DERIVATIVES AND HEDGING - Impact of Derivative Instruments Held by Consolidated Funds on Condensed Consolidated Statements of Operations (Detail) - Not Designated as Hedging Instrument - Consolidated Funds - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2016	Jun. 30, 2015	Jun. 30, 2016	Jun. 30, 2015
Derivatives, Fair Value [Line Items]
Net Realized Gain (Loss) on Investments	$ (1,969)	$ 150,121	$ (2,239)	$ 457,152
Net Change in Unrealized Appreciation (Depreciation) on Investments	1,131	(399,415)	(1,022)	(449,247)
Foreign-currency forward contracts
Derivatives, Fair Value [Line Items]
Net Realized Gain (Loss) on Investments	(298)	175,334	(500)	471,310
Net Change in Unrealized Appreciation (Depreciation) on Investments	849	(339,448)	457	(319,064)
Total-return and interest-rate swaps
Derivatives, Fair Value [Line Items]
Net Realized Gain (Loss) on Investments	(907)	(2,248)	(890)	(7,174)
Net Change in Unrealized Appreciation (Depreciation) on Investments	222	(56,008)	(1,396)	(116,226)
Options and futures
Derivatives, Fair Value [Line Items]
Net Realized Gain (Loss) on Investments	(764)	(21,778)	(849)	(3,977)
Net Change in Unrealized Appreciation (Depreciation) on Investments	60	(5,150)	(83)	(16,299)
Swaptions
Derivatives, Fair Value [Line Items]
Net Realized Gain (Loss) on Investments	0	(1,187)	0	(3,007)
Net Change in Unrealized Appreciation (Depreciation) on Investments	$ 0	$ 1,191	$ 0	$ 2,342