INVESTMENTS - Investment income (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2016	Sep. 30, 2015	Sep. 30, 2016	Sep. 30, 2015
Schedule of Equity Method Investments [Line Items]
Other investments, at fair value	$ 668	$ (1,263)	$ 10,107	$ (269)
Total investment income	65,758	10,342	136,205	38,718
Oaktree funds
Schedule of Equity Method Investments [Line Items]
Equity-method investments investment income (loss)	47,323	(4,872)	76,224	(4,545)
Non-Oaktree funds
Schedule of Equity Method Investments [Line Items]
Equity-method investments investment income (loss)	0	3,316	318	8,049
Other investments, at fair value
Schedule of Equity Method Investments [Line Items]
Equity-method investments investment income (loss)	$ 17,767	$ 13,161	$ 49,556	$ 35,483