Consolidated Statements Of Changes In Shareholders' Equity (USD $) In Thousands, unless otherwise specified		Preferred Stock [Member]	Common Stock [Member]	Capital Surplus [Member]	Retained Earnings [Member]	Accumulated Other Comprehensive Income (Loss) [Member]	Comprehensive Income [Member]	Total
Balance at Dec. 31, 2008		$ 97,358	$ 66,321	$ 569,875	$ 50,815	$ (53,504)		$ 730,865
Comprehensive income
Net income		0	0	0	13,737	0	13,737	13,737
Other comprehensive income
Change in unrealized gain (loss) on securities available for sale, net of reclassification and tax	[1]	0	0	0	0	32,792	32,792	32,792
Transferred securities, net of tax	[1]	0	0	0	0	812	812	812
Reclassification adjustment on cash flows hedges, net of tax	[1]	0	0	0	0	667	667	667
Net loss, settlement cost and amort. of net (gain) loss on defined benefit pension plans, net of tax	[1]	0	0	0	0	(1,133)	(1,133)	(1,133)
Total comprehensive income	[1]						46,875
Dividends - common stock		0	0	0	(30,380)	0		(30,380)
Dividends - preferred stock		0	0	0	(1,250)	0		(1,250)
Common stock issued		0	20,900	176,856	0	0		197,756
Preferred stock repurchased		(97,358)	0	0	(2,642)	0		(100,000)
Common stock repurchased		0	(28)	(325)	0	0		(353)
Warrants repurchased		0	0	(1,200)	0	0		(1,200)
Stock based compensation expense		0	0	1,310	0	0		1,310
Stock activity under incentive comp plans		0	(11)	259	(45)	0		203
Balance at Dec. 31, 2009		0	87,182	746,775	30,235	(20,366)		843,826
Comprehensive income
Net income		0	0	0	38,214	0	38,214	38,214
Other comprehensive income
Change in unrealized gain (loss) on securities available for sale, net of reclassification and tax	[1]	0	0	0	0	11,501	11,501	11,501
Transferred securities, net of tax	[1]	0	0	0	0	4,855	4,855	4,855
Reclassification adjustment on cash flows hedges, net of tax	[1]	0	0	0	0	659	659	659
Net loss, settlement cost and amort. of net (gain) loss on defined benefit pension plans, net of tax	[1]	0	0	0	0	2,082	2,082	2,082
Total comprehensive income	[1]						57,311
Dividends - common stock		0	0	0	(24,361)	0		(24,361)
Common stock issued		0	19	178	0	0		197
Common stock repurchased		0	(41)	(664)	0	0		(705)
Stock based compensation expense		0	0	2,369	0	0		2,369
Stock activity under incentive comp plans		0	23	215	(70)	0		168
Balance at Dec. 31, 2010		0	87,183	748,873	44,018	(1,269)		878,805
Comprehensive income
Net income		0	0	0	72,460	0	72,460	72,460
Other comprehensive income
Change in unrealized gain (loss) on securities available for sale, net of reclassification and tax	[1]	0	0	0	0	20,823	20,823	20,823
Transferred securities, net of tax	[1]	0	0	0	0	(922)	(922)	(922)
Reclassification adjustment on cash flows hedges, net of tax	[1]	0	0	0	0	(701)	(701)	(701)
Net loss, settlement cost and amort. of net (gain) loss on defined benefit pension plans, net of tax	[1]	0	0	0	0	(2,927)	(2,927)	(2,927)
Total comprehensive income	[1]						88,733
Acquisition - Monroe Bancorp		0	7,575	82,495	0	0		90,070
Dividends - common stock		0	0	0	(26,513)	0		(26,513)
Common stock issued		0	22	200	0	0		222
Common stock repurchased		0	(145)	(1,381)	0	0		(1,526)
Stock based compensation expense		0	0	3,436	0	0		3,436
Stock activity under incentive comp plans		0	19	410	(100)	0		329
Balance at Dec. 31, 2011		$ 0	$ 94,654	$ 834,033	$ 89,865	$ 15,004		$ 1,033,556

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