Condensed Consolidated Statements of Changes in Shareholders' Equity (Unaudited) (USD $) In Thousands, except Share data	Total	Common Stock [Member]	Additional Paid-in Capital [Member]	Retained Earnings [Member]	Accumulated Other Comprehensive Income (Loss), net [Member]	Treasury Stock [Member]	Unearned ESOP Shares [Member]
Beginning balance at Dec. 31, 2011	$ 758,543	$ 105,563	$ 365,868	$ 294,056	$ 2,001	$ (7,345)	$ (1,600)
Beginning balance, shares at Dec. 31, 2011		104,916,994
Net Income	33,219			33,219
Other comprehensive income (loss)	2,966				2,966
Dividends, Common Stock, Cash	(13,633)			(13,633)
Net decrease in unearned ESOP shares	1,500						1,500
ESOP market value adjustment ($685, net of $240 tax benefit)	(445)		(445)
Discount on dividend reinvestment plan purchases	(67)		(67)
Tax benefit of stock options exercised	1		1
Treasury stock acquired	(9,112)					(9,112)
Treasury stock acquired, shares		(1,342,517)
Treasury stock reissued	617			(329)		946
Restricted stock, shares		220,000
Treasury stock reissued, shares		95,552
Restricted stock	302		37	(1,264)		1,529
Ending balance at Sep. 30, 2012	773,891	105,563	365,394	312,049	4,967	(13,982)	(100)
Ending balance, shares at Sep. 30, 2012		103,890,029
Beginning balance at Dec. 31, 2012	746,007	105,563	365,354	315,608	1,259	(41,777)	0
Beginning balance, shares at Dec. 31, 2012	99,629,494	99,629,494
Net Income	32,223			32,223
Other comprehensive income (loss)	(20,728)				(20,728)
Dividends, Common Stock, Cash	(16,630)			(16,630)
Discount on dividend reinvestment plan purchases	(84)		(84)
Tax benefit of stock options exercised	0
Treasury stock acquired	(30,001)					(30,001)
Treasury stock acquired, shares		(4,168,088)
Treasury stock reissued	176			0		176
Restricted stock, shares		58,000
Treasury stock reissued, shares		25,359
Restricted stock	393		68	2		323
Ending balance at Sep. 30, 2013	$ 711,356	$ 105,563	$ 365,338	$ 331,203	$ (19,469)	$ (71,279)	$ 0
Ending balance, shares at Sep. 30, 2013	95,544,765	95,544,765