Financial Data of Segments (Detail) (USD $) In Thousands, unless otherwise specified	3 Months Ended
	Mar. 31, 2014	Mar. 31, 2013	Dec. 31, 2013
Segment Reporting Information [Line Items]
Total Management and Advisory Fees, Net	$ 573,160	$ 482,133
Performance Fees Realized - Carried Interest	333,623	294,170
Performance Fees Realized - Incentive Fees	43,794	23,741
Performance Fees Unrealized - Carried Interest	330,394	177,347
Performance Fees Unrealized - Incentive Fees	64,233	105,798
Total Performance Fees	772,044	601,056
Investment Income (Loss), Realized	153,026	42,353
Investment Income (Loss), Unrealized	13,500	106,230
Total Investment Income (Loss)	166,526	148,583
Interest and Dividend Revenue	14,069	12,557
Other	869	2,144
Total Revenues	1,526,668	1,246,473
Compensation	485,351	451,430
Performance Fee Compensation - Realized Carried Interest	149,398	89,437
Performance Fee Compensation - Realized Incentive Fees	23,635	10,508
Performance Fee Compensation - Unrealized Carried Interest	40,730	95,472
Performance Fee Compensation - Unrealized Incentive Fees	23,531	44,478
Total Compensation and Benefits	722,645	691,325
Total Expenses	887,851	835,101
Economic Income (Loss)	708,972	478,582
Segment Assets	30,028,545		29,678,606
Operating Segments
Segment Reporting Information [Line Items]
Management and Advisory Fees, Base Management Fees	476,878	408,747
Management and Advisory Fees, Advisory Fees	69,963	67,020
Management and Advisory Fees, Transaction and Other Fees, Net	59,910	37,974
Management and Advisory Fees, Management Fee Offsets	(16,644)	(9,662)
Total Management and Advisory Fees, Net	590,107	504,079
Performance Fees Realized - Carried Interest	333,623	294,170
Performance Fees Realized - Incentive Fees	53,837	24,727
Performance Fees Unrealized - Carried Interest	330,288	177,347
Performance Fees Unrealized - Incentive Fees	61,266	107,755
Total Performance Fees	779,014	603,999
Investment Income (Loss), Realized	111,917	38,110
Investment Income (Loss), Unrealized	4,550	96,661
Total Investment Income (Loss)	116,467	134,771
Interest and Dividend Revenue	22,362	14,661
Other	869	2,143
Total Revenues	1,508,819	1,259,653
Compensation	306,545	266,977
Performance Fee Compensation - Realized Carried Interest	149,398	89,437
Performance Fee Compensation - Realized Incentive Fees	23,635	10,508
Performance Fee Compensation - Unrealized Carried Interest	40,690	95,472
Performance Fee Compensation - Unrealized Incentive Fees	23,531	44,478
Total Compensation and Benefits	543,799	506,872
Other Operating Expenses	139,774	114,444
Total Expenses	683,573	621,316
Economic Income (Loss)	825,246	638,337
Segment Assets	16,458,341
Operating Segments | Private Equity
Segment Reporting Information [Line Items]
Management and Advisory Fees, Base Management Fees	98,584	86,246
Management and Advisory Fees, Transaction and Other Fees, Net	42,847	24,453
Management and Advisory Fees, Management Fee Offsets	(1,713)	(480)
Total Management and Advisory Fees, Net	139,718	110,219
Performance Fees Realized - Carried Interest	119,805	139,892
Performance Fees Unrealized - Carried Interest	167,065	(83,954)
Total Performance Fees	286,870	55,938
Investment Income (Loss), Realized	60,535	24,162
Investment Income (Loss), Unrealized	(9,033)	31,711
Total Investment Income (Loss)	51,502	55,873
Interest and Dividend Revenue	5,228	2,984
Other	864	424
Total Revenues	484,182	225,438
Compensation	73,307	60,203
Performance Fee Compensation - Realized Carried Interest	85,771	16,246
Performance Fee Compensation - Unrealized Carried Interest	(27,148)	16,619
Total Compensation and Benefits	131,930	93,068
Other Operating Expenses	33,006	29,168
Total Expenses	164,936	122,236
Economic Income (Loss)	319,246	103,202
Segment Assets	4,707,694
Operating Segments | Real Estate
Segment Reporting Information [Line Items]
Management and Advisory Fees, Base Management Fees	159,336	138,346
Management and Advisory Fees, Transaction and Other Fees, Net	13,564	9,140
Management and Advisory Fees, Management Fee Offsets	(9,224)	(7,286)
Total Management and Advisory Fees, Net	163,676	140,200
Performance Fees Realized - Carried Interest	194,658	68,773
Performance Fees Realized - Incentive Fees	(26)	3,092
Performance Fees Unrealized - Carried Interest	140,237	280,076
Performance Fees Unrealized - Incentive Fees	2,737	2,400
Total Performance Fees	337,606	354,341
Investment Income (Loss), Realized	31,357	9,534
Investment Income (Loss), Unrealized	5,379	60,303
Total Investment Income (Loss)	36,736	69,837
Interest and Dividend Revenue	6,110	4,298
Other	317	(133)
Total Revenues	544,445	568,543
Compensation	80,233	69,459
Performance Fee Compensation - Realized Carried Interest	51,833	25,863
Performance Fee Compensation - Realized Incentive Fees	(16)	1,724
Performance Fee Compensation - Unrealized Carried Interest	56,985	89,057
Performance Fee Compensation - Unrealized Incentive Fees	1,382	1,034
Total Compensation and Benefits	190,417	187,137
Other Operating Expenses	33,107	28,462
Total Expenses	223,524	215,599
Economic Income (Loss)	320,921	352,944
Segment Assets	7,449,271
Operating Segments | Hedge Fund Solutions
Segment Reporting Information [Line Items]
Management and Advisory Fees, Base Management Fees	113,384	92,791
Management and Advisory Fees, Transaction and Other Fees, Net	93	4
Management and Advisory Fees, Management Fee Offsets	(1,455)	(324)
Total Management and Advisory Fees, Net	112,022	92,471
Performance Fees Realized - Incentive Fees	39,845	13,709
Performance Fees Unrealized - Incentive Fees	18,085	55,501
Total Performance Fees	57,930	69,210
Investment Income (Loss), Realized	16,820	852
Investment Income (Loss), Unrealized	4,431	3,913
Total Investment Income (Loss)	21,251	4,765
Interest and Dividend Revenue	2,661	1,216
Other	122	85
Total Revenues	193,986	167,747
Compensation	40,571	33,868
Performance Fee Compensation - Realized Incentive Fees	13,271	5,022
Performance Fee Compensation - Unrealized Incentive Fees	6,761	19,836
Total Compensation and Benefits	60,603	58,726
Other Operating Expenses	19,480	15,159
Total Expenses	80,083	73,885
Economic Income (Loss)	113,903	93,862
Segment Assets	1,280,344
Operating Segments | Credit
Segment Reporting Information [Line Items]
Management and Advisory Fees, Base Management Fees	105,574	91,364
Management and Advisory Fees, Transaction and Other Fees, Net	3,344	4,374
Management and Advisory Fees, Management Fee Offsets	(4,252)	(1,572)
Total Management and Advisory Fees, Net	104,666	94,166
Performance Fees Realized - Carried Interest	19,160	85,505
Performance Fees Realized - Incentive Fees	14,018	7,926
Performance Fees Unrealized - Carried Interest	22,986	(18,775)
Performance Fees Unrealized - Incentive Fees	40,444	49,854
Total Performance Fees	96,608	124,510
Investment Income (Loss), Realized	3,071	3,328
Investment Income (Loss), Unrealized	3,079	1,093
Total Investment Income (Loss)	6,150	4,421
Interest and Dividend Revenue	5,861	4,547
Other	(259)	1,828
Total Revenues	213,026	229,472
Compensation	50,752	45,521
Performance Fee Compensation - Realized Carried Interest	11,794	47,328
Performance Fee Compensation - Realized Incentive Fees	10,380	3,762
Performance Fee Compensation - Unrealized Carried Interest	10,853	(10,204)
Performance Fee Compensation - Unrealized Incentive Fees	15,388	23,608
Total Compensation and Benefits	99,167	110,015
Other Operating Expenses	32,839	20,962
Total Expenses	132,006	130,977
Economic Income (Loss)	81,020	98,495
Segment Assets	2,337,262
Operating Segments | Financial Advisory
Segment Reporting Information [Line Items]
Management and Advisory Fees, Advisory Fees	69,963	67,020
Management and Advisory Fees, Transaction and Other Fees, Net	62	3
Total Management and Advisory Fees, Net	70,025	67,023
Investment Income (Loss), Realized	134	234
Investment Income (Loss), Unrealized	694	(359)
Total Investment Income (Loss)	828	(125)
Interest and Dividend Revenue	2,502	1,616
Other	(175)	(61)
Total Revenues	73,180	68,453
Compensation	61,682	57,926
Total Compensation and Benefits	61,682	57,926
Other Operating Expenses	21,342	20,693
Total Expenses	83,024	78,619
Economic Income (Loss)	(9,844)	(10,166)
Segment Assets	$ 683,770