Investments (Tables)

3 Months Ended

Mar. 31, 2013

Schedule of Available-for-sale Securities [Line Items]

Investments Classified by Contractual Maturity Date [Table Text Block]

The amortized cost and estimated fair values of the Company’s Investments in Fixed Maturities at March 31, 2013 by contractual maturity were:

(Dollars in Millions)	Amortized Cost		Fair Value
Due in One Year or Less	$	101.3	$	104.5
Due after One Year to Five Years	562.1		592.3
Due after Five Years to Ten Years	1,273.4		1,379.6
Due after Ten Years	2,177.2		2,534.3
Asset-backed Securities Not Due at a Single Maturity Date	228.6		245.8
Investments in Fixed Maturities	$	4,342.6	$	4,856.5

Schedule of Unrealized Loss on Investments [Table Text Block]

An aging of unrealized losses on the Company’s Investments in Fixed Maturities and Equity Securities at March 31, 2013 is presented below:

	Less Than 12 Months					12 Months or Longer					Total
(Dollars in Millions)	Fair Value		Unrealized Losses			Fair Value		Unrealized Losses			Fair Value		Unrealized Losses
Fixed Maturities:
U.S. Government and Government Agencies and Authorities	$	68.9	$	(1.0	)	$	—	$	—		$	68.9	$	(1.0	)
States and Political Subdivisions	41.1		(0.3		)	0.3		—			41.4		(0.3		)
Corporate Securities:
Bonds and Notes	313.1		(6.3		)	60.6		(2.9		)	373.7		(9.2		)
Redeemable Preferred Stocks	—		—			0.2		—			0.2		—
Mortgage and Asset-backed	21.3		(0.4		)	1.8		(0.1		)	23.1		(0.5		)
Total Fixed Maturities	444.4		(8.0		)	62.9		(3.0		)	507.3		(11.0		)
Equity Securities:
Preferred Stocks:
Finance, Insurance and Real Estate	—		—			2.4		(0.1		)	2.4		(0.1		)
Other Industries	1.3		(0.5		)	0.8		—			2.1		(0.5		)
Common Stocks:
Manufacturing	3.3		(0.6		)	0.2		(0.1		)	3.5		(0.7		)
Other Industries	1.6		(0.1		)	1.9		—			3.5		(0.1		)
Other Equity Interests:
Exchange Traded Funds	5.0		—			—		—			5.0		—
Limited Liability Companies and Limited Partnerships	59.2		(1.6		)	6.3		(1.1		)	65.5		(2.7		)
Total Equity Securities	70.4		(2.8		)	11.6		(1.3		)	82.0		(4.1		)
Total	$	514.8	$	(10.8	)	$	74.5	$	(4.3	)	$	589.3	$	(15.1	)

An aging of unrealized losses on the Company’s Investments in Fixed Maturities and Equity Securities at December 31, 2012 is presented below:

	Less Than 12 Months					12 Months or Longer					Total
(Dollars in Millions)	Fair Value		Unrealized Losses			Fair Value		Unrealized Losses			Fair Value		Unrealized Losses
Fixed Maturities:
U.S. Government and Government Agencies and Authorities	$	40.8	$	(0.2	)	$	—	$	—		$	40.8	$	(0.2	)
States and Political Subdivisions	6.3		(0.1		)	0.3		—			6.6		(0.1		)
Corporate Securities:
Bonds and Notes	268.5		(5.2		)	38.1		(2.3		)	306.6		(7.5		)
Redeemable Preferred Stocks	—		—			0.4		—			0.4		—
Mortgage and Asset-backed	—		—			1.7		(0.3		)	1.7		(0.3		)
Total Fixed Maturities	315.6		(5.5		)	40.5		(2.6		)	356.1		(8.1		)
Equity Securities:
Preferred Stocks:
Finance, Insurance and Real Estate	—		—			2.4		(0.1		)	2.4		(0.1		)
Other Industries	2.3		(0.8		)	3.7		(0.1		)	6.0		(0.9		)
Common Stocks:
Manufacturing	6.3		(0.4		)	—		—			6.3		(0.4		)
Other Industries	14.2		(0.4		)	1.3		(0.1		)	15.5		(0.5		)
Other Equity Interests:
Limited Liability Companies and Limited Partnerships	5.5		(0.5		)	6.7		(0.9		)	12.2		(1.4		)
Total Equity Securities	28.3		(2.1		)	14.1		(1.2		)	42.4		(3.3		)
Total	$	343.9	$	(7.6	)	$	54.6	$	(3.8	)	$	398.5	$	(11.4	)

Other than Temporary Impairment, Credit Losses Recognized in Earnings [Table Text Block]

The following table sets forth the pre-tax amount of other-than-temporary-impairment (“OTTI”) credit losses, recognized in Retained Earnings for Investments in Fixed Maturities held by the Company as of the dates indicated, for which a portion of the OTTI loss has been recognized in Accumulated Other Comprehensive Income, and the corresponding changes in such amounts.

	Three Months Ended
(Dollars in Millions)	Mar 31, 2013			Mar 31, 2012
Balance at Beginning of Period	$	4.6		$	3.9
Additions for Previously Unrecognized OTTI Credit Losses	0.7			—
Reductions to Previously Recognized OTTI Credit Losses	—			(0.1		)
Reductions for Change in Impairment Status:
From Status of Credit Loss to Status of Intent-to-sell or Required-to-sell	(1.1		)	—
Reductions for Investments Sold During Period	(0.1		)	—
Balance at End of Period	$	4.1		$	3.8

Schedule of Other Investments [Table Text Block]

The carrying values of the Company’s Other Investments at March 31, 2013 and December 31, 2012 were:

(Dollars in Millions)	Mar 31, 2013		Dec 31, 2012
Loans to Policyholders at Unpaid Principal	$	268.3	$	266.3
Real Estate at Depreciated Cost	221.3		226.2
Trading Securities at Fair Value	4.6		4.5
Other	0.6		0.5
Total	$	494.8	$	497.5

Fixed Maturities [Member]

Schedule of Available-for-sale Securities [Line Items]

Schedule of Available-for-sale Securities Reconciliation [Table Text Block]

The amortized cost and estimated fair values of the Company’s Investments in Fixed Maturities at December 31, 2012 were:

	Amortized Cost		Gross Unrealized					Fair Value
(Dollars in Millions)			Gains		Losses
U.S. Government and Government Agencies and Authorities	$	384.0	$	45.1	$	(0.2	)	$	428.9
States and Political Subdivisions	1,251.0		150.5		(0.1		)	1,401.4
Corporate Securities:
Bonds and Notes	2,615.5		385.4		(7.5		)	2,993.4
Redeemable Preferred Stocks	30.1		2.5		—			32.6
Mortgage and Asset-backed	3.2		1.0		(0.3		)	3.9
Investments in Fixed Maturities	$	4,283.8	$	584.5	$	(8.1	)	$	4,860.2

The amortized cost and estimated fair values of the Company’s Investments in Fixed Maturities at March 31, 2013 were:

	Amortized Cost		Gross Unrealized					Fair Value
(Dollars in Millions)			Gains		Losses
U.S. Government and Government Agencies and Authorities	$	389.2	$	40.9	$	(1.0	)	$	429.1
States and Political Subdivisions	1,258.9		143.2		(0.3		)	1,401.8
Canadian Government and Provinces	0.6		—		—			0.6
Corporate Securities:
Bonds and Notes	2,651.0		337.3		(9.2		)	2,979.1
Redeemable Preferred Stocks	10.8		2.2		—			13.0
Mortgage and Asset-backed	32.1		1.3		(0.5		)	32.9
Investments in Fixed Maturities	$	4,342.6	$	524.9	$	(11.0	)	$	4,856.5

Equity Securities [Member]

Schedule of Available-for-sale Securities [Line Items]

Schedule of Available-for-sale Securities Reconciliation [Table Text Block]

Gross unrealized gains and gross unrealized losses on the Company’s Investments in Equity Securities at March 31, 2013 were:

			Gross Unrealized
(Dollars in Millions)	Cost		Gains		Losses			Fair Value
Preferred Stocks:
Finance, Insurance and Real Estate	$	72.4	$	4.8	$	(0.1	)	$	77.1
Other Industries	14.1		4.6		(0.5		)	18.2
Common Stocks:
Manufacturing	67.4		29.2		(0.7		)	95.9
Other Industries	48.9		15.1		(0.1		)	63.9
Other Equity Interests:
Exchange Traded Funds	149.7		5.4		—			155.1
Limited Liability Companies and Limited Partnerships	128.1		18.5		(2.7		)	143.9
Investments in Equity Securities	$	480.6	$	77.6	$	(4.1	)	$	554.1

Gross unrealized gains and gross unrealized losses on the Company’s Investments in Equity Securities at December 31, 2012 were:

			Gross Unrealized
(Dollars in Millions)	Cost		Gains		Losses			Fair Value
Preferred Stocks:
Finance, Insurance and Real Estate	$	75.4	$	3.9	$	(0.1	)	$	79.2
Other Industries	18.4		3.8		(0.9		)	21.3
Common Stocks:
Manufacturing	67.0		20.9		(0.4		)	87.5
Other Industries	59.1		8.1		(0.5		)	66.7
Other Equity Interests:
Exchange Traded Funds	119.6		6.3		—			125.9
Limited Liability Companies and Limited Partnerships	123.2		19.5		(1.4		)	141.3
Investments in Equity Securities	$	462.7	$	62.5	$	(3.3	)	$	521.9