XML 62 R49.htm IDEA: XBRL DOCUMENT
v3.20.2

Investment Information - Other investments (Details) - Fair value option - USD ($) $ in Thousands | Jun. 30, 2020 | Dec. 31, 2019
--- | --- | ---
Schedule Of Other Investments [Line Items] |  |
Other investments | $ 2,122,490 | $ 2,429,316
Term loan investments |  |
Schedule Of Other Investments [Line Items] |  |
Other investments | 1,109,031 | 1,326,018
Lending |  |
Schedule Of Other Investments [Line Items] |  |
Other investments | 579,320 | 602,841
Credit related funds |  |
Schedule Of Other Investments [Line Items] |  |
Other investments | 92,970 | 123,020
Energy |  |
Schedule Of Other Investments [Line Items] |  |
Other investments | 66,667 | 97,402
Investment grade fixed income |  |
Schedule Of Other Investments [Line Items] |  |
Other investments | 133,936 | 151,594
Infrastructure |  |
Schedule Of Other Investments [Line Items] |  |
Other investments | 48,427 | 61,786
Private equity |  |
Schedule Of Other Investments [Line Items] |  |
Other investments | 72,888 | 49,376
Real estate |  |
Schedule Of Other Investments [Line Items] |  |
Other investments | $ 19,251 | $ 17,279

X
- Definition -- None. No documentation exists for this element. -- + References No definition available. + Details
Name: | acgl_ScheduleOfOtherInvestmentsLineItems
Namespace Prefix: | acgl_
Data Type: | xbrli:stringItemType
Balance Type: | na
Period Type: | duration

X
- Definition Amount of investments classified as other. + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 944 -SubTopic 210 -Section S99 -Paragraph 1 -Subparagraph (SX 210.7-03.1(f,g)) -URI http://asc.fasb.org/extlink&oid=120400017&loc=d3e572229-122910 Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 210 -SubTopic 10 -Section S99 -Paragraph 1 -Subparagraph (SX 210.5-02.12) -URI http://asc.fasb.org/extlink&oid=120391452&loc=d3e13212-122682 + Details
Name: | us-gaap_OtherInvestments
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | instant

X
- Details
Name: | us-gaap_InvestmentTypeAxis=acgl_FairValueOptionMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_InvestmentSecondaryCategorizationAxis=acgl_TermLoanInvestmentsMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_InvestmentSecondaryCategorizationAxis=acgl_OtherInvestmentsLendingMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_InvestmentSecondaryCategorizationAxis=acgl_CreditRelatedFundsMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_InvestmentSecondaryCategorizationAxis=acgl_OtherInvestmentsEnergyMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_InvestmentSecondaryCategorizationAxis=acgl_InvestmentGradeFixedIncomeMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_InvestmentSecondaryCategorizationAxis=acgl_OtherInvestmentsInfrastructureMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_InvestmentSecondaryCategorizationAxis=us-gaap_PrivateEquityFundsMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_InvestmentSecondaryCategorizationAxis=acgl_OtherInvestmentsRealEstateMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |