Variable Interest Entities - Summary of Fair Value of Fixed Income Securities, by Asset-Type, Held by Consolidated Variable Interest Entities (Detail) - USD ($) $ in Thousands	Dec. 31, 2024	Dec. 31, 2023
Variable Interest Entities [Line Items]
Fixed income securities, amortized cost	$ 289,712	$ 341,685
Debt Securities, Available-for-sale, Accumulated Gross Unrealized Gain, before Tax	260	643
Corporate Obligations [Member]
Variable Interest Entities [Line Items]
Fixed income securities, amortized cost	92,990	92,694
Debt Securities, Available-for-sale, Accumulated Gross Unrealized Gain, before Tax	107	262
Municipal Bonds [Member]
Variable Interest Entities [Line Items]
Fixed income securities, amortized cost	14,646	9,394
Debt Securities, Available-for-sale, Accumulated Gross Unrealized Gain, before Tax	$ 7	$ 13