Consolidated Statements Of Changes In Shareholders' Equity (USD $) In Thousands		Common Stock [Member]	Capital Surplus [Member]	Retained Earnings [Member]	Accumulated Other Comprehensive Income (Loss) [Member]	Comprehensive Income [Member]	Total
Balance at Dec. 31, 2009		$ 87,182	$ 746,775	$ 30,235	$ (20,366)		$ 843,826
Comprehensive income
Net income		0	0	32,488	0	32,488	32,488
Other comprehensive income
Change in unrealized gain (loss) on securities available for sale, net of reclassification and tax	[1]	0	0	0	29,295	29,295	29,295
Transferred securities, net of tax	[1]	0	0	0	5,110	5,110	5,110
Reclassification adjustment on cash flows hedges, net of tax	[1]	0	0	0	845	845	845
Net loss, settlement cost and amortization of net (gain) loss on defined benefit pension plans, net of tax	[1]	0	0	0	932	932	932
Total comprehensive income	[1]					68,670
Dividends - common stock		0	0	(18,268)	0		(18,268)
Common stock issued		13	123	0	0		136
Common stock repurchased		(41)	(442)	0	0		(483)
Stock based compensation expense		0	1,702	0	0		1,702
Stock activity under incentive comp plans		18	134	(51)	0		101
Balance at Sep. 30, 2010		87,172	748,292	44,404	15,816		895,684
Balance at Dec. 31, 2010		87,183	748,873	44,018	(1,269)		878,805
Comprehensive income
Net income		0	0	50,246	0	50,246	50,246
Other comprehensive income
Change in unrealized gain (loss) on securities available for sale, net of reclassification and tax	[1]	0	0	0	25,222	25,222	25,222
Transferred securities, net of tax	[1]	0	0	0	(783)	(783)	(783)
Reclassification adjustment on cash flows hedges, net of tax	[1]	0	0	0	(481)	(481)	(481)
Net loss, settlement cost and amortization of net (gain) loss on defined benefit pension plans, net of tax	[1]	0	0	0	1,882	1,882	1,882
Total comprehensive income	[1]					76,086
Acquisition - Monroe Bancorp		7,575	82,495	0	0		90,070
Dividends - common stock		0	0	(19,889)	0		(19,889)
Common stock issued		15	151	0	0		166
Common stock repurchased		(33)	(308)	0	0		(341)
Stock based compensation expense		0	2,551	0	0		2,551
Stock activity under incentive comp plans		12	298	(63)	0		247
Balance at Sep. 30, 2011		$ 94,752	$ 834,060	$ 74,312	$ 24,571		$ 1,027,695

[1] See Note 5 to the consolidated financial statements.