Derivative Financial Instruments (Schedule Of Amounts Related To Interest Rate Derivatives Included In Income Designated As Hedges Of Cash Flows) (Details) (USD $) In Thousands, unless otherwise specified	3 Months Ended
	Mar. 31, 2012	Mar. 31, 2011
Interest Rate Swaps On Variable-Rate Loans [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Amount reclassified from accumulated other comprehensive income to interest income on loans	$ 9,345	$ 9,345
Interest Rate Swaps On Junior Subordinated Deferrable Interest Debentures [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Amount reclassified from accumulated other comprehensive income to interest expense on junior subordinated deferrable interest debentures	1,033	1,086
Amount of gain (loss) recognized in other comprehensive income	$ (427)	$ 65