Condensed Consolidated Statements of Changes in Shareholders' Equity (USD $) In Thousands, except Share data	Preferred Stock [Member]	Common Stock [Member]	Retained Earnings [Member]	Accumulated Other Comprehensive Income [Member]	Total
BALANCE, VALUE at Dec. 31, 2009	$ 204,335	$ 1,253,288	$ 83,939	$ 24,955	$ 1,566,517
BALANCE, SHARES at Dec. 31, 2009		86,785,588
Net income			28,326		28,326
Other comprehensive loss, net of tax				(10)	(10)
Comprehensive income					28,316
Issuance of common stock, shares		8,625,000
Issuance of common stock, value		89,786			89,786
Stock-based compensation		3,505			3,505
Stock repurchased and retired, shares		(22,541)
Stock repurchased and retired, value		(284)			(284)
Issuances of common stock under stock plans and related net tax benefit (deficiencies), shares		173,767
Issuances of common stock under stock plans and related net tax benefit (deficiencies), value		844			844
Redemption of preferred stock issued to U.S. Treasury	(214,181)				(214,181)
Issuance of preferred stock	198,289				198,289
Conversion of preferred stock to common stock, shares		18,975,000
Conversion of preferred stock to common stock, value	(198,289)	198,289
Amortization of discount on preferred stock	9,846		(9,846)
Dividends declared on preferred stock			(3,686)		(3,686)
Repurchase of warrants issued to U.S. Treasury		(4,500)			(4,500)
Cash dividends on common stock			(22,032)		(22,032)
BALANCE, VALUE at Dec. 31, 2010		1,540,928	76,701	24,945	1,642,574
BALANCE, SHARES at Dec. 31, 2010		114,536,814			114,536,814
Net income			31,252		31,252
Other comprehensive loss, net of tax				12,009	12,009
Comprehensive income					43,261
Stock-based compensation		1,987			1,987
Stock repurchased and retired, shares		(170,205)
Stock repurchased and retired, value		(1,960)			(1,960)
Issuances of common stock under stock plans and related net tax benefit (deficiencies), shares		171,173
Issuances of common stock under stock plans and related net tax benefit (deficiencies), value		(22)			(22)
Cash dividends on common stock			(11,519)		(11,519)
BALANCE, VALUE at Jun. 30, 2011		$ 1,540,933	$ 96,434	$ 36,954	$ 1,674,321
BALANCE, SHARES at Jun. 30, 2011		114,537,782			114,537,782