SEGMENT REPORTING - Adjusted Net Income (Detail) (USD $) In Thousands, unless otherwise specified	3 Months Ended
	Mar. 31, 2013		Mar. 31, 2012
Revenues:
Management fees	$ 42,539	[1]	$ 32,020	[1]
Incentive income	0	[1]	5,048	[1]
Investment income (loss)	12,243	[1]	5,680	[1]
Total revenues	42,539		37,068
Expenses:
Compensation and benefits	93,715		84,464
Equity-based compensation	6,452		12,189	[2]
Incentive income compensation	130,271		27,757
Depreciation and amortization	1,743		1,787
Total expenses	275,505	[3]	167,567	[4]
Other income (expense), net	(20)		2,267
Adjusted net income	335,750		173,632
Segment [Member]
Revenues:
Management fees	184,214		191,262
Incentive income	327,184		62,669
Investment income (loss)	82,050		64,340
Total revenues	593,448		318,271
Expenses:
Compensation and benefits	(93,617)		(84,404)
Equity-based compensation	(652)		0
Incentive income compensation	(130,271)		(27,757)
General and Administrative Expense	(23,988)		(24,794)
Depreciation and amortization	(1,743)		(1,787)
Total expenses	(250,271)		(138,742)
Adjusted net income before interest and other income (expense)	343,177		179,529
Interest expense, net of interest income (1)	(7,407)	[5]	(8,164)	[5]
Other income (expense), net	(20)		2,267
Adjusted net income	$ 335,750		$ 173,632

[1] The adjustment represents the elimination of amounts attributable to the consolidated funds.

[2] This adjustment adds back the effect of equity-based compensation charges related to unit grants made before the Company’s initial public offering, which is excluded from adjusted net income because it is a non-cash charge that does not affect the Company's financial position.

[3] The expense adjustment consists of: (a) equity-based compensation charges of $5,800 related to unit grants made before the Company’s initial public offering, (b) consolidated fund expenses of $19,224 and (c) expenses incurred by the Intermediate Holding Companies of $210.

[4] The expense adjustment consists of: (a) equity-based compensation charges of $12,189 related to unit grants made before the Company’s initial public offering, (b) consolidated fund expenses of $16,458 and (c) expenses incurred by the Intermediate Holding Companies of $178.

[5] Interest income was $0.6 million and $0.5 million for the three months ended March 31, 2013 and 2012, respectively.