The gross amount of life insurance in force as of the balance sheet date.

No definition available.

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Namespace Prefix:	all_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- Definition

Represents the carrying amount of the investments held by trust.

+ References

No definition available.

+ Details

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

- Definition

Represents the amount of reinsurance ceded under various contracts.

+ References

No definition available.

+ Details

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

- Definition

Amount of life insurance issued and outstanding ceded to other entity, as disclosed in supplementary reinsurance information. Includes, but is not limited to, dividend and adjustment to face value.

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Publisher SEC
-Name Regulation S-X (SX)
-Number 210
-Section 12
-Paragraph Column C
-Subsection 17

Reference 2: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 944
-SubTopic 235
-Section S99
-Paragraph 2
-Subparagraph (SX 210.12-17(Column C))
-URI http://asc.fasb.org/extlink&oid=34713774&loc=d3e574992-122915

+ Details

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- Definition

For an entity that discloses a concentration risk in relation to quantitative amount, which serves as the "benchmark" (or denominator) in the equation, this concept represents the concentration percentage derived from the division.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 275
-SubTopic 10
-Section 50
-Paragraph 18
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-Publisher FASB
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-Topic 275
-SubTopic 10
-Section 50
-Paragraph 20
-URI http://asc.fasb.org/extlink&oid=99393423&loc=d3e6404-108592

+ Details

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Data Type:	num:percentItemType
Balance Type:	na
Period Type:	duration

- Definition

Amount before valuation allowance recoverable 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.

+ References

No definition available.

+ Details

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

- 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

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Reinsurance and Indemnification - Other Reinsurance Narrative (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Reinsurance Retention Policy [Line Items]
Reinsurance recoverables	$ 70
Life insurance in force ceded to unaffiliated reinsurers	74,021	$ 81,186	$ 86,642
Allstate Annuities
Reinsurance Retention Policy [Line Items]
Gross life insurance in force	449,200
Life insurance in force ceded to unaffiliated reinsurers	74,020
Life and annuity contract benefits
Reinsurance Retention Policy [Line Items]
Ceded losses incurred	165	240	179
Interest credited to contractholder funds
Reinsurance Retention Policy [Line Items]
Ceded losses incurred	20	24	25
Citigroup Subsidiaries and Scottish Re \| Operating costs and expenses \| Allstate Annuities
Reinsurance Retention Policy [Line Items]
Reinsurance recoverables	112	118
Prudential \| Allstate Annuities
Reinsurance Retention Policy [Line Items]
Reinsurance recoverables	1,290	1,360
Prudential \| Life and annuity premiums and contract charges \| Allstate Annuities
Reinsurance Retention Policy [Line Items]
Ceded losses incurred	65	72	76
Prudential \| Life and annuity contract benefits \| Allstate Annuities
Reinsurance Retention Policy [Line Items]
Ceded losses incurred	4	87	7
Prudential \| Interest credited to contractholder funds \| Allstate Annuities
Reinsurance Retention Policy [Line Items]
Ceded losses incurred	19	20	20
Prudential \| Operating costs and expenses \| Allstate Annuities
Reinsurance Retention Policy [Line Items]
Ceded losses incurred	12	$ 14	$ 15
Lincoln Benefit Life Company
Reinsurance Retention Policy [Line Items]
Investments held by trust	$ 6,250
Reinsurer Concentration Risk \| A-
Reinsurance Retention Policy [Line Items]
Concentration risk, percentage	93.00%
Reinsurer Concentration Risk \| A- \| Allstate Annuities
Reinsurance Retention Policy [Line Items]
Concentration risk, percentage		93.00%