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, 2011		$ 10,095	$ (327)	$ 5,326	$ 7,327	$ 1,715	$ 258	$ (62)
Dividends declared on Common Shares-par value reduction		(336)
Common Shares repurchased			(7)
Net shares redeemed under employee share-based compensation plans			147	(102)
Exercise of stock options				(8)
Share-based compensation expense and other				93
Funding of dividends declared to Retained earnings				(200)
Net income	1,941				1,941
Funding of dividends declared from Additional paid-in capital					200
Dividends declared on Common Shares					(200)
Change in period, net of income tax benefit (expense) of $353 and $(234)						988
Change in period, net of income tax benefit (expense) of $27 and $(44)							118
Change in period, net of income tax benefit (expense) of $(6) and $2								(3)
Balance - end of period at Sep. 30, 2012	26,963	9,759	(187)	5,109	9,268	2,703	376	(65)	3,014
Balance - beginning of period at Dec. 31, 2012	27,531	9,591	(159)	5,179	10,033	2,633	339	(85)
Dividends declared on Common Shares-par value reduction		(518)
Common Shares repurchased			(233)
Net shares redeemed under employee share-based compensation plans			170	(129)
Exercise of stock options				(34)
Share-based compensation expense and other				184
Funding of dividends declared to Retained earnings				0
Net income	2,760				2,760
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 benefit of $337						(1,233)
Amounts reclassified from AOCI, net of income tax benefit of $16						(81)
Change in period, net of income tax benefit (expense) of $353 and $(234)						(1,314)
Change in period, net of income tax benefit (expense) of $27 and $(44)							(210)
Change in period, net of income tax benefit (expense) of $(6) and $2								11
Balance - end of period at Sep. 30, 2013	$ 28,218	$ 9,073	$ (222)	$ 5,200	$ 12,793	$ 1,319	$ 129	$ (74)	$ 1,374