Name:	ace_CorporateSecuritiesCreditLossesRecognizedInNetIncome
Namespace Prefix:	ace_
Data Type:	xbrli:monetaryItemType
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Period Type:	duration

Equity Securities In Unrealized Loss Position Number

No definition available.

Name:	ace_EquitySecuritiesInUnrealizedLossPositionNumber
Namespace Prefix:	ace_
Data Type:	xbrli:decimalItemType
Balance Type:	na
Period Type:	instant

Equity Securities Largest Single Unrealized Loss

No definition available.

Name:	ace_EquitySecuritiesLargestSingleUnrealizedLoss
Namespace Prefix:	ace_
Data Type:	xbrli:monetaryItemType
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Period Type:	instant

Equity Securities Total Number

No definition available.

Name:	ace_EquitySecuritiesTotalNumber
Namespace Prefix:	ace_
Data Type:	xbrli:decimalItemType
Balance Type:	na
Period Type:	instant

Number of fixed maturities in an unrealized loss position.

No definition available.

Name:	ace_FixedMaturitiesInUnrealizedLossPositionNumber
Namespace Prefix:	ace_
Data Type:	xbrli:decimalItemType
Balance Type:	na
Period Type:	instant

Largest single unrealized loss in the fixed maturities.

No definition available.

Name:	ace_FixedMaturitiesLargestSingleUnrealizedLoss
Namespace Prefix:	ace_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

Total number of fixed maturities.

No definition available.

Name:	ace_FixedMaturitiesTotalNumber
Namespace Prefix:	ace_
Data Type:	xbrli:decimalItemType
Balance Type:	na
Period Type:	instant

Credit losses recognized in net income for mortgage backed securities.

No definition available.

Name:	ace_MortgageBackedSecuritiesCreditLossesRecognizedInNetIncome
Namespace Prefix:	ace_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

Percentage of mortgage-backed securities represented by investments in US Government Agency bonds.

No definition available.

Name:	ace_MortgageBackedSecuritiesPercentageUnitedStatesGovernmentAgencyBonds
Namespace Prefix:	ace_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	instant

Net unrealized appreciation included in other comprehensive income relating to securities upon which a credit impairment was recorded.

No definition available.

Name:	ace_NetUnrealizedAppreciationIncludedInOtherComprehensiveIncome
Namespace Prefix:	ace_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration

Net unrealized depreciation included in accumulated other comprehensive income relating to securities upon which a credit impairment was recorded.

No definition available.

Name:	ace_NetUnrealizedDepreciationIncludedInAccumulatedOtherComprehensiveIncome
Namespace Prefix:	ace_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

- Details

Name:	invest_InvestmentLineItems
Namespace Prefix:	invest_
Data Type:	xbrli:stringItemType
Balance Type:	na
Period Type:	duration

The carrying amounts of cash and cash equivalent items which are restricted as to withdrawal or usage. Restrictions may include legally restricted deposits held as compensating balances against borrowing arrangements, contracts entered into with others, or entity statements of intention with regard to particular deposits; however, time deposits and short-term certificates of deposit are not generally included in legally restricted deposits. Excludes compensating balance arrangements that are not agreements which legally restrict the use of cash amounts shown on the balance sheet. This element is for unclassified presentations; for classified presentations there is a separate and distinct element.

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher AICPA

-Name Audit and Accounting Guide (AAG)

-Number AAG-BRD

-Paragraph 80

-Subparagraph Exhibit 4-8, 3

-IssueDate 2006-05-01

-Chapter 4

-LegacyDoc This reference is SUPERSEDED by the Accounting Standards Codification effective for interim and annual periods ending after September 15, 2009. This reference is included to help users transition from the previous accounting hierarchy and will be removed from future versions of this taxonomy.

Reference 2: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 210

-SubTopic 10

-Section S99

-Paragraph 1

-Subparagraph (SX 210.5-02.1)

-URI http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682

Reference 3: http://www.xbrl.org/2003/role/presentationRef

-Publisher SEC

-Name Regulation S-X (SX)

-Number 210

-Section 02

-Paragraph 1

-Article 5

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Data Type:	xbrli:monetaryItemType
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Period Type:	instant

Investments which are not defined as or included in marketable (debt, equity, or other) securities whose use is restricted in whole or in part, generally by contractual agreements or regulatory requirements. For use in an unclassified balance sheet.

No definition available.