Commitments And Contingencies (Narrative) (Details) (USD $)	12 Months Ended
	Dec. 31, 2011 years	Dec. 31, 2010	Dec. 31, 2009
Commitments And Contingencies [Abstract]
Commitments to extend credit	$ 1,600,000,000
Commitments to fund fixed rate loans	86,700,000
Commitments to fund adjustable rate loans	1,500,000,000
Operating lease, lease term, years, minimum	1
Operating lease, lease term, years, maximum	50
Rental expense, operating lease	6,700,000	6,600,000	6,900,000
Rental income, operating lease	$ 200,000	$ 300,000	$ 300,000