Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table.

No definition available.

+ Details

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Data Type:	xbrli:stringItemType
Balance Type:	na
Period Type:	duration

- Definition

Fair value of credit risk derivative asset after deduction of credit risk derivative liability.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 815
-SubTopic 10
-Section 50
-Paragraph 4K
-Subparagraph (c)
-URI http://asc.fasb.org/extlink&oid=121590274&loc=SL5708775-113959

+ Details

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Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

- Definition

Nominal or face amount used to calculate payment on derivative.

+ References

Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 815
-SubTopic 10
-Section 50
-Paragraph 1B
-URI http://asc.fasb.org/extlink&oid=121590274&loc=SL5580258-113959

Reference 2: http://www.xbrl.org/2009/role/commonPracticeRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 815
-SubTopic 10
-Section 50
-Paragraph 1A
-Subparagraph (d)
-URI http://asc.fasb.org/extlink&oid=121590274&loc=SL5579245-113959

+ Details

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Data Type:	xbrli:monetaryItemType
Balance Type:	na
Period Type:	instant

- Details

Name:	us-gaap_CreditDerivativesByContractTypeAxis=us-gaap_CreditDefaultSwapMember
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- Details

Name:	us-gaap_UnderlyingAssetClassAxis=all_SingleNameMember
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- Details

Name:	srt_CreditRatingStandardPoorsAxis=srt_StandardPoorsAARatingMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	srt_CreditRatingStandardPoorsAxis=srt_StandardPoorsARatingMember
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Data Type:	na
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- Details

Name:	srt_CreditRatingStandardPoorsAxis=srt_StandardPoorsBBBRatingMember
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Derivative Financial Instruments and Off-balance sheet Financial Instruments - CDS notional amounts by credit rating (Details) - USD ($) $ in Millions	Dec. 31, 2021	Dec. 31, 2020
Credit Derivatives
Notional amount	$ 1,990	$ 3,148
Credit default contracts
Credit Derivatives
Notional amount		5
Fair value		0
Credit default contracts \| Single name
Credit Derivatives
Notional amount		5
Fair value		0
AA \| Credit default contracts
Credit Derivatives
Notional amount		0
AA \| Credit default contracts \| Single name
Credit Derivatives
Notional amount		0
A \| Credit default contracts
Credit Derivatives
Notional amount		0
A \| Credit default contracts \| Single name
Credit Derivatives
Notional amount		0
BBB \| Credit default contracts
Credit Derivatives
Notional amount		0
BBB \| Credit default contracts \| Single name
Credit Derivatives
Notional amount		0
BB and lower \| Credit default contracts
Credit Derivatives
Notional amount		5
BB and lower \| Credit default contracts \| Single name
Credit Derivatives
Notional amount		$ 5