Consolidated Condensed Statements Of Changes In Stockholders' Equity (USD $) In Thousands, unless otherwise specified	Total	Preferred Stock [Member]	Common Stock [Member]	Retained Earnings [Member]	Treasury Stock At Cost [Member]	Accumulated Other Comprehensive Income (loss) [Member]
Balance at Dec. 31, 2011		$ 98,146	$ 305,499	$ 424,557	$ (77,007)	$ (8,831)
Net Income	50,361			50,361
Other comprehensive income, net of tax:
Change in funded status of pension plan, net of income taxes	(412)					412
Unrealized net holding gain on cash flow hedge, net of income taxes	259					259
Unrealized net holding loss on securities available-for-sale, net of income taxes	604					604
Cash dividends on common stock at $1.88 per share				(28,962)
Cash payment for fractional shares in dividend reinvestment plan			(1)
Common stock warrant repurchased	(2,843)
Preferred stock repurchased	100,000
Accretion of discount on preferred stock		1,854		(1,854)
Preferred stock dividends				(1,571)
Balance at Jun. 30, 2012		0	302,655	442,531	(77,007)	(7,556)
Balance at Dec. 31, 2012	650,366	0	302,654	441,605	(76,375)	(17,518)
Net Income	40,744			40,744
Other comprehensive income, net of tax:
Change in funded status of pension plan, net of income taxes
Unrealized net holding gain on cash flow hedge, net of income taxes
Unrealized net holding loss on securities available-for-sale, net of income taxes	(22,916)					(22,916)
Cash dividends on common stock at $1.88 per share				(28,974)
Cash payment for fractional shares in dividend reinvestment plan			(1)
Common stock warrant repurchased	0
Balance at Jun. 30, 2013	$ 639,219	$ 0	$ 302,653	$ 453,375	$ (76,375)	$ (40,434)