Summary of Changes in Financial Assets Measured at Fair Value for Which Level III Inputs Were Used (Detail) - Level 3 - USD ($) $ in Thousands		3 Months Ended		6 Months Ended
		Jun. 30, 2015	Jun. 30, 2014	Jun. 30, 2015	Jun. 30, 2014
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Balance, Beginning of Period	[1]	$ 1,124,937	$ 2,627,444	$ 2,624,602	$ 2,643,469
Transfer In Due to Consolidation and Acquisition	[2]				205,890
Transfer In (Out) Due to Deconsolidation			(140,393)	(1,460,538)	(238,399)
Transfer In to Level III	[3]	62,711	201,063	78,081	230,963
Transfer Out of Level III	[3]	(180,534)	(244,568)	(196,800)	(303,213)
Purchases		162,580	228,400	266,785	542,084
Sales		(106,155)	(246,384)	(224,899)	(682,970)
Settlements		(1,156)	(577)	(2,297)	(1,471)
Changes in Gains (Losses) Included in Earnings and Other Comprehensive Income		62,940	46,112	40,389	74,744
Balance, End of Period		1,125,323	2,471,097	1,125,323	2,471,097
Changes in Unrealized (Gains) Losses Included in Earnings Related to Liabilities Still Held at the Reporting Date		19,770	64,924	16,733	88,366
Investments Of Consolidated Funds
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Balance, Beginning of Period	[1]	920,448	2,442,346	2,394,821	2,460,907
Transfer In Due to Consolidation and Acquisition	[2]				205,890
Transfer In (Out) Due to Deconsolidation			(140,393)	(1,460,538)	(238,399)
Transfer In to Level III	[3]	59,939	196,770	58,184	222,991
Transfer Out of Level III	[3]	(156,054)	(234,833)	(149,636)	(292,469)
Purchases		154,173	160,206	227,260	315,009
Sales		(98,872)	(210,913)	(178,391)	(487,333)
Changes in Gains (Losses) Included in Earnings and Other Comprehensive Income		57,515	47,672	45,449	74,259
Balance, End of Period		937,149	2,260,855	937,149	2,260,855
Changes in Unrealized (Gains) Losses Included in Earnings Related to Liabilities Still Held at the Reporting Date		17,044	65,791	13,511	86,668
Loans And Receivables
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Balance, Beginning of Period	[1]	40,691	61,573	40,397	137,788
Purchases			12,403	6,186	93,645
Sales		(5,464)	(31,345)	(9,535)	(188,064)
Settlements		(1,041)	(432)	(2,079)	(1,170)
Changes in Gains (Losses) Included in Earnings and Other Comprehensive Income		2,254	526	1,471	526
Balance, End of Period		36,440	42,725	36,440	42,725
Changes in Unrealized (Gains) Losses Included in Earnings Related to Liabilities Still Held at the Reporting Date		2,255	526	1,343	526
Other
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Balance, Beginning of Period	[1],[4]	163,798	123,525	189,384	44,774
Transfer In to Level III	[3],[4]	2,772	4,293	19,897	7,972
Transfer Out of Level III	[3],[4]	(24,480)	(9,735)	(47,164)	(10,744)
Purchases	[4]	8,407	55,791	33,339	133,430
Sales	[4]	(1,819)	(4,126)	(36,973)	(7,573)
Settlements	[4]	(115)	(145)	(218)	(301)
Changes in Gains (Losses) Included in Earnings and Other Comprehensive Income	[4]	3,171	(2,086)	(6,531)	(41)
Balance, End of Period	[4]	151,734	167,517	151,734	167,517
Changes in Unrealized (Gains) Losses Included in Earnings Related to Liabilities Still Held at the Reporting Date	[4]	$ 471	$ (1,393)	$ 1,879	$ 1,172

[1] Beginning of period 2015 balances have been adjusted to remove investments for which fair value is based on NAV. Pursuant to amended fair value guidance, disclosure in the fair value hierarchy is no longer required.

[2] Represents the transfer into Level III of financial assets and liabilities as a result of the consolidation of certain fund entities.

[3] Transfers in and out of Level III financial assets and liabilities were due to changes in the observability of inputs used in the valuation of such assets and liabilities.

[4] Represents Blackstone's Treasury Cash Management Strategies and Other Investments.