XML 100 R82.htm IDEA: XBRL DOCUMENT
v3.21.1

Derivative Financial Instruments - CDS notional amount by credit rating and fair value of protection sold (Details) - USD ($) $ in Millions | 3 Months Ended |
--- | --- | ---
Mar. 31, 2021 | Dec. 31, 2020
Derivative Instruments and Hedging Activities Disclosure [Abstract] |  |
Term of credit default swaps (in years) | 5 years |
Derivative [Line Items] |  |
Notional amount | $ 4,806 | $ 5,191
Credit default contracts |  |
Derivative [Line Items] |  |
Notional amount | 905 | 754
Fair value | 18 | 13
Single name | Corporate | Credit default contracts |  |
Derivative [Line Items] |  |
Notional amount | 5 | 4
Fair value | 0 | 0
Index | Corporate | Credit default contracts |  |
Derivative [Line Items] |  |
Notional amount | 900 | 750
Fair value | 18 | 13
AAA | Credit default contracts |  |
Derivative [Line Items] |  |
Notional amount | 7 | 6
AAA | Single name | Corporate | Credit default contracts |  |
Derivative [Line Items] |  |
Notional amount | 0 | 0
AAA | Index | Corporate | Credit default contracts |  |
Derivative [Line Items] |  |
Notional amount | 7 | 6
AA | Credit default contracts |  |
Derivative [Line Items] |  |
Notional amount | 14 | 12
AA | Single name | Corporate | Credit default contracts |  |
Derivative [Line Items] |  |
Notional amount | 0 | 0
AA | Index | Corporate | Credit default contracts |  |
Derivative [Line Items] |  |
Notional amount | 14 | 12
A | Credit default contracts |  |
Derivative [Line Items] |  |
Notional amount | 179 | 156
A | Single name | Corporate | Credit default contracts |  |
Derivative [Line Items] |  |
Notional amount | 0 | 0
A | Index | Corporate | Credit default contracts |  |
Derivative [Line Items] |  |
Notional amount | 179 | 156
BBB | Credit default contracts |  |
Derivative [Line Items] |  |
Notional amount | 610 | 492
BBB | Single name | Corporate | Credit default contracts |  |
Derivative [Line Items] |  |
Notional amount | 0 | 0
BBB | Index | Corporate | Credit default contracts |  |
Derivative [Line Items] |  |
Notional amount | 610 | 492
BB and lower | Credit default contracts |  |
Derivative [Line Items] |  |
Notional amount | 95 | 88
BB and lower | Single name | Corporate | Credit default contracts |  |
Derivative [Line Items] |  |
Notional amount | 5 | 4
BB and lower | Index | Corporate | Credit default contracts |  |
Derivative [Line Items] |  |
Notional amount | $ 90 | $ 84

X
- Definition Term of the credit risk derivative contract, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents the reported fact of one year, five months, and thirteen days. + 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 (a)(1) -URI http://asc.fasb.org/extlink&oid=121590274&loc=SL5708775-113959 + Details
Name: | us-gaap_CreditDerivativeTerm1
Namespace Prefix: | us-gaap_
Data Type: | xbrli:durationItemType
Balance Type: | na
Period Type: | duration

X
- 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
Name: | us-gaap_CreditRiskDerivativesAtFairValueNet
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | instant

X
- References No definition available. + Details
Name: | us-gaap_DerivativeInstrumentsAndHedgingActivitiesDisclosureAbstract
Namespace Prefix: | us-gaap_
Data Type: | xbrli:stringItemType
Balance Type: | na
Period Type: | duration

X
- Definition 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. + References No definition available. + Details
Name: | us-gaap_DerivativeLineItems
Namespace Prefix: | us-gaap_
Data Type: | xbrli:stringItemType
Balance Type: | na
Period Type: | duration

X
- 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
Name: | us-gaap_DerivativeNotionalAmount
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | na
Period Type: | instant

X
- Details
Name: | us-gaap_CreditDerivativesByContractTypeAxis=us-gaap_CreditDefaultSwapMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_UnderlyingAssetClassAxis=all_SingleNameMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_ExternalCreditRatingByGroupingAxis=us-gaap_CorporateDebtSecuritiesMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_UnderlyingAssetClassAxis=all_IndexMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | srt_CreditRatingStandardPoorsAxis=srt_StandardPoorsAAARatingMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | srt_CreditRatingStandardPoorsAxis=srt_StandardPoorsAARatingMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | srt_CreditRatingStandardPoorsAxis=srt_StandardPoorsARatingMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | srt_CreditRatingStandardPoorsAxis=srt_StandardPoorsBBBRatingMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | srt_CreditRatingStandardPoorsAxis=all_StandardPoorsBBAndLowerRatingMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |