Consolidated Statements Of Changes In Shareholders' Equity (USD $) In Millions	Total	Common Stock [Member]	Capital Surplus [Member]	Accumulated Other Comprehensive Loss [Member]	Retained Earnings [Member]	Treasury Stock [Member]
BALANCE at Dec. 31, 2010	$ 5,793	$ 1,019	$ 1,481	$ (389)	$ 5,247	$ (1,565)
BALANCE (in shares) at Dec. 31, 2010		176.5
Net income	199				199
Other comprehensive income, net of tax	81			81
Cash dividends declared on common stock	(35)				(35)
Purchase of common stock	(21)					(21)
Purchase of common stock (in shares)		(0.5)
Net issuance of common stock under employee stock plans	0		(30)		(16)	46
Net issuance of common stock under employee stock plans (in shares)		0.8
Share-based compensation	21		21
BALANCE at Jun. 30, 2011	6,038	1,019	1,472	(308)	5,395	(1,540)
BALANCE (in shares) at Jun. 30, 2011		176.8
BALANCE at Dec. 31, 2011	6,868	1,141	2,170	(356)	5,546	(1,633)
BALANCE (in shares) at Dec. 31, 2011		197.3
Net income	274				274
Other comprehensive income, net of tax	55			55
Cash dividends declared on common stock	(49)				(49)
Purchase of common stock	(125)					(125)
Purchase of common stock (in shares)		(4.1)
Net issuance of common stock under employee stock plans	(16)		(49)		(27)	60
Net issuance of common stock under employee stock plans (in shares)		1.1
Share-based compensation	21		21
Other	0		2			(2)
Other (in shares)		0
BALANCE at Jun. 30, 2012	$ 7,028	$ 1,141	$ 2,144	$ (301)	$ 5,744	$ (1,700)
BALANCE (in shares) at Jun. 30, 2012		194.3