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 at beginning of period	$ 24,304us-gaap_PolicyholderContractDeposits	$ 39,319us-gaap_PolicyholderContractDeposits	$ 42,332us-gaap_PolicyholderContractDeposits
Total, including those classified as held for sale	35,249	39,319	42,332
Deposits	1,333all_DepositsToContractHolderFunds	2,440all_DepositsToContractHolderFunds	2,275all_DepositsToContractHolderFunds
Interest credited	919all_InterestToContractHolderFunds	1,295all_InterestToContractHolderFunds	1,323all_InterestToContractHolderFunds
Benefits	(1,197)all_BenefitsPaidFromContractHolderFunds	(1,535)all_BenefitsPaidFromContractHolderFunds	(1,463)all_BenefitsPaidFromContractHolderFunds
Surrenders and partial withdrawals	(2,273)	(3,299)	(3,990)
Maturities of and interest payments on institutional products	(2)	(1,799)	(138)
Contract charges	(881)us-gaap_InsuranceCommissionsAndFees	(1,112)us-gaap_InsuranceCommissionsAndFees	(1,066)us-gaap_InsuranceCommissionsAndFees
Net transfers from separate accounts	7	12	11
Other adjustments	36	(72)	35
Sold in LBL disposition	(10,662)
Classified as held for sale		(10,945)
Balance at end of period	$ 22,529us-gaap_PolicyholderContractDeposits	$ 24,304us-gaap_PolicyholderContractDeposits	$ 39,319us-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

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

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:	duration

- Definition

Represents the policyholder contract deposits sold in LBL disposition.

+ References

No definition available.

+ Details

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

- 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

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

+ References

No definition available.

+ Details

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

- 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

Income from agency and brokerage operations (includes sales of annuities and supplemental contracts); service charges, commissions, and fees from the sale of insurance and related services; and management fees from separate accounts, deferred annuities, and universal life products.

+ References

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

-Publisher FASB

-Name Accounting Standards Codification

-Topic 944

-SubTopic 225

-Section S99

-Paragraph 1

-Subparagraph (SX 210.7-04.4)

-URI http://asc.fasb.org/extlink&oid=6879464&loc=d3e573970-122913

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

-Publisher FASB

-Name Accounting Standards Codification

-Topic 942

-SubTopic 225

-Section S99

-Paragraph 1

-Subparagraph (SX 210.9-04.13(c),(d))

-URI http://asc.fasb.org/extlink&oid=6879574&loc=d3e536633-122882

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

-Publisher SEC

-Name Regulation S-X (SX)

-Number 210

-Section 04

-Paragraph 13

-Subparagraph c, d

-Article 9

Reference 4: http://www.xbrl.org/2003/role/presentationRef

-Publisher SEC

-Name Regulation S-X (SX)

-Number 210

-Section 04

-Paragraph 4

-Article 7

+ Details

Name:	us-gaap_InsuranceCommissionsAndFees
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
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