Condensed Consolidated Statements of Changes in Shareholders' Equity (USD $) In Millions, unless otherwise specified	Total	Common Stock [Member]	Additional Paid-In Capital [Member]	Retained Earnings [Member]	Accumulated Net Unrealized Investment Gain (Loss) [Member] Accumulated Other Comprehensive Income (Loss) [Member]	Foreign Currency Gain (Loss) [Member] Accumulated Other Comprehensive Income (Loss) [Member]
Balance at Dec. 31, 2010	$ 25,825	$ 11	$ 0	$ 25,562	$ 280	$ (28)
Balance (in shares) at Dec. 31, 2010		1,086
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net earnings	1,346			1,346
Other Comprehensive Income (Loss), Unrealized Holding Gain (Loss) on Securities Arising During Period, Net of Tax	(23)				(54)
Other Comprehensive Income (Loss), Foreign Currency Transaction and Translation Gain (Loss) Arising During Period, Net of Tax	9					9
Other Comprehensive Income (Loss), Net of Tax	(45)
Issuances of common stock, and related tax benefits (in shares)		6
Issuances of common stock, and related tax benefits	61	0	61
Common stock repurchases (in shares)		(15)
Common stock repurchases	(620)	0	(200)	(420)
Share-based compensation, and related tax benefits	139		139
Common stock dividends	(135)			(135)
Balance at Mar. 31, 2011	26,571	11	0	26,353	226	(19)
Balance (in shares) at Mar. 31, 2011		1,077
Balance at Dec. 31, 2011	28,292	10	0	27,821	476	(15)
Balance (in shares) at Dec. 31, 2011	1,039	1,039
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net earnings	1,388			1,388
Other Comprehensive Income (Loss), Unrealized Holding Gain (Loss) on Securities Arising During Period, Net of Tax	19				(6)
Other Comprehensive Income (Loss), Foreign Currency Transaction and Translation Gain (Loss) Arising During Period, Net of Tax	3					3
Other Comprehensive Income (Loss), Net of Tax	(3)
Issuances of common stock, and related tax benefits (in shares)		13
Issuances of common stock, and related tax benefits	129	0	129
Common stock repurchases (in shares)		(19)
Common stock repurchases	(991)	0	(338)	(653)
Share-based compensation, and related tax benefits	209		209
Common stock dividends	(168)			(168)
Balance at Mar. 31, 2012	$ 28,856	$ 10	$ 0	$ 28,388	$ 470	$ (12)
Balance (in shares) at Mar. 31, 2012	1,033	1,033