Condensed Consolidated Statements Of Changes In Shareholders' Equity (USD $) In Thousands, except Share data	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]	Total
Balance at Dec. 31, 2010	$ 105,515	$ 366,488	$ 291,492	$ (2,458)	$ (7,660)	$ (3,600)	$ 749,777
Balance, shares at Dec. 31, 2010	104,846,194
Net income			5,246				5,246
Other comprehensive loss (income)				(211)			(211)
Cash dividends declared			(3,138)				(3,138)
Net decrease in unearned ESOP shares						500	500
ESOP market value adjustment		(147)					(147)
Discount on dividend reinvestment plan purchases		(16)					(16)
Tax benefit of stock options exercised		6					6
Treasury stock reissued			(82)		156		74
Treasury stock reissued, shares	13,760
Restricted stock		7			34		41
Balance at Mar. 31, 2011	105,515	366,338	293,518	(2,669)	(7,470)	(3,100)	752,132
Balance, shares at Mar. 31, 2011	104,859,954
Balance at Dec. 31, 2011	105,563	365,868	294,056	2,001	(7,345)	(1,600)	758,543
Balance, shares at Dec. 31, 2011	104,916,994						104,916,994
Net income			11,051				11,051
Other comprehensive loss (income)				1,039			1,039
Cash dividends declared			(3,147)				(3,147)
Net decrease in unearned ESOP shares						500	500
ESOP market value adjustment		(157)					(157)
Discount on dividend reinvestment plan purchases		(16)					(16)
Tax benefit of stock options exercised		1					1
Treasury stock reissued		0	(163)		373		210
Treasury stock reissued, shares	33,024
Restricted stock		11	(603)		(74)		(666)
Restricted stock, shares	100,000
Balance at Mar. 31, 2012	$ 105,563	$ 365,707	$ 301,194	$ 3,040	$ (7,046)	$ (1,100)	$ 767,358
Balance, shares at Mar. 31, 2012	105,050,018						105,050,018