Acquisitions (Pro forma) (Details) - USD ($) $ in Millions	3 Months Ended
Mar. 31, 2024	Mar. 31, 2023
Business Acquisition [Line Items]
Net premiums earned	$ 11,583	$ 10,142
Huatai Group \| Pro Forma
Business Acquisition [Line Items]
Net premiums earned		10,553
Total revenues		11,529
Net income		1,900
Net income attributable to Chubb		$ 1,890

Business Acquisition, Pro Forma Net income (loss), Including Portion Attributable to Noncontrolling Interests

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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

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-Topic 805
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- Definition

The pro forma net Income or Loss for the period as if the business combination or combinations had been completed at the beginning of a period.

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Topic 805
-SubTopic 10
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The pro forma revenue for a period as if the business combination or combinations had been completed at the beginning of the period.

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- Definition

Amount, after premiums ceded to other entities and premiums assumed by the entity, of premiums earned.

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Topic 944
-SubTopic 235
-Name Accounting Standards Codification
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