Reserve for Life-Contingent Contract Benefits and Contractholder Funds (Details 3) (USD $) In Millions, unless otherwise specified	12 Months Ended
Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Contractholder funds activity
Balance, beginning of year	$ 23,604us-gaap_PolicyholderContractDeposits	$ 38,634us-gaap_PolicyholderContractDeposits	$ 41,669us-gaap_PolicyholderContractDeposits
Classified as held for sale, beginning balance	10,945	0	0
Total, including those classified as held for sale	34,549us-gaap_PolicyholderFunds	38,634us-gaap_PolicyholderFunds	41,669us-gaap_PolicyholderFunds
Deposits	1,227all_DepositsToContractHolderFunds	2,338all_DepositsToContractHolderFunds	2,180all_DepositsToContractHolderFunds
Interest credited	892all_InterestToContractHolderFunds	1,268all_InterestToContractHolderFunds	1,296all_InterestToContractHolderFunds
Benefits	(1,178)all_BenefitsPaidFromContractHolderFunds	(1,521)all_BenefitsPaidFromContractHolderFunds	(1,454)all_BenefitsPaidFromContractHolderFunds
Surrenders and partial withdrawals	(2,253)	(3,279)	(3,969)
Maturities of and interest payments on institutional products	(2)	(1,799)	(138)
Contract charges	(798)all_ContractCharges	(1,032)all_ContractCharges	(995)all_ContractCharges
Net transfers from separate accounts	7	12	11
Other adjustments	34	(72)	34
Sold in LBL disposition	(10,662)	0	0
Classified as held for sale, ending balance	0	(10,945)	0
Balance, end of year	$ 21,816us-gaap_PolicyholderContractDeposits	$ 23,604us-gaap_PolicyholderContractDeposits	$ 38,634us-gaap_PolicyholderContractDeposits

Decrease in the liability for policyholder contract deposits resulting from benefits paid out of contract holder funds.

No definition available.

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

- Definition

An amount that an insurer deducts from a contract holder's account, as compensation for services rendered.

+ References

No definition available.

+ Details

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

- Definition

Increase in the liability for policyholder contract deposits resulting from amounts received during the period from the insured.

+ References

No definition available.

+ Details

Name:	all_DepositsToContractHolderFunds
Namespace Prefix:	all_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration

- Definition

Increase in the liability for policyholder contract deposits resulting from interest credited during the period by the insurer to policy owner accounts.

+ References

No definition available.

+ Details

Name:	all_InterestToContractHolderFunds
Namespace Prefix:	all_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration

- Definition

Decrease in the liability for policyholder contract deposits resulting from maturities of and interest payments on institutional products.

+ References

No definition available.

+ Details

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

- Details

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

- Definition

Other adjustments during the period to the liability for policyholder contract deposits, not specified elsewhere in the taxonomy.

+ References

No definition available.

+ Details

Name:	all_PolicyholderContractDepositsAdjustmentsOther
Namespace Prefix:	all_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration

- Definition

Policyholder Contract Deposits Adjustments, Sold in Disposition

+ References

No definition available.

+ Details

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

- Definition

Represents the liability for policyholder contract deposits classified as held for sale.

+ References

No definition available.

+ Details

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

- Definition

Change in the liability for policyholder contract deposits resulting from net amounts transferred from separate accounts during the period.

+ References

No definition available.

+ Details

Name:	all_PolicyholderContractDepositsSeparateAccountsTransfersNet
Namespace Prefix:	all_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration

- Definition

Decrease in the liability for policyholder contract deposits resulting from surrenders and partial withdrawals out of contract holder funds.

+ References

No definition available.

+ Details

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

- Definition

The liability as of the balance sheet date to the policyholders for deposits held under the terms of insurance contracts.

+ References

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

-Publisher FASB

-Name Accounting Standards Codification

-Topic 944

-SubTopic 210

-Section S99

-Paragraph 1

-Subparagraph (SX 210.7-03.13(a)(3))

-URI http://asc.fasb.org/extlink&oid=6879938&loc=d3e572229-122910

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

-Publisher FASB

-Name Accounting Standards Codification

-Topic 944

-SubTopic 40

-Section 30

-Paragraph 16

-Subparagraph (a)

-URI http://asc.fasb.org/extlink&oid=28366349&loc=d3e13951-158433

+ Details

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

- Definition

The total liability as of the balance sheet date of amounts due policy holders, excluding future policy benefits and claims, including unpaid policy dividends, retrospective refunds, and undistributed earnings on participating business.

+ References

+ Details

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