed-to-receive - broker-dealers and clearing organizations	125,022	224,816
Securities failed-to-receive - customers	405,186	71,828
Other	7,190	7,349
Total	$ 537,398	$ 303,993