Reserve for Property and Casualty Insurance Claims and Claims Expense - Narrative (Details) - Catastrophe - USD ($) $ in Millions	12 Months Ended
Dec. 31, 2025	Dec. 31, 2024	Dec. 31, 2023
Increase (decrease) in claims and claims expense
Losses from catastrophes, net of recoveries	$ 4,960	$ 4,960	$ 5,640
Minimum pre-tax losses before reinsurance	$ 1

Catastrophe Claims, Minimum Pre-Tax Losses Before Reinsurance Amount

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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

+ Details

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- Definition

Amount, after effects of reinsurance, of expense (reversal of expense) for claims incurred and costs incurred in the claim settlement process.

+ References

Reference 1: http://www.xbrl.org/2003/role/exampleRef
-Topic 944
-SubTopic 40
-Name Accounting Standards Codification
-Section 55
-Paragraph 7
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147480046/944-40-55-7

Reference 2: http://www.xbrl.org/2009/role/commonPracticeRef
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-Section 50
-Paragraph 3
-Subparagraph (b)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147480081/944-40-50-3

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