Fair Value Measurements (Summary Of Gains And Losses On Level 3 Assets And Liabilities) (Details) (USD $) In Thousands, unless otherwise specified	3 Months Ended		9 Months Ended
	Sep. 30, 2012	Sep. 30, 2011	Sep. 30, 2012	Sep. 30, 2011
Trading Activity, Gains and Losses, Net [Line Items]
Total gains or losses included in earnings	$ 2,775	$ 3,305	$ 8,371	$ 6,967
Change in unrealized gains or losses relating to assets still held	2,737	3,158	6,909	7,249
Loan Fees And Sales [Member]
Trading Activity, Gains and Losses, Net [Line Items]
Total gains or losses included in earnings	0	160	0	(243)
Change in unrealized gains or losses relating to assets still held	0	239	0	239
Other Non-Interest Income [Member]
Trading Activity, Gains and Losses, Net [Line Items]
Total gains or losses included in earnings	1	224	(3)	259
Change in unrealized gains or losses relating to assets still held	(37)	(2)	(40)	(16)
Investment Securities Gains (Losses), Net [Member]
Trading Activity, Gains and Losses, Net [Line Items]
Total gains or losses included in earnings	2,774	2,921	8,374	6,951
Change in unrealized gains or losses relating to assets still held	$ 2,774	$ 2,921	$ 6,949	$ 7,026