XML 51 R40.htm IDEA: XBRL DOCUMENT
v3.21.1

Investments (Schedule Of Amortized Cost And Fair Value Of HTM Fixed Maturities And Related OTTI Recognized In Accumulated Other Comprehensive Income) (Detail) - USD ($) $ in Millions | Mar. 31, 2021 | Dec. 31, 2020 | Mar. 31, 2020 | Dec. 31, 2019
--- | --- | --- | --- | ---
Schedule of Held-to-maturity Securities [Line Items] |  |  |  |
Debt Securities, Held-to-maturity | $ 11,175 | $ 11,697 |  |
Debt Securities, Held-to-maturity, Allowance for Credit Loss | (43) | (44) | $ (45) | $ 0
Debt securities, held to maturity, net carrying value | 11,132 | 11,653 |  |
Held-to-maturity, Gross Unrealized Appreciation | 621 | 859 |  |
Held-to-maturity, Gross Unrealized Depreciation | (1) | (2) |  |
Held to maturity, at Fair Value | 11,752 | 12,510 |  |
U.S. Treasury / Agency |  |  |  |
Schedule of Held-to-maturity Securities [Line Items] |  |  |  |
Debt Securities, Held-to-maturity | 1,158 | 1,392 |  |
Debt Securities, Held-to-maturity, Allowance for Credit Loss | 0 | 0 |  |
Debt securities, held to maturity, net carrying value | 1,158 | 1,392 |  |
Held-to-maturity, Gross Unrealized Appreciation | 39 | 60 |  |
Held-to-maturity, Gross Unrealized Depreciation | 0 | 0 |  |
Held to maturity, at Fair Value | 1,197 | 1,452 |  |
Non-U.S. |  |  |  |
Schedule of Held-to-maturity Securities [Line Items] |  |  |  |
Debt Securities, Held-to-maturity | 1,276 | 1,295 |  |
Debt Securities, Held-to-maturity, Allowance for Credit Loss | (6) | (7) |  |
Debt securities, held to maturity, net carrying value | 1,270 | 1,288 |  |
Held-to-maturity, Gross Unrealized Appreciation | 82 | 118 |  |
Held-to-maturity, Gross Unrealized Depreciation | (1) | (1) |  |
Held to maturity, at Fair Value | 1,351 | 1,405 |  |
Corporate and asset-backed securities |  |  |  |
Schedule of Held-to-maturity Securities [Line Items] |  |  |  |
Debt Securities, Held-to-maturity | 2,163 | 2,185 |  |
Debt Securities, Held-to-maturity, Allowance for Credit Loss | (35) | (35) |  |
Debt securities, held to maturity, net carrying value | 2,128 | 2,150 |  |
Held-to-maturity, Gross Unrealized Appreciation | 183 | 288 |  |
Held-to-maturity, Gross Unrealized Depreciation | 0 | 0 |  |
Held to maturity, at Fair Value | 2,311 | 2,438 |  |
Mortgage-backed securities |  |  |  |
Schedule of Held-to-maturity Securities [Line Items] |  |  |  |
Debt Securities, Held-to-maturity | 1,888 | 2,000 |  |
Debt Securities, Held-to-maturity, Allowance for Credit Loss | (1) | (1) |  |
Debt securities, held to maturity, net carrying value | 1,887 | 1,999 |  |
Held-to-maturity, Gross Unrealized Appreciation | 110 | 148 |  |
Held-to-maturity, Gross Unrealized Depreciation | 0 | (1) |  |
Held to maturity, at Fair Value | 1,997 | 2,146 |  |
Municipal |  |  |  |
Schedule of Held-to-maturity Securities [Line Items] |  |  |  |
Debt Securities, Held-to-maturity | 4,690 | 4,825 |  |
Debt Securities, Held-to-maturity, Allowance for Credit Loss | (1) | (1) |  |
Debt securities, held to maturity, net carrying value | 4,689 | 4,824 |  |
Held-to-maturity, Gross Unrealized Appreciation | 207 | 245 |  |
Held-to-maturity, Gross Unrealized Depreciation | 0 | 0 |  |
Held to maturity, at Fair Value | $ 4,896 | $ 5,069 |  |

X
- Definition Debt securities, held to maturity, net carrying value + References No definition available. + Details
Name: | cb_Debtsecuritiesheldtomaturitynetcarryingvalue
Namespace Prefix: | cb_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | instant

X
- Definition Amount of allowance for credit loss for debt security measured at amortized cost (held-to-maturity). + 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=121599337&loc=SL82919249-210447 Reference 2: http://www.xbrl.org/2003/role/disclosureRef -Publisher FASB -Name Accounting Standards Codification -Topic 320 -SubTopic 10 -Section 50 -Paragraph 5 -Subparagraph (aaa) -URI http://asc.fasb.org/extlink&oid=121645371&loc=d3e27232-111563 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=121599878&loc=SL82895884-210446 Reference 4: 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=121599337&loc=SL82919249-210447 + Details
Name: | us-gaap_DebtSecuritiesHeldToMaturityAllowanceForCreditLoss
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | instant

X
- Definition Amount of investment in debt security measured at amortized cost (held-to-maturity). + References Reference 1: http://www.xbrl.org/2003/role/disclosureRef -Publisher FASB -Name Accounting Standards Codification -Topic 320 -SubTopic 10 -Section 45 -Paragraph 1 -Subparagraph (b) -URI http://asc.fasb.org/extlink&oid=121553693&loc=d3e26610-111562 Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 320 -SubTopic 10 -Section 50 -Paragraph 5 -Subparagraph (a) -URI http://asc.fasb.org/extlink&oid=121645371&loc=d3e27232-111563 Reference 3: http://www.xbrl.org/2003/role/disclosureRef -Publisher FASB -Name Accounting Standards Codification -Topic 942 -SubTopic 210 -Section S99 -Paragraph 1 -Subparagraph (SX 210.9-03(6)) -URI http://asc.fasb.org/extlink&oid=120398452&loc=d3e534808-122878 + Details
Name: | us-gaap_HeldToMaturitySecurities
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | instant

X
- Definition Amount of accumulated unrecognized gain on investment in debt security measured at amortized cost (held-to-maturity). + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 320 -SubTopic 10 -Section 50 -Paragraph 5 -Subparagraph (b) -URI http://asc.fasb.org/extlink&oid=121645371&loc=d3e27232-111563 Reference 2: http://www.xbrl.org/2003/role/disclosureRef -Publisher FASB -Name Accounting Standards Codification -Topic 320 -SubTopic 10 -Section 50 -Paragraph 5A -Subparagraph (b) -URI http://asc.fasb.org/extlink&oid=121645371&loc=SL120269820-111563 + Details
Name: | us-gaap_HeldToMaturitySecuritiesAccumulatedUnrecognizedHoldingGain
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | instant

X
- Definition Amount of accumulated unrealized loss on investment in debt security measured at amortized cost (held-to-maturity). + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 320 -SubTopic 10 -Section 50 -Paragraph 5 -Subparagraph (c) -URI http://asc.fasb.org/extlink&oid=121645371&loc=d3e27232-111563 Reference 2: http://www.xbrl.org/2003/role/disclosureRef -Publisher FASB -Name Accounting Standards Codification -Topic 320 -SubTopic 10 -Section 50 -Paragraph 5A -Subparagraph (c) -URI http://asc.fasb.org/extlink&oid=121645371&loc=SL120269820-111563 + Details
Name: | us-gaap_HeldToMaturitySecuritiesAccumulatedUnrecognizedHoldingLoss
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | instant

X
- Definition Fair value of investment in debt security measured at amortized cost (held-to-maturity). + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 320 -SubTopic 10 -Section 50 -Paragraph 5 -Subparagraph (aa) -URI http://asc.fasb.org/extlink&oid=121645371&loc=d3e27232-111563 Reference 2: http://www.xbrl.org/2003/role/disclosureRef -Publisher FASB -Name Accounting Standards Codification -Topic 942 -SubTopic 210 -Section S99 -Paragraph 1 -Subparagraph (SX 210.9-03(6)) -URI http://asc.fasb.org/extlink&oid=120398452&loc=d3e534808-122878 Reference 3: http://www.xbrl.org/2003/role/disclosureRef -Publisher FASB -Name Accounting Standards Codification -Topic 320 -SubTopic 10 -Section 50 -Paragraph 5A -Subparagraph (a) -URI http://asc.fasb.org/extlink&oid=121645371&loc=SL120269820-111563 + Details
Name: | us-gaap_HeldToMaturitySecuritiesFairValue
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
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_ScheduleOfHeldToMaturitySecuritiesLineItems
Namespace Prefix: | us-gaap_
Data Type: | xbrli:stringItemType
Balance Type: | na
Period Type: | duration

X
- Details
Name: | us-gaap_FinancialInstrumentAxis=us-gaap_USTreasuryAndGovernmentMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_FinancialInstrumentAxis=us-gaap_ForeignGovernmentDebtSecuritiesMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_FinancialInstrumentAxis=us-gaap_CorporateDebtSecuritiesMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_FinancialInstrumentAxis=us-gaap_MortgageBackedSecuritiesMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_FinancialInstrumentAxis=us-gaap_USStatesAndPoliticalSubdivisionsMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |