Guarantees and Contingent Liabilities (Details) (USD $) In Millions, unless otherwise specified	3 Months Ended
Mar. 31, 2015 employee claim	Dec. 31, 2014
Guarantees:
Limitations or indemnifications of reinsurance agreements	$ 0
Proceedings:
Number of class action cases	2
Number of cases pending	1
Number of former employee agents plaintiffs seek benefits for	6,300
Reserves for asbestos claims	993all_LiabilityForAsbestosClaimsNet	1,010all_LiabilityForAsbestosClaimsNet
Reinsurance recoverables for asbestos claims	467all_ReinsuranceRecoverablesAsbestos	478all_ReinsuranceRecoverablesAsbestos
Reserves for environmental claims	199all_LiabilityForEnvironmentalClaimsNet	203all_LiabilityForEnvironmentalClaimsNet
Reinsurance recoverables for environmental claims	64all_ReinsuranceRecoverablesEnvironment	64all_ReinsuranceRecoverablesEnvironment
Percentage of net asbestos and environmental reserves that were for incurred but not reported estimated losses	56.00%	57.00%
Minimum
Proceedings:
Loss contingencies, reasonably possible pretax loss exposure in excess of the amount accrued	0
Maximum
Proceedings:
Loss contingencies, reasonably possible pretax loss exposure in excess of the amount accrued	690
Residual guarantee
Guarantees:
Potential leased automobiles residual value	38
Guarantee obligations term, low end of range	1 year
Guarantee obligations term, high end of range	3 years
Maximum amount at risk pursuant to a guarantee	$ 4

Name:	all_ContingentLiabilitiesAbstract
Namespace Prefix:	all_
Data Type:	xbrli:stringItemType
Balance Type:	na
Period Type:	duration

The high end of the range of the approximate term of the guarantee or each group of similar guarantees.

+ References

No definition available.

+ Details

Name:	all_GuaranteeObligationsTermHighEndOfRange
Namespace Prefix:	all_
Data Type:	xbrli:durationItemType
Balance Type:	na
Period Type:	duration

- Definition

The low end of the range of the approximate term of the guarantee or each group of similar guarantees.

+ References

No definition available.

+ Details

Name:	all_GuaranteeObligationsTermLowEndOfRange
Namespace Prefix:	all_
Data Type:	xbrli:durationItemType
Balance Type:	na
Period Type:	duration

- Definition

Carrying amount as of the balance sheet date of reserves for the costs of settling insured claims and costs incurred in the claims settlement process attributable to asbestos, net of estimated reinsurance recoveries.

+ References

No definition available.

+ Details

Name:	all_LiabilityForAsbestosClaimsNet
Namespace Prefix:	all_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- Definition

Carrying amount as of the balance sheet date of reserves for the costs of settling insured claims and costs incurred in the claims settlement process attributable to environmental claims, net of estimated reinsurance recoveries.

+ References

No definition available.

+ Details

Name:	all_LiabilityForEnvironmentalClaimsNet
Namespace Prefix:	all_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- Definition

Estimate of the reasonably possible pretax loss exposure in excess of the amount accrued for the entity's lawsuits, regulatory inquiries and other legal proceedings.

+ References

No definition available.

+ Details

Name:	all_LossContingencyReasonablyPossibleAdditionalLossesPretaxEstimate
Namespace Prefix:	all_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

- Definition

Represents the amount of former employee agents plaintiffs seek benefits for.

+ References

No definition available.

+ Details

Name:	all_NumberOfFormerEmployeeAgentsPlaintiffsSeekBenefitsFor
Namespace Prefix:	all_
Data Type:	xbrli:integerItemType
Balance Type:	na
Period Type:	duration

- Definition

The percentage of net asbestos and environment reserves that were for incurred but not reported estimated losses.

+ References

No definition available.

+ Details

Name:	all_PercentageOfAsbestosAndEnvironmentReservesIncurredButNotReportedEstimatedLosses
Namespace Prefix:	all_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	instant

- Definition

Represents the aggregate expected value at the end of useful life of leased automobiles.

+ References

No definition available.

+ Details

Name:	all_PotentialLeasedAutomobilesResidualValue
Namespace Prefix:	all_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

- Definition

Represents the limitations or indemnifications of reinsurance agreements with regard to insurance risk transfer, and transferred all of the future risks and responsibilities for performance on the underlying variable annuity contracts to prudential, including those related to benefit guarantees.

+ References

No definition available.

+ Details

Name:	all_ReinsuranceAgreementsLimitationsOnInsuranceRiskTransfer
Namespace Prefix:	all_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

- Definition

The known and estimated amount recoverable related to asbestos claims as of the balance sheet date from reinsurers for claims paid or incurred by the ceding insurer and associated claims settlement expenses, including estimated amounts for claims incurred but not reported, and policy benefits, net of any related valuation allowance.

+ References

No definition available.

+ Details

Name:	all_ReinsuranceRecoverablesAsbestos
Namespace Prefix:	all_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

- Definition

The known and estimated amount recoverable related to environment related claims as of the balance sheet date from reinsurers for claims paid or incurred by the ceding insurer and associated claims settlement expenses, including estimated amounts for claims incurred but not reported, and policy benefits, net of any related valuation allowance.

+ References

No definition available.

+ Details

Name:	all_ReinsuranceRecoverablesEnvironment
Namespace Prefix:	all_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

- Details

Name:	us-gaap_GuaranteeObligationsLineItems
Namespace Prefix:	us-gaap_
Data Type:	xbrli:stringItemType
Balance Type:	na
Period Type:	duration

- Definition

Maximum potential amount of future payments (undiscounted) the guarantor could be required to make under the guarantee or each group of similar guarantees before reduction for potential recoveries under recourse or collateralization provisions.

+ References

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

-Publisher FASB

-Name Accounting Standards Codification

-Topic 460

-SubTopic 10

-Section 50

-Paragraph 4

-Subparagraph (b)(1)

-URI http://asc.fasb.org/extlink&oid=6851643&loc=d3e12069-110248

+ Details

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

- Definition

The total number of new claims filed pertaining to a loss contingency during the period.

+ References

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

-Publisher FASB

-Name Accounting Standards Codification

-Topic 450

-SubTopic 20

-Section 50

-Paragraph 4

-Subparagraph (a)

-URI http://asc.fasb.org/extlink&oid=25496072&loc=d3e14435-108349

+ Details

Name:	us-gaap_LossContingencyNewClaimsFiledNumber
Namespace Prefix:	us-gaap_
Data Type:	xbrli:integerItemType
Balance Type:	na
Period Type:	duration

- Definition

Number of pending claims pertaining to a loss contingency.

+ References

+ Details

Name:	us-gaap_LossContingencyPendingClaimsNumber
Namespace Prefix:	us-gaap_
Data Type:	xbrli:integerItemType
Balance Type:	na
Period Type:	instant

- Details

Name:	us-gaap_GuaranteeObligationsByNatureAxis=all_ResidualGuaranteeMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_RangeAxis=us-gaap_MaximumMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_RangeAxis=us-gaap_MinimumMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type: