Financial Assets and Liabilities at Fair Value (Detail) - USD ($) $ in Thousands		Jun. 30, 2015		Dec. 31, 2014
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total Blackstone's Treasury Cash Management Strategies		$ 1,699,912		$ 1,666,061
Money Market Funds		636,975		198,278
Freestanding Derivatives, Assets		6,289		15,009
Net Investment Hedges - Foreign Currency Contracts		525		523
Freestanding Derivatives, Liabilities		19,883		30,528
Investments of Consolidated Funds		4,566,724		11,375,407
Other Investments		162,728		146,251
Total Financial Assets		7,107,934		13,430,207
Securities Sold, Not Yet Purchased		138,783		85,878
Total Financial Liabilities		3,190,996		6,913,510
Freestanding Derivatives
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Freestanding Derivatives, Assets		5,764		14,486
Freestanding Derivatives, Liabilities		19,883		30,528
Corporate Loans
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Corporate Loans		3,014,840		6,279,592
Loans And Receivables
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Loans and Receivables		36,440		40,397
Investments Of Consolidated Blackstone Funds
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Investment Funds	[1]	166,886		1,103,210
Equity Securities	[1]	262,710		352,360
Partnership and LLC Interests	[1]	661,085		1,683,562
Debt Instruments	[1]	212,705		1,608,284
Investments of Consolidated Funds	[1]	4,566,724		11,375,407
Investments Of Consolidated Blackstone Funds | Corporate Loans
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Corporate Loans	[1]	3,014,840		6,279,592
Blackstone's Treasury Cash Management Strategies
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Investment Funds		235,520		307,111
Equity Securities		96,039		71,746
Debt Instruments		1,305,293		1,226,195
Other		63,060		61,009
Total Blackstone's Treasury Cash Management Strategies		1,699,912		1,666,061
Corporate Bonds
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Corporate Bonds		247,083		292,690
Corporate Bonds | Investments Of Consolidated Blackstone Funds
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Corporate Bonds	[1]	247,083		292,690
Foreign Currency Contracts
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Net Investment Hedges - Foreign Currency Contracts		525		523
Foreign Currency Contracts | Freestanding Derivatives
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Freestanding Derivatives, Assets		2,154		2,798
Freestanding Derivatives, Liabilities		757		681
Foreign Currency Contracts | Investments Of Consolidated Blackstone Funds | Freestanding Derivatives
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Freestanding Derivatives, Assets	[1]	1,134		8,915
Interest Rate Contracts | Freestanding Derivatives
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Freestanding Derivatives, Assets		2,476		407
Freestanding Derivatives, Liabilities		4,815
Interest Rate Contracts | Investments Of Consolidated Blackstone Funds | Freestanding Derivatives
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Freestanding Derivatives, Assets	[1]			2,281
Credit Default Swaps | Freestanding Derivatives
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Freestanding Derivatives, Assets				85
Freestanding Derivatives, Liabilities		4,445		868
Other
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Other		281		44,513
Other | Investments Of Consolidated Blackstone Funds
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Other	[1]	281		44,513
Liabilities of Consolidated Funds and CLO Vehicles | Foreign Currency Contracts | Freestanding Derivatives
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Freestanding Derivatives, Liabilities	[1]	7,580		21,875
Liabilities of Consolidated Funds and CLO Vehicles | Interest Rate Contracts | Freestanding Derivatives
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Freestanding Derivatives, Liabilities				4,590
Liabilities of Consolidated Funds and CLO Vehicles | Credit Default Swaps | Freestanding Derivatives
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Freestanding Derivatives, Liabilities	[1]	2,286		2,514
Liabilities of Consolidated Funds and CLO Vehicles | Senior Secured Notes
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair value of Notes	[1]	2,912,753	[2]	6,448,352
Liabilities of Consolidated Funds and CLO Vehicles | Subordinated Notes
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair value of Notes	[1]	119,577	[2]	348,752
Level 1
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Money Market Funds		636,975		198,278
Other Investments		33,022		31,731
Total Financial Assets		1,061,164		668,076
Total Financial Liabilities		2,388		1,357
Level 1 | Investments Of Consolidated Blackstone Funds
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Equity Securities	[1]	57,720		58,934
Investments of Consolidated Funds	[1]	57,720		58,947
Level 1 | Blackstone's Treasury Cash Management Strategies
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Investment Funds		235,520		307,111
Equity Securities		95,869		71,746
Total Blackstone's Treasury Cash Management Strategies		331,389		378,857
Level 1 | Interest Rate Contracts | Freestanding Derivatives
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Freestanding Derivatives, Assets		2,058		263
Freestanding Derivatives, Liabilities		2,388
Level 1 | Other | Investments Of Consolidated Blackstone Funds
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Other	[1]			13
Level 1 | Liabilities of Consolidated Funds and CLO Vehicles | Interest Rate Contracts | Freestanding Derivatives
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Freestanding Derivatives, Liabilities				1,357
Level 2
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Other Investments				436
Total Financial Assets		4,545,350		8,913,207
Securities Sold, Not Yet Purchased		138,783		85,878
Total Financial Liabilities		3,188,608		115,049
Level 2 | Investments Of Consolidated Blackstone Funds
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Equity Securities	[1]	80,490		114,115
Partnership and LLC Interests	[1]	146,316		187,140
Debt Instruments	[1]	178,568		1,502,314
Investments of Consolidated Funds	[1]	3,404,969		7,818,427
Level 2 | Investments Of Consolidated Blackstone Funds | Corporate Loans
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Corporate Loans	[1]	2,771,457		5,691,517
Level 2 | Blackstone's Treasury Cash Management Strategies
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Equity Securities		170
Debt Instruments		1,137,114		1,090,794
Total Blackstone's Treasury Cash Management Strategies		1,137,284		1,090,794
Level 2 | Corporate Bonds | Investments Of Consolidated Blackstone Funds
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Corporate Bonds	[1]	226,723		292,690
Level 2 | Foreign Currency Contracts
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Net Investment Hedges - Foreign Currency Contracts		525		523
Level 2 | Foreign Currency Contracts | Freestanding Derivatives
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Freestanding Derivatives, Assets		2,154		2,798
Freestanding Derivatives, Liabilities		757		681
Level 2 | Foreign Currency Contracts | Investments Of Consolidated Blackstone Funds | Freestanding Derivatives
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Freestanding Derivatives, Assets	[1]	1,134		8,915
Level 2 | Interest Rate Contracts | Freestanding Derivatives
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Freestanding Derivatives, Assets		418		144
Freestanding Derivatives, Liabilities		2,427
Level 2 | Interest Rate Contracts | Investments Of Consolidated Blackstone Funds | Freestanding Derivatives
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Freestanding Derivatives, Assets	[1]			2,281
Level 2 | Credit Default Swaps | Freestanding Derivatives
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Freestanding Derivatives, Assets				85
Freestanding Derivatives, Liabilities		4,445		868
Level 2 | Other | Investments Of Consolidated Blackstone Funds
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Other	[1]	281		19,455
Level 2 | Liabilities of Consolidated Funds and CLO Vehicles | Foreign Currency Contracts | Freestanding Derivatives
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Freestanding Derivatives, Liabilities	[1]	7,580		21,875
Level 2 | Liabilities of Consolidated Funds and CLO Vehicles | Interest Rate Contracts | Freestanding Derivatives
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Freestanding Derivatives, Liabilities				3,233
Level 2 | Liabilities of Consolidated Funds and CLO Vehicles | Credit Default Swaps | Freestanding Derivatives
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Freestanding Derivatives, Liabilities	[1]	2,286		2,514
Level 2 | Liabilities of Consolidated Funds and CLO Vehicles | Senior Secured Notes
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair value of Notes	[1],[2]	2,912,753
Level 2 | Liabilities of Consolidated Funds and CLO Vehicles | Subordinated Notes
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair value of Notes	[1],[2]	119,577
Level 3
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Other Investments		102,210		104,491
Total Financial Assets		1,125,323		2,624,605
Total Financial Liabilities				6,797,104
Level 3 | Loans And Receivables
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Loans and Receivables		36,440		40,397
Level 3 | Investments Of Consolidated Blackstone Funds
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Equity Securities	[1]	124,500		179,311
Partnership and LLC Interests	[1]	514,769		1,496,422
Debt Instruments	[1]	34,137		105,970
Investments of Consolidated Funds	[1]	937,149		2,394,823
Level 3 | Investments Of Consolidated Blackstone Funds | Corporate Loans
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Corporate Loans	[1]	243,383		588,075
Level 3 | Blackstone's Treasury Cash Management Strategies
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Debt Instruments		49,524		84,894
Total Blackstone's Treasury Cash Management Strategies		49,524		84,894
Level 3 | Corporate Bonds | Investments Of Consolidated Blackstone Funds
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Corporate Bonds	[1]	20,360
Level 3 | Other | Investments Of Consolidated Blackstone Funds
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Other	[1]			25,045
Level 3 | Liabilities of Consolidated Funds and CLO Vehicles | Senior Secured Notes
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair value of Notes	[1]			6,448,352
Level 3 | Liabilities of Consolidated Funds and CLO Vehicles | Subordinated Notes
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair value of Notes	[1]			348,752
Net Asset Value
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Other Investments		27,496		9,593
Total Financial Assets		376,097		1,224,319
Net Asset Value | Investments Of Consolidated Blackstone Funds
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Investment Funds	[1]	166,886		1,103,210
Investments of Consolidated Funds	[1]	166,886		1,103,210
Net Asset Value | Blackstone's Treasury Cash Management Strategies
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Debt Instruments		118,655		50,507
Other		63,060		61,009
Total Blackstone's Treasury Cash Management Strategies		$ 181,715		$ 111,516

[1] Pursuant to GAAP consolidation guidance, the Partnership is required to consolidate all VIEs in which it has been identified as the primary beneficiary, including certain CLO vehicles, and other funds in which a consolidated entity of the Partnership, as the general partner of the fund, is presumed to have control. While the Partnership is required to consolidate certain funds, including CLO vehicles, for GAAP purposes, the Partnership has no ability to utilize the assets of these funds and there is no recourse to the Partnership for their liabilities since these are client assets and liabilities.

[2] Senior and subordinate notes issued by CLO vehicles are classified based on the more observable fair value of CLO assets less (a) the fair value of any beneficial interests held by Blackstone, and (b) the carrying value of any beneficial interests that represent compensation for services.