15. Fair Value measurements (Details 2) (USD $) In Thousands, unless otherwise specified	12 Months Ended
	Dec. 31, 2012	Dec. 31, 2011
Finance Receivables Measured at Fair Value:
Balance at beginning of year	$ 160,253
Acquisitions		199,554
Payments on finance receivables at fair value	(104,682)	(41,926)
Charge-offs on finance receivables at fair value	(6,681)	(3,528)
Discount accretion	4,144	5,979
Mark to fair value	6,634	174
Balance at end of year	59,668	160,253
Debt Secured by Finance Receivables Measured at Fair Value:
Balance at beginning of year	166,828
New issuances		196,473
Principal payments on debt at fair value	(121,413)	(34,450)
Premium accretion	4,579	5,606
Mark to fair value	7,113	(801)
Balance at end of year	57,107	166,828
Reduction for principal payments collected and payable	(5,548)	(12,218)
Adjusted balance at end of year	$ 51,559	$ 154,610