Invested Assets (Tables)

6 Months Ended

Jun. 30, 2012

Invested Assets [Abstract]

Amortized cost and fair value of fixed maturities and equity securities

	June 30, 2012
	Amortized Cost		Gross Unrealized Appreciation		Gross Unrealized Depreciation		Fair Value
	(in millions)
Fixed maturities
Tax exempt	$	18,779	$	1,509	$	28	$	20,260
Taxable
U.S. government and government agency and authority obligations		1,006		71		1		1,076
Corporate bonds		6,591		503		10		7,084
Foreign government and government agency obligations		6,276		385		1		6,660
Residential mortgage-backed securities		579		34		3		610
Commercial mortgage-backed securities		1,744		80		1		1,823
		16,196		1,073		16		17,253
Total fixed maturities	$	34,975	$	2,582	$	44	$	37,513
Equity securities	$	1,261	$	362	$	40	$	1,583

	December 31, 2011
	Amortized Cost		Gross Unrealized Appreciation		Gross Unrealized Depreciation		Fair Value
	(in millions)
Fixed maturities	$	18,786	$	1,462	$	37	$	20,211
Tax exempt
Taxable
U.S. government and government agency and authority obligations		813		57		2		868
Corporate bonds		6,049		440		24		6,465
Foreign government and government agency obligations		6,409		416		2		6,823
Residential mortgage-backed securities		821		41		7		855
Commercial mortgage-backed securities		1,884		79		1		1,962
		15,976		1,033		36		16,973
Total fixed maturities	$	34,762	$	2,495	$	73	$	37,184
Equity securities	$	1,264	$	319	$	71	$	1,512

Fair value and amortized cost of fixed maturities by contractual maturity

	Fair Value		Amortized Cost
	(in millions)
Due in one year or less	$	2,353	$	2,326
Due after one year through five years		12,565		11,919
Due after five years through ten years		12,380		11,210
Due after ten years		7,782		7,197
		35,080		32,652
Residential mortgage-backed securities		610		579
Commercial mortgage-backed securities		1,823		1,744
	$	37,513	$	34,975

Components of unrealized appreciation or depreciation of investments

	June 30 2012		December 31 2011
	(in millions)
Fixed maturities
Gross unrealized appreciation	$	2,582	$	2,495
Gross unrealized depreciation		44		73
		2,538		2,422
Equity securities
Gross unrealized appreciation		362		319
Gross unrealized depreciation		40		71
		322		248
		2,860		2,670
Deferred income tax liability		1,001		934
	$	1,859	$	1,736

Fair value and gross unrealized depreciation of investments in an unrealized loss position

	Less Than 12 Months				12 Months or More				Total
	Fair Value		Gross Unrealized Depreciation		Fair Value		Gross Unrealized Depreciation		Fair Value		Gross Unrealized Depreciation
	(in millions)
Fixed maturities
Tax exempt	$	302	$	2	$	141	$	26	$	443	$	28
Taxable
U.S. government and government agency and authority obligations		75		—		19		1		94		1
Corporate bonds		335		4		68		6		403		10
Foreign government and government agency obligations		111		1		13		—		124		1
Residential mortgage-backed securities		6		—		35		3		41		3
Commercial mortgage-backed securities		69		1		1		—		70		1
		596		6		136		10		732		16
Total fixed maturities		898		8		277		36		1,175		44
Equity securities		202		29		41		11		243		40
	$	1,100	$	37	$	318	$	47	$	1,418	$	84

	Less Than 12 Months				12 Months or More				Total
	Fair Value		Gross Unrealized Depreciation		Fair Value		Gross Unrealized Depreciation		Fair Value		Gross Unrealized Depreciation
	(in millions)
Fixed maturities
Tax exempt	$	81	$	1	$	240	$	36	$	321	$	37
Taxable
U.S. government and government agency and authority obligations		19		1		18		1		37		2
Corporate bonds		489		14		176		10		665		24
Foreign government and government agency obligations		499		1		21		1		520		2
Residential mortgage-backed securities		77		2		22		5		99		7
Commercial mortgage-backed securities		34		1		—		—		34		1
		1,118		19		237		17		1,355		36
Total fixed maturities		1,199		20		477		53		1,676		73
Equity securities		231		45		199		26		430		71
	$	1,430	$	65	$	676	$	79	$	2,106	$	144

Change in unrealized appreciation or depreciation of investments carried at fair value

	Periods Ended June 30
	Second Quarter					Six Months
	2012			2011		2012		2011
	(in millions)
Change in unrealized appreciation of fixed maturities	$	133		$	430	$	116	$	253
Change in unrealized appreciation of equity securities		(28	)		15		74		106
		105			445		190		359
Deferred income tax		37			156		67		126
	$	68		$	289	$	123	$	233

Realized investment gains and losses

	Periods Ended June 30
	Second Quarter						Six Months
	2012			2011			2012			2011
	(in millions)
Fixed maturities
Gross realized gains	$	24		$	10		$	62		$	23
Gross realized losses		(7	)		(4	)		(10	)		(15	)
Other-than-temporary impairment losses		(1	)		—			(2	)		—
		16			6			50			8
Equity securities
Gross realized gains		6			10			25			29
Gross realized losses		—			(1	)		—			(1	)
Other-than-temporary impairment losses		(30	)		(14	)		(35	)		(16	)
		(24	)		(5	)		(10	)		12
Other invested assets		55			68			63			209
	$	47		$	69		$	103		$	229