XML 66 R55.htm IDEA: XBRL DOCUMENT
v3.21.2

Reinsurance (Details) - USD ($) $ in Millions | 9 Months Ended
--- | ---
Sep. 30, 2021 | Sep. 30, 2020
Reinsurance Recoverable, Allowance for Credit Loss [Roll Forward] |  |
Reinsurance Recoverable, Allowance for Credit Loss, Beginning of period | $ 314 | $ 316
Reinsurance Recoverable, Credit Loss Expense (Reversal) | 16 | 21
Reinsurance, Loss on Uncollectible Accounts in Period, Amount | (4) | (19)
Reinsurance Recoverable, Allowance for Credit Loss, Other | (1) | 2
Reinsurance Recoverable, Allowance for Credit Loss, end of period | $ 325 | $ 320

X
- Definition Reinsurance Recoverable, Allowance for Credit Loss, Other including foreign exchange + References No definition available. + Details
Name: | cb_ReinsuranceRecoverableAllowanceForCreditLossOther
Namespace Prefix: | cb_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | duration

X
- Definition Amount of the write-down or write-off of a receivable from a reinsurer. + 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 (d) -URI http://asc.fasb.org/extlink&oid=124255953&loc=SL82919249-210447 + Details
Name: | us-gaap_ReinsuranceLossOnUncollectibleAccountsInPeriodAmount
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | duration

X
- Definition A roll forward is a reconciliation of a concept from the beginning of a period to the end of a period. + References No definition available. + Details
Name: | us-gaap_ReinsuranceRecoverableAllowanceForCreditLossRollForward
Namespace Prefix: | us-gaap_
Data Type: | xbrli:stringItemType
Balance Type: | na
Period Type: | duration

X
- Definition Amount of expense (reversal of expense) for expected 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 (b) -URI http://asc.fasb.org/extlink&oid=124255953&loc=SL82919249-210447 + Details
Name: | us-gaap_ReinsuranceRecoverableCreditLossExpenseReversal
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
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 http://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 http://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 http://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