5. Interest Income (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2015	Sep. 30, 2014	Sep. 30, 2015	Sep. 30, 2014
Components of interest income
Interest on Finance Receivables	$ 90,564	$ 73,781	$ 257,757	$ 206,761
Residual interest income	20	84	85	320
Other interest income	0	0	1	1
Interest income	$ 90,584	$ 73,865	$ 257,843	$ 207,082