DEBT OBLIGATIONS AND CREDIT FACILITIES - Revolving Bank Credit Facilities and Term Loans Outstanding of Consolidated Funds (Parenthetical) (Detail) In Thousands, unless otherwise specified	3 Months Ended			3 Months Ended						3 Months Ended
	Mar. 31, 2013	Mar. 31, 2013 Letter of Credit [Member] USD ($)	Dec. 31, 2012 Letter of Credit [Member] USD ($)	Mar. 31, 2013 Multi-currency term loan [Member] USD ($)		Mar. 31, 2013 Multi-currency term loan [Member] AUD	Mar. 31, 2013 Multi-currency term loan [Member] EUR (€)	Mar. 31, 2013 Credit Facilities [Member]		Mar. 31, 2013 5.03% [Member] USD ($)	Mar. 31, 2013 6.09% [Member] USD ($)	Mar. 31, 2013 5.82% [Member] USD ($)	Mar. 31, 2013 6.75% [Member] USD ($)	Mar. 31, 2013 2.50% Debt, Term Loan Two [Member] USD ($)
Line of Credit Facility [Line Items]
Debt Instrument, Payment Terms										$75,000, 5.03%, issued in June 2004, payable in seven equal annual installments starting June 14, 2008	$50,000, 6.09%, issued in June 2006, payable on June 6, 2016	$50,000, 5.82%, issued in November 2006, payable on November 8, 2016	$250,000, 6.75%, issued in November 2009, payable on December 2, 2019	$250,000, rate as described below, term loan issued in December 2012, payable 2.5% per quarter through September 2017, final $125,000 payment on December 21, 2017
Debt Instrument, Face Amount										$ 75,000	$ 50,000	$ 50,000	$ 250,000	$ 250,000
Outstanding amounts		77,002	76,975
LIBOR margin				3.00%	[1],[2]			1.25%	[1],[3],[4]
Debt Instrument, Basis Spread on Variable Rate, Future Rate								2.50%
Initial Borrowing Capacity				221,451		17,660	26,492
Loan Processing Fee				4,125
Term Loan Maturity	4 years
Debt Instrument, Interest Rate, Stated Percentage										5.03%	6.09%	5.82%	6.75%
Debt Instrument, Maturity Date										Jun. 14, 2008	Jun. 06, 2016	Nov. 08, 2016	Dec. 02, 2019	Dec. 21, 2017
Debt Instrument, Offering Date										Jun. 30, 2004	Jun. 30, 2006	Nov. 30, 2006	Nov. 30, 2009	Dec. 31, 2012
Final principal payment														$ 125,000
Debt Instrument, Loan Amortization Rate														2.50%
Term Loan Amortization Period	4 years

[1] The facilities bear interest, at the borrower's option, at (a) an annual rate of LIBOR plus the applicable margin or (b) an alternate base rate, as defined in the respective credit agreement.

[2] A four-year $275,000 aggregate principal amount term loan that consists of (a) a U.S. dollar-denominated loan in an aggregate principal amount of $221,451, (b) a euro-denominated loan in an aggregate principal amount of €26,492 and (c) an Australian dollar-denominated loan in an aggregate principal amount of A$17,660. The loan is guaranteed by the fund and, with certain limited exceptions, all of the subsidiaries of the fund, and is collateralized by both the unfunded capital commitments of the partners and, with certain exceptions, the portfolio investments of the fund and its subsidiaries. In connection with the term loan, $4,125 was paid to the administrative agent as a structuring fee and is being amortized over the 4-year life of the loan.

[3] Libor margin equals 1.25% through August 28, 2013 and 2.50% thereafter.

[4] The credit facility is collateralized by the portfolio investments and cash and cash-equivalents of the fund.