Fair Values of Financial Instruments (Tables)

12 Months Ended

Dec. 31, 2012

Carrying Values and Fair Values of Financial Instruments

The carrying values and fair values of financial instruments were as follows:

	December 31
	2012				2011
	Carrying Value		Fair Value		Carrying Value		Fair Value
	(in millions)
Assets
Invested assets
Short term investments	$	2,528	$	2,528	$	1,893	$	1,893
Fixed maturities (Note 3)		38,076		38,076		37,184		37,184
Equity securities		1,663		1,663		1,512		1,512
Other invested assets		46		46		27		27
Liabilities
Long term debt (Note 7)		3,575		4,372		3,575		4,085

Fair Values of Financial Instruments Categorized Based Upon Lowest Level of Input

The fair value of financial instruments categorized based upon the lowest level of input that was significant to the fair value measurement was as follows:

	December 31, 2012
	Level 1		Level 2		Level 3		Total
	(in millions)
Assets
Short term investments	$	182	$	2,346	$	—	$	2,528
Fixed maturities
Tax exempt		—		19,907		6		19,913
Taxable
U.S. government and government agency and authority obligations		—		1,039		—		1,039
Corporate bonds		—		7,779		158		7,937
Foreign government and government agency obligations		—		7,008		—		7,008
Residential mortgage-backed securities		—		446		9		455
Commercial mortgage-backed securities		—		1,724		—		1,724
		—		17,996		167		18,163
Total fixed maturities		—		37,903		173		38,076
Equity securities		1,655		—		8		1,663
Other invested assets		—		—		46		46
	$	1,837	$	40,249	$	227	$	42,313
Liabilities
Long term debt	$	—	$	4,372	$	—	$	4,372

	December 31, 2011
	Level 1		Level 2		Level 3		Total
	(in millions)
Assets
Short term investments	$	117	$	1,776	$	—	$	1,893
Fixed maturities
Tax exempt		—		20,203		8		20,211
Taxable
U.S. government and government agency and authority obligations		—		868		—		868
Corporate bonds		—		6,313		152		6,465
Foreign government and government agency obligations		—		6,820		3		6,823
Residential mortgage-backed securities		—		845		10		855
Commercial mortgage-backed securities		—		1,962		—		1,962
		—		16,808		165		16,973
Total fixed maturities		—		37,011		173		37,184
Equity securities		1,504		—		8		1,512
Other invested assets		—		—		27		27
	$	1,621	$	38,787	$	208	$	40,616
Liabilities
Long term debt	$	—	$	4,085	$	—	$	4,085

Fair Values of Pension Plan Assets Categorized Based Upon Lowest Level of Input

Based on the fair value hierarchy, the fair value of the Corporation’s pension plan assets categorized based upon the lowest level of input that was significant to the fair value measurement was as follows:

	December 31, 2012
	Level 1		Level 2		Level 3		Total
	(in millions)
Short term investments	$	—	$	33	$	—	$	33
Fixed maturities
U.S. government and government agency and authority obligations		—		238		1		239
Corporate bonds		—		321		—		321
Foreign government and government agency obligations		—		79		1		80
Mortgage-backed securities		—		174		—		174
Total fixed maturities		—		812		2		814
Equity securities		457		947		—		1,404
Other assets		29		9		16		54
	$	486	$	1,801	$	18	$	2,305

	December 31, 2011
	Level 1		Level 2		Level 3		Total
	(in millions)
Short term investments	$	—	$	45	$	—	$	45
Fixed maturities
U.S. government and government agency and authority obligations		—		204		3		207
Corporate bonds		—		289		1		290
Foreign government and government agency obligations		—		61		1		62
Mortgage-backed securities		—		175		1		176
Total fixed maturities		—		729		6		735
Equity securities		336		838		—		1,174
Other assets		21		8		18		47
	$	357	$	1,620	$	24	$	2,001