Fair Values of Financial Instruments (Tables)

9 Months Ended

Sep. 30, 2013

Fair Value Disclosures [Abstract]

Carrying Values and Fair Values of Financial Instruments

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

	September 30, 2013				December 31, 2012
	Carrying Value		Fair Value		Carrying Value		Fair Value
	(in millions)
Assets
Invested assets
Short term investments	$	1,881	$	1,881	$	2,528	$	2,528
Fixed maturities		37,610		37,610		38,076		38,076
Equity securities		1,821		1,821		1,663		1,663
Other invested assets		—		—		46		46
Liabilities
Long term debt		3,300		3,834		3,575		4,372

Fair Value 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:

	September 30, 2013
	Level 1		Level 2		Level 3		Total
	(in millions)
Assets
Short term investments	$	209	$	1,672	$	—	$	1,881
Fixed maturities
Tax exempt		—		18,946		5		18,951
Taxable
U.S. government and government agency and authority obligations		—		818		—		818
Corporate bonds		—		9,031		129		9,160
Foreign government and government agency obligations		—		6,977		10		6,987
Residential mortgage-backed securities		—		318		6		324
Commercial mortgage-backed securities		—		1,327		43		1,370
		—		18,471		188		18,659
Total fixed maturities		—		37,417		193		37,610
Equity securities		1,814		—		7		1,821
	$	2,023	$	39,089	$	200	$	41,312
Liabilities
Long term debt	$	—	$	3,834	$	—	$	3,834

	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