Finance Receivables - DriveTime - Allowance for Credit Losses (Details) (USD $)	3 Months Ended		6 Months Ended
	Jun. 30, 2013	Jun. 30, 2012	Jun. 30, 2013	Jun. 30, 2012	Dec. 31, 2012
Allowance Activity:
Balance, beginning of period	$ 269,622,000	$ 237,027,000	$ 252,590,000	$ 221,533,000
Provision for credit losses	70,313,000	51,387,000	148,155,000	111,729,000
Net charge-offs	(55,216,000)	(43,603,000)	(116,026,000)	(88,451,000)
Balance, end of period	284,719,000	244,811,000	284,719,000	244,811,000
Allowance as a percent of portfolio principal, end of period	15.80%	15.10%	15.80%	15.10%
Charge off Activity:
Principal balances	(86,942,000)	(73,075,000)	(184,859,000)	(155,926,000)
Recoveries, net	31,726,000	29,472,000	68,833,000	67,475,000
Net charge-offs	(55,216,000)	(43,603,000)	(116,026,000)	(88,451,000)
Other Receivables	$ 25,200,000		$ 25,200,000		$ 37,000,000