SEGMENT REPORTING (Revenue, Expenses and Other Income (Expense) (Details) - USD ($) $ in Thousands	3 Months Ended								12 Months Ended
	Dec. 31, 2017	Sep. 30, 2017	Jun. 30, 2017	Mar. 31, 2017	Dec. 31, 2016	Sep. 30, 2016	Jun. 30, 2016	Mar. 31, 2016	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Segment revenues
Other fees									$ 0
Total revenues	$ 356,281	$ 283,671	$ 533,890	$ 241,657	$ 358,195	$ 335,460	$ 369,535	$ 136,015	1,415,499	$ 1,199,205	$ 814,442
Segment expenses
Total expenses	$ 310,967	$ 254,127	$ 448,197	$ 491,467	$ 299,573	$ 283,374	$ 303,935	$ 129,538	1,504,758	1,016,420	769,040
Segment other income
Net investment income (loss)									(29,917)	(50,414)	(25,638)
Operating segment
Segment revenues
Performance fees—realized									317,787	292,998	121,948
Segment expenses
Performance fee compensation—realized									242,330	198,264	65,191
Segment other income
Investment income (loss)—unrealized									44,992	19,976	(27,414)
Ares Management L.P
Segment revenues
Management fees (includes ARCC Part I Fees of $105,467, $121,181 and $121,491 for the years ended December 31, 2017, 2016 and 2015, respectively)									722,419	642,068	634,399
Other fees									56,406	39,285	29,428
Total revenues									1,415,499	1,199,205	814,442
Segment expenses
Compensation and benefits									514,109	447,725	414,454
Ares Management L.P | Operating segment
Segment revenues
Management fees (includes ARCC Part I Fees of $105,467, $121,181 and $121,491 for the years ended December 31, 2017, 2016 and 2015, respectively)									744,825	659,451	650,918
Other fees									22,431	12,351	4,599
Performance fees—realized									317,787	292,998	121,948
Performance fees—unrealized									325,915	228,472	31,647
Total revenues									1,410,958	1,193,272	809,112
Segment expenses
Compensation and benefits									300,177	285,268	273,753
General, administrative and other expenses									61,388	53,821	61,735
Performance fee compensation—realized									242,330	198,264	65,191
Performance fee compensation—unrealized									237,392	189,582	46,492
Total expenses									841,287	726,935	447,171
Segment other income
Investment income (loss)—realized									35,261	24,632	22,772
Investment income (loss)—unrealized									46,860	16,653	(27,414)
Interest and other investment income									12,061	44,359	16,854
Interest expense									(19,273)	(15,254)	(13,988)
Net investment income (loss)									74,909	70,390	(1,776)
Affiliated entity | ARCC
Segment revenues
Management fees (includes ARCC Part I Fees of $105,467, $121,181 and $121,491 for the years ended December 31, 2017, 2016 and 2015, respectively)									$ 105,467	$ 121,181	$ 121,491