Finance Receivables Allowance for Credit Losses (Details) (USD $)	3 Months Ended
	Mar. 31, 2013	Mar. 31, 2012	Dec. 31, 2012
Allowance Activity:
Balance, beginning of period	$ 252,590,000	$ 221,533,000
Provision for credit losses	77,842,000	60,342,000
Net charge-offs	(60,810,000)	(44,848,000)
Balance, end of period	269,622,000	237,027,000
Allowance as a percent of portfolio principal	15.70%	15.10%
Charge off Activity:
Principal balances	(97,917,000)	(82,851,000)
Recoveries, net	37,107,000	38,003,000
Net charge-offs	(60,810,000)	(44,848,000)
Other Receivables	$ 29,400,000		$ 37,000,000