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The low end of the range of multiplicative factors used to reduce the Base Lapse Function for policies with more valuable guarantees.

+ References

No definition available.

+ Details

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

- Definition

The high end of the range of multiplicative factors used to reduce the Base Lapse Function for policies with more valuable guarantees.

+ References

No definition available.

+ Details

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

- Definition

The low end of the range of the per annum lapse assumption during the surrender charge period.

+ References

No definition available.

+ Details

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

- Definition

The high end of the range of the per annum lapse assumption during the surrender charge period.

+ References

No definition available.

+ Details

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

- Definition

The low end of the range of the per annum lapse assumption in the year immediately following the surrender charge period.

+ References

No definition available.

+ Details

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

- Definition

The high end of the range of the per annum lapse assumption in the year immediately following the surrender charge period.

+ References

No definition available.

+ Details

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

- Definition

The length of the ultimate lapse rate period.

+ References

No definition available.

+ Details

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

- Definition

The approximate per annum lapse assumption 3 or more years following the surrender charge period.

+ References

No definition available.

+ Details

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

- Definition

The highest annual annuitization rate assumption applied after the first year a policy is eligible to annuitize using a GMIB feature, used for clients for which there are several years of annuitization experience.

+ References

No definition available.

+ Details

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

- Definition

The highest annual annuitization rate assumption applied in the first year a policy is eligible to annuitize using a GMIB feature, used for clients for which there are several years of annuitization experience.

+ References

No definition available.

+ Details

Name:	ace_GuaranteedLivingBenefitsMaximumAnnuitizationRatesFirstYearUtilizingGmib
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Data Type:	num:percentItemType
Balance Type:	na
Period Type:	instant

- Definition

The number of different annuitization functions used in calculating the appropriate annuitization rate for clients without observable relevant annuitization behavior data.

+ References

No definition available.

+ Details

Name:	ace_GuaranteedLivingBenefitsNumberOfAnnuitizationFunctions
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Period Type:	instant

- Definition

Rate 1 - the highest annual annuitization rate assumption applied after the first year a policy is eligible to annuitize using a GMIB feature, as used in the weighted average for clients with no currently observable relevant annuitization behavior data.

+ References

No definition available.

+ Details

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

- Definition

Rate 2 - the highest annual annuitization rate assumption applied after the first year a policy is eligible to annuitize using a GMIB feature, as used in the weighted average for clients with no currently observable relevant annuitization behavior data.

+ References

No definition available.

+ Details

Name:	ace_GuaranteedLivingBenefitsWeightedAverageMaximumAnnuitizationRateMiddleRange
Namespace Prefix:	ace_
Data Type:	num:percentItemType
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Period Type:	instant

- Definition

Rate 3 - the highest annual annuitization rate assumption applied after the first year a policy is eligible to annuitize using a GMIB feature, as used in the weighted average for clients with no currently observable relevant annuitization behavior data.

+ References

No definition available.

+ Details

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

- 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

- Definition

The percentage of GMIB guaranteed value that is represented by clients with several years of annuitization experience

+ References

No definition available.

+ Details

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

- Definition

Amount of transfers of assets measured on a recurring basis out of Level 1 of the fair value hierarchy into Level 2.

+ References

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

-Publisher FASB

-Name Accounting Standards Codification

-Topic 820

-SubTopic 10

-Section 50

-Paragraph 2

-Subparagraph (bb)

-URI http://asc.fasb.org/extlink&oid=7578670&loc=d3e19207-110258

+ Details

Name:	us-gaap_FairValueAssetsLevel1ToLevel2TransfersAmount
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- Definition

Amount of transfers of assets measured on a recurring basis out of Level 2 of the fair value hierarchy into Level 1.

+ References

+ Details

Name:	us-gaap_FairValueAssetsLevel2ToLevel1TransfersAmount
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

Fair Value Measurements (Narrative) (Detail) (USD $) In Millions, unless otherwise specified			3 Months Ended
	Mar. 31, 2013 Year	Mar. 31, 2012	Mar. 31, 2013 Redemption Notice Periods Lower Range [Member]	Mar. 31, 2013 Redemption Notice Periods Upper Range [Member]
Fair Value Measurements Of Financial Instruments [Line Items]
GLB - Lapse rate - lower range	1.00%
GLB - Lapse rate - upper range	6.00%
GLB - Spike lapse rate - lower range	10.00%
GLB - Spike lapse rate - upper range	30.00%
GLB - Ultimate lapse rate	10.00%
GLB - Length of ultimate lapse rate period, years	2
GLB - Adjustment factor for valuable guarantees - lower	15.00%
GLB - Adjustment factor for valuable guarantees - upper	75.00%
Percent of GMIB guaranteed value that are represented by clients with several years of annuitization experience	37.00%
GLB - Maximum annuitization rate	8.00%
GLB - First year maximum annuitization rate	13.00%
GLB - Weighted average maximum annuitization rate - rate 1	8.00%
GLB - Weighted average maximum annuitization rate - rate 2	12.00%
GLB - Weighted average maximum annuitization rate - rate 3	30.00%
Notice period for redemption for alternative investments investment funds, days			5 days	120 days
Level 1 to Level 2 Transfers	$ 13	$ 5
Level 2 to Level 1 Transfers	$ 0
Guaranteed Living Benefits Number Of Annuitization Functions	3