SEGMENT REPORTING (Reconciliation of Income Before Taxes) (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2018	Jun. 30, 2017	Jun. 30, 2018	Jun. 30, 2017	Mar. 31, 2018	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Economic net income
Income (loss) before taxes	$ 51,072	$ 115,080	$ 113,118	$ (75,508)
Adjustments:
Equity compensation expenses	22,507	18,917	43,594	34,006
Consolidated Funds
Adjustments:
(Income) loss before taxes of non-controlling interests in Consolidated Funds, net of eliminations	9,882	(8,647)	10,249	7,208
Total investment income - realized	(92,633)	(38,326)	(157,055)	(79,818)
Due to affiliates	0		0			$ 0
Operating segment
Economic net income
Income (loss) before taxes	51,072	115,080	113,118	(75,508)
Adjustments:
Amortization of intangibles	3,285	5,274	6,572	10,549
Depreciation expense	4,426	2,774	8,315	5,990
Equity compensation expenses	22,507	18,917	43,594	34,006
Acquisition and merger-related expenses	47	756	(272)	255,844
Placement fees and underwriting costs	1,852	6,383	3,516	9,822
Offering costs	3	(5)	3	655
Other expense	13,551	0	13,558	0
Economic net income	134,360	209,125	272,748	329,397
Total performance income - unrealized	124,343	(263,629)	89,225	(312,890)
Total performance related compensation - unrealized	(100,886)	208,732	(89,877)	244,133
Total investment (income) loss - unrealized	(9)	(25,715)	5,565	(35,249)
Realized income	157,808	128,513	277,661	225,391
Total performance income - realized	(122,608)	(74,130)	(145,715)	(82,935)
Total performance related compensation - realized	87,881	52,973	102,750	58,274
Total investment income - realized	(10,495)	(4,522)	(12,431)	(5,908)
Fee related earnings	112,586	102,834	222,265	194,822
Economic net income	134,360	209,125	272,748	329,397
Performance related earnings	21,774	106,291	50,483	134,575
Operating segment | Consolidated Funds
Adjustments:
(Income) loss before taxes of non-controlling interests in Consolidated Funds, net of eliminations	(9,951)	8,251	(10,318)	(8,072)
Reconciling items
Adjustments:
Amortization of intangibles	3,285	5,274	6,572	10,549
Depreciation expense	4,426	2,774	8,315	5,990
Equity compensation expenses	22,507	18,917	43,594	34,006
Acquisition and merger-related expenses	47	724	(272)	276,060
Placement fees and underwriting costs	1,852	6,383	3,516	9,822
Offering costs	3	(5)	3	655
Other expense	1,715	0	1,722	0
Total consolidation adjustments and reconciling items	83,288	94,045	159,630	404,905
OMG
Adjustments:
OMG expenses, net	46,849	51,072	93,303	95,488
Economic net income	(46,849)	(51,072)	(93,303)	(95,488)
Total performance income - unrealized	0	0	0	0
Total investment (income) loss - unrealized	(2,866)	2,728	(4,097)	4,135
Realized income	(49,754)	(48,346)	(97,534)	(91,551)
Total performance income - realized	0	0	0	0
Total performance related compensation - realized	0	0	0	0
Total investment income - realized	(3,699)	1,626	(6,467)	776
Fee related earnings	(50,548)	(49,446)	(99,770)	(94,712)
Economic net income	(46,849)	(51,072)	(93,303)	(95,488)
Performance related earnings	3,699	(1,626)	6,467	(776)
Subsidiaries | Operating segment
Adjustments:
(Income) loss before taxes of non-controlling interests in Consolidated Funds, net of eliminations	719	623	1,359	623
Ares Management L.P
Adjustments:
Acquisition and merger-related expenses	0	0	0	275,177
Due to affiliates	62,344		62,344			39,184
Ares Management L.P | Operating segment
Adjustments:
Economic net income	134,360	209,125	272,748	329,397
Total performance income - unrealized	124,343	(263,629)	89,225	(312,890)
Total investment (income) loss - unrealized	(1,382)	(23,038)	4,269	(35,729)
Realized income	157,808	128,513	277,661	225,391
Total performance income - realized	(122,608)	(74,130)	(145,715)	(82,935)
Total performance related compensation - realized	87,881	52,973	102,750	58,274
Total investment income - realized	(10,504)	(30,237)	(6,866)	(41,157)
Fee related earnings	112,586	102,834	222,265	194,822
Economic net income	134,360	209,125	272,748	329,397
Performance related earnings	21,774	$ 106,291	50,483	$ 134,575
Ares Management L.P | ARCC | Affiliated entity | Rent and other occupancy expenses
Adjustments:
Due to affiliates	$ 11,800		$ 11,800		$ 600	$ 2,200	$ 3,000	$ 3,200	$ 2,900