Name:	ace_EquitySecuritiesGrossRealizedGainsExcludingOtherThanTemporaryImpairments
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Aggregate loss on all equity securities recognized in earnings during the period, before tax effects excluding other than temporary impairments.

No definition available.

Name:	ace_EquitySecuritiesGrossRealizedLossesExcludingOtherThanTemporaryImpairments
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Net realized gains/losses and OCI relating to equity securities as a result of conditions which caused the company to conclude the decline in the fair value of certain investments was other than temporary.

No definition available.

Name:	ace_EquitySecuritiesNetRealizedGainsLossesTotal
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Aggregate gain/loss relating to fair value adjustments on insurance derivative instruments recognized in earnings during the period, before tax effects.

No definition available.

Name:	ace_FairValueAdjustmentsOnInsuranceDerivativeGainsLosses
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Data Type:	xbrli:monetaryItemType
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Aggregate gain on all equity securities recognized in earnings during the period, before tax effects excluding other than temporary impairments.

No definition available.

Name:	ace_FixedMaturitiesGrossRealizedGainsExcludingOtherThanTemporaryImpairments
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Aggregate loss on all fixed maturities securities recognized in earnings during the period, before tax effects excluding other than temporary impairments.

No definition available.

Name:	ace_FixedMaturitiesGrossRealizedLossesExcludingOtherThanTemporaryImpairments
Namespace Prefix:	ace_
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Net realized gains/losses and OCI relating to fixed maturities as a result of conditions which caused the company to conclude the decline in the fair value of certain investments was other than temporary.

No definition available.

Name:	ace_FixedMaturitiesNetRealizedGainsLossesTotal
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The gross decline in fair value that is deemed to be "other than temporary" as it relates to fixed maturities.

No definition available.

Name:	ace_FixedMaturitiesOtherThanTemporaryImpairmentsGross
Namespace Prefix:	ace_
Data Type:	xbrli:monetaryItemType
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The decline in fair value that is deemed to be "other than temporary" reflected in other comprehensive income (pre-tax) as it relates to fixed maturities.

No definition available.

Name:	ace_FixedMaturitiesOtherThanTemporaryImpairmentsInOtherComprehensiveIncomePreTax
Namespace Prefix:	ace_
Data Type:	xbrli:monetaryItemType
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The net decline in fair value that is deemed to be "other than temporary" as it relates to fixed maturities (net of other than temporary impairments in other comprehensive income).

No definition available.

Name:	ace_FixedMaturitiesOtherThanTemporaryImpairmentsNet
Namespace Prefix:	ace_
Data Type:	xbrli:monetaryItemType
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Aggregate gain/loss on all investment and embedded derivative instruments recognized in earnings during the period, before tax effects.

No definition available.

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

The net realized gains or losses on investments, derivative instruments, and foreign exchange recognized during the period.

No definition available.

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

Aggregate gain/loss on all other derivative instruments recognized in earnings during the period, before tax effects

No definition available.

Name:	ace_OtherDerivativeInstrumentsGainsLosses
Namespace Prefix:	ace_
Data Type:	xbrli:monetaryItemType
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The decline in fair value that is deemed to be "other than temporary" as it relates to other investments.

No definition available.

Name:	ace_OtherInvestmentsOtherThanTemporaryImpairments
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Data Type:	xbrli:monetaryItemType
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Aggregate gain/loss on all other investments recognized in earnings during the period, before tax effects.

No definition available.

Name:	ace_OtherRealizedGainsLosses
Namespace Prefix:	ace_
Data Type:	xbrli:monetaryItemType
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Aggregate gain/loss on all Standard and Poors put options and futures recognized in earnings during the period, before tax effects.

No definition available.

Name:	ace_StandardAndPoorsPutOptionsAndFuturesGainsLosses
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Data Type:	xbrli:monetaryItemType
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This item represents an other than temporary decline in value that has been recognized against an investment accounted for under the equity method of accounting. The excess of the carrying amount over the fair value of the investment represents the amount of the write down which is or was reflected in earnings. The written down value is a new cost basis with the adjusted value of the investment becoming its new carrying value subject to the equity accounting method. Evidence of a loss in value might include, but would not necessarily be limited to, absence of an ability to recover the carrying amount of the investment or inability of the investee to sustain an earnings capacity which would justify the carrying amount of the investment.

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

-Publisher FASB

-Name Accounting Standards Codification

-Topic 323

-SubTopic 10

-Section 35

-Paragraph 32

-URI http://asc.fasb.org/extlink&oid=7658923&loc=d3e32787-111569

Name:	us-gaap_EquityMethodInvestmentOtherThanTemporaryImpairment
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Amount before tax of foreign currency transaction realized and unrealized gain (loss) recognized in the income statement.

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

-Publisher FASB

-Name Accounting Standards Codification

-Topic 830

-SubTopic 20

-Section 45

-Paragraph 1

-URI http://asc.fasb.org/extlink&oid=6450189&loc=d3e30690-110894

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

-Publisher FASB

-Name Accounting Standards Codification

-Topic 830

-SubTopic 20

-Section 50

-Paragraph 1

-URI http://asc.fasb.org/extlink&oid=6450222&loc=d3e30840-110895

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

-Publisher FASB

-Name Accounting Standards Codification

-Topic 830

-SubTopic 20

-Section 45

-Paragraph 2

-URI http://asc.fasb.org/extlink&oid=6450189&loc=d3e30700-110894