Investment Securities (Realized Gains And Losses On Sales Of Investment Securities) (Details) (USD $) In Thousands, unless otherwise specified	3 Months Ended								12 Months Ended
	Dec. 31, 2011	Sep. 30, 2011	Jun. 30, 2011	Mar. 31, 2011	Dec. 31, 2010	Sep. 30, 2010	Jun. 30, 2010	Mar. 31, 2010	Dec. 31, 2011	Dec. 31, 2010	Dec. 31, 2009
Investment Securities [Abstract]
Gross gains, Sales transactions									$ 31,456	$ 8,615	$ 8,006
Gross losses, Sales transactions										(96)	(36)
Gains on Sales transactions, net									31,456	8,519	7,970
Gross gains, Maturities and other securities transactions									623	3,158	79
Gross losses, Maturities and other securities transactions									(11)	(79)	(44)
Gains (losses) on Maturities and other securities transactions, net									612	3,079	35
Gains on securities transactions, net	$ 12,034	$ 863	$ 16,492	$ 2,679	$ 6,967	$ 112	$ 3,656	$ 863	$ 32,068	$ 11,598	$ 8,005