INVESTMENTS - Investment income (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2016	Jun. 30, 2015	Jun. 30, 2016	Jun. 30, 2015
Schedule of Equity Method Investments [Line Items]
Other investments, at fair value	$ 14,059	$ 121	$ 9,439	$ 994
Total investment income	41,000	15,694	70,447	28,376
Oaktree funds
Schedule of Equity Method Investments [Line Items]
Equity-method investments investment income (loss)	10,245	1,075	28,901	327
Non-Oaktree funds
Schedule of Equity Method Investments [Line Items]
Equity-method investments investment income (loss)	14	2,140	318	4,733
Other investments, at fair value
Schedule of Equity Method Investments [Line Items]
Equity-method investments investment income (loss)	$ 16,682	$ 12,358	$ 31,789	$ 22,322