Consolidated Statements Of Changes In Shareholders' Equity (USD $) In Millions, except Share data	Total		Common Stock	Capital Surplus	Accumulated Other Comprehensive Loss	Retained Earnings	Treasury Stock
BALANCE at Dec. 31, 2010	$ 5,793		$ 1,019	$ 1,481	$ (389)	$ 5,247	$ (1,565)
BALANCE (in shares) at Dec. 31, 2010			176,500,000
Net income	393					393
Other comprehensive income (loss), net of tax	33				33
Cash dividends declared on common stock	(75)					(75)
Purchase of common stock	(116)						(116)
Purchase of common stock (in shares)	0		(4,300,000)
Acquisition of Sterling Bancshares, Inc.	803		122	681
Acquisition of Sterling Bancshares, Inc. (in shares)			24,300,000
Net issuance of common stock under employee stock plans	0			(29)		(19)	48
Net issuance of common stock under employee stock plans (in shares)			800,000
Share-based compensation	37			37
BALANCE at Dec. 31, 2011	6,868		1,141	2,170	(356)	5,546	(1,633)
BALANCE (in shares) at Dec. 31, 2011			197,300,000
Net income	521					521
Other comprehensive income (loss), net of tax	(57)				(57)
Cash dividends declared on common stock	(106)					106
Purchase of common stock	(308)						308
Purchase of common stock (in shares)	0		10,200,000
Net issuance of common stock under employee stock plans	(13)			(46)		(30)	63
Net issuance of common stock under employee stock plans (in shares)			1,200,000
Share-based compensation	37			37
Other	0			(1)			1
BALANCE at Dec. 31, 2012	6,942		1,141	2,162	(413)	5,931	(1,879)
BALANCE (in shares) at Dec. 31, 2012			188,300,000
Net income	541					541
Other comprehensive income (loss), net of tax	22				22
Cash dividends declared on common stock	(126)					126
Purchase of common stock	(291)						291
Purchase of common stock (in shares)	(7,545,000)	[1]	7,500,000
Net issuance of common stock under employee stock plans	30			(17)		(25)	72
Net issuance of common stock under employee stock plans (in shares)			1,500,000
Share-based compensation	35			35
Other	0			1			(1)
BALANCE at Dec. 31, 2013	$ 7,153		$ 1,141	$ 2,179	$ (391)	$ 6,321	$ (2,097)
BALANCE (in shares) at Dec. 31, 2013			182,300,000

[1] Includes approximately 122,000 shares purchased pursuant to deferred compensation plans and shares purchased from employees to pay for taxes related to restricted stock vesting under the terms of an employee share-based compensation plan during the year ended December 31, 2013. These transactions are not considered part of the Corporation's repurchase program.