INVESTMENTS IN CONSUMER LOANS - Consumer Loan Variable Interest Entities (Details) - VIE, consolidated - USD ($) $ in Thousands	9 Months Ended
	Sep. 30, 2018	Dec. 31, 2017
Variable Interest Entity [Line Items]
Total assets	$ 815,516	$ 1,056,042
Notes and bonds payable	610,277	789,979
Accounts payable and accrued expenses	3,055	3,308
Total liabilities	613,332	793,287
Consumer Loan Companies
Variable Interest Entity [Line Items]
Consumer loans, held-for-investment	1,097,512	1,289,010
Restricted cash	10,479	11,563
Accrued interest receivable	16,351	19,360
Total assets	1,124,342	1,319,933
Notes and bonds payable	1,088,954	1,284,436
Accounts payable and accrued expenses	4,144	4,007
Total liabilities	1,093,098	$ 1,288,443
Face amount of bonds retained	$ 121,000