Property and Casualty Insurance Reserves - Historical Claims Duration (Details)	Dec. 31, 2024
Specialty Personal Automobile Insurance—Liability
Short-duration Insurance Contracts, Historical Claims Duration [Line Items]
Year 1	38.00%
Year 2	77.80%
Year 3	90.50%
Year 4	95.10%
Year 5	97.40%
Specialty Personal Automobile Insurance—Physical Damage
Short-duration Insurance Contracts, Historical Claims Duration [Line Items]
Year 1	93.00%
Year 2	100.00%
Year 3	100.00%
Year 4	100.00%
Year 5	100.00%
Commercial Automobile Insurance—Liability
Short-duration Insurance Contracts, Historical Claims Duration [Line Items]
Year 1	21.50%
Year 2	52.10%
Year 3	69.10%
Year 4	82.20%
Year 5	90.50%
Commercial Automobile Insurance—Physical Damage
Short-duration Insurance Contracts, Historical Claims Duration [Line Items]
Year 1	85.40%
Year 2	100.00%
Year 3	100.00%
Year 4	100.00%
Year 5	100.00%
Preferred Personal Automobile Insurance—Liability
Short-duration Insurance Contracts, Historical Claims Duration [Line Items]
Year 1	30.50%
Year 2	60.60%
Year 3	77.90%
Year 4	89.10%
Year 5	94.60%
Preferred Personal Automobile Insurance—Physical Damage
Short-duration Insurance Contracts, Historical Claims Duration [Line Items]
Year 1	97.40%
Year 2	100.00%
Year 3	100.00%
Year 4	100.00%
Year 5	100.00%
Homeowners [Member]
Short-duration Insurance Contracts, Historical Claims Duration [Line Items]
Year 1	67.00%
Year 2	92.40%
Year 3	96.60%
Year 4	98.30%
Year 5	99.30%

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.

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- Definition

Percentage of average annual payout, after reinsurance, in the fifth year after a claim is incurred, beginning with the earliest accident year disclosed for short-duration insurance contracts.

+ References

Reference 1: http://www.xbrl.org/2003/role/exampleRef
-Topic 944
-SubTopic 40
-Name Accounting Standards Codification
-Section 55
-Paragraph 9F
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147480046/944-40-55-9F

Reference 2: http://www.xbrl.org/2003/role/disclosureRef
-Topic 944
-SubTopic 40
-Name Accounting Standards Codification
-Section 50
-Paragraph 4G
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147480081/944-40-50-4G

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Percentage of average annual payout, after reinsurance, in the fourth year after a claim is incurred, beginning with the earliest accident year disclosed for short-duration insurance contracts.

+ References

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Percentage of average annual payout, after reinsurance, in the first year after a claim is incurred, beginning with the earliest accident year disclosed for short-duration insurance contracts.

+ References

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Percentage of average annual payout, after reinsurance, in the third year after a claim is incurred, beginning with the earliest accident year disclosed for short-duration insurance contracts.

+ References

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Percentage of average annual payout, after reinsurance, in the second year after a claim is incurred, beginning with the earliest accident year disclosed for short-duration insurance contracts.

+ References

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