Segment Information (Tables)

9 Months Ended

Sep. 30, 2016

Segment Reporting [Abstract]

Reconciliation of operating results by reportable segment

The following tables present the Company's operating results by reportable segment:

	Three Months Ended
	September 30, 2016							September 30, 2015
	Property & Casualty Lines		Other		Total			Property & Casualty Lines		Other		Total
	(Amounts in millions)
Net premiums earned	$	780.6	$	10.3	$	790.9		$	732.9	$	12.6	$	745.5
Less:
Losses and loss adjustment expenses	570.8		5.5		576.3			538.6		7.1		545.7
Underwriting expenses	194.8		4.5		199.3			188.6		5.1		193.7
Underwriting gain	15.0		0.3		15.3			5.7		0.4		6.1
Investment income					30.3							30.9
Net realized investment losses					(15.5		)					(26.3		)
Other income					2.4							2.3
Interest expense					(0.9		)					(0.8		)
Pre-tax income					$	31.6						$	12.2
Net income					$	26.9						$	15.3

	Nine Months Ended
	September 30, 2016								September 30, 2015
	Property & Casualty Lines			Other		Total			Property & Casualty Lines		Other		Total
	(Amounts in millions)
Net premiums earned	$	2,305.0		$	32.3	$	2,337.3		$	2,158.6	$	39.2	$	2,197.8
Less:
Losses and loss adjustment expenses	1,748.2			17.3		1,765.5			1,559.5		21.8		1,581.3
Underwriting expenses	586.1			13.6		599.7			577.4		15.5		592.9
Underwriting gain	(29.3		)	1.4		(27.9		)	21.7		1.9		23.6
Investment income						91.4							94.1
Net realized investment gains (losses)						55.0							(75.6		)
Other income						6.4							6.8
Interest expense						(2.9		)					(2.3		)
Pre-tax income						$	122.0						$	46.6
Net income						$	99.1						$	51.1

Schedule direct premiums attributable to segment

The following tables present the Company’s net premiums earned and direct premiums written by line of insurance business:

	Three Months Ended
	September 30, 2016						September 30, 2015
	Property & Casualty Lines		Other		Total		Property & Casualty Lines		Other		Total
	(Amounts in millions)
Private passenger automobile	$	614.0	$	—	$	614.0	$	581.3	$	—	$	581.3
Homeowners	105.5		—		105.5		95.8		—		95.8
Commercial automobile	41.2		—		41.2		37.0		—		37.0
Other	19.9		10.3		30.2		18.8		12.6		31.4
Net premiums earned	$	780.6	$	10.3	$	790.9	$	732.9	$	12.6	745.5
Private passenger automobile	$	630.1	$	—	$	630.1	$	609.0	$	—	$	609.0
Homeowners	116.0		—		116.0		106.6		—		106.6
Commercial automobile	41.9		—		41.9		40.1		—		40.1
Other	22.4		6.6		29.0		22.3		7.4		29.7
Direct premiums written	$	810.4	$	6.6	$	817.0	$	778.0	$	7.4	$	785.4

	Nine Months Ended
	September 30, 2016						September 30, 2015
	Property & Casualty Lines		Other		Total		Property & Casualty Lines		Other		Total
	(Amounts in millions)
Private passenger automobile	$	1,820.1	$	—	$	1,820.1	$	1,716.0	$	—	$	1,716.0
Homeowners	307.0		—		307.0		281.6		—		281.6
Commercial automobile	119.8		—		119.8		106.3		—		106.3
Other	58.1		32.3		90.4		54.7		39.2		93.9
Net premiums earned	$	2,305.0	$	32.3	$	2,337.3	$	2,158.6	$	39.2	2,197.8
Private passenger automobile	$	1,857.3	$	—	$	1,857.3	$	1,763.1	$	—	$	1,763.1
Homeowners	331.4		—		331.4		300.8		—		300.8
Commercial automobile	125.2		—		125.2		114.8		—		114.8
Other	66.3		20.9		87.2		62.6		22.8		85.4
Direct premiums written	$	2,380.2	$	20.9	$	2,401.1	$	2,241.3	$	22.8	$	2,264.1