Segment Information (Tables)

9 Months Ended

Sep. 30, 2018

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,
	2018							2017
	Property & Casualty		Other		Total			Property & Casualty		Other		Total
	(Amounts in millions)
Net premiums earned	$	850.5	$	7.6	$	858.1		$	792.7	$	8.5	$	801.2
Less:
Losses and loss adjustment expenses	610.2		3.9		614.1			591.1		4.2		595.3
Underwriting expenses	202.8		3.3		206.1			196.7		3.9		200.6
Underwriting gain	37.5		0.4		37.9			4.9		0.4		5.3
Investment income					38.2							31.0
Net realized investment (losses) gains					(3.9		)					20.7
Other income					2.4							5.4
Interest expense					(4.3		)					(4.2		)
Pre-tax income					$	70.3						$	58.2
Net income					$	58.6						$	46.5

	Nine Months Ended September 30,
	2018							2017
	Property & Casualty		Other		Total			Property & Casualty			Other		Total
	(Amounts in millions)
Net premiums earned	$	2,476.9	$	23.3	$	2,500.2		$	2,362.4		$	26.2	$	2,388.6
Less:
Losses and loss adjustment expenses	1,840.1		11.8		1,851.9			1,777.1			13.5		1,790.6
Underwriting expenses	604.0		10.9		614.9			587.7			11.9		599.6
Underwriting gain (loss)	32.8		0.6		33.4			(2.4		)	0.8		(1.6		)
Investment income					104.5								94.1
Net realized investment (losses) gains					(48.4		)						66.3
Other income					7.1								9.7
Interest expense					(12.8		)						(10.9		)
Pre-tax income					$	83.8							$	157.6
Net income					$	76.2							$	125.1

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,
	2018						2017
	Property & Casualty		Other		Total		Property & Casualty		Other		Total
	(Amounts in millions)
Private passenger automobile	$	659.6	$	—	$	659.6	$	619.8	$	—	$	619.8
Homeowners	120.0		—		120.0		108.3		—		108.3
Commercial automobile	48.7		—		48.7		43.6		—		43.6
Other	22.2		7.6		29.8		21.0		8.5		29.5
Net premiums earned	$	850.5	$	7.6	$	858.1	$	792.7	$	8.5	$	801.2
Private passenger automobile	$	695.1	$	—	$	695.1	$	633.7	$	—	$	633.7
Homeowners	140.7		—		140.7		125.8		—		125.8
Commercial automobile	50.3		—		50.3		45.6		—		45.6
Other	24.5		6.9		31.4		22.9		7.1		30.0
Direct premiums written	$	910.6	$	6.9	$	917.5	$	828.0	$	7.1	$	835.1

	Nine Months Ended September 30,
	2018						2017
	Property & Casualty		Other		Total		Property & Casualty		Other		Total
	(Amounts in millions)
Private passenger automobile	$	1,932.1	$	—	$	1,932.1	$	1,850.3	$	—	$	1,850.3
Homeowners	340.5		—		340.5		322.3		—		322.3
Commercial automobile	140.3		—		140.3		127.3		—		127.3
Other	64.0		23.3		87.3		62.5		26.2		88.7
Net premiums earned	$	2,476.9	$	23.3	$	2,500.2	$	2,362.4	$	26.2	$	2,388.6
Private passenger automobile	$	2,035.1	$	—	$	2,035.1	$	1,872.8	$	—	$	1,872.8
Homeowners	394.0		—		394.0		352.3		—		352.3
Commercial automobile	149.9		—		149.9		133.7		—		133.7
Other	73.6		20.5		94.1		69.9		21.3		91.2
Direct premiums written	$	2,652.6	$	20.5	$	2,673.1	$	2,428.7	$	21.3	$	2,450.0