LOANS RECEIVABLE AND REVENUE - Allowance For Doubtful Accounts, CSO Guarantee Liability (Details) - USD ($) $ in Thousands	3 Months Ended								12 Months Ended
	Dec. 31, 2019	Sep. 30, 2019	Jun. 30, 2019	Mar. 31, 2019	Dec. 31, 2018	Sep. 30, 2018	Jun. 30, 2018	Mar. 31, 2018	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Financing Receivable, Allowance for Credit Losses And Guarantor Obligations [Roll Forward]
Balance, beginning of period				$ 86,004				$ 81,922	$ 86,004	$ 81,922
Charge-offs									(639,627)	(642,099)
Recoveries									201,729	226,068
Net charge-offs									(437,898)	(416,031)
Provision for losses	$ 130,289	$ 123,867	$ 112,010	102,385	$ 130,678	$ 127,692	$ 86,347	76,883	468,551	421,600	$ 312,566
Effect of foreign currency translation									801	(1,487)
Balance, end of period	117,458				86,004				117,458	86,004	81,922
Consumer Portfolio Segment | Single-Pay
Financing Receivable, Allowance for Credit Losses And Guarantor Obligations [Roll Forward]
Balance, beginning of period				4,189				5,204	4,189	5,204
Charge-offs									(155,250)	(164,342)
Recoveries									109,124	115,118
Net charge-offs									(46,126)	(49,224)
Provision for losses									47,739	48,575
Effect of foreign currency translation									67	(366)
Balance, end of period	5,869				4,189				5,869	4,189	5,204
Consumer Portfolio Segment | Unsecured Installment
Financing Receivable, Allowance for Credit Losses And Guarantor Obligations [Roll Forward]
Balance, beginning of period				49,298				56,098	49,298	56,098
Charge-offs									(319,808)	(307,229)
Recoveries									56,908	52,516
Net charge-offs									(262,900)	(254,713)
Provision for losses									259,713	247,903
Effect of foreign currency translation									29	10
Balance, end of period	46,140				49,298				46,140	49,298	56,098
Consumer Portfolio Segment | Secured Installment
Financing Receivable, Allowance for Credit Losses And Guarantor Obligations [Roll Forward]
Balance, beginning of period				12,616				14,194	12,616	14,194
Charge-offs									(50,805)	(51,465)
Recoveries									13,352	13,374
Net charge-offs									(37,453)	(38,091)
Provision for losses									35,212	36,513
Effect of foreign currency translation									0	0
Balance, end of period	10,375				12,616				10,375	12,616	14,194
Consumer Portfolio Segment | Open-End
Financing Receivable, Allowance for Credit Losses And Guarantor Obligations [Roll Forward]
Balance, beginning of period				19,901				6,426	19,901	6,426
Charge-offs									(108,319)	(113,150)
Recoveries									19,061	41,457
Net charge-offs									(89,258)	(71,693)
Provision for losses									123,726	86,299
Effect of foreign currency translation									705	(1,131)
Balance, end of period	55,074				19,901				55,074	19,901	6,426
Consumer Portfolio Segment | Other
Financing Receivable, Allowance for Credit Losses And Guarantor Obligations [Roll Forward]
Balance, beginning of period				$ 0				$ 0	0	0
Charge-offs									(5,445)	(5,913)
Recoveries									3,284	3,603
Net charge-offs									(2,161)	(2,310)
Provision for losses									2,161	2,310
Effect of foreign currency translation									0	0
Balance, end of period	$ 0				$ 0				$ 0	$ 0	$ 0