XML 65 R44.htm IDEA: XBRL DOCUMENT
v3.10.0.1

Investments - Narrative (Details) - USD ($) | 3 Months Ended | 6 Months Ended |
--- | --- | --- | ---
Jun. 30, 2018 | Jun. 30, 2017 | Jun. 30, 2018 | Jun. 30, 2017 | Dec. 31, 2017
Investment [Line Items] |  |  |  |  |
Gross gains on fixed income securities | $ 29,000,000 |  | $ 74,000,000 |  |
Gross loss on fixed income securities | 107,000,000 |  | 194,000,000 |  |
Gross gains on fixed income and equity securities |  | $ 141,000,000 |  | $ 376,000,000 |
Gross loss on fixed income and equity securities |  | 50,000,000 |  | 125,000,000 |
Net unrealized gains related to changes in valuation of fixed income securities subsequent to impairment measurement date | 197,000,000 |  | 197,000,000 |  | $ 208,000,000
Unrealized losses related to securities with unrealized loss position less than 20% of cost or amortized cost | 851,000,000 |  | 851,000,000 |  |
Unrealized losses related to securities with unrealized loss position greater than or equal to 20% of cost or amortized cost | 16,000,000 |  | 16,000,000 |  |
Limited partnership interests | 7,679,000,000 |  | 7,679,000,000 |  | 6,740,000,000
Fixed income and equity securities |  |  |  |  |
Investment [Line Items] |  |  |  |  |
Unrealized losses | 867,000,000 |  | 867,000,000 |  | 295,000,000
Investment grade fixed income securities |  |  |  |  |
Investment [Line Items] |  |  |  |  |
Unrealized losses related to securities with unrealized loss position less than 20% of cost or amortized cost | 730,000,000 |  | 730,000,000 |  |
Unrealized losses related to securities with unrealized loss position greater than or equal to 20% of cost or amortized cost | 11,000,000 |  | 11,000,000 |  |
Below investment grade fixed income securities |  |  |  |  |
Investment [Line Items] |  |  |  |  |
Unrealized losses related to securities with unrealized loss position less than 20% of cost or amortized cost | 121,000,000 |  | 121,000,000 |  |
Unrealized losses having loss of less than twenty percent, less than 12 months | 107,000,000 |  | 107,000,000 |  |
Unrealized losses related to securities with unrealized loss position greater than or equal to 20% of cost or amortized cost | 5,000,000 |  | 5,000,000 |  |
Unrealized losses related to securities with unrealized loss position greater than 20% of cost or amortized cost, unrealized loss position of 12 or more consecutive months | 3,000,000 |  | 3,000,000 |  |
EMA limited partnerships |  |  |  |  |
Investment [Line Items] |  |  |  |  |
Limited partnership interests | 6,030,000,000 |  | 6,030,000,000 |  | 5,410,000,000
Carrying value | Cost-method Investments |  |  |  |  |
Investment [Line Items] |  |  |  |  |
Cost method limited partnerships | 1,650,000,000 |  | 1,650,000,000 |  | $ 1,330,000,000
Mortgage loans, non-impaired |  |  |  |  |
Investment [Line Items] |  |  |  |  |
Allowance for credit losses, period increase (decrease) | $ 0 | $ 0 | 0 | 0 |
Average impaired mortgage loans |  |  | $ 4,000,000 | $ 5,000,000 |

X
- Definition This item represents the excess of [amortized] cost over fair value of fixed income securities that have been in a loss position for twelve months or longer, and have unrealized loss position greater than 20% of cost or amortized cost for those securities which are categorized neither as held-to-maturity nor trading securities as of the balance sheet date. + References No definition available. + Details
Name: | all_AvailableForSaleSecuritiesUnrealizedLossesForFixedIncomeSecuritiesHeldForTwelveMonthsOrLongerPeriod
Namespace Prefix: | all_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | instant

X
- Definition The amount of unrealized losses that are related to securities with an unrealized loss position less than 20% of cost or amortized cost. + References No definition available. + Details
Name: | all_AvailableForSaleSecuritiesUnrealizedLossesHavingLossOfLessThanTwentyPercent
Namespace Prefix: | all_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | instant

X
- Definition The amount of unrealized losses that are related to securities with an unrealized loss position greater than 20% of cost or amortized cost. + References No definition available. + Details
Name: | all_AvailableForSaleSecuritiesUnrealizedLossesHavingLossOfTwentyPercentOrHigher
Namespace Prefix: | all_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | instant

X
- Definition Available for sale Securities, Unrealized Losses Having Loss of Less than Twenty Percent, Less than 12 Months + References No definition available. + Details
Name: | all_AvailableforsaleSecuritiesUnrealizedLossesHavingLossofLessthanTwentyPercentLessthan12Months
Namespace Prefix: | all_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
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
- Definition Line items represent reporting 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 Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher SEC -Name Regulation S-X (SX) -Number 210 -Article 12 -Section 12 -Sentence Column A + Details
Name: | invest_InvestmentLineItems
Namespace Prefix: | invest_
Data Type: | xbrli:stringItemType
Balance Type: | na
Period Type: | duration

X
- Definition Amount of accumulated unrealized loss on investments in debt and equity securities classified as available-for-sale in a continuous loss position. + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 320 -SubTopic 10 -Section 50 -Paragraph 7 -URI http://asc.fasb.org/extlink&oid=82897076&loc=d3e27337-111563 + Details
Name: | us-gaap_AvailableForSaleSecuritiesContinuousUnrealizedLossPositionAccumulatedLoss
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | instant

X
- Definition This item represents the gross profit realized on the sale of debt or equity securities categorized neither as held-to-maturity nor trading securities. + References No definition available. + Details
Name: | us-gaap_AvailableForSaleSecuritiesGrossRealizedGains
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | duration

X
- Definition This item represents the gross loss realized on the sale of debt or equity securities categorized neither as held-to-maturity nor trading securities. + References No definition available. + Details
Name: | us-gaap_AvailableForSaleSecuritiesGrossRealizedLosses
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | duration

X
- Definition Amount, after adjustment, of cost-method investment. Adjustments include, but are not limited to, dividends received in excess of earnings after date of investment that are considered a return of investment and other than temporary impairments. + References No definition available. + Details
Name: | us-gaap_CostMethodInvestments
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | instant

X
- Definition Amount of realized gain on investment in debt security measured at fair value with change in fair value recognized in other comprehensive income (available-for-sale). + References Reference 1: http://www.xbrl.org/2003/role/disclosureRef -Publisher FASB -Name Accounting Standards Codification -Topic 320 -SubTopic 10 -Section 50 -Paragraph 9 -Subparagraph (a) -URI http://asc.fasb.org/extlink&oid=82897076&loc=d3e27357-111563 + Details
Name: | us-gaap_DebtSecuritiesAvailableForSaleRealizedGain
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | duration

X
- Definition Amount of realized loss on investment in debt security measured at fair value with change in fair value recognized in other comprehensive income (available-for-sale). + References Reference 1: http://www.xbrl.org/2003/role/disclosureRef -Publisher FASB -Name Accounting Standards Codification -Topic 320 -SubTopic 10 -Section 50 -Paragraph 9 -Subparagraph (a) -URI http://asc.fasb.org/extlink&oid=82897076&loc=d3e27357-111563 + Details
Name: | us-gaap_DebtSecuritiesAvailableForSaleRealizedLoss
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | duration

X
- Definition The increase (decrease) in the allowance for credit losses related to financing receivables. + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 310 -SubTopic 10 -Section 50 -Paragraph 11B -Subparagraph (c) -URI http://asc.fasb.org/extlink&oid=84173941&loc=SL6953423-111524 + Details
Name: | us-gaap_FinancingReceivableAllowanceForCreditLossesPeriodIncreaseDecrease
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | na
Period Type: | duration

X
- Definition Average amount of investment of impaired financing receivables with related allowance for credit losses and without a related allowance for credit losses. + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 310 -SubTopic 10 -Section 50 -Paragraph 15 -Subparagraph (c)(1) -URI http://asc.fasb.org/extlink&oid=84173941&loc=d3e5212-111524 Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 310 -SubTopic 10 -Section 50 -Paragraph 17 -URI http://asc.fasb.org/extlink&oid=84173941&loc=d3e5258-111524 + Details
Name: | us-gaap_ImpairedFinancingReceivableAverageRecordedInvestment
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | duration

X
- Definition Amount of investment in equity method investee and investment in and advance to affiliate. + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 210 -SubTopic 10 -Section S99 -Paragraph 1 -Subparagraph (SX 210.5-02.12) -URI http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682 + Details
Name: | us-gaap_InvestmentsInAffiliatesSubsidiariesAssociatesAndJointVentures
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | instant

X
- Details
Name: | us-gaap_FinancialInstrumentAxis=us-gaap_AvailableforsaleSecuritiesMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_FinancialInstrumentAxis=all_InvestmentGradeFixedIncomeSecuritiesMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_FinancialInstrumentAxis=all_BelowInvestmentGradeFixedIncomeSecuritiesMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_InvestmentTypeAxis=us-gaap_EquityMethodInvestmentsMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_FairValueByMeasurementBasisAxis=us-gaap_CarryingReportedAmountFairValueDisclosureMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_InvestmentTypeAxis=us-gaap_CostmethodInvestmentsMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_AccountsNotesLoansAndFinancingReceivableByReceivableTypeAxis=all_MortgagesNonImpairedMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |