On-Balance Sheet Derivative Instruments And Hedging Activities (Schedule Of Outstanding Derivative Instruments) (Details) (USD $) In Thousands, unless otherwise specified	Dec. 31, 2011	Dec. 31, 2010
Other Assets [Member] | Asset Derivatives [Member] | Derivatives Designated As Hedging Instrument [Member]
Derivatives, Fair Value [Line Items]
Asset Derivatives Fair Value	$ 71	$ 14,414
Other Assets [Member] | Asset Derivatives [Member] | Derivatives Not Designated As Hedging Instruments [Member]
Derivatives, Fair Value [Line Items]
Asset Derivatives Fair Value	32,000	22,906
Other Assets [Member] | Asset Derivatives [Member] | Interest Rate Contracts [Member] | Derivatives Designated As Hedging Instrument [Member]
Derivatives, Fair Value [Line Items]
Asset Derivatives Fair Value	71	14,414
Other Assets [Member] | Asset Derivatives [Member] | Interest Rate Contracts [Member] | Derivatives Not Designated As Hedging Instruments [Member]
Derivatives, Fair Value [Line Items]
Asset Derivatives Fair Value	25,391	17,420
Other Assets [Member] | Asset Derivatives [Member] | Written And Purchase Options [Member] | Derivatives Not Designated As Hedging Instruments [Member]
Derivatives, Fair Value [Line Items]
Asset Derivatives Fair Value	6,609	5,486
Other Liabilities [Member] | Liability Derivatives [Member] | Derivatives Designated As Hedging Instrument [Member]
Derivatives, Fair Value [Line Items]
Liability Derivatives Fair Value	3,010
Other Liabilities [Member] | Liability Derivatives [Member] | Derivatives Not Designated As Hedging Instruments [Member]
Derivatives, Fair Value [Line Items]
Liability Derivatives Fair Value	32,000	22,904
Other Liabilities [Member] | Liability Derivatives [Member] | Interest Rate Contracts [Member] | Derivatives Designated As Hedging Instrument [Member]
Derivatives, Fair Value [Line Items]
Liability Derivatives Fair Value	3,010
Other Liabilities [Member] | Liability Derivatives [Member] | Interest Rate Contracts [Member] | Derivatives Not Designated As Hedging Instruments [Member]
Derivatives, Fair Value [Line Items]
Liability Derivatives Fair Value	25,391	17,418
Other Liabilities [Member] | Liability Derivatives [Member] | Written And Purchase Options [Member] | Derivatives Not Designated As Hedging Instruments [Member]
Derivatives, Fair Value [Line Items]
Liability Derivatives Fair Value	$ 6,609	$ 5,486