Insurance Company Subsidiary Operations - Additional Information (Details) $ in Millions			1 Months Ended	12 Months Ended
	Jun. 10, 2024 USD ($)	Apr. 28, 2023 USD ($)	Dec. 31, 2021 USD ($)	Dec. 31, 2024 USD ($) Reinsurer	Dec. 31, 2023 USD ($)	Dec. 31, 2025 USD ($)	Sep. 30, 2024
SEC Schedule, 12-17, Insurance Companies, Reinsurance [Line Items]
Ceded unpaid loss				$ 1,525	$ 125
Prepaid reinsurance premiums				520	462
Increase (decrease) in loss and loss adjustment expense reserve				0	0
Reinsurance recoverable				1,527	125
Premium net written				79	61
Net earned premiums				77	28
Ultimate loss reserve expense inclusive of IBNR claims				$ 1,543	131
Wright National Flood Insurance Company
SEC Schedule, 12-17, Insurance Companies, Reinsurance [Line Items]
Ceded rate of premiums under insurance program				100.00%
Prepaid reinsurance premiums				$ 520	461
Expenses and allowance rate received in premiums				29.10%			29.50%
Reserve for losses and loss adjustment expense				$ 1,525	125
Number of reinsurers | Reinsurer				2
Premiums written net				$ 1,005	887
Statutory capital and surplus required				8
Statutory capital and surplus				44	39
Statutory net Income				$ 9	8
Percentage of adjusted net income				100.00%
Maximum dividend payout that may be made without prior approval				$ 8
Dividend paid	$ 7	$ 3
Ceded to highly rated carriers for excess flood policies				$ 4	4
Wright National Flood Insurance Company | Scenario Forecast
SEC Schedule, 12-17, Insurance Companies, Reinsurance [Line Items]
Maximum dividend payout that may be made without prior approval						$ 9
Wright National Flood Insurance Company | Maximum
SEC Schedule, 12-17, Insurance Companies, Reinsurance [Line Items]
Preferred stock, dividend rate, percentage				10.00%
Wright National Flood Insurance Company | FEMA
SEC Schedule, 12-17, Insurance Companies, Reinsurance [Line Items]
Premiums written net				$ 1,001	883
Quota Share Captive
SEC Schedule, 12-17, Insurance Companies, Reinsurance [Line Items]
Ceded unpaid loss				2
Deferred acquisitions costs				53
Reinsurance payable				5
Reserve for losses and loss adjustment expense				14
Premium net written				75
Premiums written net				74	52
Net earned premiums				73
Initial funding			$ 6
Addition to earnings				18
Ultimate loss reserve expense inclusive of IBNR claims				21
Captive Insurance Facility
SEC Schedule, 12-17, Insurance Companies, Reinsurance [Line Items]
Net earned premiums				4	4
Maximum Underwriting Exposure				2
Captive Insurance Facility | Hurricane Ian
SEC Schedule, 12-17, Insurance Companies, Reinsurance [Line Items]
Reserve for losses and loss adjustment expense				$ 3	$ 2