Investments and Derivative Instruments Level 4 Mortgage Loans (Details) (USD $)	12 Months Ended
Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Mortgage Loans on Real Estate [Abstract]
Available-for-sale Securities, Amortized Cost Basis	$ 56,038,000,000	$ 61,491,000,000
Mortgage Loans on Real Estate, Carrying Amount of Mortgages	5,556,000,000	5,598,000,000
Available-for-sale Securities Mortgage Loans Percent	100.00%	100.00%
Movement in Valuation Allowance for Mortgage Loans [Roll Forward]
Original Weighted Average Loan to Value Ratio of Commercial Mortgage loan	62.00%
Current Weighted Average Loan to Value Ratio of Commercial Mortgage Loan	57.00%
Commercial Mortgage Loans Credit Quality [Abstract]
Average Debt Service Coverage Ratio	2.51hig_AverageDebtServiceCoverageRatio
Agricultural [Member]
Mortgage Loans on Real Estate [Abstract]
Mortgage Loans on Real Estate, Carrying Amount of Mortgages	46,000,000	125,000,000
Available-for-sale Securities Mortgage Loans Percent	0.80%	2.20%
Commercial Loan [Member]
Mortgage Loans on Real Estate [Abstract]
Available-for-sale Securities, Amortized Cost Basis	5,574,000,000	5,665,000,000
Mortgage Loans on Real Estate, Carrying Amount of Mortgages	5,556,000,000	5,598,000,000
Movement in Valuation Allowance for Mortgage Loans [Roll Forward]
Allowance, as of Jan. 1	67,000,000	68,000,000	102,000,000
Allowance for Loan and Lease Losses, Period Increase (Decrease)	4,000,000	2,000,000	(14,000,000)
Allowance for Loan and Lease Losses, Write-offs	53,000,000	3,000,000	20,000,000
Allowance, as of Dec. 31	18,000,000	67,000,000	68,000,000
Mortgage Loans on Commercial, Number of Delinquent Loans	1	1
Commercial Mortgage Loans Credit Quality [Abstract]
Average Debt Service Coverage Ratio	2.51	2.34
Industrial Property [Member]
Mortgage Loans on Real Estate [Abstract]
Mortgage Loans on Real Estate, Carrying Amount of Mortgages	1,476,000,000	1,718,000,000
Available-for-sale Securities Mortgage Loans Percent	26.60%	30.70%
Lodging [Member]
Mortgage Loans on Real Estate [Abstract]
Mortgage Loans on Real Estate, Carrying Amount of Mortgages	26,000,000	27,000,000
Available-for-sale Securities Mortgage Loans Percent	0.50%	0.50%
Multifamily [Member]
Mortgage Loans on Real Estate [Abstract]
Mortgage Loans on Real Estate, Carrying Amount of Mortgages	1,190,000,000	1,155,000,000
Available-for-sale Securities Mortgage Loans Percent	21.40%	20.60%
Office [Member]
Mortgage Loans on Real Estate [Abstract]
Mortgage Loans on Real Estate, Carrying Amount of Mortgages	1,517,000,000	1,278,000,000
Available-for-sale Securities Mortgage Loans Percent	27.30%	22.80%
Retail [Member]
Mortgage Loans on Real Estate [Abstract]
Mortgage Loans on Real Estate, Carrying Amount of Mortgages	1,147,000,000	1,140,000,000
Available-for-sale Securities Mortgage Loans Percent	20.60%	20.40%
Other Property Type Mortgage [Member]
Mortgage Loans on Real Estate [Abstract]
Mortgage Loans on Real Estate, Carrying Amount of Mortgages	154,000,000	155,000,000
Available-for-sale Securities Mortgage Loans Percent	2.80%	2.80%
Allowance for Loan and Lease Losses [Member]
Mortgage Loans on Real Estate [Abstract]
Mortgage Loans on Real Estate, Carrying Amount of Mortgages	140,000,000	191,000,000
Assets Held-for-sale [Member]
Mortgage Loans on Real Estate [Abstract]
Mortgage Loans on Real Estate, Carrying Amount of Mortgages		61,000,000
Assets Held-for-sale [Member] \| Commercial Loan [Member]
Movement in Valuation Allowance for Mortgage Loans [Roll Forward]
Allowance, as of Dec. 31		3,000,000
Mortgage Loans on Real Estate [Member] \| Commercial Loan [Member]
Movement in Valuation Allowance for Mortgage Loans [Roll Forward]
Financing Receivable, Recorded Investment, 90 Days Past Due and Still Accruing	7,000,000	0
Financing Receivable, Allowance for Credit Losses	0	0
LTV Greater Than 80% [Member] \| Commercial Loan [Member]
Mortgage Loans on Real Estate [Abstract]
Mortgage Loans on Real Estate, Carrying Amount of Mortgages	53,000,000	101,000,000
Commercial Mortgage Loans Credit Quality [Abstract]
Average Debt Service Coverage Ratio	1.07	0.99
LTV Between 65% to 80% [Member] \| Commercial Loan [Member]
Mortgage Loans on Real Estate [Abstract]
Mortgage Loans on Real Estate, Carrying Amount of Mortgages	789,000,000	1,195,000,000
Commercial Mortgage Loans Credit Quality [Abstract]
Average Debt Service Coverage Ratio	1.75	1.82
LTV Less Than 65% [Member] \| Commercial Loan [Member]
Mortgage Loans on Real Estate [Abstract]
Mortgage Loans on Real Estate, Carrying Amount of Mortgages	4,714,000,000	4,302,000,000
Commercial Mortgage Loans Credit Quality [Abstract]
Average Debt Service Coverage Ratio	2.66	2.53
East North Central [Member]
Mortgage Loans on Real Estate [Abstract]
Mortgage Loans on Real Estate, Carrying Amount of Mortgages	211,000,000	187,000,000
Available-for-sale Securities Mortgage Loans Percent	3.80%	3.30%
Middle Atlantic [Member]
Mortgage Loans on Real Estate [Abstract]
Mortgage Loans on Real Estate, Carrying Amount of Mortgages	468,000,000	409,000,000
Available-for-sale Securities Mortgage Loans Percent	8.40%	7.30%
Mountain [Member]
Mortgage Loans on Real Estate [Abstract]
Mortgage Loans on Real Estate, Carrying Amount of Mortgages	88,000,000	104,000,000
Available-for-sale Securities Mortgage Loans Percent	1.60%	0.00%
New England [Member]
Mortgage Loans on Real Estate [Abstract]
Mortgage Loans on Real Estate, Carrying Amount of Mortgages	381,000,000	353,000,000
Available-for-sale Securities Mortgage Loans Percent	6.90%	6.30%
Pacific [Member]
Mortgage Loans on Real Estate [Abstract]
Mortgage Loans on Real Estate, Carrying Amount of Mortgages	1,607,000,000	1,587,000,000
Available-for-sale Securities Mortgage Loans Percent	29.00%	28.30%
South Atlantic [Member]
Mortgage Loans on Real Estate [Abstract]
Mortgage Loans on Real Estate, Carrying Amount of Mortgages	1,019,000,000	899,000,000
Available-for-sale Securities Mortgage Loans Percent	18.30%	16.10%
West North Central [Member]
Mortgage Loans on Real Estate [Abstract]
Mortgage Loans on Real Estate, Carrying Amount of Mortgages	44,000,000	47,000,000
Available-for-sale Securities Mortgage Loans Percent	0.80%	0.80%
West South Central [Member]
Mortgage Loans on Real Estate [Abstract]
Mortgage Loans on Real Estate, Carrying Amount of Mortgages	302,000,000	338,000,000
Available-for-sale Securities Mortgage Loans Percent	5.40%	6.00%
Region Others [Member]
Mortgage Loans on Real Estate [Abstract]
Mortgage Loans on Real Estate, Carrying Amount of Mortgages	$ 1,436,000,000	$ 1,674,000,000
Available-for-sale Securities Mortgage Loans Percent	25.80%	30.00%

Available-for-sale securities mortgage loans percent.

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- Definition

Average debt service coverage ratio.

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- Definition

Current weighted average loan to value ratio of commercial mortgage loan.

+ References

No definition available.

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- Definition

Mortgage Loans on Commercial, Number of Delinquent Loans

+ References

No definition available.

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- Definition

Original weighted average loan to value ratio of commercial mortgage loan.

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- Definition

Amount of increase (decrease) of allowance reserve for credit loss.

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- Definition

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.

+ References

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

-Publisher FASB

-Name Accounting Standards Codification

-Topic 944

-SubTopic 310

-Section 45

-Paragraph 4

-URI http://asc.fasb.org/extlink&oid=6873192&loc=d3e21338-158488

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- Definition

Amount of loans and leases that have been written off from both loan receivables and allowance reserve for credit loss.

+ References

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

-Publisher FASB

-Name Accounting Standards Codification

-Topic 942

-SubTopic 210

-Section S99

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-Subparagraph (SX 210.9-03.7(d))

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-Publisher FASB

-Name Accounting Standards Codification

-Topic 310

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This item represents the cost of debt and equity securities, which are categorized neither as held-to-maturity nor trading, net of adjustments including accretion, amortization, collection of cash, previous other-than-temporary impairments recognized in earnings (less any cumulative-effect adjustments recognized, as defined), and fair value hedge accounting adjustments, if any.

+ References

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

-Publisher FASB

-Name Accounting Standards Codification

-Topic 210

-SubTopic 10

-Section S99

-Paragraph 1

-Subparagraph (SX 210.5-02.2)

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- Definition

A valuation allowance for financing receivables that are expected to be uncollectible.

+ References

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-Publisher FASB

-Name Accounting Standards Codification

-Topic 310

-SubTopic 10

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- Definition

Recorded investment in financing receivables that are 90 days or more past due and still accruing.

+ References

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

-Publisher FASB

-Name Accounting Standards Codification

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- Definition

The carrying amount of the outstanding balance due under the mortgage loan.

+ References

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

-Publisher FASB

-Name Accounting Standards Codification

-Topic 205

-SubTopic 10

-Section S99

-Paragraph 6

-Subparagraph (SX 210.5-04.(c) Schedule IV)

-URI http://asc.fasb.org/extlink&oid=27047687&loc=d3e5864-122674

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