Insurance Company Subsidiary Operations - Additional Information (Details) $ in Millions		1 Months Ended	6 Months Ended	9 Months Ended	12 Months Ended	22 Months Ended
	Apr. 28, 2023 USD ($)	Dec. 31, 2021 USD ($)	Jun. 30, 2023 USD ($)	Sep. 30, 2023 USD ($) Reinsurer	Dec. 31, 2022 USD ($)	Sep. 30, 2023 USD ($)
SEC Schedule, 12-17, Insurance Companies, Reinsurance [Line Items]
Ceded rate of premiums under insurance program				100.00%		100.00%
Ceded unpaid loss				$ 217.5		$ 217.5
Prepaid reinsurance premiums				502.7	$ 393.2	502.7
Increase (decrease) in loss and loss adjustment expense reserve				0.0
Reinsurance recoverable				220.1	831.0	220.1
Reserve for losses and loss adjustment expense				$ 217.5		217.5
Number of reinsurers | Reinsurer				2
Premium net written				$ 39.9
Net earned premiums				33.7
Ultimate loss reserve expense inclusive of IBNR claims				231.7	841.1	231.7
Hurricane Ian
SEC Schedule, 12-17, Insurance Companies, Reinsurance [Line Items]
Reinsurance recoverable				2.6		2.6
Reinsurance recoverable for net expected loss				4.8		4.8
Loss reserve inclusive of IBNR claims				7.6		7.6
Reported insured losses				$ 1.9		$ 1.9
Wright National Flood Insurance Company
SEC Schedule, 12-17, Insurance Companies, Reinsurance [Line Items]
Ceded rate of premiums under insurance program				100.00%		100.00%
Prepaid reinsurance premiums				$ 475.4		$ 475.4
Expenses and allowance rate received in premiums				29.70%		29.70%
Premiums written net				$ 681.8
Ceded to highly rated carriers for excess flood policies				2.5
Statutory capital and surplus required				7.5		$ 7.5
Statutory capital and surplus				39.0	31.8	$ 39.0
Statutory net Income				$ 8.1	$ 1.3
Percentage of adjusted net income				100.00%		100.00%
Maximum dividend payout that may be made without prior approval				$ 3.2		$ 3.2
Dividend paid	$ 3.1
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				$ 679.3
Quota Share Captive
SEC Schedule, 12-17, Insurance Companies, Reinsurance [Line Items]
Prepaid reinsurance premiums				27.4		27.4
Deferred acquisitions costs				29.7		29.7
Reserve for losses and loss adjustment expense				8.2		8.2
Premiums written net				46.3
Premium net written				37.4
Net earned premiums				31.2
Initial funding		$ 5.9
Addition to current earnings						16.1
Ultimate loss reserve expense inclusive of IBNR claims				9.8		9.8
Captive Insurance Facility
SEC Schedule, 12-17, Insurance Companies, Reinsurance [Line Items]
Reserve for losses and loss adjustment expense				6.0		6.0
Net earned premiums				2.5
Maximum underwriting exposure			$ 3.0
Captive Insurance Facility | Hurricane Ian
SEC Schedule, 12-17, Insurance Companies, Reinsurance [Line Items]
Reserve for losses and loss adjustment expense				$ 5.4		$ 5.4