LOANS RECEIVABLE AND REVENUE - CSO Guarantee Liability (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2018	Mar. 31, 2017
Guarantor Obligations [Roll Forward]
Balance, beginning of period	$ 17,795	$ 17,052
Charge-offs	(42,938)	(32,631)
Recoveries	12,145	13,987
Net charge-offs	(30,793)	(18,644)
Provision for losses	23,410	21,377
Balance, end of period	10,412	19,785
Consumer Portfolio Segment | Single-Pay
Guarantor Obligations [Roll Forward]
Balance, beginning of period		274
Charge-offs		(1,821)
Recoveries		659
Net charge-offs		(1,162)
Provision for losses		904
Balance, end of period		16
Consumer Portfolio Segment | Unsecured Installment
Guarantor Obligations [Roll Forward]
Balance, beginning of period	17,073	15,630
Charge-offs	(41,719)	(27,647)
Recoveries	10,976	10,957
Net charge-offs	(30,743)	(16,690)
Provision for losses	23,556	19,542
Balance, end of period	9,886	18,482
Consumer Portfolio Segment | Secured Installment
Guarantor Obligations [Roll Forward]
Balance, beginning of period	722	1,148
Charge-offs	(1,219)	(3,163)
Recoveries	1,169	2,371
Net charge-offs	(50)	(792)
Provision for losses	(146)	931
Balance, end of period	$ 526	$ 1,287