Segment Information

9 Months Ended

Sep. 30, 2011

Segment Reporting [Abstract]

Segment Information

Segment Information

White Mountains has determined that its reportable segments are OneBeacon, Sirius Group, and Other Operations.

 White Mountains has made its segment determination based on consideration of the following criteria: (i) the nature of the business activities of each of the Company’s subsidiaries and affiliates; (ii) the manner in which the Company’s subsidiaries and affiliates are organized; (iii) the existence of primary managers responsible for specific subsidiaries and affiliates; and (iv) the organization of information provided to the chief operating decision makers and the Board of Directors.

 Significant intercompany transactions among White Mountains’ segments have been eliminated herein. Financial information for White Mountains’ segments follows:

Millions	OneBeacon			Sirius Group			Other Operations		Total
Three Months Ended September 30, 2012
Earned insurance and reinsurance premiums	$	293.9		$	242.9		$	—	$	536.8
Net investment income	12.8			16.7			8.1		37.6
Net realized and unrealized investment gains (losses)	40.0			(8.9		)	41.6		72.7
Other revenue	(.4		)	48.2			2.5		50.3
Total revenues	346.3			298.9			52.2		697.4
Losses and loss adjustment expenses	164.7			143.4			—		308.1
Insurance and reinsurance acquisition expenses	66.6			41.0			—		107.6
Other underwriting expenses	47.4			29.1			.1		76.6
General and administrative expenses	4.4			10.2			44.1		58.7
Interest expense on debt	4.1			6.5			.7		11.3
Total expenses	287.2			230.2			44.9		562.3
Pre-tax income	$	59.1		$	68.7		$	7.3	$	135.1

Millions	OneBeacon			Sirius Group			Other Operations			Total
Three Months Ended September 30, 2011
Earned insurance and reinsurance premiums	$	259.1		$	232.0		$	—		$	491.1
Net investment income	16.1			22.1			4.6			42.8
Net realized and unrealized investment gains (losses)	(47.4		)	65.9			(15.6		)	2.9
Other revenue	.1			(29.3		)	(5.8		)	(35.0		)
Total revenues	227.9			290.7			(16.8		)	501.8
Losses and loss adjustment expenses	149.7			130.5			—			280.2
Insurance and reinsurance acquisition expenses	58.6			48.4			—			107.0
Other underwriting expenses	36.0			28.3			—			64.3
General and administrative expenses	2.5			7.4			26.3			36.2
Interest expense on debt	4.1			6.5			2.2			12.8
Total expenses	250.9			221.1			28.5			500.5
Pre-tax (loss) income	$	(23.0	)	$	69.6		$	(45.3	)	$	1.3

Millions	OneBeacon			Sirius Group		Other Operations			Total
Nine Months Ended September 30, 2012
Earned insurance and reinsurance premiums	$	846.0		$	699.3	$	—		$	1,545.3
Net investment income	41.5			50.9		27.4			119.8
Net realized and unrealized investment gains (losses)	57.9			22.9		42.4			123.2
Other revenue	(.1		)	48.9		32.2			81.0
Total revenues	945.3			822.0		102.0			1,869.3
Losses and loss adjustment expenses	452.5			369.2		—			821.7
Insurance and reinsurance acquisition expenses	185.6			140.6		—			326.2
Other underwriting expenses	146.2			82.1		.1			228.4
General and administrative expenses	9.6			35.4		101.3			146.3
Interest expense on debt	12.2			19.6		1.3			33.1
Total expenses	806.1			646.9		102.7			1,555.7
Pre-tax income (loss)	$	139.2		$	175.1	$	(.7	)	$	313.6

Millions	OneBeacon			Sirius Group			Other Operations			Total
Nine Months Ended September 30, 2011
Earned insurance and reinsurance premiums	$	748.0		$	685.5		$	—		$	1,433.5
Net investment income	55.8			68.3			14.0			138.1
Net realized and unrealized investment gains (losses)	(13.3		)	60.7			(11.0		)	36.4
Other revenue	(12.2		)	(13.8		)	(2.3		)	(28.3		)
Total revenues	778.3			800.7			.7			1,579.7
Losses and loss adjustment expenses	421.3			499.1			—			920.4
Insurance and reinsurance acquisition expenses	161.5			135.1			—			296.6
Other underwriting expenses	124.5			79.4			—			203.9
General and administrative expenses	7.4			23.3			89.7			120.4
Interest expense on debt	16.4			19.6			2.8			38.8
Total expenses	731.1			756.5			92.5			1,580.1
Pre-tax income (loss)	$	47.2		$	44.2		$	(91.8	)	$	(.4	)