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Reinsurance Recoverable Credit Ratings (Details) - USD ($) $ in Thousands	Sep. 30, 2021	Jun. 30, 2021	Dec. 31, 2020	Sep. 30, 2020	Jun. 30, 2020	Dec. 31, 2019
Reinsurance Recoverable, Credit Quality Indicator [Line Items]
Reinsurance recoverable	$ 687,812		$ 589,269
Reinsurance Recoverable, Allowance for Credit Loss	(1,595)	$ (1,777)	(1,777)	$ (1,831)	$ (2,396)	$ (4,400)
Reinsurance recoverable, net of allowance for credit losses	686,217		587,492
Change in Total Reinsurance Recoverables, net	98,700
AM Best, A++ Rating [Member]
Reinsurance Recoverable, Credit Quality Indicator [Line Items]
Reinsurance Recoverables, Gross	39,338		37,566
AM Best, A++ Rating [Member] | Financial Asset, Past Due
Reinsurance Recoverable, Credit Quality Indicator [Line Items]
Reinsurance Recoverables, Gross	13		102
AM Best, A++ Rating [Member] | Financial Asset, Not Past Due
Reinsurance Recoverable, Credit Quality Indicator [Line Items]
Reinsurance Recoverables, Gross	39,325		37,464
AM Best, A+ Rating [Member]
Reinsurance Recoverable, Credit Quality Indicator [Line Items]
Reinsurance Recoverables, Gross	339,799		357,298
AM Best, A+ Rating [Member] | Financial Asset, Past Due
Reinsurance Recoverable, Credit Quality Indicator [Line Items]
Reinsurance Recoverables, Gross	887		2,452
AM Best, A+ Rating [Member] | Financial Asset, Not Past Due
Reinsurance Recoverable, Credit Quality Indicator [Line Items]
Reinsurance Recoverables, Gross	338,912		354,846
AM Best, A Rating [Member]
Reinsurance Recoverable, Credit Quality Indicator [Line Items]
Reinsurance Recoverables, Gross	96,510		106,067
AM Best, A Rating [Member] | Financial Asset, Past Due
Reinsurance Recoverable, Credit Quality Indicator [Line Items]
Reinsurance Recoverables, Gross	439		415
AM Best, A Rating [Member] | Financial Asset, Not Past Due
Reinsurance Recoverable, Credit Quality Indicator [Line Items]
Reinsurance Recoverables, Gross	96,071		105,652
AM Best, A- Rating [Member]
Reinsurance Recoverable, Credit Quality Indicator [Line Items]
Reinsurance Recoverables, Gross	3,437		2,139
AM Best, A- Rating [Member] | Financial Asset, Past Due
Reinsurance Recoverable, Credit Quality Indicator [Line Items]
Reinsurance Recoverables, Gross	271		0
AM Best, A- Rating [Member] | Financial Asset, Not Past Due
Reinsurance Recoverable, Credit Quality Indicator [Line Items]
Reinsurance Recoverables, Gross	3,166		2,139
AM Best, B++ Rating [Member]
Reinsurance Recoverable, Credit Quality Indicator [Line Items]
Reinsurance Recoverables, Gross	0		380
AM Best, B++ Rating [Member] | Financial Asset, Past Due
Reinsurance Recoverable, Credit Quality Indicator [Line Items]
Reinsurance Recoverables, Gross	0		324
AM Best, B++ Rating [Member] | Financial Asset, Not Past Due
Reinsurance Recoverable, Credit Quality Indicator [Line Items]
Reinsurance Recoverables, Gross	0		56
AM Best, B+ Rating [Member]
Reinsurance Recoverable, Credit Quality Indicator [Line Items]
Reinsurance Recoverables, Gross	0		0
AM Best, B+ Rating [Member] | Financial Asset, Past Due
Reinsurance Recoverable, Credit Quality Indicator [Line Items]
Reinsurance Recoverables, Gross	0		0
AM Best, B+ Rating [Member] | Financial Asset, Not Past Due
Reinsurance Recoverable, Credit Quality Indicator [Line Items]
Reinsurance Recoverables, Gross	0		0
AM Best Rated Reinsurer [Member]
Reinsurance Recoverable, Credit Quality Indicator [Line Items]
Reinsurance Recoverables, Gross	479,084		503,450
AM Best Rated Reinsurer [Member] | Financial Asset, Past Due
Reinsurance Recoverable, Credit Quality Indicator [Line Items]
Reinsurance Recoverables, Gross	1,610		3,293
AM Best Rated Reinsurer [Member] | Financial Asset, Not Past Due
Reinsurance Recoverable, Credit Quality Indicator [Line Items]
Reinsurance Recoverables, Gross	477,474		500,157
Total federal and state pools [Member]
Reinsurance Recoverable, Credit Quality Indicator [Line Items]
Reinsurance Recoverables, Gross	204,001		82,575
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	204,001		82,575
Other than Federal And State Pools [Member]
Reinsurance Recoverable, Credit Quality Indicator [Line Items]
Reinsurance Recoverables, Gross	4,727		3,244
Other than Federal And State Pools [Member] | Financial Asset, Past Due
Reinsurance Recoverable, Credit Quality Indicator [Line Items]
Reinsurance Recoverables, Gross	29		568
Other than Federal And State Pools [Member] | Financial Asset, Not Past Due
Reinsurance Recoverable, Credit Quality Indicator [Line Items]
Reinsurance Recoverables, Gross	4,698		2,676
Total Non Rated Reinsurer [Member]
Reinsurance Recoverable, Credit Quality Indicator [Line Items]
Reinsurance Recoverables, Gross	208,728		85,819
Total Non Rated Reinsurer [Member] | Financial Asset, Past Due
Reinsurance Recoverable, Credit Quality Indicator [Line Items]
Reinsurance Recoverables, Gross	29		568
Total Non Rated Reinsurer [Member] | Financial Asset, Not Past Due
Reinsurance Recoverable, Credit Quality Indicator [Line Items]
Reinsurance Recoverables, Gross	208,699		85,251
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	1,639		3,861
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	$ 686,173		$ 585,408

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Increase (decrease) in total reinsurance recoverables, net

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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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