Consolidated Statements of Shareholders' Equity (USD $) In Millions	Total	Preferred Stock [Member]	Common Stock [Member]	Paid-In Surplus [Member]	Retained Earnings [Member]	Unrealized Appreciation of Investments Including Unrealized Other-Than-Temporary Impairment Losses [Member]	Postretirement Benefit Costs Not Yet Recognized in Net Income [Member]	Foreign Currency Translation Gains [Member]	Accumulated Other Comprehensive Income [Member]	Treasury Stock, at Cost [Member]
Balance, Beginning of Year at Dec. 31, 2011			$ 372	$ 190	$ 18,903	$ 1,736	$ (687)	$ 146		$ (5,359)
Net Income	1,545				1,545
Repurchase of Shares										(935)
Changes Related to Stock-Based Employee Compensation (includes tax benefit of $17, $28 and $27)				(12)
Change During Year, Net of Tax	236					277	(30)	(11)
Dividends Declared (per share $2.00, $1.76 and $1.64)					(439)
Shares Issued Under Stock-Based Employee Compensation Plans										131
Balance, End of Year at Dec. 31, 2012	15,827		372	178	20,009	2,013	(717)	135	1,431	(6,163)
Net Income	2,345				2,345
Repurchase of Shares										(1,300)
Changes Related to Stock-Based Employee Compensation (includes tax benefit of $17, $28 and $27)				(7)
Change During Year, Net of Tax	(396)					(788)	464	(72)
Dividends Declared (per share $2.00, $1.76 and $1.64)					(452)
Shares Issued Under Stock-Based Employee Compensation Plans										80
Balance, End of Year at Dec. 31, 2013	16,097		372	171	21,902	1,225	(253)	63	1,035	(7,383)
Net Income	2,100				2,100
Repurchase of Shares										(1,555)
Changes Related to Stock-Based Employee Compensation (includes tax benefit of $17, $28 and $27)
Change During Year, Net of Tax	75					528	(336)	(117)
Dividends Declared (per share $2.00, $1.76 and $1.64)					(482)
Shares Issued Under Stock-Based Employee Compensation Plans										61
Balance, End of Year at Dec. 31, 2014	$ 16,296		$ 372	$ 171	$ 23,520	$ 1,753	$ (589)	$ (54)	$ 1,110	$ (8,877)