Loans (Net (Charge-Offs)/Recoveries, Segregated by Class of Loans) (Details) (USD $) In Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2011	Jun. 30, 2010	Jun. 30, 2011	Jun. 30, 2010
Net (charge-offs)/recoveries, segregated by class of loans	$ (10,565)	$ (8,577)	$ (22,010)	$ (22,088)
Commercial And Industrial, Energy [Member]
Net (charge-offs)/recoveries, segregated by class of loans	2		4
Commercial And Industrial, Other Commercial [Member]
Net (charge-offs)/recoveries, segregated by class of loans	(4,720)	(5,606)	(11,552)	(14,239)
Commercial Real Estate, Buildings, Land And Other [Member]
Net (charge-offs)/recoveries, segregated by class of loans	(4,362)	(612)	(7,527)	(3,892)
Commercial Real Estate, Construction [Member]
Net (charge-offs)/recoveries, segregated by class of loans	(196)	(456)	(352)	(542)
Consumer Real Estate [Member]
Net (charge-offs)/recoveries, segregated by class of loans	(362)	(583)	(892)	(946)
Consumer And Other [Member]
Net (charge-offs)/recoveries, segregated by class of loans	$ (927)	$ (1,320)	$ (1,691)	$ (2,469)