SEGMENT REPORTING (Reconciliation of Income Before Taxes) (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2017	Mar. 31, 2016
Economic net income
Loss before taxes	$ (190,588)	$ (8,974)
Adjustments:
Equity compensation expenses	15,089	9,173
Income tax expense	34,264	(4,665)
Operating segment
Economic net income
Loss before taxes	(190,588)	(8,974)
Adjustments:
Amortization of intangibles	5,275	7,263
Depreciation expense	3,216	1,858
Equity compensation expenses	15,089	9,173
Acquisition and merger-related expenses	255,088	496
Placement fees and underwriting costs	3,439	930
Offering costs	660	0
Economic net income	120,708	67,425
Total performance fees income - realized	(8,805)	(6,349)
Total performance fees income - unrealized	(49,261)	37,348
Total performance fee compensation - realized	5,301	1,983
Total performance fee compensation - unrealized	35,401	(23,313)
Total investment income	(10,920)	4,782
Fee related earnings	92,424	81,876
Investment and other income (expense) realized, net	1,385	4,171
Dividend equivalent	(2,681)	(684)
One-time acquisition costs	(12)	(270)
Income tax expense	(226)	(232)
Non-cash items	(186)	164
Placement fees and underwriting costs, noncorporate	(3,439)	(938)
Depreciation and amortization	(1,470)	(931)
Distributable earnings	89,299	87,522
Economic net income	120,708	67,425
Less: fee related earnings	(92,424)	(81,876)
Performance related earnings	28,284	(14,451)
Reconciling items
Adjustments:
Amortization of intangibles	5,275	7,263
Depreciation expense	3,216	1,858
Equity compensation expenses	15,089	9,173
Acquisition and merger-related expenses	275,336	268
Placement fees and underwriting costs	3,439	930
Offering costs	660	0
Total consolidation adjustments and reconciling items	311,296	76,399
OMG
Adjustments:
OMG expenses, net	44,852	43,277
Economic net income	(44,852)	(43,277)
Total performance fees income - realized	0	0
Total performance fees income - unrealized	0	0
Total performance fee compensation - realized	0	0
Total performance fee compensation - unrealized	0	0
Total investment income	(850)	449
Fee related earnings	(45,702)	(42,828)
Distributable earnings	(48,390)	(46,241)
Economic net income	(44,852)	(43,277)
Less: fee related earnings	45,702	42,828
Performance related earnings	850	(449)
Consolidated Funds
Adjustments:
(Income) loss before taxes of non-controlling interests in Consolidated Funds, net of eliminations	15,855	(11,979)
Total investment income	(10,170)	(7,332)
Consolidated Funds | Operating segment
Adjustments:
(Income) loss before taxes of non-controlling interests in Consolidated Funds, net of eliminations	$ (16,323)	$ 13,402