Investments (Tables)

6 Months Ended

Jun. 30, 2013

Available-for-sale Securities Including Securities Pledged [Line Items]

Marketable Securities

Available-for-sale and fair value option ("FVO") fixed maturities and equity securities were as follows as of June 30, 2013:

	Amortized Cost		Gross Unrealized Capital Gains		Gross Unrealized Capital Losses		Embedded Derivatives(2)		Fair Value		OTTI(3)
Fixed maturities:
U.S. Treasuries	$	754.4	$	74.4	$	4.8	$	—	$	824.0	$	—
U.S. Government agencies and authorities	376.9		9.8		—		—		386.7		—
State, municipalities and political subdivisions	77.2		7.8		—		—		85.0		—
U.S. corporate securities	10,008.2		614.7		192.5		—		10,430.4		1.9
Foreign securities:(1)
Government	437.1		26.6		16.7		—		447.0		—
Other	4,858.9		279.8		84.0		—		5,054.7		—
Total foreign securities	5,296.0		306.4		100.7		—		5,501.7		—
Residential Mortgage-backed securities:
Agency	1,524.2		133.7		14.3		21.8		1,665.4		0.5
Non-Agency	334.0		57.2		10.7		14.6		395.1		16.2
Total Residential Mortgage-backed securities	1,858.2		190.9		25.0		36.4		2,060.5		16.7
Commercial Mortgage-backed securities	669.5		75.8		0.1		—		745.2		4.4
Other asset-backed securities	479.2		21.6		3.9		—		496.9		3.0
Total fixed maturities, including securities pledged	19,519.6		1,301.4		327.0		36.4		20,530.4		26.0
Less: Securities pledged	214.3		9.2		6.1		—		217.4		—
Total fixed maturities	19,305.3		1,292.2		320.9		36.4		20,313.0		26.0
Equity securities	110.2		16.5		—		—		126.7		—
Total fixed maturities and equity securities investments	$	19,415.5	$	1,308.7	$	320.9	$	36.4	$	20,439.7	$	26.0

⁽¹⁾ Primarily U.S. dollar denominated.

⁽²⁾ Embedded derivatives within fixed maturity securities are reported with the host investment. The changes in fair value of embedded derivatives are reported in Other net realized capital gains (losses) in the Condensed Consolidated Statements of Operations.

⁽³⁾ Represents Other-than Temporary-Impairments ("OTTI") reported as a component of Other comprehensive income.

Available-for-sale and FVO fixed maturities and equity securities were as follows as of December 31, 2012:

	Amortized Cost		Gross Unrealized Capital Gains		Gross Unrealized Capital Losses		Embedded Derivatives(2)		Fair Value		OTTI(3)
Fixed maturities:
U.S. Treasuries	$	1,011.5	$	135.6	$	0.5	$	—	$	1,146.6	$	—
U.S. Government agencies and authorities	379.4		17.6		—		—		397.0		—
State, municipalities and political subdivisions	77.2		15.9		—		—		93.1		—
U.S. corporate securities	9,438.0		1,147.4		11.1		—		10,574.3		2.0
Foreign securities(1):
Government	439.7		57.4		1.1		—		496.0		—
Other	4,570.0		501.3		15.3		—		5,056.0		—
Total foreign securities	5,009.7		558.7		16.4		—		5,552.0		—
Residential Mortgage-backed securities:
Agency	1,679.5		181.5		3.4		33.7		1,891.3		0.6
Non-Agency	390.9		70.0		14.7		20.0		466.2		17.4
Total Residential Mortgage-backed securities	2,070.4		251.5		18.1		53.7		2,357.5		18.0
Commercial Mortgage-backed securities	748.7		90.6		0.2		—		839.1		4.4
Other asset-backed securities	475.7		26.6		6.7		—		495.6		3.1
Total fixed maturities, including securities pledged	19,210.6		2,243.9		53.0		53.7		21,455.2		27.5
Less: Securities pledged	207.2		13.0		0.5		—		219.7		—
Total fixed maturities	19,003.4		2,230.9		52.5		53.7		21,235.5		27.5
Equity securities	129.3		13.6		0.1		—		142.8		—
Total fixed maturities and equity securities investments	$	19,132.7	$	2,244.5	$	52.6	$	53.7	$	21,378.3	$	27.5

⁽¹⁾ Primarily U.S. dollar denominated.

⁽²⁾ Embedded derivatives within fixed maturity securities are reported with the host investment. The changes in fair value of embedded derivatives are reported in Other net realized capital gains (losses) in the Condensed Consolidated Statements of Operations.

⁽³⁾ Represents OTTI reported as a component of Other comprehensive income.

Investments Classifed by Contractual Maturity Date

The amortized cost and fair value of fixed maturities, including securities pledged, as of June 30, 2013, are shown below by contractual maturity. Actual maturities may differ from contractual maturities as securities may be restructured, called, or prepaid. Mortgage-backed securities ("MBS") and Other asset-backed securities ("ABS") are shown separately because they are not due at a single maturity date.

	Amortized Cost		Fair Value
Due to mature:
One year or less	$	800.6	$	823.4
After one year through five years	3,905.6		4,142.0
After five years through ten years	6,152.3		6,365.7
After ten years	5,654.2		5,896.7
Mortgage-backed securities	2,527.7		2,805.7
Other asset-backed securities	479.2		496.9
Fixed maturities, including securities pledged	$	19,519.6	$	20,530.4

U.S. and Foreign Corporate Securities by Industry

The following tables set forth the composition of the U.S. and foreign corporate securities within the fixed maturity portfolio by industry category as of the dates indicated:

	Amortized Cost		Gross Unrealized Capital Gains		Gross Unrealized Capital Losses		Fair Value
June 30, 2013
Communications	$	1,318.7	$	89.8	$	29.4	$	1,379.1
Financial	1,844.1		154.3		22.4		1,976.0
Industrial and other companies	8,566.0		439.0		188.1		8,816.9
Utilities	2,697.6		186.2		28.4		2,855.4
Transportation	440.7		25.2		8.2		457.7
Total	$	14,867.1	$	894.5	$	276.5	$	15,485.1
December 31, 2012
Communications	$	1,154.1	$	161.4	$	0.9	$	1,314.6
Financial	1,859.3		240.1		10.9		2,088.5
Industrial and other companies	7,883.1		850.9		6.9		8,727.1
Utilities	2,715.4		349.8		7.3		3,057.9
Transportation	396.1		46.5		0.4		442.2
Total	$	14,008.0	$	1,648.7	$	26.4	$	15,630.3

Schedule of Unrealized Loss on Investments

Unrealized capital losses (including noncredit impairments), along with the fair value of fixed maturity securities, including securities pledged, by market sector and duration were as follows as of June 30, 2013:

	Six Months or Less Below Amortized Cost				More Than Six Months and Twelve Months or Less Below Amortized Cost				More Than Twelve Months Below Amortized Cost				Total
	Fair Value		Unrealized Capital Losses		Fair Value		Unrealized Capital Losses		Fair Value		Unrealized Capital Losses		Fair Value		Unrealized Capital Losses
U.S. Treasuries	$	217.0	$	4.8	$	—	$	—	$	—	$	—	$	217.0	$	4.8
U.S. corporate, state and municipalities	2,929.4		159.3		236.0		29.1		25.7		4.1		3,191.1		192.5
Foreign	1,411.8		88.8		53.5		5.8		44.2		6.1		1,509.5		100.7
Residential mortgage-backed	368.6		10.6		49.3		2.7		85.2		11.7		503.1		25.0
Commercial mortgage-backed	—		—		0.2		—		1.9		0.1		2.1		0.1
Other asset-backed	62.4		0.2		4.0		—		27.7		3.7		94.1		3.9
Total	$	4,989.2	$	263.7	$	343.0	$	37.6	$	184.7	$	25.7	$	5,516.9	$	327.0

Unrealized capital losses (including noncredit impairments), along with the fair value of fixed maturity securities, including securities pledged, by market sector and duration were as follows as of December 31, 2012:

	Six Months or Less Below Amortized Cost				More Than Six Months and Twelve Months or Less Below Amortized Cost				More Than Twelve Months Below Amortized Cost				Total
	Fair Value		Unrealized Capital Losses		Fair Value		Unrealized Capital Losses		Fair Value		Unrealized Capital Losses		Fair Value		Unrealized Capital Losses
U.S. Treasuries	$	300.0	$	0.5	$	—	$	—	$	—	$	—	$	300.0	$	0.5
U.S. corporate, state and municipalities	479.8		6.8		22.5		0.9		49.4		3.4		551.7		11.1
Foreign	166.8		4.7		7.8		0.5		87.7		11.2		262.3		16.4
Residential mortgage-backed	68.7		1.6		7.2		0.3		132.4		16.2		208.3		18.1
Commercial mortgage-backed	7.5		0.1		1.6		—		2.5		0.1		11.6		0.2
Other asset-backed	15.6		—		—		—		34.2		6.7		49.8		6.7
Total	$	1,038.4	$	13.7	$	39.1	$	1.7	$	306.2	$	37.6	$	1,383.7	$	53.0

Risk Exposure to Securities Based on Credit Quality

The following tables summarize the Company's exposure to subprime mortgage-backed securities by credit quality using NAIC designations, ARO ratings and vintage year as of the dates indicated:

	% of Total Subprime Mortgage-backed Securities
	NAIC Designation			ARO Ratings			Vintage
June 30, 2013
	1	67.5	%	AAA	0.1	%	2007	7.6	%
	2	3.1	%	AA	2.9	%	2006	6.8	%
	3	18.9	%	A	13.9	%	2005 and prior	85.6	%
	4	9.1	%	BBB	20.3	%		100.0	%
	5	1.2	%	BB and below	62.8	%
	6	0.2	%		100.0	%
		100.0	%
December 31, 2012
	1	67.8	%	AAA	3.2	%	2007	8.0	%
	2	3.2	%	AA	—	%	2006	6.0	%
	3	19.6	%	A	16.2	%	2005 and prior	86.0	%
	4	8.7	%	BBB	21.5	%		100.0	%
	5	0.5	%	BB and below	59.1	%
	6	0.2	%		100.0	%
		100.0	%

The following tables summarize the Company's exposure to Alt-A residential mortgage-backed securities by credit quality using NAIC designations, ARO ratings and vintage year as of the dates indicated:

	% of Total Alt-A Mortgage-backed Securities
	NAIC Designation			ARO Ratings			Vintage
June 30, 2013
	1	40.8	%	AAA	0.1	%	2007	14.0	%
	2	14.1	%	AA	—	%	2006	29.5	%
	3	28.7	%	A	3.5	%	2005 and prior	56.5	%
	4	14.5	%	BBB	3.2	%		100.0	%
	5	1.4	%	BB and below	93.2	%
	6	0.5	%		100.0	%
		100.0	%
December 31, 2012
	1	33.4	%	AAA	0.2	%	2007	13.8	%
	2	12.4	%	AA	1.4	%	2006	29.3	%
	3	21.0	%	A	3.4	%	2005 and prior	56.9	%
	4	30.3	%	BBB	5.6	%		100.0	%
	5	2.3	%	BB and below	89.4	%
	6	0.6	%		100.0	%
		100.0	%

The following tables summarize the Company's exposure to CMBS holdings by credit quality using NAIC designations, ARO ratings and vintage year as of the dates indicated:

	% of Total CMBS
	NAIC Designation			ARO Ratings			Vintage
June 30, 2013
	1	99.4	%	AAA	50.8	%	2007	30.4	%
	2	—	%	AA	15.9	%	2006	22.5	%
	3	0.6	%	A	9.8	%	2005 and prior	47.1	%
	4	—	%	BBB	3.8	%		100.0	%
	5	—	%	BB and below	19.7	%
	6	—	%		100.0	%
		100.0	%
December 31, 2012
	1	99.9	%	AAA	54.1	%	2007	28.7	%
	2	—	%	AA	17.1	%	2006	20.4	%
	3	0.1	%	A	8.4	%	2005 and prior	50.9	%
	4	—	%	BBB	5.3	%		100.0	%
	5	—	%	BB and below	15.1	%
	6	—	%		100.0	%
		100.0	%

The following tables summarize the Company's exposure to Other ABS holdings, excluding subprime exposure, by credit quality using NAIC designations, ARO ratings and vintage year as of the dates indicated:

	% of Total Other ABS
	NAIC Designation			ARO Ratings			Vintage
June 30, 2013
	1	99.4	%	AAA	90.4	%	2013	6.2	%
	2	0.5	%	AA	2.7	%	2012	21.2	%
	3	0.1	%	A	6.3	%	2011	12.0	%
	4	—	%	BBB	0.5	%	2010	5.4	%
	5	—	%	BB and below	0.1	%	2009	0.3	%
	6	—	%		100.0	%	2008	8.7	%
		100.0	%				2007 and prior	46.2	%
								100.0	%
December 31, 2012
	1	98.3	%	AAA	88.4	%	2012	21.4	%
	2	1.6	%	AA	1.9	%	2011	12.2	%
	3	0.1	%	A	8.0	%	2010	5.7	%
	4	—	%	BBB	1.6	%	2009	0.3	%
	5	—	%	BB and below	0.1	%	2008	9.5	%
	6	—	%		100.0	%	2007	22.9	%
		100.0	%				2006 and prior	28.0	%
								100.0	%

Schedule of Mortgage Loans Real Estate and Valuation Allowance

The following table summarizes the Company’s investment in mortgage loans as of the dates indicated:

	June 30, 2013			December 31, 2012
Commercial mortgage loans	$	3,189.4		$	2,874.0
Collective valuation allowance	(1.5		)	(1.3		)
Total net commercial mortgage loans	$	3,187.9		$	2,872.7

The following table summarizes the activity in the allowance for losses for all commercial mortgage loans for the periods indicated:

	June 30, 2013		December 31, 2012
Collective valuation allowance for losses, balance at January 1	$	1.3	$	1.3
Addition to (reduction of) allowance for losses	0.2		—
Collective valuation allowance for losses, end of period	$	1.5	$	1.3

Impaired Financing Receivables

The carrying values and unpaid principal balances of impaired mortgage loans were as follows as of the dates indicated:

	June 30, 2013		December 31, 2012
Impaired loans with allowances for losses	$	—	$	—
Impaired loans without allowances for losses	5.5		5.6
Subtotal	5.5		5.6
Less: Allowances for losses on impaired loans	—		—
Impaired loans, net	$	5.5	$	5.6
Unpaid principal balance of impaired loans	$	7.0	$	7.1

The following table presents information on the average investment during the period in impaired loans and interest income recognized on impaired and restructured loans for the periods indicated:

	Three Months Ended June 30,
	2013		2012
Impaired loans, average investment during the period (amortized cost)	$	5.5	$	5.8
Interest income recognized on impaired loans, on an accrual basis	0.1		0.1
Interest income recognized on impaired loans, on a cash basis	0.1		0.1
Interest income recognized on restructured loans, on an accrual basis	—		—
	Six Months Ended June 30,
	2013		2012
Impaired loans, average investment during the period (amortized cost)	$	5.6	$	5.8
Interest income recognized on impaired loans, on an accrual basis	0.2		0.2
Interest income recognized on impaired loans, on a cash basis	0.2		0.2
Interest income recognized on restructured loans, on an accrual basis	—		—

Loans Receivable, Grouped by Loan to Value and Debt Service Coverage Ratio

Loan-to-value ("LTV") and debt service coverage ("DSC") ratios are measures commonly used to assess the risk and quality of mortgage loans. The LTV ratio, calculated at time of origination, is expressed as a percentage of the amount of the loan relative to the value of the underlying property. A LTV ratio in excess of 100% indicates the unpaid loan amount exceeds the underlying collateral. The DSC ratio, based upon the most recently received financial statements, is expressed as a percentage of the amount of a property’s net income to its debt service payments. A DSC ratio of less than 1.0 indicates that a property’s operations do not generate sufficient income to cover debt payments. These ratios are utilized as part of the review process described above.

The following table presents the LTV ratios as of the dates indicated:

	June 30, 2013(1)		December 31, 2012(1)
Loan-to-Value Ratio:
0% - 50%	$	508.9	$	501.3
50% - 60%	804.8		768.9
60% - 70%	1,781.1		1,491.6
70% - 80%	79.7		96.4
80% and above	14.9		15.8
Total Commercial mortgage loans	$	3,189.4	$	2,874.0

⁽¹⁾ Balances do not include allowance for mortgage loan credit losses.

The following table presents the DSC ratios as of the dates indicated:

	June 30, 2013(1)		December 31, 2012(1)
Debt Service Coverage Ratio:
Greater than 1.5x	$	2,344.6	$	2,114.4
1.25x - 1.5x	469.5		390.5
1.0x - 1.25x	305.2		293.1
Less than 1.0x	70.1		76.0
Total Commercial mortgage loans	$	3,189.4	$	2,874.0

⁽¹⁾ Balances do not include allowance for mortgage loan credit losses.

Mortgage Loans by Geographic Location of Collateral

Properties collateralizing mortgage loans are geographically dispersed throughout the United States, as well as diversified by property type, as reflected in the following tables as of the dates indicated:

	June 30, 2013(1)				December 31, 2012(1)
	Gross Carrying Value		% of Total		Gross Carrying Value		% of Total
Commercial Mortgage Loans by U.S. Region:
Pacific	$	637.0	20.0	%	$	564.1	19.6	%
South Atlantic	612.1		19.2	%	561.0		19.5	%
Middle Atlantic	415.9		13.0	%	332.7		11.6	%
East North Central	377.1		11.8	%	337.8		11.8	%
West South Central	497.1		15.6	%	460.4		16.0	%
Mountain	248.3		7.8	%	214.5		7.5	%
West North Central	208.8		6.5	%	205.2		7.1	%
New England	117.3		3.7	%	119.1		4.1	%
East South Central	75.8		2.4	%	79.2		2.8	%
Total Commercial mortgage loans	$	3,189.4	100.0	%	$	2,874.0	100.0	%

⁽¹⁾ Balances do not include allowance for mortgage loan credit losses.

	June 30, 2013(1)				December 31, 2012(1)
	Gross Carrying Value		% of Total		Gross Carrying Value		% of Total
Commercial Mortgage Loans by Property Type:
Industrial	$	1,062.0	33.3	%	$	1,035.2	36.0	%
Retail	989.5		31.0	%	824.0		28.7	%
Office	458.3		14.4	%	427.0		14.8	%
Apartments	338.0		10.6	%	298.7		10.4	%
Hotel/Motel	117.3		3.7	%	92.1		3.2	%
Mixed use	67.3		2.1	%	34.2		1.2	%
Other	157.0		4.9	%	162.8		5.7	%
Total Commercial mortgage loans	$	3,189.4	100.0	%	$	2,874.0	100.0	%

Mortgage Loans by Property Type of Collateral

	June 30, 2013(1)				December 31, 2012(1)
	Gross Carrying Value		% of Total		Gross Carrying Value		% of Total
Commercial Mortgage Loans by Property Type:
Industrial	$	1,062.0	33.3	%	$	1,035.2	36.0	%
Retail	989.5		31.0	%	824.0		28.7	%
Office	458.3		14.4	%	427.0		14.8	%
Apartments	338.0		10.6	%	298.7		10.4	%
Hotel/Motel	117.3		3.7	%	92.1		3.2	%
Mixed use	67.3		2.1	%	34.2		1.2	%
Other	157.0		4.9	%	162.8		5.7	%
Total Commercial mortgage loans	$	3,189.4	100.0	%	$	2,874.0	100.0	%

⁽¹⁾ Balances do not include allowance for mortgage loan credit losses.

Mortgage Loans by Year of Origination

The following table sets forth the breakdown of mortgages by year of origination as of the dates indicated:

	June 30, 2013(1)		December 31, 2012(1)
Year of Origination:
2013	$	404.9	$	—
2012	927.1		939.0
2011	815.7		836.9
2010	122.3		124.0
2009	72.5		73.0
2008	116.4		119.0
2007 and prior	730.5		782.1
Total Commercial mortgage loans	$	3,189.4	$	2,874.0

⁽¹⁾ Balances do not include allowance for mortgage loan credit losses.

Other than Temporary Impairment, Credit Losses Recognized in Earnings

The following tables identify the Company’s credit-related and intent-related impairments included in the Condensed Consolidated Statements of Operations, excluding impairments included in Other comprehensive income (loss) by type for the periods indicated:

	Three Months Ended June 30,
	2013			2012
	Impairment		No. of Securities	Impairment		No. of Securities
U.S. corporate	$	—	—	$	0.2	1
Foreign(1)	—		—	0.4		2
Residential mortgage-backed	1.3		21	0.9		24
Commercial mortgage-backed	—		—	—		—
Other asset-backed	—		—	0.2		2
Total	$	1.3	21	$	1.7	29
(1) Primarily U.S. dollar denominated.
	Six Months Ended June 30,
	2013			2012
	Impairment		No. of Securities	Impairment		No. of Securities
U.S. corporate	$	—	—	$	0.2	1
Foreign(1)	—		—	0.8		3
Residential mortgage-backed	1.8		27	1.6		28
Commercial mortgage-backed	0.1		2	—		—
Other asset-backed	—		—	0.4		3
Total	$	1.9	29	$	3.0	35
(1) Primarily U.S. dollar denominated.

Net Investment Income

The following table summarizes Net investment income for the periods indicated:

	Three Months Ended June 30,						Six Months Ended June 30,
	2013			2012			2013			2012
Fixed maturities	$	300.7		$	303.7		$	608.3		$	608.0
Equity securities, available-for-sale	(1.0		)	3.0			(0.1		)	4.1
Mortgage loans on real estate	40.9			37.5			77.5			71.1
Policy loans	3.2			3.3			6.4			6.6
Short-term investments and cash equivalents	0.3			0.3			0.5			0.5
Other	11.2			(24.2		)	22.9			(3.4		)
Gross investment income	355.3			323.6			715.5			686.9
Less: Investment expenses	12.4			11.7			24.4			23.0
Net investment income	$	342.9		$	311.9		$	691.1		$	663.9

Realized Gain (Loss) on Investments

Net realized capital gains (losses) were as follows for the periods indicated:

	Three Months Ended June 30,						Six Months Ended June 30,
	2013			2012			2013			2012
Fixed maturities, available-for-sale, including securities pledged	$	(2.0	)	$	17.8		$	(2.2	)	$	57.3
Fixed maturities, at fair value option	(66.2		)	(3.4		)	(105.1		)	(46.3		)
Derivatives	(41.9		)	39.3			(61.8		)	26.2
Embedded derivative - fixed maturities	(11.8		)	4.6			(17.2		)	(0.2		)
Embedded derivative - product guarantees	52.2			(59.5		)	76.5			89.5
Other investments	(0.2		)	—			(0.2		)	(0.4		)
Net realized capital gains (losses)	$	(69.9	)	$	(1.2	)	$	(110.0	)	$	126.1
After-tax net realized capital gains (losses)	$	(47.3	)	$	(6.7	)	$	(73.4	)	$	72.0

Gain (Loss) on Investments

Proceeds from the sale of fixed maturities and equity securities, available-for-sale and the related gross realized gains and losses, before tax were as follows for the periods indicated:

	Six Months Ended June 30,
	2013		2012
Proceeds on sales	$	923.2	$	1,803.3
Gross gains	9.2		67.9
Gross losses	8.3		7.3

Intent related impairment

Available-for-sale Securities Including Securities Pledged [Line Items]

Other than Temporary Impairment, Credit Losses Recognized in Earnings

The following tables summarize these intent impairments, which are also recognized in earnings, by type for the periods indicated:

	Three Months Ended June 30,
	2013			2012
	Impairment		No. of Securities	Impairment		No. of Securities
U.S. corporate	$	—	—	$	0.2	1
Foreign(1)	—		—	0.4		2
Commercial mortgage-backed	—		—	—		—
Other asset-backed	—		—	—		—
Total	$	—	—	$	0.6	3
(1) Primarily U.S. dollar denominated.
	Six Months Ended June 30,
	2013			2012
	Impairment		No. of Securities	Impairment		No. of Securities
U.S. corporate	$	—	—	$	0.2	1
Foreign(1)	—		—	0.8		3
Commercial mortgage-backed	0.1		2	—		—
Other asset-backed	—		—	0.1		1
Total	$	0.1	2	$	1.1	5
(1) Primarily U.S. dollar denominated.

Credit related impairment

Available-for-sale Securities Including Securities Pledged [Line Items]

Other than Temporary Impairment, Credit Losses Recognized in Earnings

The following tables identify the amount of credit impairments on fixed maturities for which a portion of the OTTI loss was recognized in Other comprehensive income (loss) and the corresponding changes in such amounts for the periods indicated:

	Three Months Ended June 30,
	2013			2012
Balance at April 1	$	19.8		$	19.5
Additional credit impairments:
On securities not previously impaired	0.6			1.1
On securities previously impaired	0.6			—
Reductions:
Securities sold, matured, prepaid or paid down	(0.8		)	(0.6		)
Balance at June 30	$	20.2		$	20.0
	Six Months Ended June 30,
	2013			2012
Balance at January 1	$	20.0		$	19.4
Additional credit impairments:
On securities not previously impaired	0.8			1.2
On securities previously impaired	1.0			0.6
Reductions:
Securities sold, matured, prepaid or paid down	(1.6		)	(1.2		)
Balance at June 30	$	20.2		$	20.0

Duration

Available-for-sale Securities Including Securities Pledged [Line Items]

Schedule of Unrealized Loss on Investments

Unrealized capital losses (including noncredit impairments) in fixed maturities, including securities pledged, for instances in which fair value declined below amortized cost by greater than or less than 20% for consecutive months as indicated in the tables below, were as follows as of the dates indicated:

	Amortized Cost				Unrealized Capital Losses				Number of Securities
	< 20%		> 20%		< 20%		> 20%		< 20%	> 20%
June 30, 2013
Six months or less below amortized cost	$	5,267.8	$	40.9	$	265.2	$	9.4	712	12
More than six months and twelve months or less below amortized cost	406.8		4.5		39.7		1.1		71	4
More than twelve months below amortized cost	103.3		20.6		6.1		5.5		98	9
Total	$	5,777.9	$	66.0	$	311.0	$	16.0	881	25
December 31, 2012
Six months or less below amortized cost	$	1,110.8	$	15.2	$	19.3	$	3.9	141	10
More than six months and twelve months or less below amortized cost	49.5		1.5		2.6		0.4		31	2
More than twelve months below amortized cost	198.1		61.6		6.2		20.6		99	28
Total	$	1,358.4	$	78.3	$	28.1	$	24.9	271	40

Market Sector (Type of Security)

Available-for-sale Securities Including Securities Pledged [Line Items]

Schedule of Unrealized Loss on Investments

Unrealized capital losses (including noncredit impairments) in fixed maturities, including securities pledged, by market sector for instances in which fair value declined below amortized cost by greater than or less than 20% were as follows as of the dates indicated:

	Amortized Cost				Unrealized Capital Losses				Number of Securities
	< 20%		> 20%		< 20%		> 20%		< 20%	> 20%
June 30, 2013
U.S. Treasuries	$	221.8	$	—	$	4.8	$	—	3	—
U.S. corporate, state and municipalities	3,355.2		28.4		186.0		6.5		452	4
Foreign	1,595.5		14.7		97.3		3.4		231	3
Residential mortgage-backed	510.0		18.1		20.3		4.7		169	14
Commercial mortgage-backed	2.2		—		0.1		—		2	—
Other asset-backed	93.2		4.8		2.5		1.4		24	4
Total	$	5,777.9	$	66.0	$	311.0	$	16.0	881	25
December 31, 2012
U.S. Treasuries	$	300.5	$	—	$	0.5	$	—	2	—
U.S. corporate, state and municipalities	558.1		4.7		9.1		2.0		82	2
Foreign	242.7		36.0		5.7		10.7		38	8
Residential mortgage-backed	201.2		25.2		10.2		7.9		124	24
Commercial mortgage-backed	11.8		—		0.2		—		8	—
Other asset-backed	44.1		12.4		2.4		4.3		17	6
Total	$	1,358.4	$	78.3	$	28.1	$	24.9	271	40