HEDGES AND OTHER DERIVATIVE FINANCIAL INSTRUMENTS - Summary of Impact of Freestanding Derivative Instruments on Condensed Consolidated Statement of Operations (Detail) (Not Designated as Hedging Instrument [Member], Forward contracts (net) [Member], USD $) In Thousands, unless otherwise specified	3 Months Ended		12 Months Ended
	Mar. 31, 2013		Dec. 31, 2012
Not Designated as Hedging Instrument [Member] | Forward contracts (net) [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Foreign currency forward contracts	$ 4,359	[1]	$ 764	[1]

[1] To the extent that the Company's freestanding derivatives are utilized to hedge its exposure to investment income and management fees earned from consolidated funds, the related hedged items are eliminated in consolidation with the derivative impact (a positive number reflects a reduction of expenses) reflected in consolidated general and administrative expenses.