Investments (Tables)

9 Months Ended

Sep. 30, 2016

Investments [Abstract]

Schedule of Available-for-sale Securities Reconciliation

	September 30, 2016
	Amortized		Gross		Gross				OTTI
	Cost or		Unrealized		Unrealized				Unrealized
(in millions)	Cost		Gains		Losses		Fair Value		Losses
Fixed maturities:
U.S. Treasury and government agencies	$	311.1	$	9.4	$	0.1	$	320.4	$	-
Foreign government		234.5		8.2		-		242.7		-
Municipal		1,071.8		65.7		1.1		1,136.4		-
Corporate		3,937.4		190.5		19.7		4,108.2		15.8
Residential mortgage-backed		921.8		23.5		1.0		944.3		0.3
Commercial mortgage-backed		546.5		23.7		0.4		569.8		-
Asset-backed		77.3		1.4		0.3		78.4		-
Total fixed maturities	$	7,100.4	$	322.4	$	22.6	$	7,400.2	$	16.1
Equity securities	$	533.6	$	79.8	$	0.9	$	612.5	$	-

	December 31, 2015
	Amortized		Gross		Gross				OTTI
	Cost or		Unrealized		Unrealized				Unrealized
(in millions)	Cost		Gains		Losses		Fair Value		Losses
Fixed maturities:
U.S. Treasury and government agencies	$	447.1	$	5.5	$	3.5	$	449.1	$	-
Foreign government		244.7		2.6		1.5		245.8		-
Municipal		1,074.5		50.0		4.2		1,120.3		-
Corporate		3,699.9		86.8		95.7		3,691.0		27.5
Residential mortgage-backed		887.6		13.4		4.9		896.1		0.3
Commercial mortgage-backed		499.6		5.8		4.3		501.1		-
Asset-backed		80.6		0.2		0.8		80.0		-
Total fixed maturities	$	6,934.0	$	164.3	$	114.9	$	6,983.4	$	27.8
Equity securities	$	528.5	$	55.7	$	7.6	$	576.6	$	-

Investments Classified by Contractual Maturity Date

	September 30, 2016
	Amortized		Fair
(in millions)	Cost		Value
Due in one year or less	$	375.0	$	378.2
Due after one year through five years		2,575.9		2,692.0
Due after five years through ten years		2,120.6		2,220.4
Due after ten years		483.3		517.1
		5,554.8		5,807.7
Mortgage-backed and asset-backed securities		1,545.6		1,592.5
Total fixed maturities	$	7,100.4	$	7,400.2

Schedule of Unrealized Loss on Investments

	September 30, 2016
	12 months or less				Greater than 12 months				Total
	Gross				Gross				Gross
	Unrealized		Fair		Unrealized		Fair		Unrealized		Fair
(in millions)	Losses		Value		Losses		Value		Losses		Value
Fixed maturities:
Investment grade:
U.S. Treasury and government agencies	$	0.1	$	37.8	$	-	$	-	$	0.1	$	37.8
Foreign governments		-		11.5		-		1.5		-		13.0
Municipal		0.2		43.7		0.9		31.7		1.1		75.4
Corporate		1.3		209.7		4.3		55.5		5.6		265.2
Residential mortgage-backed		0.2		122.3		0.8		40.1		1.0		162.4
Commercial mortgage-backed		0.4		56.8		-		7.1		0.4		63.9
Asset-backed		0.1		3.7		0.2		6.2		0.3		9.9
Total investment grade		2.3		485.5		6.2		142.1		8.5		627.6
Below investment grade:
Corporate		0.9		30.1		13.2		105.2		14.1		135.3
Total fixed maturities		3.2		515.6		19.4		247.3		22.6		762.9
Equity securities		0.9		18.7		-		-		0.9		18.7
Total	$	4.1	$	534.3	$	19.4	$	247.3	$	23.5	$	781.6

	December 31, 2015
	12 months or less				Greater than 12 months				Total
	Gross				Gross				Gross
	Unrealized		Fair		Unrealized		Fair		Unrealized		Fair
(in millions)	Losses		Value		Losses		Value		Losses		Value
Fixed maturities:
Investment grade:
U.S. Treasury and government agencies	$	1.5	$	139.0	$	2.0	$	77.2	$	3.5	$	216.2
Foreign governments		0.8		63.6		0.7		8.4		1.5		72.0
Municipal		2.3		143.0		1.9		57.4		4.2		200.4
Corporate		30.7		1,138.3		18.9		122.3		49.6		1,260.6
Residential mortgage-backed		3.0		334.5		1.9		47.0		4.9		381.5
Commercial mortgage-backed		4.2		293.8		0.1		9.7		4.3		303.5
Asset-backed		0.8		56.6		-		1.4		0.8		58.0
Total investment grade		43.3		2,168.8		25.5		323.4		68.8		2,492.2
Below investment grade:
Corporate		19.6		165.5		26.5		63.2		46.1		228.7
Total fixed maturities		62.9		2,334.3		52.0		386.6		114.9		2,720.9
Equity securities		7.6		166.8		-		-		7.6		166.8
Total	$	70.5	$	2,501.1	$	52.0	$	386.6	$	122.5	$	2,887.7

Schedule of Realized Gain (Loss)

	Three Months Ended September 30,
	2016						2015
	Proceeds from		Gross		Gross		Proceeds from		Gross		Gross
(in millions)	Sales		Gains		Losses		Sales		Gains		Losses
Fixed maturities	$	94.2	$	3.6	$	0.3	$	145.2	$	0.7	$	0.6
Equity securities	$	20.7	$	-	$	1.2	$	17.4	$	4.1	$	0.1

	Nine Months Ended September 30,
	2016						2015
	Proceeds from		Gross		Gross		Proceeds from		Gross		Gross
(in millions)	Sales		Gains		Losses		Sales		Gains		Losses
Fixed maturities	$	402.1	$	9.5	$	4.5	$	969.9	$	13.6	$	5.3
Equity securities	$	194.1	$	26.4	$	2.9	$	185.2	$	24.2	$	0.1

Rollforward of Cumulative Amounts Related to Credit Loss Portion of OTTI Losses

	Three Months Ended September 30,				Nine Months Ended September 30,
(in millions)	2016		2015		2016		2015
Credit losses at beginning of period	$	11.7	$	6.1	$	18.0	$	4.2
Credit losses for which an OTTI was not previously recognized		-		2.5		5.2		5.2
Additional credit losses on securities for which an
OTTI was previously recognized		0.1		1.0		2.2		1.0
Reductions for securities sold, matured or called		(2.3)		-		(3.9)		(0.8)
Reductions for securities reclassified as intended to sell		-		-		(12.0)		-
Credit losses at end of period	$	9.5	$	9.6	$	9.5	$	9.6