SEGMENT REPORTING (Details) (USD $)	3 Months Ended
	Mar. 31, 2013 item	Mar. 31, 2012	Dec. 31, 2012
SEGMENT REPORTING
Number of reportable segments of the entity	3
Management and incentive fees:
Incentive fees	$ 18,830,000	$ 9,670,000
Monitoring and transaction fees:
Total fees	151,240,000	116,307,000
Expenses
Compensation and benefits	331,121,000	372,410,000
Occupancy and Related Charges	14,521,000	15,197,000
Total Expenses	439,330,000	445,258,000
Fee related earnings	88,000,000	73,356,000
Investment income (loss)
Total Investment Income (Loss)	2,395,632,000	3,317,998,000
Income (loss) before noncontrolling interests in income of consolidated entities	2,107,542,000	2,989,047,000
Income (loss) attributable to noncontrolling interests	1,880,124,000	2,776,267,000
Economic net income (loss)	647,742,000	727,202,000
Allocation of economic net income (loss)
Total Assets	45,542,791,000	43,520,412,000	44,426,353,000
Book Value	2,156,069,000	1,510,273,000
Fee Credits as a percentage of monitoring and transaction fees net of fund-related expenses	80.00%	80.00%
Amount of carried interest subject to management fee refunds	0	66,000,000
Management fee refunds liability		0
Maximum
Allocation of economic net income (loss)
Percentage of cash management fees to be refunded if carried interest is recognized	20.00%	20.00%
Reduction in carried interest as percentage of cash management fees on recognition of carried interest	20.00%	20.00%
Private Markets
Management and incentive fees:
Management fees	106,605,000	106,912,000
Management and incentive fees	106,605,000	106,912,000
Monitoring and transaction fees:
Monitoring fees	32,068,000	25,822,000
Transaction fees	16,412,000	11,667,000
Fee Credits	(21,009,000)	(17,706,000)
Net monitoring and transaction fees	27,471,000	19,783,000
Total fees	134,076,000	126,695,000
Expenses
Compensation and benefits	48,001,000	44,486,000
Occupancy and Related Charges	11,425,000	12,805,000
Other operating expenses	33,942,000	31,675,000
Total Expenses	93,368,000	88,966,000
Fee related earnings	40,708,000	37,729,000
Investment income (loss)
Realized carried interest	88,167,000	74,878,000
Unrealized carried interest	310,799,000	379,627,000
Gross carried interest	398,966,000	454,505,000
Less: Allocation to KKR carry pool	(161,344,000)	(185,562,000)
Less: Management fee refunds	(9,216,000)	(40,708,000)
Net carried interest	228,406,000	228,235,000
Other investment income (loss)	(2,035,000)	1,652,000
Total Investment Income (Loss)	226,371,000	229,887,000
Income (loss) before noncontrolling interests in income of consolidated entities	267,079,000	267,616,000
Income (loss) attributable to noncontrolling interests	398,000	2,296,000
Economic net income (loss)	266,681,000	265,320,000
Allocation of economic net income (loss)
Total Assets	1,378,436,000	977,928,000
Book Value	1,288,030,000	818,495,000
Public Markets
Management and incentive fees:
Management fees	46,358,000	21,731,000
Incentive fees	18,849,000	9,670,000
Management and incentive fees	65,207,000	31,401,000
Monitoring and transaction fees:
Transaction fees	3,106,000	2,422,000
Fee Credits	(2,056,000)	(1,637,000)
Net monitoring and transaction fees	1,050,000	785,000
Total fees	66,257,000	32,186,000
Expenses
Compensation and benefits	19,700,000	11,382,000
Occupancy and Related Charges	1,542,000	1,418,000
Other operating expenses	7,826,000	3,977,000
Total Expenses	29,068,000	16,777,000
Fee related earnings	37,189,000	15,409,000
Investment income (loss)
Unrealized carried interest	20,399,000	14,859,000
Gross carried interest	20,399,000	14,859,000
Less: Allocation to KKR carry pool	(8,160,000)	(5,944,000)
Net carried interest	12,239,000	8,915,000
Other investment income (loss)	62,000	(23,000)
Total Investment Income (Loss)	12,301,000	8,892,000
Income (loss) before noncontrolling interests in income of consolidated entities	49,490,000	24,301,000
Income (loss) attributable to noncontrolling interests	355,000	431,000
Economic net income (loss)	49,135,000	23,870,000
Allocation of economic net income (loss)
Total Assets	383,213,000	82,917,000
Book Value	359,112,000	70,903,000
Equity ownership in the business (as a percent)	1.00%	1.00%
Capital Markets and Principle Activities
Monitoring and transaction fees:
Transaction fees	20,781,000	30,209,000
Net monitoring and transaction fees	20,781,000	30,209,000
Total fees	20,781,000	30,209,000
Expenses
Compensation and benefits	7,461,000	6,856,000
Occupancy and Related Charges	355,000	238,000
Other operating expenses	2,862,000	2,897,000
Total Expenses	10,678,000	9,991,000
Fee related earnings	10,103,000	20,218,000
Investment income (loss)
Other investment income (loss)	322,171,000	418,278,000
Total Investment Income (Loss)	322,171,000	418,278,000
Income (loss) before noncontrolling interests in income of consolidated entities	332,274,000	438,496,000
Income (loss) attributable to noncontrolling interests	348,000	484,000
Economic net income (loss)	331,926,000	438,012,000
Allocation of economic net income (loss)
Total Assets	6,458,470,000	5,714,419,000
Book Value	5,421,250,000	5,187,758,000
Equity ownership in the business (as a percent)	2.00%	2.00%
Total Reportable Segments
Management and incentive fees:
Management fees	152,963,000	128,643,000
Incentive fees	18,849,000	9,670,000
Management and incentive fees	171,812,000	138,313,000
Monitoring and transaction fees:
Monitoring fees	32,068,000	25,822,000
Transaction fees	40,299,000	44,298,000
Fee Credits	(23,065,000)	(19,343,000)
Net monitoring and transaction fees	49,302,000	50,777,000
Total fees	221,114,000	189,090,000
Expenses
Compensation and benefits	75,162,000	62,724,000
Occupancy and Related Charges	13,322,000	14,461,000
Other operating expenses	44,630,000	38,549,000
Total Expenses	133,114,000	115,734,000
Fee related earnings	88,000,000	73,356,000
Investment income (loss)
Realized carried interest	88,167,000	74,878,000
Unrealized carried interest	331,198,000	394,486,000
Gross carried interest	419,365,000	469,364,000
Less: Allocation to KKR carry pool	(169,504,000)	(191,506,000)
Less: Management fee refunds	(9,216,000)	(40,708,000)
Net carried interest	240,645,000	237,150,000
Other investment income (loss)	320,198,000	419,907,000
Total Investment Income (Loss)	560,843,000	657,057,000
Income (loss) before noncontrolling interests in income of consolidated entities	648,843,000	730,413,000
Income (loss) attributable to noncontrolling interests	1,101,000	3,211,000
Economic net income (loss)	647,742,000	727,202,000
Allocation of economic net income (loss)
Total Assets	8,220,119,000	6,775,264,000
Book Value	$ 7,068,392,000	$ 6,077,156,000