Insurance Company Subsidiary Operations - Additional Information (Details) $ in Millions		1 Months Ended	3 Months Ended	12 Months Ended
	Jun. 10, 2024 USD ($)	Dec. 31, 2021 USD ($)	Mar. 31, 2025 USD ($) Reinsurer	Dec. 31, 2024 USD ($)
SEC Schedule, 12-17, Insurance Companies, Reinsurance [Line Items]
Ceded rate of premiums under insurance program			100.00%
Ceded unpaid loss			$ 445
Prepaid reinsurance premiums			480	$ 520
Increase (decrease) in loss and loss adjustment expense reserve			$ 0
Number of reinsurers | Reinsurer			2
Premium net written			$ 24
Net earned premiums			19
Ultimate loss reserve expense inclusive of IBNR claims			$ 462	1,543
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			$ 480
Reserve for losses and loss adjustment expense			$ 445
Expenses and allowance rate received in premiums			29.10%
Premiums written net			$ 210
Ceded to highly rated carriers for excess flood policies			1
Statutory capital and surplus required			8
Statutory capital and surplus			46	44
Statutory net Income			$ 1	$ 9
Percentage of adjusted net income			100.00%
Maximum dividend payout that may be made without prior approval			$ 9
Dividend paid	$ 7
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			$ 209
Quota Share Captive
SEC Schedule, 12-17, Insurance Companies, Reinsurance [Line Items]
Deferred acquisitions costs			60
Reinsurance payable			2
Reserve for losses and loss adjustment expense			14
Premiums written net			17
Premium net written			23
Net earned premiums			18
Initial funding		$ 6
Addition to earnings			25
Ultimate loss reserve expense inclusive of IBNR claims			22
Captive Insurance Facility
SEC Schedule, 12-17, Insurance Companies, Reinsurance [Line Items]
Maximum aggregate annual underwriting exposure			2
Captive Insurance Facility | Hurricane Ian
SEC Schedule, 12-17, Insurance Companies, Reinsurance [Line Items]
Reserve for losses and loss adjustment expense			$ 4