Significant Accounting Policies - Summary of Post-Trade Services Revenue by Timing of Recognition (Detail) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2023	Jun. 30, 2022	Jun. 30, 2023	Jun. 30, 2022
Significant Accounting Policies [Line Items]
Revenues	$ 179,846	$ 182,229	$ 383,015	$ 368,286
Post-trade Services [Member]
Significant Accounting Policies [Line Items]
Revenues	9,415	9,144	19,395	19,056
Post-trade Services [Member] | Transferred over Time [Member]
Significant Accounting Policies [Line Items]
Revenues	9,397	9,143	19,352	19,014
Post-trade Services [Member] | Transferred at a Point in Time [Member]
Significant Accounting Policies [Line Items]
Revenues	$ 18	$ 1	$ 43	$ 42