XML 101 R82.htm IDEA: XBRL DOCUMENT
v3.22.4

Reinsurance (Reinsurance Recoverable by Category and Listing of Largest Reinsurers) (Details) - USD ($) $ in Millions | Dec. 31, 2022 | Dec. 31, 2021 | Dec. 31, 2020
--- | --- | --- | ---
Ceded Credit Risk [Line Items] |  |  |
Gross Reinsurance Recoverable on Losses and Loss Expenses | $ 19,252 |  |
Valuation allowance for Uncollectible Reinsurance | $ 351 | $ 329 | $ 314
% of Gross Reinsurance Recoverable | 1.80% |  |
Largest reinsurers |  |  |
Ceded Credit Risk [Line Items] |  |  |
Gross Reinsurance Recoverable on Losses and Loss Expenses | $ 10,826 |  |
Valuation allowance for Uncollectible Reinsurance | $ 114 |  |
% of Gross Reinsurance Recoverable | 1.10% |  |
Other reinsurers rated A- or better |  |  |
Ceded Credit Risk [Line Items] |  |  |
Gross Reinsurance Recoverable on Losses and Loss Expenses | $ 4,161 |  |
Valuation allowance for Uncollectible Reinsurance | $ 47 |  |
% of Gross Reinsurance Recoverable | 1.10% |  |
Other reinsurers rated lower than A- or not rated |  |  |
Ceded Credit Risk [Line Items] |  |  |
Gross Reinsurance Recoverable on Losses and Loss Expenses | $ 443 |  |
Valuation allowance for Uncollectible Reinsurance | $ 70 |  |
% of Gross Reinsurance Recoverable | 15.80% |  |
Pools |  |  |
Ceded Credit Risk [Line Items] |  |  |
Gross Reinsurance Recoverable on Losses and Loss Expenses | $ 425 |  |
Valuation allowance for Uncollectible Reinsurance | $ 14 |  |
% of Gross Reinsurance Recoverable | 3.30% |  |
Structured settlements |  |  |
Ceded Credit Risk [Line Items] |  |  |
Gross Reinsurance Recoverable on Losses and Loss Expenses | $ 507 |  |
Valuation allowance for Uncollectible Reinsurance | $ 11 |  |
% of Gross Reinsurance Recoverable | 2.20% |  |
Captives |  |  |
Ceded Credit Risk [Line Items] |  |  |
Gross Reinsurance Recoverable on Losses and Loss Expenses | $ 2,455 |  |
Valuation allowance for Uncollectible Reinsurance | $ 13 |  |
% of Gross Reinsurance Recoverable | 0.50% |  |
Other |  |  |
Ceded Credit Risk [Line Items] |  |  |
Gross Reinsurance Recoverable on Losses and Loss Expenses | $ 435 |  |
Valuation allowance for Uncollectible Reinsurance | $ 82 |  |
% of Gross Reinsurance Recoverable | 18.80% |  |

X
- Definition Allowance For Reinsurance Recoverable, Percentage + References No definition available. + Details
Name: | cb_AllowanceForReinsuranceRecoverablePercentage
Namespace Prefix: | cb_
Data Type: | dtr-types:percentItemType
Balance Type: | na
Period Type: | instant

X
- 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 No definition available. + Details
Name: | us-gaap_CededCreditRiskLineItems
Namespace Prefix: | us-gaap_
Data Type: | xbrli:stringItemType
Balance Type: | na
Period Type: | duration

X
- Definition Amount of allowance for credit loss on reinsurance recoverable. + References Reference 1: http://www.xbrl.org/2003/role/disclosureRef -Publisher FASB -Name Accounting Standards Codification -Topic 326 -SubTopic 20 -Section 50 -Paragraph 13 -Subparagraph (a) -URI https://asc.fasb.org/extlink&oid=124255953&loc=SL82919249-210447 Reference 2: http://www.xbrl.org/2003/role/disclosureRef -Publisher FASB -Name Accounting Standards Codification -Topic 326 -SubTopic 20 -Section 50 -Paragraph 13 -Subparagraph (f) -URI https://asc.fasb.org/extlink&oid=124255953&loc=SL82919249-210447 Reference 3: http://www.xbrl.org/2003/role/disclosureRef -Publisher FASB -Name Accounting Standards Codification -Topic 326 -SubTopic 20 -Section 45 -Paragraph 1 -URI https://asc.fasb.org/extlink&oid=124255206&loc=SL82895884-210446 + Details
Name: | us-gaap_ReinsuranceRecoverablesAllowance
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | instant

X
- Definition Amount before valuation allowance recoverable under reinsurance contracts. Examples include, but are not limited to, settled and unsettled claims, incurred but not reported losses, loss adjustment expense, premium paid, policy benefits and policy reserves. + References Reference 1: http://www.xbrl.org/2003/role/disclosureRef -Publisher FASB -Name Accounting Standards Codification -Topic 326 -SubTopic 20 -Section 50 -Paragraph 14 -URI https://asc.fasb.org/extlink&oid=124255953&loc=SL82919253-210447 Reference 2: http://www.xbrl.org/2003/role/disclosureRef -Publisher FASB -Name Accounting Standards Codification -Topic 310 -SubTopic 10 -Section 50 -Paragraph 7A -URI https://asc.fasb.org/extlink&oid=123577603&loc=SL6953401-111524 + Details
Name: | us-gaap_ReinsuranceRecoverablesGross
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | instant

X
- Details
Name: | us-gaap_CededCreditRiskAxis=cb_ReinsuranceLargestReinsurersMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_CededCreditRiskAxis=cb_ReinsuranceOtherReinsurersBalancesRatedMinusOrBetterMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_CededCreditRiskAxis=cb_ReinsuranceOtherReinsurersBalancesWithRatingsLowerThanMinusOrNotRatedMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_CededCreditRiskAxis=cb_ReinsuranceOtherPoolsAndGovernmentAgenciesMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_CededCreditRiskAxis=cb_ReinsuranceStructuredSettlementsMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_CededCreditRiskAxis=cb_ReinsuranceOtherCaptivesMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_CededCreditRiskAxis=cb_ReinsuranceOtherMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |