XML 183 R156.htm IDEA: XBRL DOCUMENT
v3.8.0.1

Benefit Plans - Estimated future benefit payments (Details) $ in Millions | Dec. 31, 2017 USD ($)
--- | ---
Pension benefits |
Estimated future benefit payments |
2018 | $ 426
2019 | 463
2020 | 485
2021 | 514
2022 | 533
2023-2027 | 2,477
Total benefit payments | 4,898
Postretirement benefits |
Estimated future benefit payments |
2018 | 22
2019 | 24
2020 | 24
2021 | 25
2022 | 26
2023-2027 | 136
Total benefit payments | $ 257

X
- Definition The amount of the total benefits expected to be paid. + References No definition available. + Details
Name: | all_DefinedBenefitPlanAggregateExpectedFutureBenefitPayments
Namespace Prefix: | all_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | instant

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

X
- Definition Amount of benefits for defined benefit plan expected to be paid in five fiscal years after fifth fiscal year following latest fiscal year. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 715 -SubTopic 20 -Section 50 -Paragraph 1 -Subparagraph (f) -URI http://asc.fasb.org/extlink&oid=82843861&loc=d3e1928-114920 + Details
Name: | us-gaap_DefinedBenefitPlanExpectedFutureBenefitPaymentsFiveFiscalYearsThereafter
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | instant

X
- Definition Amount of benefits for defined benefit plan expected to be paid in next fiscal year following latest fiscal year. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 715 -SubTopic 20 -Section 50 -Paragraph 1 -Subparagraph (f) -URI http://asc.fasb.org/extlink&oid=82843861&loc=d3e1928-114920 + Details
Name: | us-gaap_DefinedBenefitPlanExpectedFutureBenefitPaymentsNextTwelveMonths
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | instant

X
- Definition Amount of benefits for defined benefit plan expected to be paid in fifth fiscal year following latest fiscal year. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 715 -SubTopic 20 -Section 50 -Paragraph 1 -Subparagraph (f) -URI http://asc.fasb.org/extlink&oid=82843861&loc=d3e1928-114920 + Details
Name: | us-gaap_DefinedBenefitPlanExpectedFutureBenefitPaymentsYearFive
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | instant

X
- Definition Amount of benefits for defined benefit plan expected to be paid in fourth fiscal year following latest fiscal year. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 715 -SubTopic 20 -Section 50 -Paragraph 1 -Subparagraph (f) -URI http://asc.fasb.org/extlink&oid=82843861&loc=d3e1928-114920 + Details
Name: | us-gaap_DefinedBenefitPlanExpectedFutureBenefitPaymentsYearFour
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | instant

X
- Definition Amount of benefits for defined benefit plan expected to be paid in third fiscal year following latest fiscal year. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 715 -SubTopic 20 -Section 50 -Paragraph 1 -Subparagraph (f) -URI http://asc.fasb.org/extlink&oid=82843861&loc=d3e1928-114920 + Details
Name: | us-gaap_DefinedBenefitPlanExpectedFutureBenefitPaymentsYearThree
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | instant

X
- Definition Amount of benefits for defined benefit plan expected to be paid in second fiscal year following latest fiscal year. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 715 -SubTopic 20 -Section 50 -Paragraph 1 -Subparagraph (f) -URI http://asc.fasb.org/extlink&oid=82843861&loc=d3e1928-114920 + Details
Name: | us-gaap_DefinedBenefitPlanExpectedFutureBenefitPaymentsYearTwo
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | instant

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

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