Derivative Financial Instruments And Hedging Activities (Details) (USD $) In Thousands, unless otherwise specified	Sep. 30, 2012	Dec. 31, 2011
Interest Rate Swap [Member]
Derivatives, Fair Value [Line Items]
Fair Value Hedge Assets	$ 301	$ 2,004
Fair Value Hedge Liabilities	301	6,440
Interest Rate Cap [Member]
Derivatives, Fair Value [Line Items]
Fair Value Hedge Assets	1,471	4,548
Fair Value Hedge Liabilities	1,501	4,768
Derivative Financial Instruments, Assets [Member]
Derivatives, Fair Value [Line Items]
Notional Amount of Interest Rate Derivatives	1,518,708	2,022,354
Fair Value Hedge Assets	1,772	6,552
Derivative Financial Instruments, Liabilities [Member]
Derivatives, Fair Value [Line Items]
Notional Amount of Interest Rate Derivatives	1,518,708	1,980,417
Fair Value Hedge Liabilities	1,802	11,208
Other Assets [Member] | Interest Rate Swap [Member]
Derivatives, Fair Value [Line Items]
Notional Amount of Interest Rate Derivatives	25,404	509,561
Other Assets [Member] | Interest Rate Cap [Member]
Derivatives, Fair Value [Line Items]
Notional Amount of Interest Rate Derivatives	1,493,304	1,512,793
Interest Rate Swap And Cap Agreements [Member] | Interest Rate Swap [Member]
Derivatives, Fair Value [Line Items]
Notional Amount of Interest Rate Derivatives	25,404	509,561
Interest Rate Swap And Cap Agreements [Member] | Interest Rate Cap [Member]
Derivatives, Fair Value [Line Items]
Notional Amount of Interest Rate Derivatives	$ 1,493,304	$ 1,470,856