Insurance Company Subsidiary Operations - Additional Information (Details)	1 Months Ended	9 Months Ended	10 Months Ended	12 Months Ended
	Dec. 31, 2021 USD ($)	Sep. 30, 2022 USD ($) Reinsurer	Sep. 30, 2022 USD ($)	Dec. 31, 2021 USD ($)
SEC Schedule, 12-17, Insurance Companies, Reinsurance [Line Items]
Ceded rate of premiums under insurance program		100.00%	100.00%
Prepaid reinsurance premiums	$ 392,200,000	$ 409,900,000	$ 409,900,000	$ 392,200,000
Increase (decrease) in loss and loss adjustment expense reserve		0
Reinsurance recoverable	63,100,000	1,021,600,000	1,021,600,000	63,100,000
Reserve for losses and loss adjustment expense		$ 1,014,800,000	1,014,800,000
Number of reinsurers | Reinsurer		2
Premium net written		$ 31,700,000
Net earned premiums		18,100,000
Ultimate loss reserve expense inclusive of IBNR claims	63,100,000	1,033,500,000	1,033,500,000	63,100,000
Hurricane Ian
SEC Schedule, 12-17, Insurance Companies, Reinsurance [Line Items]
Reinsurance recoverable		6,800,000	6,800,000
Reinsurance recoverable for net expected loss		4,400,000	4,400,000
Loss reserve inclusive of IBNR claims		11,200,000	11,200,000
Reported insured losses		$ 0	$ 0
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%
Ceded unpaid loss		$ 1,014,800,000	$ 1,014,800,000
Prepaid reinsurance premiums		$ 397,100,000	$ 397,100,000
Expenses and allowance rate received in premiums		29.90%	29.90%
Premiums written net		$ 567,900,000
Ceded to highly rated carriers for excess flood policies		2,200,000
Statutory capital and surplus required		7,500,000	$ 7,500,000
Statutory capital and surplus	33,100,000	33,500,000	$ 33,500,000	33,100,000
Statutory net Income		$ 600,000		$ 1,600,000
Percentage of adjusted net income		100.00%	100.00%
Maximum dividend payout that may be made without prior approval		$ 3,300,000	$ 3,300,000
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		$ 565,700,000
Quota Share Captive
SEC Schedule, 12-17, Insurance Companies, Reinsurance [Line Items]
Prepaid reinsurance premiums		12,800,000	12,800,000
Deferred acquisitions costs		13,500,000	13,500,000
Reinsurance payable		8,900,000	8,900,000
Reserve for losses and loss adjustment expense		11,700,000	11,700,000
Premiums written net		22,300,000
Premium net written		31,700,000
Net earned premiums		13,500,000
Initial funding	$ 5,900,000
Addition to current earnings			1,800,000
Ultimate loss reserve expense inclusive of IBNR claims		11,700,000	11,700,000
Captive Insurance Facility
SEC Schedule, 12-17, Insurance Companies, Reinsurance [Line Items]
Net earned premiums		4,600,000
Loss reserve inclusive of IBNR claims		100,000	100,000
Maximum underwriting exposure		5,200,000
Captive Insurance Facility | Hurricane Ian
SEC Schedule, 12-17, Insurance Companies, Reinsurance [Line Items]
Reserve for losses and loss adjustment expense		7,000,000.0	7,000,000.0
Net earned premiums		2,200,000
Loss reserve inclusive of IBNR claims		7,000,000.0	$ 7,000,000.0
Reserve partially offset by accelerated earned premiums		2,400,000
Underwriting loss		$ 2,400,000