Consolidated Statements of Changes in Shareholders' Equity (USD $) In Thousands	Total	Common Stock [Member]	Retained Earnings [Member]	Accumulated Other Comprehensive Income [Member]	Series B Preferred Stock [Member]
Balance, value at Dec. 31, 2012	$ 764,008	$ 581,471	$ 162,388	$ 20,149	$ 0
Balance, shares at Dec. 31, 2012		39,686			0
Net Income	12,176		12,176
Other comprehensive income	(3,430)			(3,430)
Issuance of common stock - stock option and other plans, value	326	326
Issuance of common stock - stock option and other plans, shares		18
Issuance of common stock - restricted stock awards, net of cancelled awards, value	551	551
Issuance of common stock - restricted stock awards, net of cancelled awards, shares		140
Cash dividends paid on common stock	3,971		3,971
Balance, value at Mar. 31, 2013	769,660	582,348	170,593	16,719	0
Balance, shares at Mar. 31, 2013		39,844			0
Balance, value at Dec. 31, 2013	1,053,249	860,562	202,514	(12,044)	2,217
Balance, shares at Dec. 31, 2013		51,265			9
Net Income	19,844		19,844
Other comprehensive income	7,001			7,001
Issuance of common stock - cashless exercise of warrants, shares		1,140
Issuance of common stock - cashless exercise of warrants, value	0	0
Issuance of common stock - stock option and other plans, value	405	405
Issuance of common stock - stock option and other plans, shares		19
Issuance of common stock - restricted stock awards, net of cancelled awards, value	680	680
Issuance of common stock - restricted stock awards, net of cancelled awards, shares		197
Stock Repurchased During Period, Shares		(21)
Stock Repurchased and Retired During Period, Value	(522)	(522)
Dividends, Preferred Stock, Cash	(12)
Cash dividends paid on common stock	6,154		6,154
Balance, value at Mar. 31, 2014	$ 1,074,491	$ 861,125	$ 216,192	$ (5,043)	$ 2,217
Balance, shares at Mar. 31, 2014		52,600			9