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Represents the number of reinstatements each year for each contract.

No definition available.

Name:	all_CatastropheInsuranceNumberOfReinstatementsPerYear
Namespace Prefix:	all_
Data Type:	xbrli:integerItemType
Balance Type:	na
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Catastrophe Reinsurance Aggregate Annual Loss Limit

No definition available.

Name:	all_CatastropheReinsuranceAggregateAnnualLossLimit
Namespace Prefix:	all_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

The limit of aggregated losses per contract year beyond which coverage provided by an aggregate excess agreement applies.

No definition available.

Name:	all_CatastropheReinsuranceAggregateLossLimitPerContractYear
Namespace Prefix:	all_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

Represents the number of layers subject to reinstatement in which catastrophe reinsurance agreement contracts are placed.

No definition available.

Name:	all_CatastropheReinsuranceAgreementContractNumberofLayersSubjecttoReinstatement
Namespace Prefix:	all_
Data Type:	xbrli:integerItemType
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Represents the period of catastrophe reinsurance agreement contract.

No definition available.

Name:	all_CatastropheReinsuranceAgreementContractTerm
Namespace Prefix:	all_
Data Type:	xbrli:durationItemType
Balance Type:	na
Period Type:	duration

Represents the retention amount of catastrophe reinsurance agreement contracts.

No definition available.

Name:	all_CatastropheReinsuranceAgreementContractsRetentionAmount
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Data Type:	xbrli:monetaryItemType
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Reinsurance Fund, Net Income

No definition available.

Name:	all_ReinsuranceFundNetIncome
Namespace Prefix:	all_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration

Reinsurance, Incremental Reinstatement Premiums

No definition available.

Name:	all_ReinsuranceIncrementalReinstatementPremiums
Namespace Prefix:	all_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

Amount, after valuation allowance, recoverable under reinsurance contracts including premium paid under reinsurance contracts. Examples include, but are not limited to, settled and unsettled claims, incurred but not reported losses, loss adjustment expense, premium paid, policy benefits and policy reserves.

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 944
-SubTopic 210
-Section S99
-Paragraph 1
-Subparagraph (SX 210.7-03.(a),6)
-URI http://asc.fasb.org/extlink&oid=6879938&loc=d3e572229-122910

Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 944
-SubTopic 20
-Section 50
-Paragraph 5
-URI http://asc.fasb.org/extlink&oid=99397103&loc=d3e6824-158387

Reference 3: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 944
-SubTopic 310
-Section 45
-Paragraph 5
-URI http://asc.fasb.org/extlink&oid=99404803&loc=d3e21409-158489

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Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

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.

No definition available.

Name:	us-gaap_ReinsuranceRetentionPolicyLineItems
Namespace Prefix:	us-gaap_
Data Type:	xbrli:stringItemType
Balance Type:	na
Period Type:	duration

Percentage of risk reinsured on insurance products per entity policy.

No definition available.

Name:	us-gaap_ReinsuranceRetentionPolicyReinsuredRiskPercentage
Namespace Prefix:	us-gaap_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	duration

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Balance Type:
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Namespace Prefix:
Data Type:	na
Balance Type:
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Namespace Prefix:
Data Type:	na
Balance Type:
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Namespace Prefix:
Data Type:	na
Balance Type:
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