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, 2009	$ 86,600	$ 301,523	$ 278,887	$ (6,045)	$ (16,554)	$ (5,600)	$ 638,811
Balance, shares at Dec. 31, 2009	85,151,875
Comprehensive income
Net income			374				374
Other comprehensive income, net of tax:
Unrealized holding gains on securities arising during the period				6,431			6,431
Non-credit related gains on securities not expected to be sold				2,297			2,297
Reclassification adjustment for gains (losses) on securities included in net income				2,553			2,553
Total other comprehensive income							11,281
Total comprehensive income							11,655
Cash dividends declared			(3,402)				(3,402)
Net decrease in unearned ESOP shares						1,000	1,000
ESOP market value adjustment		(325)					(325)
Discount on dividend reinvestment plan purchases		(22)					(22)
Treasury stock acquired					(8)		(8)
Treasury stock acquired, shares	(1,291)
Treasury stock reissued		656	(4,552)		7,808		3,912
Treasury stock reissued, shares	690,537
Restricted stock	0	0	(168)		297		129
Restricted stock, shares	30,120
Common stock issuance	371	2,129					2,500
Common stock issuance, shares	370,898
Balance at Jun. 30, 2010	86,971	303,961	271,139	5,236	(8,457)	(4,600)	654,250
Balance, shares at Jun. 30, 2010	86,242,139
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						104,846,194
Comprehensive income
Net income			12,665				12,665
Other comprehensive income, net of tax:
Unrealized holding gains on securities arising during the period				4,881			4,881
Non-credit related gains on securities not expected to be sold				1,506			1,506
Reclassification adjustment for gains (losses) on securities included in net income				(1,420)			(1,420)
Total other comprehensive income							4,967
Total comprehensive income							17,632
Cash dividends declared			(6,278)				(6,278)
Net decrease in unearned ESOP shares						1,000	1,000
ESOP market value adjustment		(307)					(307)
Discount on dividend reinvestment plan purchases		(32)					(32)
Tax benefit of stock options exercised		6					6
Treasury stock acquired					(9)		(9)
Treasury stock acquired, shares	(1,336)
Treasury stock reissued		0	(83)		155		72
Treasury stock reissued, shares	13,760
Restricted stock	25	(10)	0		56		71
Restricted stock, shares	25,000
Common stock issuance	23	121			0		144
Common stock issuance, shares	23,376
Balance at Jun. 30, 2011	$ 105,563	$ 366,266	$ 297,796	$ 2,509	$ (7,458)	$ (2,600)	$ 762,076
Balance, shares at Jun. 30, 2011	104,906,994						104,906,994