Finance Receivables - DriveTime - Concentration of Credit Risk (Details) (USD $) In Thousands, unless otherwise specified	Jun. 30, 2013	Dec. 31, 2012	Jun. 30, 2012
Concentration Risk [Line Items]
Percent of Portfolio	100.00%	100.00%
Loan Principal	$ 1,792,566	$ 1,601,710	$ 1,616,165
TEXAS [Member]
Concentration Risk [Line Items]
Percent of Portfolio	21.90%	23.00%
Loan Principal	393,122	369,021
FLORIDA [Member]
Concentration Risk [Line Items]
Percent of Portfolio	15.40%	15.40%
Loan Principal	276,175	247,281
NORTH CAROLINA [Member]
Concentration Risk [Line Items]
Percent of Portfolio	9.40%	9.90%
Loan Principal	165,688	157,670
GEORGIA [Member]
Concentration Risk [Line Items]
Percent of Portfolio	7.70%	7.60%
Loan Principal	138,694	122,027
VIRGINIA [Member]
Concentration Risk [Line Items]
Percent of Portfolio	6.30%	6.70%
Loan Principal	113,696	106,749
ARIZONA [Member]
Concentration Risk [Line Items]
Percent of Portfolio	6.30%	6.80%
Loan Principal	113,374	108,792
TENNESSEE [Member]
Concentration Risk [Line Items]
Percent of Portfolio	5.20%	4.60%
Loan Principal	92,078	72,967
CALIFORNIA [Member]
Concentration Risk [Line Items]
Percent of Portfolio	4.40%	4.40%
Loan Principal	79,261	71,005
NEVADA [Member]
Concentration Risk [Line Items]
Percent of Portfolio	3.70%	4.00%
Loan Principal	66,635	63,346
SOUTH CAROLINA [Member]
Concentration Risk [Line Items]
Percent of Portfolio	3.80%	3.60%
Loan Principal	68,118	58,163
ALABAMA [Member]
Concentration Risk [Line Items]
Percent of Portfolio	3.30%	2.80%
Loan Principal	59,663	44,787
NEW MEXICO [Member]
Concentration Risk [Line Items]
Percent of Portfolio	2.70%	3.00%
Loan Principal	48,712	48,421
OKLAHOMA [Member]
Concentration Risk [Line Items]
Percent of Portfolio	2.30%	2.30%
Loan Principal	41,490	36,109
COLORADO [Member]
Concentration Risk [Line Items]
Percent of Portfolio	2.00%	2.20%
Loan Principal	35,304	35,268
OHIO [Member]
Concentration Risk [Line Items]
Percent of Portfolio	2.00%	1.10%
Loan Principal	36,271	17,417
INDIANA [Member]
Concentration Risk [Line Items]
Percent of Portfolio	1.40%	1.30%
Loan Principal	25,921	21,603
MISSISSIPPI [Member]
Concentration Risk [Line Items]
Percent of Portfolio	1.20%	1.00%
Loan Principal	20,856	15,847
ARKANSAS [Member]
Concentration Risk [Line Items]
Percent of Portfolio	0.50%	0.20%
Loan Principal	8,329	3,218
MISSOURI [Member]
Concentration Risk [Line Items]
Percent of Portfolio	0.50%	0.10%
Loan Principal	$ 9,179	$ 2,019