11. Fair Value measurements (Details) (USD $) In Thousands, unless otherwise specified	3 Months Ended
	Mar. 31, 2013	Mar. 31, 2012
Finance Receivables Measured at Fair Value:
Balance at beginning of period	$ 59,668	$ 160,253
Payments on finance receivables at fair value	(16,519)	(36,500)
Charge-offs on finance receivables at fair value	(1,001)	(2,503)
Discount accretion	886	4,163
Mark to fair value	(13)	1,510
Balance at end of period	43,021	126,923
Balance at beginning of period	57,107	166,828
Principal payments on debt at fair value	(17,930)	(39,191)
Premium accretion	1,104	2,980
Mark to fair value	106	2,400
Balance at end of period	40,387	133,017
Reduction for principal payments collected and payable	(5,687)	(13,270)
Adjusted balance at end of period	$ 34,700	$ 119,747