Derivatives - Derivative Balance Sheet Classification (Details) - USD ($) $ in Millions	Dec. 31, 2023	Dec. 31, 2022
Derivatives, Fair Value [Line Items]
Derivative, Notional Amount	$ 12,363	$ 10,755
Fair Value	7	47
Asset Derivatives	57	62
Liability Derivatives	(50)	(15)
Fixed maturities, AFS
Derivatives, Fair Value [Line Items]
Derivative, Notional Amount	645	569
Fair Value	0	0
Asset Derivatives	0	0
Liability Derivatives	0	0
Other investments
Derivatives, Fair Value [Line Items]
Derivative, Notional Amount	1,662	9,108
Fair Value	(1)	34
Asset Derivatives	18	38
Liability Derivatives	(19)	(4)
Other liabilities
Derivatives, Fair Value [Line Items]
Derivative, Notional Amount	10,056	1,078
Fair Value	8	13
Asset Derivatives	39	24
Liability Derivatives	(31)	(11)
Cash Flow Hedging
Derivatives, Fair Value [Line Items]
Derivative, Notional Amount	4,094	2,723
Fair Value	12	53
Asset Derivatives	30	57
Liability Derivatives	(18)	(4)
Designated as Hedging Instrument \| Interest rate swaps
Derivatives, Fair Value [Line Items]
Derivative, Notional Amount	3,450	2,155
Fair Value	(1)	0
Asset Derivatives	1	0
Liability Derivatives	(2)	0
Designated as Hedging Instrument \| Foreign currency swaps
Derivatives, Fair Value [Line Items]
Derivative, Notional Amount	644	568
Fair Value	13	53
Asset Derivatives	29	57
Liability Derivatives	(16)	(4)
Not Designated as Hedging Instrument
Derivatives, Fair Value [Line Items]
Derivative, Notional Amount	8,269	8,032
Fair Value	(5)	(6)
Asset Derivatives	27	5
Liability Derivatives	(32)	(11)
Not Designated as Hedging Instrument \| Interest rate swaps
Derivatives, Fair Value [Line Items]
Derivative, Notional Amount	6,600	6,600
Not Designated as Hedging Instrument \| Interest rate swaps and futures
Derivatives, Fair Value [Line Items]
Derivative, Notional Amount	6,626	7,245
Fair Value	(5)	(6)
Asset Derivatives	0	2
Liability Derivatives	(5)	(8)
Not Designated as Hedging Instrument \| Foreign currency swaps and forwards
Derivatives, Fair Value [Line Items]
Derivative, Notional Amount	645	569
Fair Value	0	0
Asset Derivatives	0	0
Liability Derivatives	0	0
Not Designated as Hedging Instrument \| Credit derivatives that purchase credit protection
Derivatives, Fair Value [Line Items]
Derivative, Notional Amount	0	11
Fair Value	0	0
Asset Derivatives	0	0
Liability Derivatives	0	0
Not Designated as Hedging Instrument \| Credit derivatives in offsetting positions
Derivatives, Fair Value [Line Items]
Derivative, Notional Amount	998	207
Fair Value	0	0
Asset Derivatives	27	3
Liability Derivatives	$ (27)	$ (3)

Fair value, before effects of master netting arrangements, of a financial asset or other contract with one or more underlyings, notional amount or payment provision or both, and the contract can be net settled by means outside the contract or delivery of an asset. Includes assets elected not to be offset. Excludes assets not subject to a master netting arrangement.

Reference 1: http://www.xbrl.org/2003/role/exampleRef
-Topic 210
-SubTopic 20
-Name Accounting Standards Codification
-Section 55
-Paragraph 22
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147483444/210-20-55-22

Reference 2: http://www.xbrl.org/2003/role/disclosureRef
-Topic 210
-SubTopic 20
-Name Accounting Standards Codification
-Section 50
-Paragraph 3
-Subparagraph (a)
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147483466/210-20-50-3

Reference 3: http://fasb.org/us-gaap/role/ref/legacyRef
-Topic 210
-SubTopic 20
-Name Accounting Standards Codification
-Section 55
-Paragraph 7
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147483444/210-20-55-7

Reference 4: http://fasb.org/us-gaap/role/ref/legacyRef
-Name Accounting Standards Codification
-Topic 815
-SubTopic 10
-Section 50
-Paragraph 4B
-Subparagraph (a),(c)
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147480434/815-10-50-4B

Reference 5: http://fasb.org/us-gaap/role/ref/legacyRef
-Name Accounting Standards Codification
-Section 50
-Paragraph 4D
-Subparagraph (c)(2)
-SubTopic 20
-Topic 860
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147481326/860-20-50-4D

+ Details

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

- Definition

Fair value, before effects of master netting arrangements, of a financial liability or contract with one or more underlyings, notional amount or payment provision or both, and the contract can be net settled by means outside the contract or delivery of an asset. Includes liabilities elected not to be offset. Excludes liabilities not subject to a master netting arrangement.

+ References

+ Details

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

- Definition

Fair value of the assets less the liabilities of a derivative or group of derivatives.

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Topic 825
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 10
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147482907/825-10-50-10

+ Details

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

- Definition

Nominal or face amount used to calculate payment on derivative.

+ References

Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef
-Topic 815
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 1B
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147480434/815-10-50-1B

Reference 2: http://www.xbrl.org/2009/role/commonPracticeRef
-Topic 815
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 1A
-Subparagraph (d)
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147480434/815-10-50-1A

+ Details

Name:	us-gaap_DerivativeNotionalAmount
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	na
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_DerivativesFairValueLineItems
Namespace Prefix:	us-gaap_
Data Type:	xbrli:stringItemType
Balance Type:	na
Period Type:	duration

- Details

Name:	us-gaap_BalanceSheetLocationAxis=hig_AvailableforsaleSecuritiesDebtSecuritiesMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_BalanceSheetLocationAxis=us-gaap_OtherInvestmentsMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_BalanceSheetLocationAxis=us-gaap_OtherLiabilitiesMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_DerivativeInstrumentRiskAxis=us-gaap_CashFlowHedgingMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_HedgingDesignationAxis=us-gaap_DesignatedAsHedgingInstrumentMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_DerivativeInstrumentRiskAxis=us-gaap_InterestRateSwapMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_DerivativeInstrumentRiskAxis=us-gaap_CurrencySwapMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_HedgingDesignationAxis=us-gaap_NondesignatedMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_DerivativeInstrumentRiskAxis=hig_InterestRateSwapsandFuturesMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_DerivativeInstrumentRiskAxis=hig_ForeignCurrencySwapsandForwardsMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_DerivativeInstrumentRiskAxis=us-gaap_CreditDefaultSwapBuyingProtectionMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_DerivativeInstrumentRiskAxis=hig_CreditDerivativesInOffsettingPositionsMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type: