XML 37 R88.htm IDEA: XBRL DOCUMENT
v3.20.1

Benefit Plans - Narrative (Details) - USD ($) $ in Millions | 3 Months Ended |
--- | --- | ---
Mar. 31, 2020 | Mar. 31, 2019 | Dec. 31, 2019
Components of net periodic cost |  |  |
Remeasurement of projected benefit obligation (gains) losses - discount rate | $ 36 | $ (265) |
Pension benefits |  |  |
Components of net periodic cost |  |  |
Discount rate | 3.37% |  | 3.31%

X
- Definition Defined Benefit Plan, Benefit Obligation, (Increase) Decrease for Remeasurement due to Change in Weighted Average Discount Rate + References No definition available. + Details
Name: | all_DefinedBenefitPlanBenefitObligationIncreaseDecreaseforRemeasurementduetoChangeinWeightedAverageDiscountRate
Namespace Prefix: | all_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | duration

X
- Definition Weighted average rate for present value of future retirement benefits cash flows, used to determine benefit obligation of defined benefit plan. + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 715 -SubTopic 20 -Section 50 -Paragraph 1 -Subparagraph (k)(1) -URI http://asc.fasb.org/extlink&oid=118255775&loc=d3e1928-114920 + Details
Name: | us-gaap_DefinedBenefitPlanAssumptionsUsedCalculatingBenefitObligationDiscountRate
Namespace Prefix: | us-gaap_
Data Type: | num:percentItemType
Balance Type: | na
Period Type: | instant

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_DefinedBenefitPlanDisclosureLineItems
Namespace Prefix: | us-gaap_
Data Type: | xbrli:stringItemType
Balance Type: | na
Period Type: | duration

X
- Details
Name: | us-gaap_RetirementPlanTypeAxis=us-gaap_PensionPlansDefinedBenefitMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |