INVESTMENTS IN CONSUMER LOANS - Noncontrolling Interest (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2018	Mar. 31, 2017	Dec. 31, 2017
Noncontrolling Interest [Line Items]
Total Consumer Loan Companies equity	$ 5,663,936		$ 4,690,205
Others’ interests in equity of consolidated subsidiary	97,751		105,957
Noncontrolling interests in income (loss) of consolidated subsidiaries	10,111	$ 15,780
Consumer Loan Companies
Noncontrolling Interest [Line Items]
Total Consumer Loan Companies equity	69,589		$ 74,071
Net Consumer Loan Companies income (loss)	$ 18,769	$ 21,420
Consumer Loan Companies
Noncontrolling Interest [Line Items]
Others’ ownership interest	46.50%	46.50%	46.50%
Others’ interests in equity of consolidated subsidiary	$ 32,359		$ 34,466
Noncontrolling interests in income (loss) of consolidated subsidiaries	$ 8,728	$ 9,960