v2.4.0.6

Summary of Financial Instruments for Which Fair Value Option Has Been Elected (Detail) (USD $) In Thousands, unless otherwise specified | Jun. 30, 2012 | Dec. 31, 2011
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Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] |  |  |  |
Assets of Consolidated CLO Vehicles: Corporate Loans | $ 11,427,207 | [1] | $ 7,895,148 | [1]
Assets of Consolidated CLO Vehicles: Corporate Bonds | 228,741 | [1] | 153,653 | [1]
Assets of Consolidated CLO Vehicles: Other | 24,114 | [1] | 53,881 | [1]
Total Assets | 11,830,719 |  | 8,140,523 |
Liabilities of Consolidated CLO Vehicles: Senior Secured Notes | 10,534,253 | [1] | 7,449,766 | [1]
Liabilities of Consolidated CLO Vehicles: Subordinated Notes | 701,648 | [1] | 630,236 | [1]
Total Liabilities | 11,235,901 |  | 8,080,002 |
Loans And Receivables |  |  |  |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] |  |  |  |
Loans and Receivables | 104,207 |  | 8,555 |
Corporate Loans |  |  |  |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] |  |  |  |
Assets of Consolidated CLO Vehicles: Corporate Loans | 11,427,207 |  | 7,901,020 |
Corporate Bonds |  |  |  |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] |  |  |  |
Assets of Consolidated CLO Vehicles: Corporate Bonds | 228,741 |  | 153,653 |
Other |  |  |  |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] |  |  |  |
Assets of Consolidated CLO Vehicles: Other | 70,564 |  | 77,295 |
Senior Secured Notes |  |  |  |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] |  |  |  |
Liabilities of Consolidated CLO Vehicles: Senior Secured Notes | 10,534,253 |  | 7,449,766 |
Subordinated Notes |  |  |  |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] |  |  |  |
Liabilities of Consolidated CLO Vehicles: Subordinated Notes | $ 701,648 |  | $ 630,236 |
[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 its investments in 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.

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- Definition Assets Of Consolidated CLO Vehicles Corporate Bonds Fair Value Disclosure + References No definition available. + Details
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Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | instant

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- Definition Assets Of Consolidated CLO Vehicles Corporate Loans Fair Value Disclosure + References No definition available. + Details
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Namespace Prefix: | bx_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | instant

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- Definition Assets Of Consolidated CLO Vehicles Other Fair Value Disclosure + References No definition available. + Details
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Data Type: | xbrli:monetaryItemType
Balance Type: | debit
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- Definition Liabilities Of Consolidated CLO Vehicles Senior Secured Notes Fair Value Disclosures + References No definition available. + Details
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Namespace Prefix: | bx_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | instant

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- Definition Liabilities Of Consolidated CLO Vehicles Subordinated Notes Fair Value Disclosures + References No definition available. + Details
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Namespace Prefix: | bx_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | instant

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- Definition This element represents the aggregate of the assets reported on the balance sheet at period end measured at fair value by the entity. This element is intended to be used in connection with the fair value disclosures required in the footnote disclosures to the financial statements. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 820 -SubTopic 10 -Section 50 -Paragraph 2 -Subparagraph (a) -URI http://asc.fasb.org/extlink&oid=7578670&loc=d3e19207-110258 + Details
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- Details
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- Definition This element represents the aggregate of the liabilities reported on the balance sheet at period end measured at fair value by the entity. This element is intended to be used in connection with the fair value disclosures required in the footnote disclosures to the financial statements. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 820 -SubTopic 10 -Section 50 -Paragraph 2 -Subparagraph (a) -URI http://asc.fasb.org/extlink&oid=7578670&loc=d3e19207-110258 + Details
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- Definition This element represents the portion of the balance sheet assertion valued at fair value by the entity whether such amount is presented as a separate caption or as a parenthetical disclosure. Additionally, this element may be used in connection with the fair value disclosures required in the footnote disclosures to the financial statements. The element may be used in both the balance sheet and disclosure in the same submission. This item represents loan receivable as presented on the statement of financial position which may include mortgage loans held for investment, finance receivables held for investment, policy loans on insurance contracts, or any other loans which are due the Company as of the balance sheet date. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 310 -SubTopic 10 -Glossary Loan -URI http://asc.fasb.org/extlink&oid=6517073 Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Statement of Financial Accounting Standard (FAS) -Number 114 -Paragraph 4 -LegacyDoc This reference is SUPERSEDED by the Accounting Standards Codification effective for interim and annual periods ending after September 15, 2009. This reference is included to help users transition from the previous accounting hierarchy and will be removed from future versions of this taxonomy. + Details
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Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | instant