Leases - Schedule of Components of Operating Lease Expense (Detail) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2023	Dec. 31, 2022	Dec. 31, 2021
Lease Cost [Line Items]
Net operating lease cost	$ 13,196	$ 13,175	$ 13,190
Finance lease cost - interest	100
Other, net [Member]
Lease Cost [Line Items]
Operating lease cost for subleased/assigned properties	0	469	2,054
Sublease income	0	(405)	(2,079)
Occupancy [Member]
Lease Cost [Line Items]
Operating lease cost - office space	12,861	13,015	13,202
Variable lease costs	237	96	13
Technology and Communications [Member]
Lease Cost [Line Items]
Operating lease cost - equipment	$ 98	$ 0	$ 0