Losses and Loss Adjustment Expenses - Reconciliation of Net Incurred and Paid Loss Development Tables to Liability for Losses and Loss Adjustment Expenses (Detail) - USD ($) $ in Thousands	Dec. 31, 2023	Dec. 31, 2022		Dec. 31, 2021		Dec. 31, 2020	[1]
Shortduration Insurance Contracts Reconciliation Of Claims Development To Liability [Line Items]
Liabilities for unpaid losses and loss adjustment expenses, net of reinsurance	$ 254,351	$ 246,546	[1]	$ 172,410	[1]	$ 141,065
Add: reinsurance recoverable before allowance for credit losses	330,722	617,219		64,755
Total gross liability for unpaid losses and loss adjustment expenses	585,073	863,765		$ 237,165
Homeowners Multi-peril and Dwelling Fire Insurance [Member]
Shortduration Insurance Contracts Reconciliation Of Claims Development To Liability [Line Items]
Liabilities for unpaid losses and loss adjustment expenses, net of reinsurance	218,993	201,627
Homeowners Wind-only Insurance [Member]
Shortduration Insurance Contracts Reconciliation Of Claims Development To Liability [Line Items]
Liabilities for unpaid losses and loss adjustment expenses, net of reinsurance	3,573	3,082
Losses Specific To Any Hurricane And Storm Events Prior To 2023 [Member]
Shortduration Insurance Contracts Reconciliation Of Claims Development To Liability [Line Items]
Liabilities for unpaid losses and loss adjustment expenses, net of reinsurance	31,773	41,380
Other Short-Duration Insurance Lines [Member]
Shortduration Insurance Contracts Reconciliation Of Claims Development To Liability [Line Items]
Liabilities for unpaid losses and loss adjustment expenses, net of reinsurance	$ 12	$ 457

[1] Net balance represents beginning-of-year liability for unpaid losses and LAE less beginning-of-year reinsurance recoverable for unpaid losses and LAE.