Consolidated Condensed Statements Of Changes In Stockholders' Equity (USD $) In Thousands, unless otherwise specified	Preferred Stock [Member]	Common Stock [Member]	Retained Earnings [Member]	Treasury Stock At Cost [Member]	Accumulated Other Comprehensive Income (Loss) [Member]	Comprehensive Income [Member]	Total
Balance at Dec. 31, 2009	$ 96,483	$ 306,569	$ 423,872	$ (125,321)	$ 15,661
Net Income			20,779			20,779	20,779
Other comprehensive income (loss), net of tax:
Unrealized net holding gain (loss) on cash flow hedge, net of income taxes					(111)	(111)
Unrealized net holding gain (loss) on securities available-for-sale, net of income taxes					(1,793)	(1,793)
Total comprehensive income						18,875
Cash dividends on common stock			(13,990)
Cash payment for fractional shares in dividend reinvestment plan		(1)
Accretion of discount on preferred stock	202		(202)
Preferred stock dividends			(1,250)
Balance at Mar. 31, 2010	96,685	306,568	429,209	(125,321)	13,757
Balance at Dec. 31, 2010	97,290	305,677	406,342	(77,733)	(1,868)		729,708
Net Income			22,196			22,196	22,196
Other comprehensive income (loss), net of tax:
Unrealized net holding gain (loss) on cash flow hedge, net of income taxes					133	133
Unrealized net holding gain (loss) on securities available-for-sale, net of income taxes					(6,371)	(6,371)
Total comprehensive income						15,958
Cash dividends on common stock			(14,475)
Cash payment for fractional shares in dividend reinvestment plan		(1)
Accretion of discount on preferred stock	214		(214)
Preferred stock dividends			(1,250)
Balance at Mar. 31, 2011	$ 97,504	$ 305,676	$ 412,599	$ (77,733)	$ (8,106)		$ 729,940