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	Jun. 30, 2023	Dec. 31, 2022
Receivables from broker-dealers, clearing organizations and customers:
Securities failed-to-deliver - broker-dealers and clearing organizations	$ 115,280	$ 144,523
Securities failed-to-deliver - customers	249,698	235,056
Deposits with clearing organizations and broker-dealers	108,719	88,923
Other	6,044	7,833
Total	479,741	476,335
Payables to broker-dealers, clearing organizations and customers:
Securities failed-to-receive - broker-dealers and clearing organizations	168,100	224,816
Securities failed-to-receive - customers	113,186	71,828
Other	6,074	7,349
Total	$ 287,360	$ 303,993