Dealer Finance Receivables non-accretable yield (Details) (USD $) In Thousands, unless otherwise specified	3 Months Ended
	Mar. 31, 2013
Receivables [Abstract]
Contractual Cash Not Expected to be Received, Maximum, Percentage	100.00%
Contractual Net Cash Flows	$ 103,306	[1]
Expected Net Cash Flows	(91,602)
Non-accretable Yield	$ 11,704

[1] Contractual net cash flows represents total cash payments due across all dealer servicing agreements for repayment of dealer advances and contract servicing.