Consolidated Statements Of Shareholders' Equity (USD $) In Millions	Total	Common Stock [Member]	Treasury Stock [Member]	Additional Paid-in Capital [Member]	Retained Earnings [Member]	Accumulated Net Unrealized Investment Gain (Loss) [Member]	Accumulated Translation Adjustment [Member]	Accumulated Defined Benefit Plans Adjustment [Member]	Accumulated Other Comprehensive Income (Loss) [Member]
Balance - beginning of period at Dec. 31, 2012		$ 9,591	$ (159)	$ 5,179	$ 10,033	$ 2,633	$ 339	$ (85)
Dividends declared on Common Shares – par value reduction		(342)
Common Shares repurchased			(212)
Net shares redeemed under employee share-based compensation plans			152	(128)
Exercise of stock options				(28)
Share-based compensation expense and other				105
Funding of dividends declared to Retained earnings				0
Net income	1,844				1,844
Funding of dividends declared from Additional paid-in capital					0
Dividends declared on Common Shares					0
Change in period, before reclassification from AOCI, net of income tax (expense) benefit of $(210) and $332						(1,254)
Amounts reclassified from AOCI, net of income tax benefit of $2 and $12						(61)
Change in period, net of income tax (expense) benefit of $(208) and $344						(1,315)
Change in period, net of income tax (expense) benefit of $(42) and $62							(324)
Change in period, net of income tax (expense) benefit of $5 and $(7)								12
Balance - end of period at Jun. 30, 2013	27,295	9,249	(219)	5,128	11,877	1,318	15	(73)	1,260
Balance - beginning of period at Dec. 31, 2013	28,825	8,899	(255)	5,238	13,791	1,174	63	(85)
Dividends declared on Common Shares – par value reduction		(398)
Common Shares repurchased			(569)
Net shares redeemed under employee share-based compensation plans			194	(169)
Exercise of stock options				(33)
Share-based compensation expense and other				100
Funding of dividends declared to Retained earnings				(81)
Net income	1,513				1,513
Funding of dividends declared from Additional paid-in capital					81
Dividends declared on Common Shares					(81)
Change in period, before reclassification from AOCI, net of income tax (expense) benefit of $(210) and $332						898
Amounts reclassified from AOCI, net of income tax benefit of $2 and $12						(25)
Change in period, net of income tax (expense) benefit of $(208) and $344						873
Change in period, net of income tax (expense) benefit of $(42) and $62							78
Change in period, net of income tax (expense) benefit of $5 and $(7)								(8)
Balance - end of period at Jun. 30, 2014	$ 30,325	$ 8,501	$ (630)	$ 5,055	$ 15,304	$ 2,047	$ 141	$ (93)	$ 2,095