Reconciliation of Total Segments to Income (Loss) Before Provision (Benefit) for Taxes and Total Assets (Parenthetical) (Detail) (USD $) In Thousands, unless otherwise specified	12 Months Ended
	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2010
Segment Reporting Information [Line Items]
Fund Management Fees and Performance Fees Eliminated in Consolidation and Transactional Investment Loss	$ 43,393	$ 21,000	$ 17,165
Fund Expenses Added in Consolidation	37,548	30,129	30,776
Non-Controlling Interests in Income (Loss) of Consolidated Entities	203,557	(16,916)	431,149
Transaction-Related Other Income	(28,353)	178,538	22,904
Total Consolidation Adjustments and Reconciling Items	256,145	212,751	501,994
Economic Income (Loss)	2,041,007	1,584,971	1,580,770
Amortization of Intangibles	(150,148)	(220,865)	(165,378)
IPO and Acquisition-Related Charges	(1,079,511)	(1,269,932)	(2,369,195)
Non-Controlling Interests in Income (Loss) of Consolidated Entities	203,557	(16,916)	431,149
Total Consolidation Adjustments and Reconciling Items	(1,026,102)	(1,507,713)	(2,103,424)
Income (Loss) Before Provision for Taxes	$ 1,014,905	$ 77,258	$ (522,654)