Consolidated Statements of Stockholders' Equity (USD $) In Millions, unless otherwise specified	Total	Common Stock	Additional Paid-In Capital	Retained Earnings	Treasury Stock, at cost	Accumulated Other Comprehensive Income (Loss)
Balance at Dec. 31, 2008	$ 4,061	$ 14	$ 2,214	$ 6,735	$ (4,349)	$ (553)
Balance (in shares) at Dec. 31, 2008		1,392
Comprehensive income:
Net Income	787			787
Other comprehensive income, net of tax:
Net unrealized (loss) gain on securities available for sale	362					362
Total comprehensive income	1,149
Dividends declared on common stock	(279)			(279)
Stock option exercises and other	52				52
Stock-based compensation and related tax effects	80		80
Other	10		4		6
Balance at Dec. 31, 2009	5,073	14	2,298	7,243	(4,291)	(191)
Balance (in shares) at Dec. 31, 2009		1,392
Comprehensive income:
Net Income	454			454
Other comprehensive income, net of tax:
Net unrealized (loss) gain on securities available for sale	208					208
Net unrealized loss on cash flow hedging instruments	(1)					(1)
Total comprehensive income	661
Issuance of common stock (in shares)		30
Issuance of common stock	543		543
Issuance of common stock for business acquisition (in shares)		7
Issuance of common stock for business acquisition	106		106
Dividends declared on common stock	(288)			(288)
Stock option exercises and other	35		(4)		39
Stock-based compensation and related tax effects	87		87
Other	9		4		5
Balance at Dec. 31, 2010	6,226	14	3,034	7,409	(4,247)	16
Balance (in shares) at Dec. 31, 2010		1,429
Comprehensive income:
Net Income	864			864
Other comprehensive income, net of tax:
Net unrealized (loss) gain on securities available for sale	(7)					(7)
Foreign currency translation adjustment	(1)					(1)
Total comprehensive income	856
Issuance of common stock for business acquisition (in shares)		59
Issuance of common stock for business acquisition	714	1	713
Dividends declared on common stock	(295)			(295)
Stock option exercises and other	98		(24)		122
Stock-based compensation and related tax effects	99		99
Other	16		4		12
Balance at Dec. 31, 2011	$ 7,714	$ 15	$ 3,826	$ 7,978	$ (4,113)	$ 8
Balance (in shares) at Dec. 31, 2011		1,488