XML 104 R77.htm IDEA: XBRL DOCUMENT
v3.8.0.1

Investments - OTTI losses included in AOCI at the time of impairment for fixed income securities (Details) - USD ($) $ in Millions | Dec. 31, 2017 | Dec. 31, 2016
--- | --- | ---
Investments [Abstract] |  |
Net unrealized gains related to changes in valuation of fixed income securities subsequent to impairment measurement date | $ 208 | $ 221
Other-than Impairment Losses Included in Accumulated Other Comprehensive Income |  |
Amount of other-than-temporary impairment losses included in accumulated other comprehensive income for fixed income securities, not included in earnings | (101) | (133)
Municipal |  |
Other-than Impairment Losses Included in Accumulated Other Comprehensive Income |  |
Amount of other-than-temporary impairment losses included in accumulated other comprehensive income for fixed income securities, not included in earnings | (5) | (8)
Corporate |  |
Other-than Impairment Losses Included in Accumulated Other Comprehensive Income |  |
Amount of other-than-temporary impairment losses included in accumulated other comprehensive income for fixed income securities, not included in earnings | 0 | (7)
ABS |  |
Other-than Impairment Losses Included in Accumulated Other Comprehensive Income |  |
Amount of other-than-temporary impairment losses included in accumulated other comprehensive income for fixed income securities, not included in earnings | (15) | (21)
RMBS |  |
Other-than Impairment Losses Included in Accumulated Other Comprehensive Income |  |
Amount of other-than-temporary impairment losses included in accumulated other comprehensive income for fixed income securities, not included in earnings | (77) | (90)
CMBS |  |
Other-than Impairment Losses Included in Accumulated Other Comprehensive Income |  |
Amount of other-than-temporary impairment losses included in accumulated other comprehensive income for fixed income securities, not included in earnings | $ (4) | $ (7)

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

X
- Definition The pre-tax amount of other than temporary impairment loss on debt securities related to factors other than credit losses when the entity does not intend to sell the security and it is not more likely than not that the entity will be required to sell the security before recovery of its amortized cost basis. Such amount is included in accumulated other comprehensive income, attributable to the parent entity. + References No definition available. + Details
Name: | all_OtherThanTemporaryImpairmentLossesInvestmentsPortionInAccumulatedOtherComprehensiveIncomeLossBeforeTaxPortionAttributableToParent
Namespace Prefix: | all_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | instant

X
- Definition The net unrealized gain or loss related to changes in valuation of fixed income securities subsequent to the impairment measurement date for fixed income securities with other than temporary impairment losses recorded in accumulated other comprehensive income. + References No definition available. + Details
Name: | all_UnrealizedGainLossFixedIncomeSecuritiesChangesInValuationSubsequentToImpairment
Namespace Prefix: | all_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | instant

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

X
- Details
Name: | us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis=us-gaap_USStatesAndPoliticalSubdivisionsMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

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

X
- Details
Name: | us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis=us-gaap_AssetBackedSecuritiesMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis=us-gaap_ResidentialMortgageBackedSecuritiesMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis=us-gaap_CommercialMortgageBackedSecuritiesMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |