Investment Securities (Roll Forward Of Credit Losses Of Held-To-Maturity Securities Written Down As Other-Than-Temporary Impairment Recognized In Earnings And Other Comprehensive Income) (Details) (USD $) In Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2011	Sep. 30, 2010	Sep. 30, 2011	Sep. 30, 2010
Investment Securities [Abstract]
Balance, beginning of period	$ 12,850	$ 12,652	$ 12,778	$ 12,364
Subsequent OTTI credit losses		44	72	332
Securities sold, matured or paid-off	(1,016)		(1,016)
Balance, end of period	$ 11,834	$ 12,696	$ 11,834	$ 12,696