Investments (Tables)

12 Months Ended

Dec. 31, 2011

Investments [Abstract]

Schedule Of Amortized Cost And Fair Value Of Fixed Maturities And Related OTTI Recognized In AOCI

December 31, 2011 (in millions of U.S. dollars)	Amortized Cost		Gross Unrealized Appreciation		Gross Unrealized Depreciation			Fair Value		OTTI Recognized in AOCI
Available for sale
U.S. Treasury and agency	$	2,774	$	186	$	–		$	2,960	$	–
Foreign		12,025		475		(99	)		12,401		(2	)
Corporate securities		14,055		773		(135	)		14,693		(22	)
Mortgage-backed securities		9,979		397		(175	)		10,201		(151	)
States, municipalities, and political subdivisions		1,617		96		(1	)		1,712		–
	$	40,450	$	1,927	$	(410	)	$	41,967	$	(175	)
Held to maturity
U.S. Treasury and agency	$	1,078	$	48	$	–		$	1,126	$	–
Foreign		935		18		(23	)		930		–
Corporate securities		2,338		44		(45	)		2,337		–
Mortgage-backed securities		2,949		90		(3	)		3,036		–
States, municipalities, and political subdivisions		1,147		32		(3	)		1,176		–
	$	8,447	$	232	$	(74	)	$	8,605	$	–

December 31, 2010 (in millions of U.S. dollars)	Amortized Cost		Gross Unrealized Appreciation		Gross Unrealized Depreciation			Fair Value		OTTI Recognized in AOCI
Available for sale
U.S. Treasury and agency	$	2,904	$	74	$	(15	)	$	2,963	$	–
Foreign		10,926		340		(80	)		11,186		(28	)
Corporate securities		12,902		754		(69	)		13,587		(29	)
Mortgage-backed securities		8,508		213		(205	)		8,516		(228	)
States, municipalities, and political subdivisions		1,302		15		(30	)		1,287		–
	$	36,542	$	1,396	$	(399	)	$	37,539	$	(285	)
Held to maturity
U.S. Treasury and agency	$	1,105	$	32	$	(10	)	$	1,127	$	–
Foreign		1,049		1		(37	)		1,013		–
Corporate securities		2,361		12		(60	)		2,313		–
Mortgage-backed securities		3,811		62		(27	)		3,846		–
States, municipalities, and political subdivisions		1,175		5		(18	)		1,162		–
	$	9,501	$	112	$	(152	)	$	9,461	$	–

Schedule Of Amortized Cost And Fair Value Of Fixed Maturities By Contractual Maturity

	December 31 2011				December 31 2010
(in millions of U.S. dollars)	Amortized Cost		Fair Value		Amortized Cost		Fair Value
Available for sale
Due in 1 year or less	$	2,321	$	2,349	$	1,846	$	1,985
Due after 1 year through 5 years		12,325		12,722		13,094		13,444
Due after 5 years through 10 years		12,379		12,995		10,276		10,782
Due after 10 years		3,446		3,700		2,818		2,812
		30,471		31,766		28,034		29,023
Mortgage-backed securities		9,979		10,201		8,508		8,516
	$	40,450	$	41,967	$	36,542	$	37,539
Held to maturity
Due in 1 year or less	$	393	$	396	$	400	$	404
Due after 1 year through 5 years		2,062		2,090		1,983		2,010
Due after 5 years through 10 years		2,376		2,399		2,613		2,524
Due after 10 years		667		684		694		677
		5,498		5,569		5,690		5,615
Mortgage-backed securities		2,949		3,036		3,811		3,846
	$	8,447	$	8,605	$	9,501	$	9,461

Schedule Of Cost And Fair Value Of Equity Securities

(in millions of U.S. dollars)	December 31 2011			December 31 2010
Cost	$	671		$	666
Gross unrealized appreciation		18			28
Gross unrealized depreciation		(42	)		(2	)
Fair value	$	647		$	692

Schedule Of Default Assumptions By Moody's Rating Category

Moody's Rating Category	1-in-100 Year Default Rate		Historical Mean Default Rate
Investment Grade:
Aaa-Baa		0.0-1.4%		0.0-0.3%
Below Investment Grade:
Ba		4.8%		1.1%
B		12.8%		3.4%
Caa-C		53.5%		13.9%

Schedule Of Significant Assumptions For Future Cash Flows For Mortgage Backed Securities

Range of Significant Assumptions Used
Sector(1)	Vintage		Default Rate(2)		Loss Severity Rate(2)
Prime		2003 and prior		16%		29%
		2004		17-42%		31-49%
		2005		25-45%		44-58%
		2006-2007		26-53%		43-58%
ALT-A		2003 and prior		23%		48%
		2004		33%		53%
		2005		30-47%		54-67%
		2006-2007		57-66%		61-72%
Sub-prime		2003 and prior		45%		62%
		2004		49%		76%
		2005		58%		78%
		2006-2007		70-78%		70-86%

⁽¹⁾ Prime, ALT-A, and Sub-prime sector bonds are categorized based on creditworthiness of the borrower.

⁽²⁾ Default rate and loss severity rate assumptions vary within a given sector and vintage depending upon the geographic concentration of the collateral underlying the bond and the level of serious delinquencies, among other factors.

Schedule Of Net Realized Gains (Losses) And The Losses Included In Net Realized Gains (Losses) And OCI

	Years Ended December 31
(in millions of U.S. dollars)	2011			2010			2009
Fixed maturities:
OTTI on fixed maturities, gross	$	(61	)	$	(115	)	$	(536	)
OTTI on fixed maturities recognized in OCI (pre-tax)		15			69			302
OTTI on fixed maturities, net		(46	)		(46	)		(234	)
Gross realized gains excluding OTTI		410			569			591
Gross realized losses excluding OTTI		(200	)		(143	)		(398	)
Total fixed maturities		164			380			(41	)
Equity securities:
OTTI on equity securities		(1	)		–			(26	)
Gross realized gains excluding OTTI		15			86			105
Gross realized losses excluding OTTI		(5	)		(2	)		(224	)
Total equity securities		9			84			(145	)
OTTI on other investments		(3	)		(13	)		(137	)
Foreign exchange losses		(13	)		(54	)		(21	)
Investment and embedded derivative instruments		(143	)		58			68
Fair value adjustments on insurance derivative		(779	)		(28	)		368
S&P put options and futures		(4	)		(150	)		(363	)
Other derivative instruments		(4	)		(19	)		(93	)
Other		(22	)		174			168
Net realized gains (losses)		(795	)		432			(196	)
Change in net unrealized appreciation (depreciation) on investments:
Fixed maturities available for sale		569			451			2,723
Fixed maturities held to maturity		(89	)		522			(6	)
Equity securities		(47	)		(44	)		213
Other		40			(35	)		162
Income tax expense		(157	)		(152	)		(481	)
Change in net unrealized appreciation on investments		316			742			2,611
Total net realized gains (losses) and change in net unrealized appreciation (depreciation) on investments	$	(479	)	$	1,174		$	2,415

Schedule Of Roll Forward Of Pre-Tax Credit Losses Related To Fixed Maturities For Which A Portion Of OTTI Was Recognized In OCI

	Years Ended December 31						Nine Months Ended December 31 2009
(in millions of U.S. dollars)	2011			2010
Balance of credit losses related to securities still held-beginning of period	$	137		$	174		$	130
Additions where no OTTI was previously recorded		12			34			104
Additions where an OTTI was previously recorded		8			12			11
Reductions reflecting amounts previously recorded in OCI but subsequently reflected in net income		–			–			(2	)
Reductions for securities sold during the period		(83	)		(83	)		(69	)
Balance of credit losses related to securities still held-end of period	$	74		$	137		$	174

Schedule Of Other Investments

	December 31 2011				December 31 2010
(in millions of U.S. dollars)	Fair Value		Cost		Fair Value		Cost
Investment funds	$	378	$	277	$	329	$	232
Limited partnerships		531		429		438		356
Partially-owned investment companies		904		904		688		688
Life insurance policies		127		127		118		118
Policy loans		143		143		54		54
Trading securities		194		195		37		35
Other		37		37		28		28
Total	$	2,314	$	2,112	$	1,692	$	1,511

Schedule Of Partially Owned Insurance Companies

	December 31 2011						December 31 2010
(in millions of U.S. dollars, except percentages)	Carrying Value		Issued Share Capital		Ownership Percentage		Carrying Value		Issued Share Capital		Ownership Percentage		Domicile
Freisenbruch-Meyer	$	8	$	5		40.0%	$	8	$	5		40.0%		Bermuda
ACE Cooperative Ins. Co. – Saudi Arabia		7		27		30.0%		7		27		30.0%		Saudi Arabia
Huatai Insurance Company		241		457		20.0%		229		207		21.3%		China
Huatai Life Insurance Company		118		196		20.0%		112		179		20.0%		China
Russian Reinsurance Company		2		4		23.3%		–		–		–		Russia
Island Heritage		4		27		10.8%		4		27		10.8%		Cayman Islands
Total	$	380	$	716			$	360	$	445

Schedule Of Aggregate Fair Value And Gross Unrealized Loss By Length Of Time The Security Has Continuously Been In An Unrealized Loss Position

	0 – 12 Months					Over 12 Months					Total
December 31, 2011 (in millions of U.S. dollars)	Fair Value		Gross Unrealized Loss			Fair Value		Gross Unrealized Loss			Fair Value		Gross Unrealized Loss
Foreign	$	1,801	$	(82.2	)	$	529	$	(40.0	)	$	2,330	$	(122.2	)
Corporate securities		3,084		(148.2	)		268		(32.2	)		3,352		(180.4	)
Mortgage-backed securities		440		(7.5	)		586		(170.2	)		1,026		(177.7	)
States, municipalities, and political subdivisions		30		(0.4	)		98		(3.5	)		128		(3.9	)
Total fixed maturities		5,355		(238.3	)		1,481		(245.9	)		6,836		(484.2	)
Equity securities		484		(42.3	)		–		–			484		(42.3	)
Other investments		88		(8.3	)		–		–			88		(8.3	)
Total	$	5,927	$	(288.9	)	$	1,481	$	(245.9	)	$	7,408	$	(534.8	)

	0 – 12 Months					Over 12 Months					Total
December 31, 2010 (in millions of U.S. dollars)	Fair Value		Gross Unrealized Loss			Fair Value		Gross Unrealized Loss			Fair Value		Gross Unrealized Loss
U.S. Treasury and agency	$	864	$	(24.6	)	$	–	$	–		$	864	$	(24.6	)
Foreign		4,409		(79.0	)		312		(37.6	)		4,721		(116.6	)
Corporate securities		3,553		(85.1	)		273		(43.9	)		3,826		(129.0	)
Mortgage-backed securities		3,904		(67.3	)		1,031		(165.1	)		4,935		(232.4	)
States, municipalities, and political subdivisions		1,115		(36.2	)		79		(11.9	)		1,194		(48.1	)
Total fixed maturities		13,845		(292.2	)		1,695		(258.5	)		15,540		(550.7	)
Equity securities		45		(1.9	)		1		(0.3	)		46		(2.2	)
Other investments		66		(8.7	)		–		–			66		(8.7	)
Total	$	13,956	$	(302.8	)	$	1,696	$	(258.8	)	$	15,652	$	(561.6	)

Schedule Of Sources Of Net Investment Income

	Years Ended December 31
(in millions of U.S. dollars)	2011			2010			2009
Fixed maturities	$	2,196		$	2,071		$	1,985
Short-term investments		43			34			38
Equity securities		36			26			54
Other		62			44			48
Gross investment income		2,337			2,175			2,125
Investment expenses		(95	)		(105	)		(94	)
Net investment income	$	2,242		$	2,070		$	2,031

Schedule Of Components Of Restricted Assets

(in millions of U.S. dollars)	December 31 2011		December 31 2010
Trust funds	$	9,940	$	8,200
Deposits with non-U.S. regulatory authorities		2,240		2,289
Deposits with U.S. regulatory authorities		1,307		1,384
Other pledged assets(1)		1,615		1,190
	$	15,102	$	13,063

⁽¹⁾ Includes restricted assets of $1.3 billion and $1.0 billion at December 31, 2011 and 2010, respectively, pledged under reverse repurchase agreements.