SEGMENT REPORTING - Adjusted Net Income (Detail) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2016	Sep. 30, 2015	Sep. 30, 2016	Sep. 30, 2015
Revenues:
Management fees	$ 190,974	$ 47,106	$ 584,542	$ 148,848
Incentive income	99,256	3,385	242,894	3,949
Total revenues	290,230	50,491	827,436	152,797
Expenses:
Compensation and benefits	(97,552)	(101,240)	(308,959)	(319,133)
Equity-based compensation	(19,838)	(12,494)	(48,460)	(40,283)
Incentive income compensation	(47,385)	(4,907)	(92,653)	(107,010)
General and administrative	(32,252)	(37,627)	(113,032)	(77,695)
Depreciation and amortization	(3,867)	(4,032)	(12,076)	(10,031)
Total expenses	(202,339)	(190,518)	(579,171)	(672,421)
Interest expense, net of interest income	(32,414)	(56,023)	(86,849)	(155,334)
Other income (expense), net	543	6,368	11,892	13,925
Adjusted net income	162,140	26,980	409,810	262,285
Investment Management
Revenues:
Management fees	194,349	185,766	593,069	566,058
Incentive income	99,731	16,925	283,966	230,952
Investment income (loss)	70,928	(19,950)	133,730	56,873
Total revenues	365,008	182,741	1,010,765	853,883
Expenses:
Compensation and benefits	(94,624)	(97,348)	(298,067)	(310,996)
Equity-based compensation	(16,041)	(8,836)	(39,189)	(27,760)
Incentive income compensation	(47,378)	(7,596)	(132,534)	(127,252)
General and administrative	(29,258)	(30,279)	(91,339)	(90,181)
Depreciation and amortization	(2,866)	(3,031)	(9,074)	(7,027)
Total expenses	(190,167)	(147,090)	(570,203)	(563,216)
Adjusted net income before interest and other income (expense)	174,841	35,651	440,562	290,667
Interest expense, net of interest income	(7,799)	(8,388)	(24,458)	(26,103)
Other income (expense), net	(4,902)	(283)	(6,294)	(2,279)
Adjusted net income	$ 162,140	$ 26,980	$ 409,810	$ 262,285