Finance Receivables - DriveTime - Allowance for Credit Losses (Details) (USD $)	3 Months Ended		9 Months Ended
	Sep. 30, 2013	Sep. 30, 2012	Sep. 30, 2013	Sep. 30, 2012	Dec. 31, 2012
Allowance Activity:
Balance, beginning of period	$ 284,719,000	$ 244,811,000	$ 252,590,000	$ 221,533,000
Provision for credit losses	92,335,000	70,110,000	240,489,000	181,840,000
Net charge-offs	(76,430,000)	(63,506,000)	(192,455,000)	(151,958,000)
Balance, end of period	300,624,000	251,415,000	300,624,000	251,415,000
Allowance as a percent of portfolio principal, end of period	16.20%	15.20%	16.20%	15.20%
Charge off Activity:
Principal balances	(117,383,000)	(102,060,000)	(302,241,000)	(257,986,000)
Recoveries, net	40,953,000	38,554,000	109,786,000	106,028,000
Net charge-offs	(76,430,000)	(63,506,000)	(192,455,000)	(151,958,000)
Other Receivables	$ 28,900,000		$ 28,900,000		$ 37,000,000