INVESTMENTS IN AFFILIATES (Detail) - Schedule of Equity investment in Operating affiliates and equity in net income (loss) from such affiliates (USD $) In Thousands, unless otherwise specified	12 Months Ended
	Dec. 31, 2011		Dec. 31, 2010		Dec. 31, 2009
Operating affiliates:
Carrying value of equity method investment, operating affiliates	$ 1,052,729		$ 1,127,181
Equity in net income (loss) in operating affiliates	103,039		172,474		139,347
Financial operating affiliates [Member]
Operating affiliates:
Carrying value of equity method investment, operating affiliates	732		1,750
Equity in net income (loss) in operating affiliates	(1,018)		53,031
Estimated assets in operating affiliates	11,957,534	[1]	6,212,583	[1]
Estimated liabilities in operating affiliates	11,931,662	[1]	6,179,978	[1]
Revenue (loss) of operating affiliates	12,564	[1]	(688)	[1]
Net income (loss) of operating affiliates	1,115	[1]	(15,641)	[1]
Other Strategic Operating Affiliates [Member]
Operating affiliates:
Carrying value of equity method investment, operating affiliates	153,955		122,266
Equity in net income (loss) in operating affiliates	20,891		28,161
Estimated assets in operating affiliates	1,295,921	[1]	1,075,578	[1]
Estimated liabilities in operating affiliates	967,264	[1]	772,572	[1]
Revenue (loss) of operating affiliates	348,831	[1]	274,786	[1]
Net income (loss) of operating affiliates	48,641	[1]	48,792	[1]
Investment Manager Affiliates [Member]
Operating affiliates:
Carrying value of equity method investment, operating affiliates	129,191	[2]	174,106	[2]
Equity in net income (loss) in operating affiliates	56,913	[2]	40,180	[2]
Estimated assets in operating affiliates	601,511	[1],[2]	654,229	[1],[2]
Estimated liabilities in operating affiliates	38,349	[1],[2]	70,816	[1],[2]
Revenue (loss) of operating affiliates	319,984	[1],[2]	375,384	[1],[2]
Net income (loss) of operating affiliates	222,260	[1],[2]	348,615	[1],[2]
Operating Affiliates [Member]
Operating affiliates:
Carrying value of equity method investment, operating affiliates	283,878		298,122
Equity in net income (loss) in operating affiliates	76,786		121,372
Estimated assets in operating affiliates	13,854,966	[1]	7,942,390	[1]
Estimated liabilities in operating affiliates	12,937,275	[1]	7,023,366	[1]
Revenue (loss) of operating affiliates	681,379	[1]	649,482	[1]
Net income (loss) of operating affiliates	$ 272,016	[1]	$ 381,766	[1]

[1] The Company generally records its operating affiliates on a one quarter lag. Estimated assets and liabilities are generally at September 30, 2011 and 2010, respectively.

[2] During the year ended December 31, 201,1 the Company received distributions from its Investment Manager Affiliates of approximately $23.2 million, sold its interests in Finisterre for total proceeds of $35.0 million as explained below at "Investment Manager Affiliates," and received $44.2 million as repayment of a note.