Securities Available For Sale (Schedule Of OTTI Related To Historical Estimated Credit Losses On Debt Securities And Changes In Estimated Credit Losses Recognized In Pre-Tax Earnings) (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
Securities Available For Sale [Abstract]
Estimated credit losses as of beginning of period	$ 4,958	$ 4,527	$ 4,697	$ 3,373
Additions for credit losses for securities on which OTTI has been previously recognized	101	503	675	1,313
Additions for credit losses for securities on which OTTI has not been previously recognized		69	106	413
Reductions for securities paid off during the period			419
Estimated credit losses as of June 30	$ 5,059	$ 5,099	$ 5,059	$ 5,099