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Reinsurance Recoverable Credit Ratings (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2023	Dec. 31, 2022	Mar. 31, 2022	Dec. 31, 2021
Reinsurance Recoverable, Credit Quality Indicator [Line Items]
Reinsurance recoverable, gross	$ 669,342	$ 784,410
Reinsurance Recoverable, Allowance for Credit Loss	(2,300)	(1,600)	$ (1,600)	$ (1,600)
Reinsurance recoverable, net of allowance for credit losses	$ 667,042	782,810
National Flood Insurance Program [Member]
Reinsurance Recoverable, Credit Quality Indicator [Line Items]
Percentage of unpaid NFIP Claims ceded to federal government	100.00%
Reinsurance Recoverable for Paid and Unpaid Claims and Claims Adjustments, Gross [Member] | Financial Asset, Past Due
Reinsurance Recoverable, Credit Quality Indicator [Line Items]
Reinsurance Recoverables, Gross	$ 6,730	5,011
Reinsurance Recoverable for Paid and Unpaid Claims and Claims Adjustments, Gross [Member] | Financial Asset, Not Past Due
Reinsurance Recoverable, Credit Quality Indicator [Line Items]
Reinsurance Recoverables, Gross	662,612	779,399
Total federal and state pools [Member]
Reinsurance Recoverable, Credit Quality Indicator [Line Items]
Reinsurance Recoverables, Gross	104,500	180,794
Change in Reinsurance Recoverable, Gross	(76,300)
Total federal and state pools [Member] | Financial Asset, Past Due
Reinsurance Recoverable, Credit Quality Indicator [Line Items]
Reinsurance Recoverables, Gross	0	0
Total federal and state pools [Member] | Financial Asset, Not Past Due
Reinsurance Recoverable, Credit Quality Indicator [Line Items]
Reinsurance Recoverables, Gross	104,500	180,794
Other than Federal And State Pools [Member]
Reinsurance Recoverable, Credit Quality Indicator [Line Items]
Reinsurance Recoverables, Gross	7,302	14,093
Other than Federal And State Pools [Member] | Financial Asset, Past Due
Reinsurance Recoverable, Credit Quality Indicator [Line Items]
Reinsurance Recoverables, Gross	497	415
Other than Federal And State Pools [Member] | Financial Asset, Not Past Due
Reinsurance Recoverable, Credit Quality Indicator [Line Items]
Reinsurance Recoverables, Gross	6,805	13,678
Non Rated Reinsurer [Member]
Reinsurance Recoverable, Credit Quality Indicator [Line Items]
Reinsurance Recoverables, Gross	111,802	194,887
Non Rated Reinsurer [Member] | Financial Asset, Past Due
Reinsurance Recoverable, Credit Quality Indicator [Line Items]
Reinsurance Recoverables, Gross	497	415
Non Rated Reinsurer [Member] | Financial Asset, Not Past Due
Reinsurance Recoverable, Credit Quality Indicator [Line Items]
Reinsurance Recoverables, Gross	111,305	194,472
AM Best, A++ Rating [Member]
Reinsurance Recoverable, Credit Quality Indicator [Line Items]
Reinsurance Recoverables, Gross	81,143	46,283
AM Best, A++ Rating [Member] | Financial Asset, Past Due
Reinsurance Recoverable, Credit Quality Indicator [Line Items]
Reinsurance Recoverables, Gross	356	1
AM Best, A++ Rating [Member] | Financial Asset, Not Past Due
Reinsurance Recoverable, Credit Quality Indicator [Line Items]
Reinsurance Recoverables, Gross	80,787	46,282
AM Best, A+ Rating [Member]
Reinsurance Recoverable, Credit Quality Indicator [Line Items]
Reinsurance Recoverables, Gross	350,723	428,586
AM Best, A+ Rating [Member] | Financial Asset, Past Due
Reinsurance Recoverable, Credit Quality Indicator [Line Items]
Reinsurance Recoverables, Gross	3,825	3,191
AM Best, A+ Rating [Member] | Financial Asset, Not Past Due
Reinsurance Recoverable, Credit Quality Indicator [Line Items]
Reinsurance Recoverables, Gross	346,898	425,395
AM Best, A Rating [Member]
Reinsurance Recoverable, Credit Quality Indicator [Line Items]
Reinsurance Recoverables, Gross	121,899	107,417
AM Best, A Rating [Member] | Financial Asset, Past Due
Reinsurance Recoverable, Credit Quality Indicator [Line Items]
Reinsurance Recoverables, Gross	1,963	1,315
AM Best, A Rating [Member] | Financial Asset, Not Past Due
Reinsurance Recoverable, Credit Quality Indicator [Line Items]
Reinsurance Recoverables, Gross	119,936	106,102
AM Best, A- Rating [Member]
Reinsurance Recoverable, Credit Quality Indicator [Line Items]
Reinsurance Recoverables, Gross	3,775	7,237
AM Best, A- Rating [Member] | Financial Asset, Past Due
Reinsurance Recoverable, Credit Quality Indicator [Line Items]
Reinsurance Recoverables, Gross	89	89
AM Best, A- Rating [Member] | Financial Asset, Not Past Due
Reinsurance Recoverable, Credit Quality Indicator [Line Items]
Reinsurance Recoverables, Gross	3,686	7,148
AM Best Rated Reinsurer [Member]
Reinsurance Recoverable, Credit Quality Indicator [Line Items]
Reinsurance Recoverables, Gross	557,540	589,523
AM Best Rated Reinsurer [Member] | Financial Asset, Past Due
Reinsurance Recoverable, Credit Quality Indicator [Line Items]
Reinsurance Recoverables, Gross	6,233	4,596
AM Best Rated Reinsurer [Member] | Financial Asset, Not Past Due
Reinsurance Recoverable, Credit Quality Indicator [Line Items]
Reinsurance Recoverables, Gross	$ 551,307	$ 584,927

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Amount, after valuation allowance, recoverable under reinsurance contracts including premium paid under reinsurance contracts. Examples include, but are not limited to, settled and unsettled claims, incurred but not reported losses, loss adjustment expense, premium paid, policy benefits and policy reserves.

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Amount of allowance for credit loss on reinsurance recoverable.

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Amount before valuation allowance of reinsurance recoverables for losses reported to the ceding insurer but not yet paid, and for amounts expected based upon statistical projections and other measures of incurred losses and loss settlement expenses which have not yet been reported to the ceding insurer.

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