Loans Receivable (Schedule Of Consumer Loans Performance) (Details) (USD $) In Thousands, unless otherwise specified	Jun. 30, 2012	Mar. 31, 2012	Dec. 31, 2011	Jun. 30, 2011	Mar. 31, 2011	Dec. 31, 2010
Loans receivable	$ 1,977,794	$ 1,897,169	$ 1,752,891	$ 1,582,905	$ 1,488,356	$ 1,344,881
Allowance for credit losses	(161,905)	(159,373)	(154,318)	(144,819)	(135,868)	(126,868)
Loans receivable, net	1,815,889		1,598,573
Loan Pool Performance Meets Or Exceeds Initial Estimates [Member]
Loans receivable	795,165		704,428
Loans receivable, net	795,165		704,428
Loan Pool Performance Less Than Initial Estimates [Member]
Loans receivable	1,182,629		1,048,463
Allowance for credit losses	(161,905)		(154,318)
Loans receivable, net	1,020,724		894,145
Dealer Loans [Member]
Loans receivable	1,736,578	1,652,065	1,506,539	1,331,973	1,233,387	1,082,039
Allowance for credit losses	(152,031)	(148,225)	(141,712)	(131,728)	(122,801)	(113,227)
Loans receivable, net	1,584,547		1,364,827
Dealer Loans [Member] | Loan Pool Performance Meets Or Exceeds Initial Estimates [Member]
Loans receivable	592,319		511,926
Loans receivable, net	592,319		511,926
Dealer Loans [Member] | Loan Pool Performance Less Than Initial Estimates [Member]
Loans receivable	1,144,259		994,613
Allowance for credit losses	(152,031)		(141,712)
Loans receivable, net	992,228		852,901
Purchased Loans [Member]
Loans receivable	241,216	245,104	246,352	250,932	254,969	262,842
Allowance for credit losses	(9,874)	(11,148)	(12,606)	(13,091)	(13,067)	(13,641)
Loans receivable, net	231,342		233,746
Purchased Loans [Member] | Loan Pool Performance Meets Or Exceeds Initial Estimates [Member]
Loans receivable	202,846		192,502
Loans receivable, net	202,846		192,502
Purchased Loans [Member] | Loan Pool Performance Less Than Initial Estimates [Member]
Loans receivable	38,370		53,850
Allowance for credit losses	(9,874)		(12,606)
Loans receivable, net	$ 28,496		$ 41,244