Derivative Financial Instruments (Schedule Of Fair Value Of Derivative Financial Instruments) (Details) (USD $) In Thousands, unless otherwise specified	Dec. 31, 2011	Dec. 31, 2010
Derivative [Line Items]
Total derivative assets	$ 44,415	$ 33,421
Total derivative liabilities	37,332	29,060
Designated As Hedging Instruments [Member]
Derivative [Line Items]
Total derivative assets	7,444	4,766
Designated As Hedging Instruments [Member] | Other Assets [Member] | Interest Rate Contracts [Member]
Derivative [Line Items]
Total derivative assets	7,444	4,766
Derivatives Not Designated As Hedging Instruments [Member]
Derivative [Line Items]
Total derivative assets	36,971	28,655
Total derivative liabilities	37,332	29,060
Derivatives Not Designated As Hedging Instruments [Member] | Other Assets [Member] | Interest Rate Contracts [Member]
Derivative [Line Items]
Total derivative assets	36,755	28,269
Derivatives Not Designated As Hedging Instruments [Member] | Other Assets [Member] | Commodity Contracts [Member]
Derivative [Line Items]
Total derivative assets	0	132
Derivatives Not Designated As Hedging Instruments [Member] | Other Assets [Member] | Mortgage Contracts [Member]
Derivative [Line Items]
Total derivative assets	216	254
Derivatives Not Designated As Hedging Instruments [Member] | Other Liabilities [Member] | Interest Rate Contracts [Member]
Derivative [Line Items]
Total derivative liabilities	37,332	28,928
Derivatives Not Designated As Hedging Instruments [Member] | Other Liabilities [Member] | Commodity Contracts [Member]
Derivative [Line Items]
Total derivative liabilities	$ 0	$ 132