Consolidated Statements of Shareholders' Equity and Comprehensive Income (loss) (USD $) In Thousands	Total	Preferred Stock	Common Stock	Additional Paid-In Capital	Retained Earnings	Accumulated Other Comprehensive Income (Loss)	Treasury Stock
Beginning Balance at Dec. 31, 2008
Cumulative effect of FSP FAS 115-2 and FAS 124-2 adoption (net of $3.4 million tax effect)					$ 6,298	$ (6,298)
Net Income	73,924				73,924
Other comprehensive income	31,663					31,663
Total comprehensive income	105,587
Stock issued, including related tax benefits	7,419		1,513	(4,998)			10,904
Stock issued, including related tax benefits (in shares)			1,320
Stock-based compensation awards	1,781			1,781
Preferred stock discount accretion	0	1,346			(1,346)
Preferred stock cash dividends	(16,836)				(16,836)
Common stock cash dividends	(21,116)				(21,116)
Ending Balance at Dec. 31, 2009	1,936,482	370,290	482,491	1,257,730	71,999	7,458	(253,486)
Ending Balance (in shares) at Dec. 31, 2009			176,364
Net Income	128,332				128,332
Other comprehensive income	5,037					5,037
Total comprehensive income	133,369
Stock issued, including related tax benefits	231,510		56,001	171,201			4,308
Stock issued, including related tax benefits (in shares)			22,686
Stock-based compensation awards	1,996			1,996
Redemption Of Preferred Stock And repurchase of common stock warrant	(387,300)	(376,500)		(10,800)
Preferred stock discount accretion	0	6,210			(6,210)
Preferred stock cash dividends	(12,496)				(12,496)
Common stock cash dividends	(23,172)				(23,172)
Ending Balance at Dec. 31, 2010	1,880,389	0	538,492	1,420,127	158,453	12,495	(249,178)
Ending Balance (in shares) at Dec. 31, 2010			199,050
Net Income	145,573				145,573
Other comprehensive income	(4,540)					(4,540)
Total comprehensive income	141,033
Stock issued, including related tax benefits	6,835		1,894	(649)			5,590
Stock issued, including related tax benefits (in shares)			1,114
Stock-based compensation awards	4,249			4,249
Common stock cash dividends	(39,967)				(39,967)
Ending Balance at Dec. 31, 2011	$ 1,992,539	$ 0	$ 540,386	$ 1,423,727	$ 264,059	$ 7,955	$ (243,588)
Ending Balance (in shares) at Dec. 31, 2011			200,164