Derivative Financial Instruments (Schedule Of Weighted-Average Rates Paid And Received For Interest Rate Swaps Outstanding) (Details) (Interest Rate Swaps [Member])	Mar. 31, 2012
Weighted-Average Interest Rate Paid [Member]
Weighted Average Discount Rate [Line Items]
Fair value hedge commercial loan/lease interest rate swaps	4.30%
Cash flow hedge interest rate swaps on junior subordinated deferrable interest debentures	5.47%
Non-hedging interest rate swaps	1.81%
Non-hedging interest rate swaps (2)	4.89%
Weighted-Average Interest Rate Received [Member]
Weighted Average Discount Rate [Line Items]
Fair value hedge commercial loan/lease interest rate swaps	0.24%
Cash flow hedge interest rate swaps on junior subordinated deferrable interest debentures	1.86%
Non-hedging interest rate swaps	4.89%
Non-hedging interest rate swaps (2)	1.81%