Derivative Financial Instruments (Schedule Of Effect Of Derivative Instruments On The Consolidated Statement Of Income) (Details) (USD $) In Thousands	3 Months Ended				9 Months Ended
	Sep. 30, 2011		Sep. 30, 2010		Sep. 30, 2011		Sep. 30, 2010
Interest Rate Contracts [Member] | Interest Income / (Expense) [Member] | Derivatives In Fair Value Hedging Relationships [Member]
Amount of Gain or (Loss) Recognized in Income on Derivative	$ 744	[1]	$ 843	[1]	$ 2,205	[1]	$ 2,750	[1]
Interest Rate Contracts [Member] | Interest Income / (Expense) [Member] | Derivatives In Cash Flow Hedging Relationships [Member]
Amount of Gain or (Loss) Recognized in Income on Derivative	410	[1]	383	[1]	1,197	[1]	1,158	[1]
Interest Rate Contracts [Member] | Other Income / (Expense) [Member] | Derivatives In Fair Value Hedging Relationships [Member]
Amount of Gain or (Loss) Recognized in Income on Derivative	345	[2]	238	[2]	714	[2]	1,555	[2]
Interest Rate Contracts [Member] | Other Income / (Expense) [Member] | Derivatives Not Designated As Hedging Instruments [Member]
Amount of Gain or (Loss) Recognized in Income on Derivative	(196)	[3]	132	[3]	(12)	[3]	(169)	[3]
Mortgage Contracts [Member] | Mortgage Banking Revenue [Member] | Derivatives Not Designated As Hedging Instruments [Member]
Amount of Gain or (Loss) Recognized in Income on Derivative	(47)		131		(68)		(93)
Derivatives In Fair Value Hedging Relationships [Member]
Amount of Gain or (Loss) Recognized in Income on Derivative	1,089		1,081		2,919		4,305
Derivatives In Cash Flow Hedging Relationships [Member]
Amount of Gain or (Loss) Recognized in Income on Derivative	410		383		1,197		1,158
Derivatives Not Designated As Hedging Instruments [Member]
Amount of Gain or (Loss) Recognized in Income on Derivative	$ (243)		$ 263		$ (80)		$ (262)

[1] Amounts represent the net interest payments as stated in the contractual agreements.

[2] Amounts represent ineffectiveness on derivatives designated as fair value hedges.

[3] Includes the valuation differences between the customer and offsetting counterparty swaps.