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Reinsurance (Total Reinsurance Balances Segregated By Reinsurer) (Details) - USD ($) $ in Thousands | Dec. 31, 2023 | Dec. 31, 2022 | Dec. 31, 2021
--- | --- | --- | ---
Reinsurance recoverable, net of allowance for credit losses |  | $ 656,825 | $ 782,810 |
Total prepaid reinsurance premiums |  | 203,320 | 172,371 |
Total reinsurance balance |  | 860,145 | 955,181 |
Less: collateral | [1] | (126,418) | (126,167) |
Reinsurance Recoverable, Allowance for Credit Loss |  | (1,700) | (1,600) | $ (1,600)
National Flood Insurance Program [Member] |  |  |  |
Total reinsurance balance | [2] | $ 203,273 | $ 276,541 |
% of Net Reinsurance Balance | [2] | 24.00% | 29.00% |
NJ Unsatisfied Claim Judgment Fund [Member] |  |  |  |
Total reinsurance balance | [2] | $ 46,715 | $ 45,496 |
% of Net Reinsurance Balance | [2] | 5.00% | 5.00% |
Other Federal And State Pools [Member] |  |  |  |
Total reinsurance balance | [2] | $ 1,779 | $ 3,488 |
% of Net Reinsurance Balance | [2] | 0.00% | 0.00% |
Total Federal And State Pools [Member] |  |  |  |
Total reinsurance balance | [2] | $ 251,767 | $ 325,525 |
% of Net Reinsurance Balance | [2] | 29.00% | 34.00% |
Remaining Unsecured Reinsurance [Member] |  |  |  |
Total reinsurance balance |  | $ 610,078 | $ 631,256 |
% of Net Reinsurance Balance |  | 71.00% | 66.00% |
Remaining Reinsurance, before Allowance for Credit Loss |  | $ 608,378 | $ 629,656 |
Reinsurance Recoverables, net of allowance for credit losses |  | 608,378 | 629,656 |
Munich Re Group [Member] |  |  |  |
Total reinsurance balance |  | $ 135,564 | $ 124,706 |
% of Net Reinsurance Balance |  | 16.00% | 13.00% |
Hanover Ruckversicherungs AG [Member] |  |  |  |
Total reinsurance balance |  | $ 132,831 | $ 127,106 |
% of Net Reinsurance Balance |  | 15.00% | 13.00% |
AXIS Reinsurance Company [Member] |  |  |  |
Total reinsurance balance |  | $ 76,286 | $ 70,957 |
% of Net Reinsurance Balance |  | 9.00% | 8.00% |
Swiss Re Group [Member] |  |  |  |
Total reinsurance balance |  | $ 30,222 | $ 36,525 |
% of Net Reinsurance Balance |  | 4.00% | 4.00% |
Transatlantic Reinsurance Company [Member] |  |  |  |
Total reinsurance balance |  | $ 27,475 | $ 32,730 |
% of Net Reinsurance Balance |  | 3.00% | 3.00% |
All Other Reinsurers [Member] |  |  |  |
Total reinsurance balance |  | $ 207,700 | $ 239,232 |
% of Net Reinsurance Balance |  | 24.00% | 25.00% |
Remaining Unsecured Reinsurance, Net of Collateral [Member] |  |  |  |
Total reinsurance balance |  | $ 481,960 | $ 503,489 |
[1] | Includes letters of credit, trust funds, and funds held against reinsurance recoverables
[2] | Considered to have minimal risk of default.

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- Definition This element represents the amount collateralized by the entity's reinsurers. The amount includes letters of credit, trust funds, and funds withheld. + References No definition available. + Details
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- Definition This element represents the percentage of the total net unsecured reinsurance balance. + References No definition available. + Details
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- Definition This element represents the known and estimated amount of reinsurance recoverables and the unexpired portion of premiums ceded on policies in force, less all federal and state pools, as of the balance sheet date. + References No definition available. + Details
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- Definition This element represents the known and estimated amount of reinsurance recoverables and the unexpired portion of premiums ceded on policies in force, less all federal and state pools, as of the balance sheet date. + References No definition available. + Details
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- Definition The unexpired portion of premiums ceded on policies in force as of the balance sheet date. + References Reference 1: http://www.xbrl.org/2003/role/disclosureRef -Topic 944 -SubTopic 825 -Name Accounting Standards Codification -Section 50 -Paragraph 1B -Subparagraph (b) -Publisher FASB -URI https://asc.fasb.org//1943274/2147479383/944-825-50-1B Reference 2: http://www.xbrl.org/2003/role/disclosureRef -Topic 944 -SubTopic 340 -Name Accounting Standards Codification -Section 25 -Paragraph 1 -Publisher FASB -URI https://asc.fasb.org//1943274/2147479928/944-340-25-1 + Details
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- Definition 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. + References Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef -Topic 944 -SubTopic 20 -Name Accounting Standards Codification -Section 50 -Paragraph 5 -Publisher FASB -URI https://asc.fasb.org//1943274/2147479838/944-20-50-5 Reference 2: http://www.xbrl.org/2009/role/commonPracticeRef -Topic 944 -SubTopic 310 -Name Accounting Standards Codification -Section 45 -Paragraph 5 -Publisher FASB -URI https://asc.fasb.org//1943274/2147479616/944-310-45-5 Reference 3: http://www.xbrl.org/2009/role/commonPracticeRef -Topic 944 -SubTopic 210 -Name Accounting Standards Codification -Section S99 -Paragraph 1 -Subparagraph (SX 210.7-03(a)(6)) -Publisher FASB -URI https://asc.fasb.org//1943274/2147479440/944-210-S99-1 + Details
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- Definition Amount of allowance for credit loss on reinsurance recoverable. + References Reference 1: http://www.xbrl.org/2003/role/disclosureRef -Topic 944 -SubTopic 20 -Name Accounting Standards Codification -Section 50 -Paragraph 5 -Publisher FASB -URI https://asc.fasb.org//1943274/2147479838/944-20-50-5 Reference 2: http://www.xbrl.org/2003/role/disclosureRef -Topic 944 -SubTopic 310 -Name Accounting Standards Codification -Section 45 -Paragraph 5 -Publisher FASB -URI https://asc.fasb.org//1943274/2147479616/944-310-45-5 Reference 3: http://www.xbrl.org/2003/role/disclosureRef -Topic 326 -SubTopic 20 -Name Accounting Standards Codification -Section 45 -Paragraph 1 -Publisher FASB -URI https://asc.fasb.org//1943274/2147479344/326-20-45-1 Reference 4: http://www.xbrl.org/2003/role/disclosureRef -Topic 326 -SubTopic 20 -Name Accounting Standards Codification -Section 50 -Paragraph 13 -Subparagraph (a) -Publisher FASB -URI https://asc.fasb.org//1943274/2147479319/326-20-50-13 Reference 5: http://www.xbrl.org/2003/role/disclosureRef -Topic 326 -SubTopic 20 -Name Accounting Standards Codification -Section 50 -Paragraph 13 -Subparagraph (f) -Publisher FASB -URI https://asc.fasb.org//1943274/2147479319/326-20-50-13 + Details
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- Definition Amount, after valuation allowance, recoverable under reinsurance contracts. Examples include, but are not limited to, settled and unsettled claims, incurred but not reported losses, loss adjustment expense, policy benefits and policy reserves. Excludes premiums paid under reinsurance contracts. + References Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef -Topic 944 -SubTopic 310 -Name Accounting Standards Codification -Section 50 -Paragraph 2 -Publisher FASB -URI https://asc.fasb.org//1943274/2147479584/944-310-50-2 Reference 2: http://www.xbrl.org/2009/role/commonPracticeRef -Topic 944 -SubTopic 20 -Name Accounting Standards Codification -Section 50 -Paragraph 5 -Publisher FASB -URI https://asc.fasb.org//1943274/2147479838/944-20-50-5 Reference 3: http://www.xbrl.org/2009/role/commonPracticeRef -Topic 944 -SubTopic 310 -Name Accounting Standards Codification -Section 45 -Paragraph 5 -Publisher FASB -URI https://asc.fasb.org//1943274/2147479616/944-310-45-5 Reference 4: http://www.xbrl.org/2009/role/commonPracticeRef -Topic 944 -SubTopic 310 -Name Accounting Standards Codification -Section 45 -Paragraph 6 -Publisher FASB -URI https://asc.fasb.org//1943274/2147479616/944-310-45-6 Reference 5: http://www.xbrl.org/2003/role/disclosureRef -Topic 944 -SubTopic 825 -Name Accounting Standards Codification -Section 50 -Paragraph 1B -Subparagraph (a) -Publisher FASB -URI https://asc.fasb.org//1943274/2147479383/944-825-50-1B + Details
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