Finance Receivables - DriveTime - Credit Quality Indicators (Details) (USD $) In Thousands, unless otherwise specified	Sep. 30, 2013 loan		Dec. 31, 2012 loan		Sep. 30, 2012
Financing Receivable, Recorded Investment [Line Items]
Percentage of Portfolio Loans	100.00%		100.00%
Total Loans	151,431		140,748
Percentage of Portfolio Principal	100.00%		100.00%
Loan Principal	$ 1,851,055		$ 1,601,710		$ 1,643,281
Internally Assigned Credit Grade A Plus [Member]
Financing Receivable, Recorded Investment [Line Items]
Average FICO Score	554	[1]	556	[1]
Percentage of Portfolio Loans	10.40%		10.40%
Total Loans	15,692		14,660
Percentage of Portfolio Principal	10.50%		10.60%
Loan Principal	194,200		169,023
Internally Assigned Credit Grade A [Member]
Financing Receivable, Recorded Investment [Line Items]
Average FICO Score	541	[1]	539	[1]
Percentage of Portfolio Loans	18.40%		18.50%
Total Loans	27,912		25,998
Percentage of Portfolio Principal	18.80%		18.80%
Loan Principal	347,452		301,173
Internally Assigned Credit Grade B [Member]
Financing Receivable, Recorded Investment [Line Items]
Average FICO Score	518	[1]	517	[1]
Percentage of Portfolio Loans	38.10%		37.30%
Total Loans	57,665		52,476
Percentage of Portfolio Principal	38.60%		38.20%
Loan Principal	715,545		612,084
Internally Assigned Credit Grade C [Member]
Financing Receivable, Recorded Investment [Line Items]
Average FICO Score	505	[1]	503	[1]
Percentage of Portfolio Loans	28.40%		28.40%
Total Loans	43,020		40,066
Percentage of Portfolio Principal	28.00%		27.80%
Loan Principal	517,836		445,497
Internally Assigned Credit Grade C Minus [Member]
Financing Receivable, Recorded Investment [Line Items]
Average FICO Score	493	[1]	488	[1]
Percentage of Portfolio Loans	3.40%		3.90%
Total Loans	5,136		5,447
Percentage of Portfolio Principal	2.90%		3.30%
Loan Principal	54,345		53,512
Internally Assigned Credit Grade D Plus And Below [Member]
Financing Receivable, Recorded Investment [Line Items]
Average FICO Score	486	[1]	478	[1]
Percentage of Portfolio Loans	1.30%		1.50%
Total Loans	2,006		2,101
Percentage of Portfolio Principal	1.20%		1.30%
Loan Principal	$ 21,677		$ 20,421

[1] Average FICO score is provided as an external metric of credit quality. FICO score is not utilized as the primary tool in determining internal credit grade.