v3.2.0.727

Fair Value Measurements (Narrative) (Detail)	6 Months Ended
	Jun. 30, 2015
Redemption Notice Periods Lower Range [Member]
Fair Value Measurements Of Financial Instruments [Line Items]
Notice period for redemption for alternative investments investment funds, days	5 days
Redemption Notice Periods Upper Range [Member]
Fair Value Measurements Of Financial Instruments [Line Items]
Notice period for redemption for alternative investments investment funds, days	120 days

X

- Definition

Fair Value Measurements Of Financial Instruments [Line Items]

+ References

No definition available.

+ Details

Name:	ace_FairValueMeasurementsOfFinancialInstrumentsLineItems
Namespace Prefix:	ace_
Data Type:	xbrli:stringItemType
Balance Type:	na
Period Type:	duration

X

- Definition

Notice period in days for redemption of investment funds alternative investments (employ various investment strategies such as long/short equity and arbitrage/distressed.)

+ References

No definition available.

+ Details

Name:	ace_NoticePeriodForRedemptionForAlternativeInvestmentsInvestmentFunds
Namespace Prefix:	ace_
Data Type:	xbrli:durationItemType
Balance Type:	na
Period Type:	duration

X

- Details

Name:	ace_AlternativeInvestmentsLiquidationAxis=ace_RedemptionNoticePeriodLowerRangeMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

X

- Details

Name:	ace_AlternativeInvestmentsLiquidationAxis=ace_RedemptionNoticePeriodUpperRangeMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type: