Schedule IV Reinsurance Level 4 (Details) (USD $) In Millions, unless otherwise specified	12 Months Ended
Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Life Insurance in Force, Net [Abstract]
Life Insurance in Force, Gross	$ 875,229us-gaap_LifeInsuranceInForceGross	$ 883,387us-gaap_LifeInsuranceInForceGross	$ 946,160us-gaap_LifeInsuranceInForceGross
Ceded Premiums, Life Insurance in Force	240,285us-gaap_LifeInsuranceInForceCeded	278,059us-gaap_LifeInsuranceInForceCeded	137,719us-gaap_LifeInsuranceInForceCeded
Assumed Premiums, Life Insurance in Force	21,987us-gaap_LifeInsuranceInForceAssumed	49,789us-gaap_LifeInsuranceInForceAssumed	48,032us-gaap_LifeInsuranceInForceAssumed
Premiums, Net, Life Insurance in Force	656,931us-gaap_LifeInsuranceInForceNet	655,117us-gaap_LifeInsuranceInForceNet	856,473us-gaap_LifeInsuranceInForceNet
Life Insurance in Force Premiums, Percentage Assumed to Net	3.00%	8.00%	6.00%
Insurance Services Revenue [Abstract]
Direct Premiums Earned	16,560us-gaap_DirectPremiumsEarned	16,929us-gaap_DirectPremiumsEarned	17,389us-gaap_DirectPremiumsEarned
Ceded to Other Companies	2,419us-gaap_CededPremiumsEarned	2,651us-gaap_CededPremiumsEarned	1,320us-gaap_CededPremiumsEarned
Assumed From Other Companies	457us-gaap_AssumedPremiumsEarned	379us-gaap_AssumedPremiumsEarned	342us-gaap_AssumedPremiumsEarned
Premiums Earned, Net, Life	14,598us-gaap_PremiumsEarnedNetLife	14,657us-gaap_PremiumsEarnedNetLife	16,411us-gaap_PremiumsEarnedNetLife
Percentage of Amount Assumed to Net	3.00%us-gaap_PremiumsPercentageAssumedToNet	3.00%us-gaap_PremiumsPercentageAssumedToNet	2.00%us-gaap_PremiumsPercentageAssumedToNet
Property, Liability and Casualty Insurance Product Line [Member]
Insurance Services Revenue [Abstract]
Direct Premiums Earned	10,531	10,494	10,484
Ceded to Other Companies	699	871	796
Assumed From Other Companies	264	241	205
Premiums Earned, Net, Property and Casualty	10,096	9,864	9,893
Percentage of Amount Assumed to Net	3.00%	2.00%	2.00%
Life and Annuity Insurance Product Line [Member]
Insurance Services Revenue [Abstract]
Gross Fee Income Earned Premium and Other Life	4,414	4,819	4,977
Ceded to Other Companies	1,666	1,718	458
Assumed From Other Companies	137	80	69
Premiums Earned, Net, Life	2,885	3,181	4,588
Percentage of Amount Assumed to Net	5.00%	3.00%	2.00%
Accident and Health Insurance [Member]
Insurance Services Revenue [Abstract]
Gross Fee Income Earned Premium and Other Life	1,615	1,616	1,928
Ceded to Other Companies	54	62	66
Assumed From Other Companies	56	58	68
Premiums Earned, Net, Life	$ 1,617	$ 1,612	$ 1,930
Percentage of Amount Assumed to Net	3.00%	4.00%	4.00%

Gross fee income earned premium and other life.

No definition available.

Name:	hig_GrossFeeIncomeEarnedPremiumAndOtherLife
Namespace Prefix:	hig_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration

- Definition

Amount of earned premiums assumed from other entities.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher SEC

-Name Regulation S-X (SX)

-Number 210

-Section 17

-Article 12

Reference 2: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 944

-SubTopic 235

-Section S99

-Paragraph 2

-Subparagraph (SX 210.12-17)

-URI http://asc.fasb.org/extlink&oid=34713774&loc=d3e574992-122915

Reference 3: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 944

-SubTopic 225

-Section S99

-Paragraph 1

-Subparagraph (SX 210.7-04.1)

-URI http://asc.fasb.org/extlink&oid=6879464&loc=d3e573970-122913

Reference 4: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 944

-SubTopic 605

-Section 50

-Paragraph 1

-Subparagraph (b),(c)(2)

-URI http://asc.fasb.org/extlink&oid=6486672&loc=d3e27261-158547

Reference 5: http://www.xbrl.org/2003/role/presentationRef

-Publisher SEC

-Name Regulation S-X (SX)

-Number 210

-Section 04

-Paragraph 1

-Article 7

+ Details

Name:	us-gaap_AssumedPremiumsEarned
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration

- Definition

Amount of earned premiums ceded to other entities.

+ References

+ Details

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

- Definition

Amount, before premiums ceded to other entities and premiums assumed by the entity, of premiums earned.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher SEC

-Name Regulation S-X (SX)

-Number 210

-Section 17

-Article 12

Reference 2: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 944

-SubTopic 235

-Section S99

-Paragraph 2

-Subparagraph (SX 210.12-17)

-URI http://asc.fasb.org/extlink&oid=34713774&loc=d3e574992-122915

Reference 3: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 944

-SubTopic 225

-Section S99

-Paragraph 1

-Subparagraph (SX 210.7-04.1)

-URI http://asc.fasb.org/extlink&oid=6879464&loc=d3e573970-122913

Reference 4: http://www.xbrl.org/2003/role/presentationRef

-Publisher SEC

-Name Regulation S-X (SX)

-Number 210

-Section 04

-Paragraph 1

-Article 7

Reference 5: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 944

-SubTopic 605

-Section 50

-Paragraph 1

-Subparagraph (b),(c)(1)

-URI http://asc.fasb.org/extlink&oid=6486672&loc=d3e27261-158547

+ Details

Name:	us-gaap_DirectPremiumsEarned
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration

- Details

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

- Definition

Amount of life insurance issued and outstanding assumed from other entities. Includes, but not limited to, dividends and adjustments to face value.

+ References

+ Details

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

- Definition

Amount of life insurance issued and outstanding ceded to other entities. Includes, but not limited to, dividends and adjustments to face value.

+ References

+ Details

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

- Definition

Amount before contracts ceded to other entities and contracts assumed by the entity of life insurance issued and outstanding. Includes, but not limited to, dividends and adjustments to face value.

+ References

+ Details

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

- Definition

Amount after contracts ceded to other entities and contracts assumed by the entity of life insurance issued and outstanding. Includes, but not limited to, dividends and adjustments to face value.

+ References

+ Details

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

- Details

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

- Definition

Percentage of assumed life insurance issued and outstanding contracts to life insurance issued and outstanding after contracts ceded to other entities and contracts assumed by the entity. Includes, but not limited to, dividends and adjustments to face value.

+ References

+ Details

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

- Definition

Amount, after premiums ceded to other entities and premiums assumed by the entity, of life premiums earned.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 944

-SubTopic 225

-Section S99

-Paragraph 1

-Subparagraph (SX 210.7-04.1)

-URI http://asc.fasb.org/extlink&oid=6879464&loc=d3e573970-122913

Reference 2: http://www.xbrl.org/2003/role/presentationRef

-Publisher SEC

-Name Regulation S-X (SX)

-Number 210

-Section 04

-Paragraph 1

-Article 7

Reference 3: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 944

-SubTopic 605

-Section 45

-Paragraph 1

-URI http://asc.fasb.org/extlink&oid=6486662&loc=d3e27175-158546

Reference 4: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 944

-SubTopic 605

-Section 50

-Paragraph 1

-Subparagraph (b),(c)

-URI http://asc.fasb.org/extlink&oid=6486672&loc=d3e27261-158547

+ Details

Name:	us-gaap_PremiumsEarnedNetLife
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration

- Definition

Amount, after premiums ceded to other entities and premiums assumed by the entity, of property and casualty premiums earned.

+ References

+ Details

Name:	us-gaap_PremiumsEarnedNetPropertyAndCasualty
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration

- Definition

Percentage of assumed premiums earned by the entity to net premiums earned.

+ References

+ Details

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

- Details

Name:	us-gaap_ReinsurancePremiumsForInsuranceCompaniesByProductSegmentAxis=us-gaap_AccidentAndHealthInsuranceSegmentMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_ReinsurancePremiumsForInsuranceCompaniesByProductSegmentAxis=us-gaap_LifeAndAnnuityInsuranceProductLineMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_ReinsurancePremiumsForInsuranceCompaniesByProductSegmentAxis=us-gaap_PropertyLiabilityAndCasualtyInsuranceSegmentMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type: