Assumed Reinsurance, Consideration Received

No definition available.

Name:	tl_AssumedReinsuranceConsiderationReceived
Namespace Prefix:	tl_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

- Definition

Assumed Reinsurance, Consideration Transferred

+ References

No definition available.

+ Details

Name:	tl_AssumedReinsuranceConsiderationTransferred
Namespace Prefix:	tl_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration

- Definition

Assumed Reinsurance, Deferred Gain (Loss)

+ References

No definition available.

+ Details

Name:	tl_AssumedReinsuranceDeferredGainLoss
Namespace Prefix:	tl_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- Definition

Coinsurance Basis, General Account Reserves Assumed, Percent

+ References

No definition available.

+ Details

Name:	tl_CoinsuranceBasisGeneralAccountReservesAssumedPercent
Namespace Prefix:	tl_
Data Type:	dtr-types:percentItemType
Balance Type:	na
Period Type:	instant

- Definition

Life insurance recoveries on ceded reinsurance contracts.

+ References

No definition available.

+ Details

Name:	tl_LifeInsuranceRecoveriesOnCededReinsuranceContracts
Namespace Prefix:	tl_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration

- Definition

Modified Coinsurance Basis, Separate Account Assets And Liabilities Assumed, Percent

+ References

No definition available.

+ Details

Name:	tl_ModifiedCoinsuranceBasisSeparateAccountAssetsAndLiabilitiesAssumedPercent
Namespace Prefix:	tl_
Data Type:	dtr-types:percentItemType
Balance Type:	na
Period Type:	instant

- Definition

Proceeds From (Payments For) Ceded Commissions And Other

+ References

No definition available.

+ Details

Name:	tl_ProceedsFromPaymentsForCededCommissionsAndOther
Namespace Prefix:	tl_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

- Definition

Reinsurance, Administrative Service Agreement Period

+ References

No definition available.

+ Details

Name:	tl_ReinsuranceAdministrativeServiceAgreementPeriod
Namespace Prefix:	tl_
Data Type:	xbrli:durationItemType
Balance Type:	na
Period Type:	duration

- Definition

The total amount of cash and securities held by third party trustees pursuant to terms of debt instruments or other agreements as of the date of each statement of financial position presented, which can be used by the trustee only to pay the noncurrent portion of specified obligations.

+ References

Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef
-Topic 235
-SubTopic 10
-Name Accounting Standards Codification
-Section S99
-Paragraph 1
-Subparagraph (SX 210.4-08(b))
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147480678/235-10-S99-1

+ Details

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

- Definition

Amount of liability position for contract or contract feature in long-duration contract issued by insurance entity that both protects contract holder from other-than-nominal capital market risk and exposes insurance entity to other-than-nominal capital market risk.

+ References

Reference 1: http://www.xbrl.org/2003/role/exampleRef
-Topic 944
-SubTopic 40
-Name Accounting Standards Codification
-Section 55
-Paragraph 29G
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147480046/944-40-55-29G

Reference 2: http://www.xbrl.org/2003/role/disclosureRef
-Topic 944
-SubTopic 40
-Name Accounting Standards Codification
-Section 50
-Paragraph 7B
-Subparagraph (c)
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147480081/944-40-50-7B

+ Details

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

- Definition

Amount of policy benefits and costs incurred for policies assumed.

+ References

Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef
-Topic 944
-SubTopic 20
-Name Accounting Standards Codification
-Section 50
-Paragraph 3
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147479838/944-20-50-3

Reference 2: http://www.xbrl.org/2009/role/commonPracticeRef
-Topic 944
-SubTopic 220
-Name Accounting Standards Codification
-Section S99
-Paragraph 1
-Subparagraph (SX 210.7-04(5))
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147483586/944-220-S99-1

+ Details

Name:	us-gaap_ReinsuranceEffectOnClaimsAndBenefitsIncurredAmountAssumed
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

- Definition

The carrying amount as of the balance sheet date of the known and estimated amounts owed to insurers under reinsurance treaties or other arrangements.

+ References

No definition available.

+ Details

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

- Definition

Percentage of risk undertaken originally by insurer ceded to reinsurer.

+ References

+ Details

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

- Details

Name:	srt_ProductOrServiceAxis=us-gaap_FixedAnnuityMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	srt_CounterpartyNameAxis=tl_GuardianInsuranceAnnuityCompanyIncMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_ReinsuranceContractAxis=GIAC Reinsurance Agreement
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	srt_ProductOrServiceAxis=tl_GeneralAccountReservesMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	srt_ProductOrServiceAxis=tl_SeparateAccountReservesMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	srt_CounterpartyNameAxis=tl_AllianzMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_ReinsuranceContractAxis=Allianz Reinsurance Agreement
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

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

- Details

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

- Details

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

- Details

Name:	srt_CounterpartyNameAxis=tl_TRReMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_ReinsuranceContractAxis=Inforce Agreement and Flow Agreement
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

Reinsurance - Narrative (Details) - USD ($) $ in Millions				6 Months Ended		12 Months Ended
Reinsurance - Narrative (Details) - USD ($) $ in Millions	Dec. 31, 2022	Nov. 01, 2022	Dec. 30, 2021	Dec. 31, 2021	Jun. 30, 2021	Dec. 31, 2023	Dec. 31, 2022
Effects of Reinsurance [Line Items]
Life insurance recoveries on ceded reinsurance contracts				$ 782	$ 958	$ (1,670)	$ 1,648
Market risk benefits	$ 1,204					1,074	1,204
Fixed Annuity
Effects of Reinsurance [Line Items]
Policyholder benefits and claims incurred, assumed						7,300
Guardian
Effects of Reinsurance [Line Items]
Proceeds from (payments for) ceding commissions and other		$ 65
Guardian \| Reinsurance Contract [Axis]: GIAC Reinsurance Agreement
Effects of Reinsurance [Line Items]
Reinsurance payable		7,100
Assumed reinsurance, consideration received		121
Proceeds from (payments for) ceding commissions and other		$ 65
Administrative service agreement period		2 years
Guardian \| Reinsurance Contract [Axis]: GIAC Reinsurance Agreement \| General Account Reserves
Effects of Reinsurance [Line Items]
Reinsurance payable		$ 439
General account reserves assumed		100.00%
Guardian \| Reinsurance Contract [Axis]: GIAC Reinsurance Agreement \| Separate Account Reserves
Effects of Reinsurance [Line Items]
Reinsurance payable		$ 6,700
Separate account assets and liabilities assumed		100.00%
Allianz
Effects of Reinsurance [Line Items]
Proceeds from (payments for) ceding commissions and other			$ (866)
Allianz \| Reinsurance Contract [Axis]: Allianz Reinsurance Agreement
Effects of Reinsurance [Line Items]
Proceeds from (payments for) ceding commissions and other			(866)
Assumed reinsurance, consideration transferred			693
Allianz \| Reinsurance Contract [Axis]: Allianz Reinsurance Agreement \| Fixed Annuity
Effects of Reinsurance [Line Items]
Policyholder benefits and claims incurred, assumed			$ 8,000
Allianz \| Fixed income securities
Effects of Reinsurance [Line Items]
Assets held in trust	6,200					6,400	6,200
Allianz \| Short-term investments
Effects of Reinsurance [Line Items]
Assets held in trust	199					58	199
Allianz \| Cash
Effects of Reinsurance [Line Items]
Assets held in trust	$ 130					$ 202	130
TR Re \| Reinsurance Contract [Axis]: Inforce Agreement and Flow Agreement
Effects of Reinsurance [Line Items]
Reinsured risk, percentage	75.00%
Assumed reinsurance, deferred gain	$ 511			$ 129			$ 511