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Investments Investments (Components Of Restricted Assets) (Details) - USD ($) $ in Thousands | Dec. 31, 2023 | Dec. 31, 2022
--- | --- | ---
Components Of Restricted Assets [Line Items] |  |
Restricted assets | $ 5,499,358 | $ 5,244,923
Assets held in trust or on deposit to support underwriting activities [Member] |  |
Components Of Restricted Assets [Line Items] |  |
Restricted assets | 5,048,857 | 4,807,135
Assets pledged as security for letters of credit [Member] |  |
Components Of Restricted Assets [Line Items] |  |
Restricted assets | $ 450,501 | $ 437,788

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- Definition [Line Items] for Components Of Restricted Assets [Table] + References No definition available. + Details
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- Definition Cash and investments whose use in whole or in part is restricted for the long-term, generally by contractual agreements or regulatory requirements. For use in an unclassified balance sheet. + References Reference 1: http://www.xbrl.org/2003/role/disclosureRef -Topic 954 -SubTopic 210 -Name Accounting Standards Codification -Section 45 -Paragraph 4 -Publisher FASB -URI https://asc.fasb.org//1943274/2147480632/954-210-45-4 Reference 2: http://www.xbrl.org/2003/role/disclosureRef -Topic 954 -SubTopic 210 -Name Accounting Standards Codification -Section 50 -Paragraph 2 -Publisher FASB -URI https://asc.fasb.org//1943274/2147480602/954-210-50-2 + Details
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- Details
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- Details
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