Fair Values of Financial Instruments (Tables)

12 Months Ended

Dec. 31, 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:

	December 31
	2013				2012
	Carrying Value		Fair Value		Carrying Value		Fair Value
	(in millions)
Assets
Invested assets
Short term investments	$	2,114	$	2,114	$	2,528	$	2,528
Fixed maturities (Note 2)		37,091		37,091		38,076		38,076
Equity securities		1,810		1,810		1,663		1,663
Other invested assets		—		—		46		46
Liabilities
Long term debt (Note 6)		3,300		3,806		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:

	December 31, 2013
	Level 1		Level 2		Level 3		Total
	(in millions)
Assets
Short term investments	$	399	$	1,715	$	—	$	2,114
Fixed maturities
Tax exempt		—		18,416		5		18,421
Taxable
U.S. government and government agency and authority obligations		—		802		—		802
Corporate bonds		—		9,179		135		9,314
Foreign government and government agency obligations		—		6,881		9		6,890
Residential mortgage-backed securities		—		293		6		299
Commercial mortgage-backed securities		—		1,345		20		1,365
		—		18,500		170		18,670
Total fixed maturities		—		36,916		175		37,091
Equity securities		1,803		—		7		1,810
	$	2,202	$	38,631	$	182	$	41,015
Liabilities
Long term debt	$	—	$	3,806	$	—	$	3,806

	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

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, 2013
	Level 1		Level 2		Level 3		Total
	(in millions)
Short term investments	$	—	$	37	$	—	$	37
Fixed maturities
U.S. government and government agency and authority obligations		—		224		—		224
Corporate bonds		—		370		1		371
Foreign government and government agency obligations		—		104		—		104
Mortgage-backed securities		—		211		6		217
Total fixed maturities		—		909		7		916
Equity securities		573		1,145		—		1,718
Other assets		21		14		11		46
	$	594	$	2,105	$	18	$	2,717

	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