Segment Information

12 Months Ended

Dec. 31, 2012

Disclosure - Segment Reporting [Abstract]

Segment Information

20. Segment Information

The Company monitors the performance of its operations in three segments, Non-life, Life and Corporate and Other. The Non-life segment is further divided into four sub-segments: North America, Global (Non-U.S.) P&C, Global (Non-U.S.) Specialty and Catastrophe. Segments and sub-segments represent markets that are reasonably homogeneous in terms of geography, client types, buying patterns, underlying risk patterns and approach to risk management.

The North America sub-segment includes agriculture, casualty, motor, multiline, property, surety and other risks generally originating in the United States. The Global (Non-U.S.) P&C sub-segment includes casualty, motor and property business generally originating outside of the United States. The Global (Non-U.S.) Specialty sub-segment is comprised of business that is generally considered to be specialized due to the sophisticated technical underwriting required to analyze risks, and is global in nature. This sub-segment consists of several lines of business for which the Company believes it has developed specialized knowledge and underwriting capabilities. These lines of business include agriculture, aviation/space, credit/surety, energy, engineering, marine, specialty casualty, specialty property and other lines. The Catastrophe sub-segment is comprised of the Company's catastrophe line of business. The Life segment includes mortality, longevity and accident and health lines of business. Corporate and Other is comprised of the capital markets and investment related activities of the Company, including principal finance transactions, insurance-linked securities and strategic investments, and its corporate activities, including other operating expenses.

Because the Company does not manage its assets by segment, net investment income is not allocated to the Non-life segment. However, because of the interest-sensitive nature of some of the Company's Life products, net investment income is considered in Management's assessment of the profitability of the Life segment. The following items are not considered in evaluating the results of the Non-life and Life segments: net realized and unrealized investment gains and losses, interest expense, amortization of intangible assets, net foreign exchange gains and losses, income tax expense or benefit and interest in earnings and losses of equity investments. Segment results are shown before consideration of intercompany transactions.

Management measures results for the Non-life segment on the basis of the loss ratio, acquisition ratio, technical ratio, other operating expense ratio and combined ratio (all defined below). Management measures results for the Non-life sub-segments on the basis of the loss ratio, acquisition ratio and technical ratio. Management measures results for the Life segment on the basis of the allocated underwriting result, which includes revenues from net premiums earned, other income or loss and allocated net investment income for Life, and expenses from life policy benefits, acquisition costs and other operating expenses.

The following tables provide a summary of the segment results for the years endedDecember 31, 2012, 2011 and 2010 (in millions of U.S. dollars, except ratios):

Segment Information
For the year ended December 31, 2012
					Global			Global						Total
		North			(Non-U.S.)			(Non-U.S.)						Non-life			Life		Corporate
		America			P&C			Specialty			Catastrophe			segment			segment		and Other		Total
Gross premiums written		$	1,221		$	684		$	1,505		$	500		$	3,910		$	802	$	6	$	4,718
Net premiums written		$	1,219		$	681		$	1,415		$	453		$	3,768		$	799	$	6	$	4,573
(Increase) decrease in unearned premiums			(43)			(3)			(42)			4			(84)			(4)		1		(87)
Net premiums earned		$	1,176		$	678		$	1,373		$	457		$	3,684		$	795	$	7	$	4,486
Losses and loss expenses and
life policy benefits			(816)			(415)			(821)			(103)			(2,155)			(647)		(3)		(2,805)
Acquisition costs			(291)			(167)			(321)			(42)			(821)			(116)		0		(937)
Technical result		$	69		$	96		$	231		$	312		$	708		$	32	$	4	$	744
Other income															5			4		3		12
Other operating expenses															(257)			(52)		(102)		(411)
Underwriting result														$	456		$	(16)		n/a	$	345
Net investment income																		64		507		571
Allocated underwriting result	(1)																$	48		n/a		n/a
Net realized and unrealized investment gains																				494		494
Interest expense																				(49)		(49)
Amortization of intangible assets																				(32)		(32)
Net foreign exchange losses																				0		0
Income tax expense																				(204)		(204)
Interest in earnings of equity investments																				10		10
Net income																				n/a	$	1,135
Loss ratio (2)			69.4	%		61.3	%		59.8	%		22.4	%		58.5	%
Acquisition ratio (3)			24.7			24.6			23.4			9.3			22.3
Technical ratio (4)			94.1	%		85.9	%		83.2	%		31.7	%		80.8	%
Other operating expense ratio (5)															7.0
Combined ratio (6)															87.8	%

_______________

(1)       Allocated underwriting result is defined as net premiums earned, other income or loss and allocated net investment income less life policy benefits, acquisition costs and other operating expenses.

(2)       Loss ratio is obtained by dividing losses and loss expenses by net premiums earned.

(3)       Acquisition ratio is obtained by dividing acquisition costs by net premiums earned.

(4)       Technical ratio is defined as the sum of the loss ratio and the acquisition ratio.

(5)       Other operating expense ratio is obtained by dividing other operating expenses by net premiums earned.

(6)       Combined ratio is defined as the sum of the technical ratio and the other operating expense ratio.

Segment Information
For the year ended December 31, 2011
				Global			Global						Total
	North			(Non-U.S.)			(Non-U.S.)						Non-life			Life		Corporate
	America			P&C			Specialty			Catastrophe			segment			segment		and Other		Total
Gross premiums written	$	1,104		$	682		$	1,446		$	599		$	3,831		$	790	$	12	$	4,633
Net premiums written	$	1,104		$	678		$	1,344		$	562		$	3,688		$	786	$	12	$	4,486
Decrease in unearned premiums		31			81			32			12			156			6		0		162
Net premiums earned	$	1,135		$	759		$	1,376		$	574		$	3,844		$	792	$	12	$	4,648
Losses and loss expenses and
life policy benefits		(741)			(567)			(950)			(1,459)			(3,717)			(650)		(6)		(4,373)
Acquisition costs		(276)			(191)			(328)			(26)			(821)			(117)		0		(938)
Technical result	$	118		$	1		$	98		$	(911)		$	(694)		$	25	$	6	$	(663)
Other income														4			1		3		8
Other operating expenses														(283)			(53)		(99)		(435)
Underwriting result													$	(973)		$	(27)		n/a	$	(1,090)
Net investment income																	66		563		629
Allocated underwriting result																$	39		n/a		n/a
Net realized and unrealized investment gains																			67		67
Interest expense																			(49)		(49)
Amortization of intangible assets																			(36)		(36)
Net foreign exchange gains																			34		34
Income tax expense																			(69)		(69)
Interest in losses of equity investments																			(6)		(6)
Net loss																			n/a	$	(520)
Loss ratio		65.3	%		74.7	%		69.1	%		254.2	%		96.7	%
Acquisition ratio		24.3			25.1			23.8			4.5			21.3
Technical ratio		89.6	%		99.8	%		92.9	%		258.7	%		118.0	%
Other operating expense ratio														7.4
Combined ratio														125.4	%

Segment Information
For the year ended December 31, 2010
				Global			Global						Total
	North			(Non-U.S.)			(Non-U.S.)						Non-life			Life		Corporate
	America			P&C			Specialty			Catastrophe			segment			segment		and Other		Total
Gross premiums written	$	1,028		$	909		$	1,479		$	716		$	4,132		$	749	$	4	$	4,885
Net premiums written	$	1,026		$	898		$	1,391		$	646		$	3,961		$	742	$	2	$	4,705
Decrease in unearned premiums		12			16			14			26			68			2		1		71
Net premiums earned	$	1,038		$	914		$	1,405		$	672		$	4,029		$	744	$	3	$	4,776
Losses and loss expenses and
life policy benefits		(577)			(702)			(985)			(393)			(2,657)			(624)		(3)		(3,284)
Acquisition costs		(288)			(227)			(292)			(49)			(856)			(116)		0		(972)
Technical result	$	173		$	(15)		$	128		$	230		$	516		$	4	$	0	$	520
Other income														5			2		3		10
Other operating expenses														(317)			(57)		(166)		(540)
Underwriting result													$	204		$	(51)		n/a	$	(10)
Net investment income																	71		602		673
Allocated underwriting result																$	20		n/a		n/a
Net realized and unrealized investment gains																			402		402
Interest expense																			(44)		(44)
Amortization of intangible assets																			(31)		(31)
Net foreign exchange losses																			(21)		(21)
Income tax expense																			(129)		(129)
Interest in earnings of equity investments																			13		13
Net income																			n/a	$	853
Loss ratio		55.6	%		76.8	%		70.0	%		58.5	%		65.9	%
Acquisition ratio		27.8			24.9			20.8			7.2			21.3
Technical ratio		83.4	%		101.7	%		90.8	%		65.7	%		87.2	%
Other operating expense ratio														7.8
Combined ratio														95.0	%

The following table provides the distribution of net premiums written by line of business for the years ended December 31, 2012, 2011 and 2010:

			2012		2011		2010
Non-life
	Property and casualty
		Casualty	13	%	11	%	11	%
		Motor	5		5		7
		Multiline and other	3		2		2
		Property	14		15		18
	Specialty
		Agriculture	7		7		4
		Aviation/Space	5		5		5
		Catastrophe	10		13		14
		Credit/Surety	7		7		6
		Energy	2		2		2
		Engineering	4		4		4
		Marine	7		6		6
		Specialty casualty	2		2		3
		Specialty property	4		3		2
Life			17		18		16
Total			100	%	100	%	100	%

The following table provides the geographic distribution of gross premiums written based on the location of the underlying risk for the years ended December 31, 2012, 2011 and 2010:

	2012		2011		2010
Europe	41	%	41	%	43	%
North America	37		36		36
Asia, Australia and New Zealand	11		12		10
Latin America, Caribbean and Africa	11		11		11
Total	100	%	100	%	100	%

The Company produces its business both through brokers and through direct relationships with insurance company clients. None of the Company's cedants accounted for more than 5% of total gross premiums written during the years ended December 31, 2012, 2011 and 2010.

The Company had two brokers that individually accounted for 10% or more of its gross premiums written during the years ended December 31, 2012, 2011 and 2010. The brokers accounted for 24%, 26%, and 25% and 22%, 21%, and 21% of gross premiums written for the years ended December 31, 2012, 2011 and 2010, respectively.

The following table summarizes the percentage of gross premiums written through these two brokers by segment and sub-segment for the years ended December 31, 2012, 2011 and 2010:

		2012		2011		2010
Non-life
	North America	70	%	64	%	77	%
	Global (Non-U.S.) P&C	28		29		32
	Global (Non-U.S.) Specialty	42		43		37
	Catastrophe	74		81		70
Life		13		16		15