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Catastrophe Reinsurance - Coverage for Catastrophe Reinsurance (Details) - USD ($) | 12 Months Ended
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Dec. 31, 2024 | Dec. 31, 2023 | Dec. 31, 2022
Retained |  |  |
Liability for Catastrophe Claims [Line Items] |  |  |
Reinsurance retention policy, reinsured risk, percentage | 0.00% | 0.00% | 0.00%
1st Layer of Coverage |  |  |
Liability for Catastrophe Claims [Line Items] |  |  |
Reinsurance retention policy, excess retention, percentage | 85.00% | 95.00% | 95.00%
2nd Layer of Coverage |  |  |
Liability for Catastrophe Claims [Line Items] |  |  |
Reinsurance retention policy, excess retention, percentage | 95.00% | 95.00% | 95.00%
3rd Layer of Coverage |  |  |
Liability for Catastrophe Claims [Line Items] |  |  |
Reinsurance retention policy, excess retention, percentage | 31.70% | 95.00% | 95.00%
4th Layer of Coverage |  |  |
Liability for Catastrophe Claims [Line Items] |  |  |
Reinsurance retention policy, excess retention, percentage |  | 95.00% | 95.00%
Minimum |  |  |
Liability for Catastrophe Claims [Line Items] |  |  |
Reinsurance retention policy, amount retained |  |  | $ 0
Reinsurance retention policy, excess retention, amount reinsured |  |  | 65,000,000.0
Minimum | Retained |  |  |
Liability for Catastrophe Claims [Line Items] |  |  |
Reinsurance retention policy, amount retained | $ 0 | $ 0 | 0
Minimum | 1st Layer of Coverage |  |  |
Liability for Catastrophe Claims [Line Items] |  |  |
Reinsurance retention policy, excess retention, amount reinsured | 50,000,000.0 | 50,000,000.0 | 50,000,000.0
Minimum | 2nd Layer of Coverage |  |  |
Liability for Catastrophe Claims [Line Items] |  |  |
Reinsurance retention policy, excess retention, amount reinsured | 150,000,000.0 | 150,000,000.0 | 150,000,000.0
Minimum | 3rd Layer of Coverage |  |  |
Liability for Catastrophe Claims [Line Items] |  |  |
Reinsurance retention policy, excess retention, amount reinsured | 240,000,000.0 | 250,000,000.0 | 250,000,000.0
Minimum | 4th Layer of Coverage |  |  |
Liability for Catastrophe Claims [Line Items] |  |  |
Reinsurance retention policy, excess retention, amount reinsured |  | 295,000,000.0 | 325,000,000.0
Maximum |  |  |
Liability for Catastrophe Claims [Line Items] |  |  |
Reinsurance retention policy, amount retained |  |  | 65,000,000.0
Reinsurance retention policy, excess retention, amount reinsured |  |  | 115,000,000.0
Maximum | Retained |  |  |
Liability for Catastrophe Claims [Line Items] |  |  |
Reinsurance retention policy, amount retained | 50,000,000.0 | 50,000,000.0 | 50,000,000.0
Maximum | 1st Layer of Coverage |  |  |
Liability for Catastrophe Claims [Line Items] |  |  |
Reinsurance retention policy, excess retention, amount reinsured | 150,000,000.0 | 150,000,000.0 | 150,000,000.0
Maximum | 2nd Layer of Coverage |  |  |
Liability for Catastrophe Claims [Line Items] |  |  |
Reinsurance retention policy, excess retention, amount reinsured | 240,000,000.0 | 250,000,000.0 | 250,000,000.0
Maximum | 3rd Layer of Coverage |  |  |
Liability for Catastrophe Claims [Line Items] |  |  |
Reinsurance retention policy, excess retention, amount reinsured | $ 250,000,000.0 | 295,000,000.0 | 325,000,000.0
Maximum | 4th Layer of Coverage |  |  |
Liability for Catastrophe Claims [Line Items] |  |  |
Reinsurance retention policy, excess retention, amount reinsured |  | $ 325,000,000.0 | $ 350,000,000.0

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- Definition Amount per event of risk undertaken originally by insurer that is not ceded to reinsurer. + References Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef -Topic 944 -SubTopic 20 -Name Accounting Standards Codification -Section 50 -Paragraph 3 -Publisher FASB -URI https://asc.fasb.org/1943274/2147479838/944-20-50-3 + Details
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- Definition Amount per event of risk ceded to reinsurer in excess of risk undertaken originally by insurer that is not ceded to reinsurer. + References Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef -Topic 944 -SubTopic 20 -Name Accounting Standards Codification -Section 50 -Paragraph 3 -Publisher FASB -URI https://asc.fasb.org/1943274/2147479838/944-20-50-3 + Details
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- Definition Percentage of risk ceded to reinsurer in excess of risk undertaken originally by insurer that is not ceded to reinsurer. + References Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef -Topic 944 -SubTopic 20 -Name Accounting Standards Codification -Section 50 -Paragraph 3 -Publisher FASB -URI https://asc.fasb.org/1943274/2147479838/944-20-50-3 + Details
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