INVESTMENTS (Investments, Excluding Held-to-Maturity Investments) (Details) - Ares Management L.P - USD ($) $ in Thousands	Dec. 31, 2017	Dec. 31, 2016
Investments
Fair value investments	$ 647,335	$ 451,952
Equity method private investment partnership interests(1)
Investments
Fair value investments	$ 369,774	$ 309,512
Fair value as a percentage of total investments	57.10%	68.50%
Other private investment partnership Interests
Investments
Fair value investments	$ 80,767	$ 53,229
Fair value as a percentage of total investments	12.50%	11.80%
Partnership interests
Investments
Fair value investments	$ 450,541	$ 362,741
Fair value as a percentage of total investments	69.60%	80.30%
Fixed income - collateralized loan obligations
Investments
Fair value investments	$ 195,158	$ 89,111
Fair value as a percentage of total investments	30.10%	19.70%
Common Stock
Investments
Fair value investments	$ 1,636	$ 100
Fair value as a percentage of total investments	0.30%	0.00%