Investments (Tables)

3 Months Ended

Mar. 31, 2016

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 March 31, 2016:

	Amortized Cost		Gross Unrealized Capital Gains		Gross Unrealized Capital Losses		Embedded Derivatives(2)		Fair Value		OTTI(3)
Fixed maturities:
U.S. Treasuries	$	661.8	$	143.8	$	0.1	$	—	$	805.5	$	—
U.S. Government agencies and authorities	4.2		0.1		—		—		4.3		—
State, municipalities and political subdivisions	627.9		31.9		1.0		—		658.8		—
U.S. corporate public securities	9,487.4		639.1		134.3		—		9,992.2		1.3
U.S. corporate private securities	2,297.0		123.5		38.8		—		2,381.7		—
Foreign corporate public securities and foreign governments(1)	2,817.0		131.7		96.9		—		2,851.8		—
Foreign corporate private securities(1)	2,698.6		148.9		17.6		—		2,829.9		—
Residential mortgage-backed securities:
Agency	1,825.3		115.1		3.2		12.9		1,950.1		—
Non-Agency	266.0		48.2		3.0		11.4		322.6		6.2
Total Residential mortgage-backed securities	2,091.3		163.3		6.2		24.3		2,272.7		6.2
Commercial mortgage-backed securities	1,266.0		89.9		0.4		—		1,355.5		6.7
Other asset-backed securities	244.4		11.4		1.7		—		254.1		2.3
Total fixed maturities, including securities pledged	22,195.6		1,483.6		297.0		24.3		23,406.5		16.5
Less: Securities pledged	622.2		88.3		10.0		—		700.5		—
Total fixed maturities	21,573.4		1,395.3		287.0		24.3		22,706.0		16.5
Equity securities	67.8		15.1		—		—		82.9		—
Total fixed maturities and equity securities investments	$	21,641.2	$	1,410.4	$	287.0	$	24.3	$	22,788.9	$	16.5

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

Available-for-sale and FVO fixed maturities and equity securities were as follows as of December 31, 2015:

	Amortized Cost		Gross Unrealized Capital Gains		Gross Unrealized Capital Losses		Embedded Derivatives(2)		Fair Value		OTTI(3)
Fixed maturities:
U.S. Treasuries	$	616.6	$	105.1	$	0.3	$	—	$	721.4	$	—
U.S. Government agencies and authorities	4.3		—		—		—		4.3		—
State, municipalities and political subdivisions	589.9		13.8		7.9		—		595.8		—
U.S. corporate public securities	9,472.4		384.9		256.8		—		9,600.5		1.4
U.S. corporate private securities	2,336.0		86.3		62.4		—		2,359.9		—
Foreign corporate public securities and foreign governments(1)	2,868.7		95.0		151.5		—		2,812.2		—
Foreign corporate private securities(1)	2,678.8		96.1		63.5		—		2,711.4		—
Residential mortgage-backed securities:
Agency	1,579.5		105.3		4.8		12.8		1,692.8		—
Non-Agency	181.6		46.3		2.1		10.6		236.4		6.4
Total Residential mortgage-backed securities	1,761.1		151.6		6.9		23.4		1,929.2		6.4
Commercial mortgage-backed securities	1,228.9		49.5		3.5		—		1,274.9		6.7
Other asset-backed securities	240.7		9.9		1.4		—		249.2		2.4
Total fixed maturities, including securities pledged	21,797.4		992.2		554.2		23.4		22,258.8		16.9
Less: Securities pledged	252.3		16.0		19.1		—		249.2		—
Total fixed maturities	21,545.1		976.2		535.1		23.4		22,009.6		16.9
Equity securities	116.7		14.6		—		—		131.3		—
Total fixed maturities and equity securities investments	$	21,661.8	$	990.8	$	535.1	$	23.4	$	22,140.9	$	16.9

⁽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 (loss).

Investments Classified by Contractual Maturity Date

The amortized cost and fair value of fixed maturities, including securities pledged, as of March 31, 2016, 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	$	601.4	$	609.8
After one year through five years	4,534.2		4,755.7
After five years through ten years	6,331.8		6,579.8
After ten years	7,126.5		7,578.9
Mortgage-backed securities	3,357.3		3,628.2
Other asset-backed securities	244.4		254.1
Fixed maturities, including securities pledged	$	22,195.6	$	23,406.5

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
March 31, 2016
Communications	$	1,229.5	$	103.3	$	10.9	$	1,321.9
Financial	2,609.4		183.5		6.1		2,786.8
Industrial and other companies	7,946.4		472.2		68.8		8,349.8
Energy	2,408.4		52.4		181.5		2,279.3
Utilities	2,201.9		177.6		11.3		2,368.2
Transportation	569.5		32.2		2.8		598.9
Total	$	16,965.1	$	1,021.2	$	281.4	$	17,704.9
December 31, 2015
Communications	$	1,218.8	$	67.1	$	28.6	$	1,257.3
Financial	2,651.5		146.8		13.1		2,785.2
Industrial and other companies	7,778.2		267.7		180.7		7,865.2
Energy	2,655.2		26.1		261.8		2,419.5
Utilities	2,150.7		122.1		21.8		2,251.0
Transportation	560.6		14.0		13.8		560.8
Total	$	17,015.0	$	643.8	$	519.8	$	17,139.0

Schedule of Securities Borrowed Under Securities Lending Transactions [Table Text Block]

The following table sets forth borrowings under securities lending transactions by class of collateral pledged for the dates indicated:

	March 31, 2016 (1)		December 31, 2015
U.S. Treasuries	$	186.1	$	—
U.S. corporate public securities	238.0		111.7
Foreign corporate public securities and foreign governments	116.7		74.2
Payables under securities loan agreements	$	540.8	$	185.9

⁽¹⁾ Borrowings under securities lending transactions include both cash and non-cash collateral of $230.5 and $310.3, respectively.

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 March 31, 2016:

	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	$	34.1	$	0.1		$	—	$	—	$	—	$	—	$	34.1	$	0.1
State, municipalities and political subdivisions	4.1		0.1			27.8		0.5		2.7		0.4		34.6		1.0
U.S. corporate public securities	303.0		12.7			828.0		67.6		303.2		54.0		1,434.2		134.3
U.S. corporate private securities	85.0		1.7			195.4		28.1		71.3		9.0		351.7		38.8
Foreign corporate public securities and foreign governments	165.2		6.2			314.7		33.8		321.5		56.9		801.4		96.9
Foreign corporate private securities	43.5		2.3			270.5		11.9		26.9		3.4		340.9		17.6
Residential mortgage-backed	81.0		1.6			12.6		1.1		140.2		3.5		233.8		6.2
Commercial mortgage-backed	68.9		0.3			9.4		0.1		—		—		78.3		0.4
Other asset-backed	16.7		—		*	11.6		0.2		13.4		1.5		41.7		1.7
Total	$	801.5	$	25.0		$	1,670.0	$	143.3	$	879.2	$	128.7	$	3,350.7	$	297.0
*Less than $0.1

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, 2015:

	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	$	69.4	$	0.3	$	—	$	—		$	—	$	—	$	69.4	$	0.3
State, municipalities and political subdivisions	191.3		2.2		150.3		5.7			—		—		341.6		7.9
U.S. corporate public securities	1,764.0		67.6		1,708.3		136.4			209.6		52.8		3,681.9		256.8
U.S. corporate private securities	373.2		10.9		410.5		43.8			35.8		7.7		819.5		62.4
Foreign corporate public securities and foreign governments	670.0		33.8		485.8		55.8			195.7		61.9		1,351.5		151.5
Foreign corporate private securities	546.0		42.1		213.3		16.5			19.6		4.9		778.9		63.5
Residential mortgage-backed	116.5		1.7		42.3		0.9			128.4		4.3		287.2		6.9
Commercial mortgage-backed	156.9		1.4		78.8		2.1			—		—		235.7		3.5
Other asset-backed	22.6		0.1		0.4		—		*	13.7		1.3		36.7		1.4
Total	$	3,909.9	$	160.1	$	3,089.7	$	261.2		$	602.8	$	132.9	$	7,602.4	$	554.2
*Less than $0.1

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:

	March 31, 2016								December 31, 2015
	Impaired		Non Impaired			Total			Impaired		Non Impaired			Total
Commercial mortgage loans	$	4.8	$	3,926.4		$	3,931.2		$	10.7	$	3,719.6		$	3,730.3
Collective valuation allowance for losses	N/A		(1.2		)	(1.2		)	N/A		(1.2		)	(1.2		)
Total net commercial mortgage loans	$	4.8	$	3,925.2		$	3,930.0		$	10.7	$	3,718.4		$	3,729.1
N/A- Not Applicable

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

	March 31, 2016		December 31, 2015
Collective valuation allowance for losses, balance at January 1	$	1.2	$	1.1
Addition to (reduction of) allowance for losses	—		0.1
Collective valuation allowance for losses, end of period	$	1.2	$	1.2

Impaired Financing Receivables

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

	March 31, 2016		December 31, 2015
Impaired loans without allowances for losses	$	4.8	$	10.7
Less: Allowances for losses on impaired loans	—		—
Impaired loans, net	$	4.8	$	10.7
Unpaid principal balance of impaired loans	$	6.3	$	12.2

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

	Three Months Ended March 31,
	2016		2015
Impaired loans, average investment during the period (amortized cost)(1)	$	7.8	$	26.6
Interest income recognized on impaired loans, on an accrual basis(1)	0.1		0.4
Interest income recognized on impaired loans, on a cash basis(1)	0.1		0.5
Interest income recognized on troubled debt restructured loans, on an accrual basis	—		0.3
(1)Includes amounts for Troubled debt restructured loans.

Troubled Debt Restructurings on Financing Receivables

The following table presents information on restructured loans as of the dates indicated:

	March 31, 2016		December 31, 2015
Troubled debt restructured loans	$	—	$	5.9

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

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

	March 31, 2016 (1)		December 31, 2015 (1)
Loan-to-Value Ratio:
0% - 50%	$	368.1	$	395.1
>50% - 60%	1,070.4		969.4
>60% - 70%	2,256.8		2,158.2
>70% - 80%	233.3		204.8
>80% and above	2.6		2.8
Total Commercial mortgage loans	$	3,931.2	$	3,730.3

⁽¹⁾ Balances do not include collective valuation allowance for losses.

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

	March 31, 2016 (1)		December 31, 2015 (1)
Debt Service Coverage Ratio:
Greater than 1.5x	$	3,150.3	$	2,957.7
>1.25x - 1.5x	514.3		494.5
>1.0x - 1.25x	205.4		208.6
Less than 1.0x	38.4		38.6
Commercial mortgage loans secured by land or construction loans	22.8		30.9
Total Commercial mortgage loans	$	3,931.2	$	3,730.3

⁽¹⁾ Balances do not include collective valuation allowance for 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:

	March 31, 2016 (1)				December 31, 2015 (1)
	Gross Carrying Value		% of Total		Gross Carrying Value		% of Total
Commercial Mortgage Loans by U.S. Region:
Pacific	$	888.1	22.6	%	$	867.5	23.3	%
South Atlantic	927.7		23.6	%	857.3		23.0	%
Middle Atlantic	559.0		14.2	%	556.1		14.9	%
West South Central	426.6		10.9	%	414.8		11.1	%
Mountain	344.4		8.8	%	304.1		8.2	%
East North Central	418.4		10.6	%	380.8		10.2	%
New England	79.4		2.0	%	81.4		2.2	%
West North Central	225.5		5.7	%	208.6		5.6	%
East South Central	62.1		1.6	%	59.7		1.5	%
Total Commercial mortgage loans	$	3,931.2	100.0	%	$	3,730.3	100.0	%

⁽¹⁾ Balances do not include collective valuation allowance for losses.

Mortgage Loans by Property Type of Collateral

	March 31, 2016 (1)				December 31, 2015 (1)
	Gross Carrying Value		% of Total		Gross Carrying Value		% of Total
Commercial Mortgage Loans by Property Type:
Retail	$	1,347.1	34.2	%	$	1,330.8	35.7	%
Industrial	804.6		20.5	%	741.3		19.9	%
Apartments	709.0		18.0	%	630.4		16.9	%
Office	632.9		16.1	%	586.3		15.7	%
Hotel/Motel	176.2		4.5	%	177.6		4.7	%
Mixed Use	50.8		1.3	%	47.1		1.3	%
Other	210.6		5.4	%	216.8		5.8	%
Total Commercial mortgage loans	$	3,931.2	100.0	%	$	3,730.3	100.0	%

⁽¹⁾ Balances do not include collective valuation allowance for losses.

Mortgage Loans by Year of Origination

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

	March 31, 2016 (1)		December 31, 2015 (1)
Year of Origination:
2016	$	275.5	$	—
2015	742.7		745.3
2014	557.3		558.0
2013	703.7		709.2
2012	742.8		748.2
2011	522.0		553.2
2010 and prior	387.2		416.4
Total Commercial mortgage loans	$	3,931.2	$	3,730.3

⁽¹⁾ Balances do not include collective valuation allowance for losses.

Other than Temporary Impairment, Credit Losses Recognized in Earnings

The following table identifies 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 March 31,
	2016			2015
	Impairment		No. of Securities	Impairment		No. of Securities
U.S. corporate public securities	$	0.1	1	$	—	—
Foreign corporate public securities and foreign governments(1)	6.9		1	0.5		1
Residential mortgage-backed	0.3		14	1.4		19
Total	$	7.3	16	$	1.9	20
(1) Primarily U.S. dollar denominated.

Net Investment Income

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

	Three Months Ended March 31,
	2016			2015
Fixed maturities	$	324.0		$	305.4
Equity securities, available-for-sale	1.6			1.6
Mortgage loans on real estate	43.0			45.5
Policy loans	3.0			3.2
Short-term investments and cash equivalents	0.4			0.2
Other	(1.4		)	8.3
Gross investment income	370.6			364.2
Less: Investment expenses	14.1			12.7
Net investment income	$	356.5		$	351.5

Realized Gain (Loss) on Investments

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

	Three Months Ended March 31,
	2016			2015
Fixed maturities, available-for-sale, including securities pledged	$	(41.2	)	$	(2.8	)
Fixed maturities, at fair value option	(17.3		)	(13.9		)
Derivatives	62.9			31.8
Embedded derivative - fixed maturities	0.9			(0.2		)
Guaranteed benefit derivatives	(62.8		)	(45.5		)
Other investments	(0.1		)	0.1
Net realized capital gains (losses)	$	(57.6	)	$	(30.5	)
After-tax net realized capital gains (losses)	$	(37.4	)	$	(19.8	)

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:

	Three Months Ended March 31,
	2016		2015
Proceeds on sales	$	692.7	$	162.5
Gross gains	3.9		1.5
Gross losses	37.8		3.7

Intent related impairment

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

Other than Temporary Impairment, Credit Losses Recognized in Earnings

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

	Three Months Ended March 31,
	2016				2015
	Impairment			No. of Securities	Impairment		No. of Securities
U.S. corporate public securities	$	—		—	$	—	—
Foreign corporate public securities and foreign governments(1)	6.9			1	0.5		1
Residential mortgage-backed	—		*	1	0.5		2
Total	$	6.9		2	$	1.0	3
(1) Primarily U.S. dollar denominated.
*Less than $0.1

Credit related impairment

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

Other than Temporary Impairment, Credit Losses Recognized in Earnings

The following table identifies 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 March 31,
	2016		2015
Balance at January 1	$	19.3	$	22.4
Additional credit impairments:
On securities previously impaired	0.3		0.8
Reductions:
Increase in cash flows	0.1		0.1
Securities sold, matured, prepaid or paid down	0.4		1.3
Balance at March 31	$	19.1	$	21.8

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%
March 31, 2016
Six months or less below amortized cost	$	1,309.8	$	307.7	$	86.4	$	90.9	250	45
More than six months and twelve months or less below amortized cost	1,242.3		134.9		47.4		43.6		234	19
More than twelve months below amortized cost	651.2		1.8		28.2		0.5		170	1
Total	$	3,203.3	$	444.4	$	162.0	$	135.0	654	65
December 31, 2015
Six months or less below amortized cost	$	3,980.3	$	747.5	$	141.7	$	211.4	762	104
More than six months and twelve months or less below amortized cost	3,001.4		27.6		156.6		13.4		485	2
More than twelve months below amortized cost	382.5		17.3		26.9		4.2		144	2
Total	$	7,364.2	$	792.4	$	325.2	$	229.0	1,391	108

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%
March 31, 2016
U.S. Treasuries	$	34.2	$	—	$	0.1	$	—	5	—
State, municipalities and political subdivisions	35.6		—		1.0		—		12	—
U.S. corporate public securities	1,420.7		147.8		88.9		45.4		265	25
U.S. corporate private securities	317.8		72.7		14.5		24.3		28	4
Foreign corporate public securities and foreign governments	698.1		200.2		37.4		59.5		142	27
Foreign corporate private securities	338.8		19.7		12.9		4.7		44	4
Residential mortgage-backed	238.1		1.9		5.7		0.5		124	2
Commercial mortgage-backed	78.6		0.1		0.3		0.1		16	1
Other asset-backed	41.4		2.0		1.2		0.5		18	2
Total	$	3,203.3	$	444.4	$	162.0	$	135.0	654	65
December 31, 2015
U.S. Treasuries	$	69.7	$	—	$	0.3	$	—	14	—
State, municipalities and political subdivisions	349.5		—		7.9		—		117	—
U.S. corporate public securities	3,565.2		373.5		153.5		103.3		651	58
U.S. corporate private securities	791.0		90.9		34.6		27.8		87	4
Foreign corporate public securities and foreign governments	1,211.9		291.1		63.6		87.9		254	40
Foreign corporate private securities	807.3		35.1		53.9		9.6		85	5
Residential mortgage-backed	294.1		—		6.9		—		130	—
Commercial mortgage-backed	239.2		—		3.5		—		38	—
Other asset-backed	36.3		1.8		1.0		0.4		15	1
Total	$	7,364.2	$	792.4	$	325.2	$	229.0	1,391	108