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Reserves For Losses And Loss Expenses (Supplementary Information Regarding Average Historical Claims Duration) (Details) | Dec. 31, 2022
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Insurance | Other liability |
Short-duration Insurance Contracts, Historical Claims Duration [Line Items] |
Average annual percentage payout of incurred claims by age, net of reinsurance, Year 1 | 6.90%
Average annual percentage payout of incurred claims by age, net of reinsurance, Year 2 | 13.70%
Average annual percentage payout of incurred claims by age, net of reinsurance, Year 3 | 16.30%
Average annual percentage payout of incurred claims by age, net of reinsurance, Year 4 | 16.00%
Average annual percentage payout of incurred claims by age, net of reinsurance, Year 5 | 13.10%
Average annual percentage payout of incurred claims by age, net of reinsurance, Year 6 | 9.20%
Average annual percentage payout of incurred claims by age, net of reinsurance, Year 7 | 6.70%
Average annual percentage payout of incurred claims by age, net of reinsurance, Year 8 | 4.20%
Average annual percentage payout of incurred claims by age, net of reinsurance, Year 9 | 2.70%
Average annual percentage payout of incurred claims by age, net of reinsurance, Year 10 | 2.80%
Insurance | Workers' compensation |
Short-duration Insurance Contracts, Historical Claims Duration [Line Items] |
Average annual percentage payout of incurred claims by age, net of reinsurance, Year 1 | 23.50%
Average annual percentage payout of incurred claims by age, net of reinsurance, Year 2 | 29.90%
Average annual percentage payout of incurred claims by age, net of reinsurance, Year 3 | 15.70%
Average annual percentage payout of incurred claims by age, net of reinsurance, Year 4 | 9.10%
Average annual percentage payout of incurred claims by age, net of reinsurance, Year 5 | 5.50%
Average annual percentage payout of incurred claims by age, net of reinsurance, Year 6 | 3.20%
Average annual percentage payout of incurred claims by age, net of reinsurance, Year 7 | 2.10%
Average annual percentage payout of incurred claims by age, net of reinsurance, Year 8 | 1.70%
Average annual percentage payout of incurred claims by age, net of reinsurance, Year 9 | 1.50%
Average annual percentage payout of incurred claims by age, net of reinsurance, Year 10 | 1.00%
Insurance | Professional liability |
Short-duration Insurance Contracts, Historical Claims Duration [Line Items] |
Average annual percentage payout of incurred claims by age, net of reinsurance, Year 1 | 7.40%
Average annual percentage payout of incurred claims by age, net of reinsurance, Year 2 | 17.60%
Average annual percentage payout of incurred claims by age, net of reinsurance, Year 3 | 17.70%
Average annual percentage payout of incurred claims by age, net of reinsurance, Year 4 | 15.70%
Average annual percentage payout of incurred claims by age, net of reinsurance, Year 5 | 9.10%
Average annual percentage payout of incurred claims by age, net of reinsurance, Year 6 | 10.30%
Average annual percentage payout of incurred claims by age, net of reinsurance, Year 7 | 5.10%
Average annual percentage payout of incurred claims by age, net of reinsurance, Year 8 | 2.60%
Average annual percentage payout of incurred claims by age, net of reinsurance, Year 9 | 3.00%
Average annual percentage payout of incurred claims by age, net of reinsurance, Year 10 | 1.90%
Insurance | Commercial automobile |
Short-duration Insurance Contracts, Historical Claims Duration [Line Items] |
Average annual percentage payout of incurred claims by age, net of reinsurance, Year 1 | 36.10%
Average annual percentage payout of incurred claims by age, net of reinsurance, Year 2 | 20.90%
Average annual percentage payout of incurred claims by age, net of reinsurance, Year 3 | 15.50%
Average annual percentage payout of incurred claims by age, net of reinsurance, Year 4 | 11.50%
Average annual percentage payout of incurred claims by age, net of reinsurance, Year 5 | 6.70%
Average annual percentage payout of incurred claims by age, net of reinsurance, Year 6 | 2.80%
Average annual percentage payout of incurred claims by age, net of reinsurance, Year 7 | 1.60%
Average annual percentage payout of incurred claims by age, net of reinsurance, Year 8 | 0.40%
Average annual percentage payout of incurred claims by age, net of reinsurance, Year 9 | 0.10%
Average annual percentage payout of incurred claims by age, net of reinsurance, Year 10 | 0.40%
Insurance | Short-tail lines |
Short-duration Insurance Contracts, Historical Claims Duration [Line Items] |
Average annual percentage payout of incurred claims by age, net of reinsurance, Year 1 | 54.70%
Average annual percentage payout of incurred claims by age, net of reinsurance, Year 2 | 32.80%
Average annual percentage payout of incurred claims by age, net of reinsurance, Year 3 | 5.80%
Average annual percentage payout of incurred claims by age, net of reinsurance, Year 4 | 2.00%
Average annual percentage payout of incurred claims by age, net of reinsurance, Year 5 | 1.00%
Average annual percentage payout of incurred claims by age, net of reinsurance, Year 6 | 0.80%
Average annual percentage payout of incurred claims by age, net of reinsurance, Year 7 | 0.40%
Average annual percentage payout of incurred claims by age, net of reinsurance, Year 8 | 0.10%
Average annual percentage payout of incurred claims by age, net of reinsurance, Year 9 | 0.20%
Average annual percentage payout of incurred claims by age, net of reinsurance, Year 10 | 0.00%
Reinsurance & Monoline Excess | Casualty |
Short-duration Insurance Contracts, Historical Claims Duration [Line Items] |
Average annual percentage payout of incurred claims by age, net of reinsurance, Year 1 | 5.70%
Average annual percentage payout of incurred claims by age, net of reinsurance, Year 2 | 10.90%
Average annual percentage payout of incurred claims by age, net of reinsurance, Year 3 | 12.50%
Average annual percentage payout of incurred claims by age, net of reinsurance, Year 4 | 13.70%
Average annual percentage payout of incurred claims by age, net of reinsurance, Year 5 | 11.00%
Average annual percentage payout of incurred claims by age, net of reinsurance, Year 6 | 9.30%
Average annual percentage payout of incurred claims by age, net of reinsurance, Year 7 | 7.40%
Average annual percentage payout of incurred claims by age, net of reinsurance, Year 8 | 5.50%
Average annual percentage payout of incurred claims by age, net of reinsurance, Year 9 | 4.00%
Average annual percentage payout of incurred claims by age, net of reinsurance, Year 10 | 3.00%
Reinsurance & Monoline Excess | Monoline excess |
Short-duration Insurance Contracts, Historical Claims Duration [Line Items] |
Average annual percentage payout of incurred claims by age, net of reinsurance, Year 1 | 6.10%
Average annual percentage payout of incurred claims by age, net of reinsurance, Year 2 | 4.70%
Average annual percentage payout of incurred claims by age, net of reinsurance, Year 3 | 3.10%
Average annual percentage payout of incurred claims by age, net of reinsurance, Year 4 | 1.70%
Average annual percentage payout of incurred claims by age, net of reinsurance, Year 5 | 2.60%
Average annual percentage payout of incurred claims by age, net of reinsurance, Year 6 | 3.30%
Average annual percentage payout of incurred claims by age, net of reinsurance, Year 7 | 4.60%
Average annual percentage payout of incurred claims by age, net of reinsurance, Year 8 | 3.50%
Average annual percentage payout of incurred claims by age, net of reinsurance, Year 9 | 7.20%
Average annual percentage payout of incurred claims by age, net of reinsurance, Year 10 | 2.90%
Reinsurance & Monoline Excess | Property |
Short-duration Insurance Contracts, Historical Claims Duration [Line Items] |
Average annual percentage payout of incurred claims by age, net of reinsurance, Year 1 | 30.50%
Average annual percentage payout of incurred claims by age, net of reinsurance, Year 2 | 33.20%
Average annual percentage payout of incurred claims by age, net of reinsurance, Year 3 | 16.10%
Average annual percentage payout of incurred claims by age, net of reinsurance, Year 4 | 5.80%
Average annual percentage payout of incurred claims by age, net of reinsurance, Year 5 | 3.60%
Average annual percentage payout of incurred claims by age, net of reinsurance, Year 6 | 1.70%
Average annual percentage payout of incurred claims by age, net of reinsurance, Year 7 | 1.60%
Average annual percentage payout of incurred claims by age, net of reinsurance, Year 8 | 0.30%
Average annual percentage payout of incurred claims by age, net of reinsurance, Year 9 | 0.10%
Average annual percentage payout of incurred claims by age, net of reinsurance, Year 10 | 0.00%

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