Percentage points added to the reference rate to compute the variable rate on the debt instrument.

No definition available.

Name:	us-gaap_DebtInstrumentBasisSpreadOnVariableRate1
Namespace Prefix:	us-gaap_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	duration

- Definition

Face (par) amount of debt instrument at time of issuance.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 835
-SubTopic 30
-Section 45
-Paragraph 2
-URI http://asc.fasb.org/extlink&oid=114775744&loc=d3e28551-108399

Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 835
-SubTopic 30
-Section 55
-Paragraph 8
-URI http://asc.fasb.org/extlink&oid=114775985&loc=d3e28878-108400

+ Details

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

- Definition

Contractual interest rate for funds borrowed, under the debt agreement.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 210
-SubTopic 10
-Section S99
-Paragraph 1
-Subparagraph (SX 210.5-02.22(a)(1))
-URI http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682

+ Details

Name:	us-gaap_DebtInstrumentInterestRateStatedPercentage
Namespace Prefix:	us-gaap_
Data Type:	num:percentItemType
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_DebtInstrumentLineItems
Namespace Prefix:	us-gaap_
Data Type:	xbrli:stringItemType
Balance Type:	na
Period Type:	duration

- Definition

Fixed interest rate related to the interest rate derivative.

+ References

No definition available.

+ Details

Name:	us-gaap_DerivativeFixedInterestRate
Namespace Prefix:	us-gaap_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	instant

- Details

Name:	us-gaap_DebtInstrumentAxis=hig_JuniorSubordinatedNotesSevenPointEightSevenFivePercentDueTwoThousandFortyTwoMember
Namespace Prefix:
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- Details

Name:	us-gaap_DebtInstrumentAxis=hig_LIBORPlusTwoPointOneTwoFivePercentJuniorSubordinatedNotesDueTwoThousandSixtySevenMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_VariableRateAxis=us-gaap_LondonInterbankOfferedRateLIBORMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_DebtInstrumentAxis=hig_LIBORPlusFivePointFiveNineSixPercentJuniorSubordinatedNotesDueTwoThousandTwentyTwoMemberDomain
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

Debt - Junior Subordinated Debt (Details) - USD ($) $ in Millions	1 Months Ended	12 Months Ended
	Apr. 30, 2017	Dec. 31, 2018	Dec. 31, 2017
Junior Subordinated Notes Seven Point Eight Seven Five Percent Due Two Thousand Forty Two [Member]
Debt Instrument [Line Items]
Face Value		$ 600
Interest rate		7.875%	7.875%
3 month Libor 2.125% Notes, due 2067 [1]
Debt Instrument [Line Items]
Face Value		$ 500
3 month Libor 2.125% Notes, due 2067 [1] \| LIBOR
Debt Instrument [Line Items]
Variable interest rate	2.125%	2.125%
Derivative, Fixed Interest Rate	4.39%
LIBOR Plus Five Point Five Nine Six Percent Junior Subordinated Notes Due Two Thousand Twenty Two [Member] [Domain] \| LIBOR
Debt Instrument [Line Items]
Variable interest rate		5.596%