XML 65 R53.htm IDEA: XBRL DOCUMENT
v3.24.2.u1

Investment Information - Investment in operating affiliates (Details) - USD ($) $ in Millions | 3 Months Ended | 6 Months Ended |
--- | --- | --- | ---
Jun. 30, 2024 | Jun. 30, 2023 | Jun. 30, 2024 | Jun. 30, 2023 | Dec. 31, 2023
Schedule of Equity Method Investments [Line Items] |  |  |  |  |
Investment in operating affiliates | $ 1,143 |  | $ 1,143 |  | $ 1,119
Income (loss) from operating affiliates | $ 45 | $ 22 | $ 100 | $ 61 |
Coface |  |  |  |  |
Schedule of Equity Method Investments [Line Items] |  |  |  |  |
Percentage ownership | 29.90% |  | 29.90% |  |
Investment in operating affiliates | $ 543 |  | $ 543 |  | 570
Greysbridge Holdings Ltd |  |  |  |  |
Schedule of Equity Method Investments [Line Items] |  |  |  |  |
Percentage ownership | 40.00% |  | 40.00% |  |
Investment in operating affiliates | $ 484 |  | $ 484 |  | $ 430
Issued Shares Excluding Treasury Stock | Coface |  |  |  |  |
Schedule of Equity Method Investments [Line Items] |  |  |  |  |
Percentage ownership | 30.00% |  | 30.00% |  |

X
- Definition Income Loss From Operating Affiliates Equity Method + References No definition available. + Details
Name: | acgl_IncomeLossFromOperatingAffiliatesEquityMethod
Namespace Prefix: | acgl_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | duration

X
- Definition Investments in which the Company has significant influence over the operating and financial policies and are accounted for under the equity method. + References No definition available. + Details
Name: | acgl_InvestmentInOperatingAffiliateEquityMethod
Namespace Prefix: | acgl_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | instant

X
- Definition The percentage of ownership of common stock or equity participation in the investee accounted for under the equity method of accounting. + References Reference 1: http://www.xbrl.org/2003/role/disclosureRef -Topic 323 -SubTopic 10 -Name Accounting Standards Codification -Section 50 -Paragraph 3 -Subparagraph (a)(1) -Publisher FASB -URI https://asc.fasb.org/1943274/2147481687/323-10-50-3 + Details
Name: | us-gaap_EquityMethodInvestmentOwnershipPercentage
Namespace Prefix: | us-gaap_
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 Reference 1: http://www.xbrl.org/2003/role/disclosureRef -Topic 235 -SubTopic 10 -Name Accounting Standards Codification -Section S99 -Paragraph 1 -Subparagraph (SX 210.4-08(g)(1)(ii)) -Publisher FASB -URI https://asc.fasb.org/1943274/2147480678/235-10-S99-1 Reference 2: http://www.xbrl.org/2003/role/disclosureRef -Topic 323 -SubTopic 10 -Name Accounting Standards Codification -Section 50 -Paragraph 3 -Subparagraph (c) -Publisher FASB -URI https://asc.fasb.org/1943274/2147481687/323-10-50-3 Reference 3: http://www.xbrl.org/2003/role/disclosureRef -Topic 825 -SubTopic 10 -Name Accounting Standards Codification -Section 50 -Paragraph 28 -Subparagraph (f) -Publisher FASB -URI https://asc.fasb.org/1943274/2147482907/825-10-50-28 Reference 4: http://www.xbrl.org/2003/role/disclosureRef -Topic 323 -SubTopic 10 -Name Accounting Standards Codification -Section 50 -Paragraph 3 -Subparagraph (a)(1) -Publisher FASB -URI https://asc.fasb.org/1943274/2147481687/323-10-50-3 Reference 5: http://www.xbrl.org/2003/role/disclosureRef -Topic 323 -SubTopic 10 -Name Accounting Standards Codification -Section 50 -Paragraph 3 -Subparagraph (a)(2) -Publisher FASB -URI https://asc.fasb.org/1943274/2147481687/323-10-50-3 Reference 6: http://www.xbrl.org/2003/role/disclosureRef -Topic 323 -SubTopic 10 -Name Accounting Standards Codification -Section 50 -Paragraph 3 -Subparagraph (b) -Publisher FASB -URI https://asc.fasb.org/1943274/2147481687/323-10-50-3 + Details
Name: | us-gaap_ScheduleOfEquityMethodInvestmentsLineItems
Namespace Prefix: | us-gaap_
Data Type: | xbrli:stringItemType
Balance Type: | na
Period Type: | duration

X
- Details
Name: | srt_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis=acgl_CofaceMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | srt_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis=acgl_GreysbridgeHoldingsLtdMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_StatementClassOfStockAxis=acgl_IssuedSharesExcludingTreasuryStockMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |