Investments (Tables)

9 Months Ended

Sep. 30, 2013

Notes to Financial Statements [Abstract]

Schedule of Available-for-sale Securities Reconciliation

At September 30, 2013 and December 31, 2012, all fixed maturity securities were classified as available-for-sale. The amortized cost and fair values of securities by security type are shown as follows.

	September 30, 2013
	Amortized Cost		Gross Unrealized Gain		Gross Unrealized Loss		Fair Value
	(in millions of dollars)
United States Government and Government Agencies and Authorities	$	1,020.8	$	206.7	$	4.3	$	1,223.2
States, Municipalities, and Political Subdivisions	1,675.5		131.2		36.9		1,769.8
Foreign Governments	1,203.1		174.2		2.0		1,375.3
Public Utilities	9,372.1		1,233.7		49.1		10,556.7
Mortgage/Asset-Backed Securities	1,947.0		216.0		1.4		2,161.6
All Other Corporate Bonds	22,935.7		2,731.0		193.9		25,472.8
Redeemable Preferred Stocks	33.0		5.2		—		38.2
Total Fixed Maturity Securities	$	38,187.2	$	4,698.0	$	287.6	$	42,597.6

	December 31, 2012
	Amortized Cost		Gross Unrealized Gain		Gross Unrealized Loss		Fair Value
	(in millions of dollars)
United States Government and Government Agencies and Authorities	$	1,020.9	$	329.0	$	1.1	$	1,348.8
States, Municipalities, and Political Subdivisions	1,498.4		316.2		7.8		1,806.8
Foreign Governments	1,280.4		226.6		—		1,507.0
Public Utilities	9,294.3		1,865.0		15.1		11,144.2
Mortgage/Asset-Backed Securities	1,927.9		289.1		0.5		2,216.5
All Other Corporate Bonds	22,696.6		4,245.3		31.5		26,910.4
Redeemable Preferred Stocks	33.0		6.3		—		39.3
Total Fixed Maturity Securities	$	37,751.5	$	7,277.5	$	56.0	$	44,973.0

As of September 30, 2013 and December 31, 2012, we held no fixed maturity securities for which a portion of an other-than-temporary impairment had previously been recognized in other comprehensive income.

Length of Time Fixed Maturity Securities had been in a Gross Unrealized Loss Position

The following charts indicate the length of time our fixed maturity securities have been in a gross unrealized loss position.

	September 30, 2013
	Less Than 12 Months				12 Months or Greater
	Fair Value		Gross Unrealized Loss		Fair Value		Gross Unrealized Loss
	(in millions of dollars)
United States Government and Government Agencies and Authorities	$	42.0	$	2.1	$	5.4	$	2.2
States, Municipalities, and Political Subdivisions	336.3		31.1		37.2		5.8
Foreign Governments	32.4		2.0		—		—
Public Utilities	764.4		42.5		43.1		6.6
Mortgage/Asset-Backed Securities	47.9		0.9		3.1		0.5
All Other Corporate Bonds	3,136.5		175.6		197.1		18.3
Total Fixed Maturity Securities	$	4,359.5	$	254.2	$	285.9	$	33.4

	December 31, 2012
	Less Than 12 Months				12 Months or Greater
	Fair Value		Gross Unrealized Loss		Fair Value		Gross Unrealized Loss
	(in millions of dollars)
United States Government and Government Agencies and Authorities	$	—	$	—	$	6.5	$	1.1
States, Municipalities, and Political Subdivisions	30.8		0.9		42.1		6.9
Public Utilities	110.3		3.9		147.6		11.2
Mortgage/Asset-Backed Securities	4.4		—		3.8		0.5
All Other Corporate Bonds	441.3		7.0		396.8		24.5
Total Fixed Maturity Securities	$	586.8	$	11.8	$	596.8	$	44.2

Distribution of the Maturity Dates for Fixed Maturity Securities

The following is a distribution of the maturity dates for fixed maturity securities. The maturity dates have not been adjusted for possible calls or prepayments.

	September 30, 2013
	Total Amortized Cost		Unrealized Gain Position				Unrealized Loss Position
			Gross Gain		Fair Value		Gross Loss		Fair Value
	(in millions of dollars)
1 year or less	$	882.7	$	15.8	$	874.5	$	0.1	$	23.9
Over 1 year through 5 years	7,027.3		728.5		7,629.0		2.2		124.6
Over 5 years through 10 years	9,052.5		1,003.4		8,094.1		88.7		1,873.1
Over 10 years	19,277.7		2,734.3		19,244.0		195.2		2,572.8
	36,240.2		4,482.0		35,841.6		286.2		4,594.4
Mortgage/Asset-Backed Securities	1,947.0		216.0		2,110.6		1.4		51.0
Total Fixed Maturity Securities	$	38,187.2	$	4,698.0	$	37,952.2	$	287.6	$	4,645.4

	December 31, 2012
	Total Amortized Cost		Unrealized Gain Position				Unrealized Loss Position
			Gross Gain		Fair Value		Gross Loss		Fair Value
	(in millions of dollars)
1 year or less	$	956.4	$	21.2	$	934.1	$	0.5	$	43.0
Over 1 year through 5 years	5,922.8		628.1		6,449.8		5.0		96.1
Over 5 years through 10 years	9,752.3		1,606.4		10,997.0		7.6		354.1
Over 10 years	19,192.1		4,732.7		23,200.2		42.4		682.2
	35,823.6		6,988.4		41,581.1		55.5		1,175.4
Mortgage/Asset-Backed Securities	1,927.9		289.1		2,208.3		0.5		8.2
Total Fixed Maturity Securities	$	37,751.5	$	7,277.5	$	43,789.4	$	56.0	$	1,183.6

Mortgage Loans by Property Type

Mortgage loans by property type and geographic region are presented below. Prior year amounts by property type have been reclassified to conform to the current year presentation.

	September 30, 2013				December 31, 2012
	(in millions of dollars)
	Carrying		Percent of		Carrying		Percent of
	Amount		Total		Amount		Total
Property Type
Apartment	$	70.4	4.0	%	$	47.2	2.7	%
Industrial	564.5		31.8		545.7		31.9
Office	732.4		41.2		721.2		42.1
Retail	408.8		23.0		398.6		23.3
Total	$	1,776.1	100.0	%	$	1,712.7	100.0	%

Mortgage Loans by Geographic Region

Region
New England	$	102.0	5.7	%	$	114.3	6.7	%
Mid-Atlantic	166.8		9.4		160.0		9.3
East North Central	241.0		13.6		224.7		13.1
West North Central	168.4		9.5		160.8		9.4
South Atlantic	433.9		24.4		440.9		25.7
East South Central	68.2		3.8		79.6		4.7
West South Central	202.4		11.4		159.5		9.3
Mountain	83.2		4.7		90.5		5.3
Pacific	310.2		17.5		282.4		16.5
Total	$	1,776.1	100.0	%	$	1,712.7	100.0	%

Mortgage Loans, Sorted by Applicable Credit Quality Indicators, Internal Rating

Mortgage loans, sorted by the applicable credit quality indicators, are as follows:

	September 30 2013		December 31 2012
	(in millions of dollars)
Internal Rating
Aa	$	10.9	$	11.5
A	678.8		659.4
Baa	1,049.3		994.5
Ba	24.0		34.2
B	13.1		13.1
Total	$	1,776.1	$	1,712.7

Mortgage Loans, Sorted by Applicable Credit Quality Indicators, Loan to Value Ratio

Loan-to-Value Ratio
<= 65%	$	771.8	$	624.7
> 65% <= 75%	816.0		858.8
> 75% <= 85%	121.9		142.5
> 85%	66.4		86.7
Total	$	1,776.1	$	1,712.7

Activity in the Allowance for Credit Losses

The activity in the allowance for credit losses is as follows:

	Three Months Ended September 30				Nine Months Ended September 30
	2013		2012		2013		2012
	(in millions of dollars)
Balance at Beginning of Period	$	1.5	$	1.5	$	1.5	$	1.5
Provision	—		1.3		—		1.8
Charge-offs, Net of Recoveries	—		—		—		(0.5		)
Balance at End of Period	$	1.5	$	2.8	$	1.5	$	2.8

Impaired Mortgage Loans

Impaired mortgage loans are as follows:

	September 30, 2013
	(in millions of dollars)
			Unpaid
	Recorded		Principal		Related
	Investment		Balance		Allowance
With an Allowance Recorded	$	13.1	$	14.6	$	1.5
	December 31, 2012
	(in millions of dollars)
			Unpaid
	Recorded		Principal		Related
	Investment		Balance		Allowance
With No Related Allowance Recorded	$	4.3	$	4.3	$	—
With an Allowance Recorded	13.1		14.6		1.5
Total	$	17.4	$	18.9	$	1.5

Troubled Debt Restructurings on Financing Receivables [Table Text Block]

Our troubled debt restructurings during the nine months ended September 30, 2013 and 2012 were comprised entirely of loan foreclosures. A summary of our troubled debt restructurings is as follows:

	Nine Months Ended September 30
	2013		2012
	(in millions of dollars)
Carrying Amount	$	4.3	$	13.1
Number of Loans	1		2

We had no realized losses on loan foreclosures for the three and nine months ended September 30, 2013 and 2012, other than the initial impairment losses recognized prior to foreclosure.

Schedule of Financial Instrument and Derivative Offsetting [Table Text Block]

Shown below are our financial instruments that either meet the accounting requirements that allow them to be offset in our balance sheets or that are subject to an enforceable master netting arrangement or similar agreement. Our accounting policy is to not offset these financial instruments in our balance sheets. Net amounts disclosed below have been reduced by the amount of collateral pledged to or received from our counterparties.

	September 30, 2013
	Gross Amount						Gross Amount Not
	of Recognized		Gross Amount		Net Amount		Offset in Balance Sheet
	Financial		Offset in		Presented in		Financial			Cash			Net
	Instruments		Balance Sheet		Balance Sheet		Instruments			Collateral			Amount
	(in millions of dollars)
Financial Assets:
Derivatives	$	24.5	$	—	$	24.5	$	(22.8	)	$	(1.3	)	$	0.4
Securities Lending	254.4		—		254.4		(113.9		)	(140.5		)	—
Total	$	278.9	$	—	$	278.9	$	(136.7	)	$	(141.8	)	$	0.4
Financial Liabilities:
Derivatives	$	142.9	$	—	$	142.9	$	(112.3	)	$	—		$	30.6
Securities Lending	140.5		—		140.5		(140.5		)	—			—
Total	$	283.4	$	—	$	283.4	$	(252.8	)	$	—		$	30.6

	December 31, 2012
	Gross Amount						Gross Amount Not
	of Recognized		Gross Amount		Net Amount		Offset in Balance Sheet
	Financial		Offset in		Presented in		Financial			Cash			Net
	Instruments		Balance Sheet		Balance Sheet		Instruments			Collateral			Amount
	(in millions of dollars)
Financial Assets:
Derivatives	$	81.6	$	—	$	81.6	$	(72.9	)	$	—		$	8.7
Securities Lending	452.8		—		452.8		—			(452.8		)	—
Total	$	534.4	$	—	$	534.4	$	(72.9	)	$	(452.8	)	$	8.7
Financial Liabilities:
Derivatives	$	170.5	$	—	$	170.5	$	(129.8	)	$	(1.8	)	$	38.9
Securities Lending	455.8		—		455.8		(452.8		)	—			3.0
Total	$	626.3	$	—	$	626.3	$	(582.6	)	$	(1.8	)	$	41.9

Investment Income [Table Text Block]

Net Investment Income

Net investment income reported in our consolidated statements of income is as follows:

	Three Months Ended September 30				Nine Months Ended September 30
	2013		2012		2013		2012
	(in millions of dollars)
Fixed Maturity Securities	$	584.2	$	589.0	$	1,771.3	$	1,790.8
Derivative Financial Instruments	8.9		9.1		25.6		22.0
Mortgage Loans	28.5		25.5		81.6		76.5
Policy Loans	4.0		3.7		11.6		10.8
Other Long-term Investments	4.0		5.4		14.5		13.2
Short-term Investments	0.5		1.0		1.9		3.3
Gross Investment Income	630.1		633.7		1,906.5		1,916.6
Less Investment Expenses	7.2		6.3		21.1		20.3
Less Investment Income on Participation Fund Account Assets	3.9		4.1		11.8		12.1
Less Amortization of Tax Credit Partnerships	3.5		4.1		10.9		12.0
Net Investment Income	$	615.5	$	619.2	$	1,862.7	$	1,872.2

Realized Investment Gains and Losses Reported in Consolidated Statements of Income

Realized Investment Gain and Loss

Realized investment gains and losses reported in our consolidated statements of income are as follows:

	Three Months Ended September 30						Nine Months Ended September 30
	2013			2012			2013			2012
	(in millions of dollars)
Fixed Maturity Securities
Gross Gains on Sales	$	4.3		$	4.6		$	13.5		$	14.0
Gross Losses on Sales	(33.0		)	(2.3		)	(40.1		)	(9.0		)
Other-Than-Temporary Impairment Loss	—			—			(0.8		)	—
Mortgage Loans and Other Invested Assets
Gross Gains on Sales	5.6			2.3			14.6			2.3
Impairment Loss	(1.0		)	(1.3		)	(2.0		)	(1.8		)
Embedded Derivative in Modified Coinsurance Arrangement	(0.3		)	19.7			18.5			28.7
Other Derivatives	(1.0		)	—			(1.5		)	—
Foreign Currency Transactions	(0.7		)	(1.7		)	(4.7		)	(2.6		)
Net Realized Investment Gain (Loss)	$	(26.1	)	$	21.3		$	(2.5	)	$	31.6