On-Balance Sheet Derivative Instruments And Hedging Activities (Schedule Of Other Derivatives Not Designated As Hedging Instruments, Statements Of Financial Performance And Financial Position, Locations) (Details) (USD $) In Thousands	6 Months Ended			12 Months Ended	6 Months Ended	12 Months Ended	6 Months Ended
	Jun. 30, 2011	Jun. 30, 2010	Jun. 30, 2011 Other Income [Member] Interest Rate Contracts [Member] Not Designated As Hedging Instrument [Member]	Dec. 31, 2010 Other Income [Member] Interest Rate Contracts [Member] Not Designated As Hedging Instrument [Member]	Jun. 30, 2011 Not Designated As Hedging Instrument [Member]	Dec. 31, 2010 Not Designated As Hedging Instrument [Member]	Jun. 30, 2011 Cash Flow Hedging [Member] Interest Income [Member] Interest Rate Contracts [Member]	Jun. 30, 2010 Cash Flow Hedging [Member] Interest Income [Member] Interest Rate Contracts [Member]	Jun. 30, 2011 Cash Flow Hedging [Member] Other Income [Member] Interest Rate Contracts [Member]	Jun. 30, 2010 Cash Flow Hedging [Member] Other Income [Member] Interest Rate Contracts [Member]	Jun. 30, 2011 Cash Flow Hedging [Member] Interest Rate Contracts [Member]	Jun. 30, 2010 Cash Flow Hedging [Member] Interest Rate Contracts [Member]
Derivative Instruments, Gain (Loss) Recognized in Income, Net	$ 8,953	$ 6,617	$ (2)		$ (2)						$ 8,953	$ 6,617
Derivative Instruments, Gain (Loss) Reclassified from Accumulated OCI into Income, Effective Portion, Net	(856)	(811)					(856)	(811)
Derivative Instruments, Gain (Loss) Recognized in Income, Ineffective Portion and Amount Excluded from Effectiveness Testing, Net