XML 75 R64.htm IDEA: XBRL DOCUMENT
v3.21.2

Shareholders' equity (Details) | 6 Months Ended |  |  |  |
--- | --- | --- | --- | --- | ---
Jun. 30, 2021 SFr / shares shares | May 20, 2021 $ / shares | Dec. 31, 2020 SFr / shares shares | May 20, 2020 $ / shares | May 31, 2019 $ / shares
Stockholders' Equity Note [Abstract] |  |  |  |  |
Common Shares, par value | SFr / shares | SFr 24.15 |  | SFr 24.15 |  |
Common Shares in treasury, shares | shares | 38,888,051 |  | 26,872,639 |  |
Stock Issued During Period, Shares, Restricted Stock Award, Net of Forfeitures | shares | 2,449,988 |  |  |  |
Common Stock, Dividend Rate Approved | $ / shares |  | $ 0.80 |  | $ 0.78 | $ 0.75
Annual dividend per share approved by shareholders | $ / shares |  | $ 3.20 |  | $ 3.12 | $ 3.00

X
- Definition Annual dividend per share approved by shareholders + References No definition available. + Details
Name: | cb_Annualdividendpershareapprovedbyshareholders
Namespace Prefix: | cb_
Data Type: | num:perShareItemType
Balance Type: | na
Period Type: | instant

X
- Definition Common Stock, Dividend Rate Approved + References No definition available. + Details
Name: | cb_CommonStockDividendRateApproved
Namespace Prefix: | cb_
Data Type: | num:perShareItemType
Balance Type: | na
Period Type: | instant

X
- Definition Face amount or stated value per share of common stock. + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 210 -SubTopic 10 -Section S99 -Paragraph 1 -Subparagraph (SX 210.5-02(29)) -URI http://asc.fasb.org/extlink&oid=120391452&loc=d3e13212-122682 + Details
Name: | us-gaap_CommonStockParOrStatedValuePerShare
Namespace Prefix: | us-gaap_
Data Type: | num:perShareItemType
Balance Type: | na
Period Type: | instant

X
- Definition Number of shares issued during the period related to Restricted Stock Awards, net of any shares forfeited. + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 505 -SubTopic 10 -Section 50 -Paragraph 2 -URI http://asc.fasb.org/extlink&oid=109259400&loc=d3e21463-112644 Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 505 -SubTopic 10 -Section S99 -Paragraph 1 -Subparagraph (SX 210.3-04) -URI http://asc.fasb.org/extlink&oid=120397183&loc=d3e187085-122770 Reference 3: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 210 -SubTopic 10 -Section S99 -Paragraph 1 -Subparagraph (SX 210.5-02(28)) -URI http://asc.fasb.org/extlink&oid=120391452&loc=d3e13212-122682 Reference 4: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 210 -SubTopic 10 -Section S99 -Paragraph 1 -Subparagraph (SX 210.5-02(29)) -URI http://asc.fasb.org/extlink&oid=120391452&loc=d3e13212-122682 + Details
Name: | us-gaap_StockIssuedDuringPeriodSharesRestrictedStockAwardNetOfForfeitures
Namespace Prefix: | us-gaap_
Data Type: | xbrli:sharesItemType
Balance Type: | na
Period Type: | duration

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

X
- Definition Number of common and preferred shares that were previously issued and that were repurchased by the issuing entity and held in treasury on the financial statement date. This stock has no voting rights and receives no dividends. + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 210 -SubTopic 10 -Section S99 -Paragraph 1 -Subparagraph (SX 210.5-02.29,30) -URI http://asc.fasb.org/extlink&oid=120391452&loc=d3e13212-122682 Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 505 -SubTopic 30 -Section 45 -Paragraph 1 -URI http://asc.fasb.org/extlink&oid=6405813&loc=d3e23239-112655 + Details
Name: | us-gaap_TreasuryStockShares
Namespace Prefix: | us-gaap_
Data Type: | xbrli:sharesItemType
Balance Type: | na
Period Type: | instant