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Reinsurance and Indemnification - Mandatory FHCF Contracts (Details) $ in Millions | 7 Months Ended | 12 Months Ended
--- | --- | ---
Dec. 31, 2019 USD ($) hurricane | Dec. 31, 2019 USD ($)
Reinsurance Retention Policy [Line Items] |  |
Limit of aggregate losses under aggregate excess agreement |  | $ 3,400
Florida Excess Catastrophe Reinsurance Agreement |  |
Reinsurance Retention Policy [Line Items] |  |
Catastrophe reinsurance loss amount |  | $ 151
Catastrophe reinsurance aggregate, loss limit per contract year, percent |  | 90.00%
Catastrophe reinsurance loss amount, placement |  | $ 136
Limit of aggregate losses under aggregate excess agreement | $ 54 |
Percent eligible for reimbursement |  | 10.00%
Florida Excess Catastrophe Reinsurance Agreement, Two Largest Hurricanes |  |
Reinsurance Retention Policy [Line Items] |  |
Number of hurricanes | hurricane | 2 |
Limit of aggregate losses under aggregate excess agreement | $ 54 |
Retention amount for catastrophe reinsurance agreement contracts | $ 18 |

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- Definition The limit of aggregated losses per contract year beyond which coverage provided by an aggregate excess agreement applies. + References No definition available. + Details
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Data Type: | xbrli:monetaryItemType
Balance Type: | debit
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- Definition Catastrophe Reinsurance Aggregate, Loss Limit Per Contract Year, Percent + References No definition available. + Details
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Data Type: | num:percentItemType
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- Definition Catastrophe Reinsurance Aggregate, Loss Limit Per Contract Year, Percent Eligible for Reimbursement + References No definition available. + Details
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- Definition Represents the retention amount of catastrophe reinsurance agreement contracts. + References No definition available. + Details
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Data Type: | xbrli:monetaryItemType
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- Definition Catastrophe Reinsurance Loss Amount + References No definition available. + Details
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Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | duration

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- Definition Catastrophe Reinsurance Loss Amount, Placement + References No definition available. + Details
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Balance Type: | debit
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- Definition Number of Hurricanes + References No definition available. + Details
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- Definition Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table. + References No definition available. + Details
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- Details
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- Details
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