Loan Sales And Securitizations (Schedule Of Sensitivity Of Fair Value Of Other Retained Interests To Immediate 10 Percent And 20 Percent Adverse Changes Assumptions) (Details) (USD $) In Thousands, unless otherwise specified				3 Months Ended
	Mar. 31, 2012	Dec. 31, 2011	Mar. 31, 2011	Mar. 31, 2012 Interest Only Trading Securities [Member]	Mar. 31, 2011 Interest Only Trading Securities [Member]	Mar. 31, 2012 Certificated Principal Only [Member]	Mar. 31, 2011 Certificated Principal Only [Member]
Sensitivity Analysis of Fair Value of Interests Continued to be Held by Transferor, Servicing Assets or Liabilities, Impact of Adverse Change in Assumption [Line Items]
Fair value of retained interests	$ 1,238,041	$ 988,217	$ 924,854	$ 17,124	$ 25,131	$ 7,229	$ 8,791
Weighted average life (in years)				4.0	4.8	3.2	5.1
Annual prepayment rate				18.60%	16.00%	24.70%	23.00%
Annual prepayment rate, Impact on fair value of 10% adverse change				(758)	(1,038)	(315)	(328)
Annual prepayment rate, Impact on fair value of 20% adverse change				(1,462)	(2,011)	(661)	(643)
Annual discount rate on residual cash flows				13.40%	13.00%	19.10%	20.60%
Annual discount rate on servicing cash flows, Impact on fair value of 10% adverse change				(675)	(1,063)	(245)	(491)
Annual discount rate on servicing cash flows, Impact on fair value of 20% adverse change				$ (1,294)	$ (2,033)	$ (470)	$ (987)