Dealer Finance Receivables Credit Quality Indicators (Details) (USD $) In Thousands, unless otherwise specified	Dec. 31, 2012 loan		Dec. 31, 2011 loan
Financing Receivable, Recorded Investment [Line Items]
Total Contracts Outstanding	140,748		137,293
Percentage of Portfolio Contracts	100.00%		100.00%
Principal Balances	$ 1,601,710		$ 1,466,680
Percentage of Portfolio Principal	100.00%		100.00%
Dealer Loans Auto Financing Receivable [Member]
Financing Receivable, Recorded Investment [Line Items]
Total Contracts Outstanding	4,777
Percentage of Portfolio Contracts	100.00%
Principal Balances	49,270
Percentage of Portfolio Principal	100.00%
Average Advance Rate	74.40%
A Plus [Member]
Financing Receivable, Recorded Investment [Line Items]
Average FICO Score	556	[1]	557	[1]
Total Contracts Outstanding	14,660		14,270
Percentage of Portfolio Contracts	10.40%		10.40%
Principal Balances	169,023		156,935
Percentage of Portfolio Principal	10.60%		10.70%
A Plus [Member] | Dealer Loans Auto Financing Receivable [Member]
Financing Receivable, Recorded Investment [Line Items]
Average FICO Score	557	[2]
Total Contracts Outstanding	319
Percentage of Portfolio Contracts	6.70%
Principal Balances	3,399
Percentage of Portfolio Principal	6.90%
Average Advance Rate	79.20%
A [Member]
Financing Receivable, Recorded Investment [Line Items]
Average FICO Score	539	[1]	538	[1]
Total Contracts Outstanding	25,998		24,954
Percentage of Portfolio Contracts	18.50%		18.20%
Principal Balances	301,173		274,269
Percentage of Portfolio Principal	18.80%		18.70%
A [Member] | Dealer Loans Auto Financing Receivable [Member]
Financing Receivable, Recorded Investment [Line Items]
Average FICO Score	541	[2]
Total Contracts Outstanding	706
Percentage of Portfolio Contracts	14.80%
Principal Balances	7,744
Percentage of Portfolio Principal	15.70%
Average Advance Rate	77.50%
B [Member]
Financing Receivable, Recorded Investment [Line Items]
Average FICO Score	517	[1]	516	[1]
Total Contracts Outstanding	52,476		50,582
Percentage of Portfolio Contracts	37.30%		36.80%
Principal Balances	612,084		561,738
Percentage of Portfolio Principal	38.20%		38.30%
B [Member] | Dealer Loans Auto Financing Receivable [Member]
Financing Receivable, Recorded Investment [Line Items]
Average FICO Score	531	[2]
Total Contracts Outstanding	1,617
Percentage of Portfolio Contracts	33.80%
Principal Balances	17,092
Percentage of Portfolio Principal	34.70%
Average Advance Rate	75.50%
C [Member]
Financing Receivable, Recorded Investment [Line Items]
Average FICO Score	503	[1]	500	[1]
Total Contracts Outstanding	40,066		38,756
Percentage of Portfolio Contracts	28.40%		28.20%
Principal Balances	445,497		397,470
Percentage of Portfolio Principal	27.80%		27.10%
C [Member] | Dealer Loans Auto Financing Receivable [Member]
Financing Receivable, Recorded Investment [Line Items]
Average FICO Score	521	[2]
Total Contracts Outstanding	1,598
Percentage of Portfolio Contracts	33.40%
Principal Balances	16,185
Percentage of Portfolio Principal	32.80%
Average Advance Rate	72.50%
C Minus [Member]
Financing Receivable, Recorded Investment [Line Items]
Average FICO Score	488	[1]	486	[1]
Total Contracts Outstanding	5,447		6,400
Percentage of Portfolio Contracts	3.90%		4.70%
Principal Balances	53,512		55,734
Percentage of Portfolio Principal	3.30%		3.80%
C Minus [Member] | Dealer Loans Auto Financing Receivable [Member]
Financing Receivable, Recorded Investment [Line Items]
Average FICO Score	508	[2]
Total Contracts Outstanding	366
Percentage of Portfolio Contracts	7.70%
Principal Balances	3,342
Percentage of Portfolio Principal	6.80%
Average Advance Rate	70.80%
D [Member] | Dealer Loans Auto Financing Receivable [Member]
Financing Receivable, Recorded Investment [Line Items]
Average FICO Score	497	[2]
Total Contracts Outstanding	171
Percentage of Portfolio Contracts	3.60%
Principal Balances	$ 1,508
Percentage of Portfolio Principal	3.10%
Average Advance Rate	67.60%

[1] Average FICO score is provided as an external metric of credit quality, but is generally not utilized to determine internal credit grade.

[2] Average FICO score is provided as an external metric of credit quality, but is generally not utilized to determine internal credit grade. Our internal scoring model is the primary driver of our internal credit grade. Average FICO presented excludes originations with no FICO.