XML 104 R87.htm IDEA: XBRL DOCUMENT v3.20.4

Investment Information - Restricted Assets (Details) - USD ($) $ in Thousands	Dec. 31, 2020	Dec. 31, 2019
Restricted Assets [Line Items]
Restricted assets	$ 8,733,309	$ 7,721,618
Collateral or guarantees - affiliated transactions
Restricted Assets [Line Items]
Restricted assets	4,643,334	4,526,761
Collateral or guarantees - third party agreements
Restricted Assets [Line Items]
Restricted assets	3,083,324	2,278,248
Deposits with US regulatory authorities
Restricted Assets [Line Items]
Restricted assets	827,552	797,371
Deposits with non-US regulatory authorities
Restricted Assets [Line Items]
Restricted assets	179,099	119,238
Watford Holdings Ltd
Restricted Assets [Line Items]
Assets pledged as collateral	$ 954,600	$ 1,000,000

X

- Definition

Assets, consisting primarily of fixed maturities, that the Company is required to maintain with various regulatory authorities to support its insurance and reinsurance operations. The Company's insurance and reinsurance subsidiaries maintain assets in trust accounts as collateral for insurance and reinsurance transactions with affiliated companies and also have investments in segregated portfolios primarily to provide collateral or guarantees for letters of credit to third parties.

+ References

No definition available.

+ Details

Name:	acgl_RestrictedAssets
Namespace Prefix:	acgl_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

X

- Definition

-- None. No documentation exists for this element. --

+ References

No definition available.

+ Details

Name:	acgl_RestrictedAssetsLineItems
Namespace Prefix:	acgl_
Data Type:	xbrli:stringItemType
Balance Type:	na
Period Type:	duration

X

- Definition

Total assets that cannot be used for operating purposes because of contract or regulatory requirements that are in effect for a period that extends beyond one year.

+ 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 210.5-02.17)
-URI http://asc.fasb.org/extlink&oid=120391452&loc=d3e13212-122682

+ Details

Name:	us-gaap_OtherRestrictedAssets
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

X

- Details

Name:	acgl_RestrictedAssetsRestrictionTypeAxis=acgl_CollateralOrGuaranteesAffiliatedTransactionsMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

X

- Details

Name:	acgl_RestrictedAssetsRestrictionTypeAxis=acgl_CollateralOrGuaranteesThirdPartyAgreementsMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

X

- Details

Name:	acgl_RestrictedAssetsRestrictionTypeAxis=acgl_DepositsWithUsRegulatoryAuthoritiesMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

X

- Details

Name:	acgl_RestrictedAssetsRestrictionTypeAxis=acgl_DepositsWithNonUsRegulatoryAuthoritiesMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

X

- Details

Name:	dei_LegalEntityAxis=acgl_WatfordHoldingsLtdMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type: