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Claim, Claim Adjustment Expense and Future Policy Benefit Reserves (Specialty - Net Prior Year Claim and Allocated Claim Adjustment Expense Reserve Development) (Details) - Specialty - USD ($) $ in Millions | 12 Months Ended
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Dec. 31, 2021 | Dec. 31, 2020 | Dec. 31, 2019
Liability for Claims and Claims Adjustment Expense [Line Items] |  |  |
Medical Professional Liability | $ 23 | $ 35 | $ 75
Other Professional Liability and Management Liability | 24 | (15) | (69)
Surety | (73) | (69) | (92)
Warranty | (14) | (7) | (15)
Other | (5) | (5) | 9
Total pretax (favorable) unfavorable development | $ (45) | $ (61) | $ (92)

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- Definition Net prior year claim and allocated claim adjustment expense reserve development, Medical Professional Liability + References No definition available. + Details
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- Definition Net prior year claim and allocated claim adjustment expense reserve development, Other + References No definition available. + Details
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- Definition Net prior year claim and allocated claim adjustment expense reserve development, Surety + References No definition available. + Details
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- Definition Net prior year claim and allocated claim adjustment expense reserve development, Warranty + References No definition available. + Details
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- Definition Net prior year claim and allocated claim adjustment expense reserve development, Other Professional Liability and Management Liability + References No definition available. + Details
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- Definition Pretax (favorable) unfavorable net prior year claim and allocated claim adjustment expense reserve development, excluding Life & Group + 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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