Segment Information (Tables)

9 Months Ended

Sep. 30, 2017

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,
	2017							2016
	Property & Casualty		Other		Total			Property & Casualty		Other		Total
	(Amounts in millions)
Net premiums earned	$	792.7	$	8.5	$	801.2		$	780.6	$	10.3	$	790.9
Less:
Losses and loss adjustment expenses	591.1		4.2		595.3			570.8		5.5		576.3
Underwriting expenses	196.7		3.9		200.6			194.8		4.5		199.3
Underwriting gain	4.9		0.4		5.3			15.0		0.3		15.3
Investment income					31.0							30.3
Net realized investment gains (losses)					20.7							(15.5		)
Other income					5.4							2.4
Interest expense					(4.2		)					(0.9		)
Pre-tax income					$	58.2						$	31.6
Net income					$	46.5						$	26.9

	Nine Months Ended September 30,
	2017								2016
	Property & Casualty			Other		Total			Property & Casualty			Other		Total
	(Amounts in millions)
Net premiums earned	$	2,362.4		$	26.2	$	2,388.6		$	2,305.0		$	32.3	$	2,337.3
Less:
Losses and loss adjustment expenses	1,777.1			13.5		1,790.6			1,748.2			17.3		1,765.5
Underwriting expenses	587.7			11.9		599.6			586.1			13.6		599.7
Underwriting (loss) gain	(2.4		)	0.8		(1.6		)	(29.3		)	1.4		(27.9		)
Investment income						94.1								91.4
Net realized investment gains						66.3								55.0
Other income						9.7								6.4
Interest expense						(10.9		)						(2.9		)
Pre-tax income						$	157.6							$	122.0
Net income						$	125.1							$	99.1

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,
	2017						2016
	Property & Casualty		Other		Total		Property & Casualty		Other		Total
	(Amounts in millions)
Private passenger automobile	$	619.8	$	—	$	619.8	$	614.0	$	—	$	614.0
Homeowners	108.3		—		108.3		105.5		—		105.5
Commercial automobile	43.6		—		43.6		41.2		—		41.2
Other	21.0		8.5		29.5		19.9		10.3		30.2
Net premiums earned	$	792.7	$	8.5	$	801.2	$	780.6	$	10.3	$	790.9
Private passenger automobile	$	633.7	$	—	$	633.7	$	630.1	$	—	$	630.1
Homeowners	125.8		—		125.8		116.0		—		116.0
Commercial automobile	45.6		—		45.6		41.9		—		41.9
Other	22.9		7.1		30.0		22.4		6.6		29.0
Direct premiums written	$	828.0	$	7.1	$	835.1	$	810.4	$	6.6	$	817.0

	Nine Months Ended September 30,
	2017						2016
	Property & Casualty		Other		Total		Property & Casualty		Other		Total
	(Amounts in millions)
Private passenger automobile	$	1,850.3	$	—	$	1,850.3	$	1,820.1	$	—	$	1,820.1
Homeowners	322.3		—		322.3		307.0		—		307.0
Commercial automobile	127.3		—		127.3		119.8		—		119.8
Other	62.5		26.2		88.7		58.1		32.3		90.4
Net premiums earned	$	2,362.4	$	26.2	$	2,388.6	$	2,305.0	$	32.3	$	2,337.3
Private passenger automobile	$	1,872.8	$	—	$	1,872.8	$	1,857.3	$	—	$	1,857.3
Homeowners	352.3		—		352.3		331.4		—		331.4
Commercial automobile	133.7		—		133.7		125.2		—		125.2
Other	69.9		21.3		91.2		66.3		20.9		87.2
Direct premiums written	$	2,428.7	$	21.3	$	2,450.0	$	2,380.2	$	20.9	$	2,401.1