The reserve to cover probable credit losses related to specifically identified fixed maturity real estate loans as well as probable credit losses inherent in the remainder of that loan portfolio.

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 944
-SubTopic 310
-Section 45
-Paragraph 4
-URI https://asc.fasb.org/extlink&oid=123605502&loc=d3e21338-158488

+ Details

Name:	us-gaap_AllowanceForLoanAndLeaseLossesRealEstate
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- Definition

Amortized cost excluding accrued interest, before allowance for credit loss, of financing receivable. Excludes net investment in lease.

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 326
-SubTopic 20
-Section 50
-Paragraph 5
-Subparagraph (b)
-URI https://asc.fasb.org/extlink&oid=124255953&loc=SL82919230-210447

Reference 2: http://www.xbrl.org/2009/role/commonPracticeRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 326
-SubTopic 20
-Section 45
-Paragraph 1
-URI https://asc.fasb.org/extlink&oid=124255206&loc=SL82895884-210446

Reference 3: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 326
-SubTopic 20
-Section 50
-Paragraph 3B
-URI https://asc.fasb.org/extlink&oid=124255953&loc=SL120267963-210447

+ Details

Name:	us-gaap_FinancingReceivableExcludingAccruedInterestBeforeAllowanceForCreditLoss
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

- Definition

The balance represents the amount of loans that are secured by real estate mortgages, offset by the reserve to cover probable credit losses on the loan portfolio.

+ References

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 210.7-03.1(c))
-URI https://asc.fasb.org/extlink&oid=126734703&loc=d3e572229-122910

+ Details

Name:	us-gaap_MortgageLoansOnRealEstateCommercialAndConsumerNet
Namespace Prefix:	us-gaap_
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

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

- Details

Name:	us-gaap_FairValueByAssetClassAxis=all_BankLoansMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	all_BankLoanAcquisitionPeriodAxis=all_Acquisition2017AndPriorMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	all_BankLoanAcquisitionPeriodAxis=all_Acquisition2018Member
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	all_BankLoanAcquisitionPeriodAxis=all_Acquisition2019Member
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	all_BankLoanAcquisitionPeriodAxis=all_Acquisition2020Member
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	all_BankLoanAcquisitionPeriodAxis=all_Acquisition2021Member
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	all_BankLoanAcquisitionPeriodAxis=all_AcquisitionCurrentMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	srt_CreditRatingStandardPoorsAxis=srt_StandardPoorsBBBRatingMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	srt_CreditRatingStandardPoorsAxis=srt_StandardPoorsBBRatingMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	srt_CreditRatingStandardPoorsAxis=srt_StandardPoorsBRatingMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	srt_CreditRatingStandardPoorsAxis=all_StandardPoorsCCCRatingandBelowMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

Investments - Bank loans amortized cost by credit quality and year of acquisition (Details) - USD ($) $ in Millions	Dec. 31, 2022	Dec. 31, 2021
Schedule of Available for Sale Securities
Amortized cost, net	$ 762	$ 821
Bank loans, net
Schedule of Available for Sale Securities
Amortized cost before allowance	743	1,635
Allowance	(57)	(61)
Amortized cost, net	686	1,574
2017 and prior \| Bank loans, net
Schedule of Available for Sale Securities
Amortized cost before allowance	34
2018 \| Bank loans, net
Schedule of Available for Sale Securities
Amortized cost before allowance	26
2019 \| Bank loans, net
Schedule of Available for Sale Securities
Amortized cost before allowance	64
2020 \| Bank loans, net
Schedule of Available for Sale Securities
Amortized cost before allowance	31
2021 \| Bank loans, net
Schedule of Available for Sale Securities
Amortized cost before allowance	531
Current \| Bank loans, net
Schedule of Available for Sale Securities
Amortized cost before allowance	57
NAIC 2 / BBB \| Bank loans, net
Schedule of Available for Sale Securities
Amortized cost before allowance	54	86
NAIC 2 / BBB \| 2017 and prior \| Bank loans, net
Schedule of Available for Sale Securities
Amortized cost before allowance	0
NAIC 2 / BBB \| 2018 \| Bank loans, net
Schedule of Available for Sale Securities
Amortized cost before allowance	0
NAIC 2 / BBB \| 2019 \| Bank loans, net
Schedule of Available for Sale Securities
Amortized cost before allowance	6
NAIC 2 / BBB \| 2020 \| Bank loans, net
Schedule of Available for Sale Securities
Amortized cost before allowance	6
NAIC 2 / BBB \| 2021 \| Bank loans, net
Schedule of Available for Sale Securities
Amortized cost before allowance	37
NAIC 2 / BBB \| Current \| Bank loans, net
Schedule of Available for Sale Securities
Amortized cost before allowance	5
NAIC 3 / BB \| Bank loans, net
Schedule of Available for Sale Securities
Amortized cost before allowance	266	656
NAIC 3 / BB \| 2017 and prior \| Bank loans, net
Schedule of Available for Sale Securities
Amortized cost before allowance	6
NAIC 3 / BB \| 2018 \| Bank loans, net
Schedule of Available for Sale Securities
Amortized cost before allowance	0
NAIC 3 / BB \| 2019 \| Bank loans, net
Schedule of Available for Sale Securities
Amortized cost before allowance	5
NAIC 3 / BB \| 2020 \| Bank loans, net
Schedule of Available for Sale Securities
Amortized cost before allowance	2
NAIC 3 / BB \| 2021 \| Bank loans, net
Schedule of Available for Sale Securities
Amortized cost before allowance	239
NAIC 3 / BB \| Current \| Bank loans, net
Schedule of Available for Sale Securities
Amortized cost before allowance	14
NAIC 4 / B \| Bank loans, net
Schedule of Available for Sale Securities
Amortized cost before allowance	329	768
NAIC 4 / B \| 2017 and prior \| Bank loans, net
Schedule of Available for Sale Securities
Amortized cost before allowance	7
NAIC 4 / B \| 2018 \| Bank loans, net
Schedule of Available for Sale Securities
Amortized cost before allowance	16
NAIC 4 / B \| 2019 \| Bank loans, net
Schedule of Available for Sale Securities
Amortized cost before allowance	17
NAIC 4 / B \| 2020 \| Bank loans, net
Schedule of Available for Sale Securities
Amortized cost before allowance	15
NAIC 4 / B \| 2021 \| Bank loans, net
Schedule of Available for Sale Securities
Amortized cost before allowance	241
NAIC 4 / B \| Current \| Bank loans, net
Schedule of Available for Sale Securities
Amortized cost before allowance	33
NAIC 5-6 / CCC and below \| Bank loans, net
Schedule of Available for Sale Securities
Amortized cost before allowance	94	$ 125
NAIC 5-6 / CCC and below \| 2017 and prior \| Bank loans, net
Schedule of Available for Sale Securities
Amortized cost before allowance	21
NAIC 5-6 / CCC and below \| 2018 \| Bank loans, net
Schedule of Available for Sale Securities
Amortized cost before allowance	10
NAIC 5-6 / CCC and below \| 2019 \| Bank loans, net
Schedule of Available for Sale Securities
Amortized cost before allowance	36
NAIC 5-6 / CCC and below \| 2020 \| Bank loans, net
Schedule of Available for Sale Securities
Amortized cost before allowance	8
NAIC 5-6 / CCC and below \| 2021 \| Bank loans, net
Schedule of Available for Sale Securities
Amortized cost before allowance	14
NAIC 5-6 / CCC and below \| Current \| Bank loans, net
Schedule of Available for Sale Securities
Amortized cost before allowance	$ 5