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Reinsurance - Florida Excess Catastrophe Reinsurance Agreement (Details) $ in Millions | 6 Months Ended | 7 Months Ended | 12 Months Ended
--- | --- | --- | ---
Jun. 30, 2017 USD ($) | Dec. 31, 2017 USD ($) hurricane | Dec. 31, 2017 USD ($) contract limit
Ceded Credit Risk [Line Items] |  |  |
Retention amount for catastrophe reinsurance agreement contracts |  |  | $ 500
Number of hurricanes | hurricane |  | 2 |
Florida Excess Catastrophe Reinsurance Agreement |  |  |
Ceded Credit Risk [Line Items] |  |  |
Contracts number | contract |  |  | 5
Number of contracts, traditional market | contract |  |  | 2
Catastrophe reinsurance aggregate loss limit, remaining |  | $ 168 | $ 168
Catastrophe reinsurance aggregate, loss limit per contract year, percent | 90.00% |  |
Catastrophe reinsurance loss amount | $ 187 |  |
Florida Excess Catastrophe Reinsurance Agreement, Provisional |  |  |
Ceded Credit Risk [Line Items] |  |  |
Retention percentage of reinsurance limit |  |  | 100.00%
Number of limits available per contract year | limit |  |  | 3
Limit of aggregate losses under aggregate excess agreement |  |  | $ 38
Retention amount for catastrophe reinsurance agreement contracts |  |  | $ 20
Catastrophe reinsurance agreement contracts, number of limits remaining per a contract year | limit |  |  | 2
Florida Excess Catastrophe Reinsurance Agreement, Two Largest Hurricanes |  |  |
Ceded Credit Risk [Line Items] |  |  |
Limit of aggregate losses under aggregate excess agreement |  | 56 |
Retention amount for catastrophe reinsurance agreement contracts |  | 19 |
Florida Excess Catastrophe Reinsurance Agreement, Personal Property Lines |  |  |
Ceded Credit Risk [Line Items] |  |  |
Retention percentage of reinsurance limit |  |  | 100.00%
Limit of aggregate losses under aggregate excess agreement |  |  | $ 231
Retention amount for catastrophe reinsurance agreement contracts |  |  | 20
Catastrophe reinsurance aggregate loss limit, exhausted |  | 27 | 27
Hurricane | Florida Excess Catastrophe Reinsurance Agreement |  |  |
Ceded Credit Risk [Line Items] |  |  |
Catastrophe reinsurance aggregate loss limit, exhausted |  | 19 | 19
Hurricane | Florida Excess Catastrophe Reinsurance Agreement, Provisional |  |  |
Ceded Credit Risk [Line Items] |  |  |
Catastrophe reinsurance aggregate loss limit, exhausted |  | $ 38 | $ 38

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- Definition Represents the retention percentage of annual coverage limit provided by the insurance arrangement for catastrophe claims. + References No definition available. + Details
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- Definition Catastrophe Reinsurance Aggregate Loss Limit, Exhausted + References No definition available. + Details
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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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- Definition Catastrophe Reinsurance Aggregate, Loss Limit Per Contract Year, Percent + References No definition available. + Details
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- Definition Catastrophe Reinsurance Aggregate Loss Limit, Remaining + References No definition available. + Details
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- Definition Catastrophe Reinsurance Agreement Contracts, Number of Limits Available Per Contract Year + References No definition available. + Details
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- Definition Catastrophe Reinsurance Agreement Contracts, Number of Limits Remaining Per Contract Year + 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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- Definition Catastrophe Reinsurance Loss Amount + References No definition available. + Details
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- Definition Number Of Reinsurance Contracts, Traditional Market + References No definition available. + Details
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- Definition Represents the number of reinsurance contracts under the agreement. + References No definition available. + Details
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