DEBT OBLIGATIONS (Details)					3 Months Ended			3 Months Ended						1 Months Ended	3 Months Ended			1 Months Ended	3 Months Ended				0 Months Ended	3 Months Ended		1 Months Ended	3 Months Ended			3 Months Ended			1 Months Ended	3 Months Ended	1 Months Ended			3 Months Ended		1 Months Ended	3 Months Ended			1 Months Ended		3 Months Ended							0 Months Ended				3 Months Ended
	Mar. 31, 2013 USD ($)	Dec. 31, 2012 USD ($)	Mar. 31, 2013 Investment Financing Arrangements USD ($)	Dec. 31, 2012 Investment Financing Arrangements USD ($)	Mar. 31, 2013 Term Facility USD ($)	Mar. 31, 2012 Term Facility USD ($)	Dec. 31, 2012 Term Facility USD ($)	Mar. 31, 2013 Term Facility March 12, 2010 Through June 7, 2012	Mar. 31, 2013 Term Facility June 8, 2012 Through Maturity	Mar. 31, 2013 Revolver Facility USD ($)	Mar. 31, 2012 Revolver Facility USD ($)	Dec. 31, 2012 Revolver Facility USD ($)	Apr. 30, 2011 Revolver Facility item	May 31, 2011 Mezzanine Investment Credit Agreement USD ($)	Mar. 31, 2013 Mezzanine Investment Credit Agreement USD ($)	Mar. 31, 2012 Mezzanine Investment Credit Agreement USD ($)	Dec. 31, 2012 Mezzanine Investment Credit Agreement USD ($)	Sep. 30, 2010 2020 Senior Notes USD ($)	Mar. 31, 2013 2020 Senior Notes USD ($)	Mar. 31, 2012 2020 Senior Notes USD ($)	Dec. 31, 2012 2020 Senior Notes USD ($)	Sep. 29, 2010 2020 Senior Notes	Feb. 02, 2013 2043 Senior Notes USD ($)	Mar. 31, 2013 2043 Senior Notes USD ($)	Feb. 01, 2013 2043 Senior Notes	Nov. 30, 2011 Lending Partners Credit Agreement USD ($)	Mar. 31, 2013 Lending Partners Credit Agreement USD ($)	Mar. 31, 2012 Lending Partners Credit Agreement USD ($)	Dec. 31, 2012 Lending Partners Credit Agreement USD ($)	Mar. 31, 2013 Lending Partners Credit Agreement After November 15, 2016	Mar. 31, 2013 Lending Partners Credit Agreement Broadly syndicated loans Through November 15, 2016	Mar. 31, 2013 Lending Partners Credit Agreement Other loans Through November 15, 2016	Jan. 31, 2013 2013 Lending Partners Credit Agreement USD ($)	Mar. 31, 2013 2013 Lending Partners Credit Agreement USD ($)	Dec. 31, 2012 KKR European Fund III Investment Credit Agreement USD ($)	Dec. 31, 2011 KKR European Fund III Investment Credit Agreement USD ($)	Dec. 31, 2011 KKR European Fund III Investment Credit Agreement EUR (€)	Mar. 31, 2013 KKR European Fund III Investment Credit Agreement USD ($)	Mar. 31, 2012 KKR European Fund III Investment Credit Agreement USD ($)	Jan. 31, 2012 KKR Debt Investors II Investment Credit Agreement	Mar. 31, 2013 KKR Debt Investors II Investment Credit Agreement USD ($)	Mar. 31, 2012 KKR Debt Investors II Investment Credit Agreement USD ($)	Dec. 31, 2012 KKR Debt Investors II Investment Credit Agreement USD ($)	Mar. 31, 2013 Special Situations Investment Credit Agreement USD ($)	Jun. 30, 2011 Corporate Credit Agreement USD ($)	Mar. 31, 2013 Corporate Credit Agreement USD ($)	Mar. 31, 2012 Corporate Credit Agreement USD ($)	Dec. 31, 2012 Corporate Credit Agreement USD ($)	Jun. 03, 2011 Corporate Credit Agreement USD ($)	Feb. 22, 2011 Corporate Credit Agreement USD ($)	Feb. 26, 2008 Corporate Credit Agreement USD ($)	Feb. 26, 2008 Corporate Credit Agreement Swing-line notes USD ($)	Aug. 20, 2012 Corporate Credit Agreement Letters of Credit USD ($)	Jul. 02, 2012 Corporate Credit Agreement Letters of Credit USD ($)	Mar. 31, 2013 Corporate Credit Agreement Letters of Credit USD ($)	Feb. 26, 2008 Corporate Credit Agreement Letters of Credit USD ($)	Mar. 31, 2013 KCM Credit Agreement USD ($)	Mar. 31, 2012 KCM Credit Agreement USD ($)	Dec. 31, 2012 KCM Credit Agreement USD ($)	Mar. 31, 2013 KCM Credit Agreement Letters of Credit USD ($)
Debt obligations
Total Debt obligations	$ 1,633,597,000	$ 1,123,414,000	$ 640,845,000	$ 625,026,000															$ 992,752,000		$ 498,388,000
Original amount financed					80,900,000		80,900,000
Variable interest rate base								5-Year interest rate swap rate	One year LIBOR	Hong Kong interbank market rate					LIBOR															LIBOR	LIBOR	LIBOR				LIBOR	LIBOR							LIBOR
Percentage points added to the reference rate								1.75%	1.75%	3.75%					2.75%															4.00%	1.75%	2.75%				1.75%	1.75%							1.60%
Interest rate (as a percent)								4.65%
Interest rate on outstanding borrowings (as a percent)					2.82%					4.30%					2.98%												2.98%							2.43%							3.50%
Number of investment vehicles entering into revolving credit facility (in entities)													1
Maximum borrowing capacity										50,100,000				200,000,000												200,000,000	400,000,000						150,000,000			66,500,000	50,000,000				200,000,000			75,000,000					750,000,000	700,000,000	1,000,000,000	50,000,000				25,000,000	500,000,000			500,000,000
Number of additional years agreement can be extended										2 years																	2 years						1 year
Optional expansion, maximum borrowing capacity										75,100,000
Outstanding amount										40,800,000		40,900,000			125,100,000		143,700,000										228,000,000		170,000,000					16,000,000	39,500,000			0			150,000,000		150,000,000	0		0		0									0		0
Term of revolving credit agreement														3 years												5 years							5 years			1 year	1 year			3 years				3 years
Amount borrowed					0	0				0	0				0	52,000,000											58,000,000	13,100,000						16,000,000				0	30,200,000		0	150,000,000				0	0						20,000,000	14,500,000			0	0
Amount repaid					0	0				0	0				14,900,000	89,200,000											0	0						0				39,500,000	0		0	0
Renewed term of revolving credit agreement																																			1 year
Aggregate principal amount of notes issued																		500,000,000					500,000,000
Interest rate (as a percent)																			6.375%			6.375%			5.50%
Percentage of par value at which debt was issued																						99.584%			98.856%
Interest expenses on senior notes																			8,000,000	8,000,000				4,600,000
Fair value of senior notes																			592,500,000					479,200,000
Minimum percentage of aggregate principal amount held by trustee or holders to declare notes due and payable																			25.00%					25.00%
Percentage of principal amount at which notes are subject to repurchase in event of change of control																			101.00%					101.00%
Additions to maximum borrowing capacity																																													50,000,000
Line of credit facility available borrowing capacity																																																							$ 5,000,000