RESERVE FOR CLAIMS AND CLAIM EXPENSES - Historical Claims Duration (Details)	Dec. 31, 2025
Property
Short-duration Insurance Contracts, Historical Claims Duration [Line Items]
Average annual percentage payout, year one	22.70%
Average annual percentage payout, year two	30.00%
Average annual percentage payout, year three	17.00%
Average annual percentage payout, year four	7.70%
Average annual percentage payout, year five	3.80%
Average annual percentage payout, year six	1.10%
Average annual percentage payout, year seven	0.80%
Average annual percentage payout, year eight	0.70%
Average annual percentage payout, year nine	1.30%
Average annual percentage payout, year ten	(0.30%)
Casualty and Specialty
Short-duration Insurance Contracts, Historical Claims Duration [Line Items]
Average annual percentage payout, year one	10.60%
Average annual percentage payout, year two	15.70%
Average annual percentage payout, year three	12.60%
Average annual percentage payout, year four	13.40%
Average annual percentage payout, year five	11.20%
Average annual percentage payout, year six	8.40%
Average annual percentage payout, year seven	7.50%
Average annual percentage payout, year eight	5.70%
Average annual percentage payout, year nine	3.00%
Average annual percentage payout, year ten	2.10%

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 eighth 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 fifth year after a claim is incurred, beginning with the earliest accident year disclosed for short-duration insurance contracts.

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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.

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

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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.

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

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

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

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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.

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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.

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