Fair Value Measurements (tables)

9 Months Ended

Sep. 30, 2015

Fair Value Measurements disclosure

Level within the fair value hierarchy at which the Company's financial assets and financial liabilities reported at fair value are measured [Table Text Block]

(at September 30, 2015, in millions)	Total		Level 1		Level 2		Level 3
Invested assets:
Fixed maturities
U.S. Treasury securities and obligations of U.S. government and government agencies and authorities	$	2,345	$	2,345	$	—	$	—
Obligations of states, municipalities and political subdivisions	31,627		25		31,588		14
Debt securities issued by foreign governments	1,989		—		1,989		—
Mortgage-backed securities, collateralized mortgage obligations and pass-through securities	2,013		—		1,979		34
All other corporate bonds	23,582		101		23,266		215
Redeemable preferred stock	115		4		104		7
Total fixed maturities	61,671		2,475		58,926		270
Equity securities
Public common stock	544		544		—		—
Non-redeemable preferred stock	175		63		112		—
Total equity securities	719		607		112		—
Other investments	56		17		—		39
Total	$	62,446	$	3,099	$	59,038	$	309

(at December 31, 2014, in millions)	Total		Level 1		Level 2		Level 3
Invested assets:
Fixed maturities
U.S. Treasury securities and obligations of U.S. government and government agencies and authorities	$	2,053	$	2,049	$	4	$	—
Obligations of states, municipalities and political subdivisions	33,573		—		33,560		13
Debt securities issued by foreign governments	2,368		—		2,368		—
Mortgage-backed securities, collateralized mortgage obligations and pass-through securities	2,213		—		2,203		10
All other corporate bonds	23,135		—		22,934		201
Redeemable preferred stock	132		2		122		8
Total fixed maturities	63,474		2,051		61,191		232
Equity securities
Public common stock	691		691		—		—
Non-redeemable preferred stock	208		82		126		—
Total equity securities	899		773		126		—
Other investments	55		19		—		36
Total	$	64,428	$	2,843	$	61,317	$	268

Carrying value and fair value of financial instruments disclosed, but not carried, at fair value and the level within the fair value hierarchy at which such financial instruments are categorized [Table Text Block]

(at September 30, 2015, in millions)	Carrying Value		Fair Value		Level 1		Level 2		Level 3
Financial assets:
Short-term securities	$	5,128	$	5,128	$	1,943	$	3,148	$	37
Financial liabilities:
Debt	$	6,643	$	7,623	$	—	$	7,623	$	—
Commercial paper	$	100	$	100	$	—	$	100	$	—

(at December 31, 2014, in millions)	Carrying Value		Fair Value		Level 1		Level 2		Level 3
Financial assets:
Short-term securities	$	4,364	$	4,364	$	1,283	$	3,042	$	39
Financial liabilities:
Debt	$	6,249	$	7,522	$	—	$	7,522	$	—
Commercial paper	$	100	$	100	$	—	$	100	$	—