v2.4.1.9

Reconciliation of Total Segments to Income Before Provision for Taxes and Total Assets (Parenthetical) (Detail) (USD $) In Thousands, unless otherwise specified	3 Months Ended
	Mar. 31, 2015	Mar. 31, 2014
Segment Reporting Information [Line Items]
Fund Management Fees and Performance Fees Eliminated in Consolidation and Transactional Investment Loss	$ 15,067bx_FundManagementFeesAndPerformanceFeesEliminatedInConsolidation	$ (17,878)bx_FundManagementFeesAndPerformanceFeesEliminatedInConsolidation
Fund Expenses Added in Consolidation	15,748bx_FundExpensesAddedInConsolidation	(746)bx_FundExpensesAddedInConsolidation
Non-Controlling Interests in Income of Consolidated Entities	209,580us-gaap_NetIncomeLossAttributableToNoncontrollingInterest	89,753us-gaap_NetIncomeLossAttributableToNoncontrollingInterest
Transaction-Related Other Loss	(1,423)bx_TransactionRelatedOtherIncomeExpense	(974)bx_TransactionRelatedOtherIncomeExpense
Total Other Income	238,972us-gaap_OtherNonoperatingIncomeExpense	70,155us-gaap_OtherNonoperatingIncomeExpense
Economic Income	1,631,783bx_EconomicIncome	825,246bx_EconomicIncome
Amortization of Intangibles	(25,899)bx_SegmentReconciliationAmortizationOfIntangibleAssets	(29,003)bx_SegmentReconciliationAmortizationOfIntangibleAssets
IPO and Acquisition-Related Charges	(231,862)bx_IpoAndAcquisitionRelatedCharges	(177,024)bx_IpoAndAcquisitionRelatedCharges
Non-Controlling Interests in Income of Consolidated Entities	209,580us-gaap_NetIncomeLossAttributableToNoncontrollingInterest	89,753us-gaap_NetIncomeLossAttributableToNoncontrollingInterest
Total Consolidation Adjustments and Reconciling Items	(48,181)bx_ConsolidationAdjustmentsAndReconcilingItemsForEconomicIncomeToIncomeBeforeProvisionForTaxes	(116,274)bx_ConsolidationAdjustmentsAndReconcilingItemsForEconomicIncomeToIncomeBeforeProvisionForTaxes
Income Before Provision for Taxes	$ 1,583,602us-gaap_IncomeLossFromContinuingOperationsBeforeIncomeTaxesExtraordinaryItemsNoncontrollingInterest	$ 708,972us-gaap_IncomeLossFromContinuingOperationsBeforeIncomeTaxesExtraordinaryItemsNoncontrollingInterest

X

- Definition

Consolidation Adjustments and Reconciling Items for Economic Income to Income Before Provision for Taxes.

+ References

No definition available.

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- Definition

Economic Income

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No definition available.

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X

- Definition

Fund Expenses Added in Consolidation

+ References

No definition available.

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- Definition

Fund Management Fees And Performance Fees Eliminated In Consolidation

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- Definition

IPO And Acquisition Related Charges

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- Definition

Segment Reconciliation Amortization Of Intangible Assets

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- Definition

Transaction Related Other Income (Expense)

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No definition available.

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X

- Definition

This element represents the income or loss from continuing operations attributable to the economic entity which may also be defined as revenue less expenses from ongoing operations, after income or loss from equity method investments, but before income taxes, extraordinary items, and noncontrolling interest.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 940

-SubTopic 20

-Section 25

-Paragraph 1

-URI http://asc.fasb.org/extlink&oid=35710027&loc=d3e41242-110953



Reference 2: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 235

-SubTopic 10

-Section S99

-Paragraph 1

-URI http://asc.fasb.org/extlink&oid=26873400&loc=d3e23780-122690



Reference 3: http://www.xbrl.org/2003/role/presentationRef

-Publisher SEC

-Name Regulation S-X (SX)

-Number 210

-Section 03

-Paragraph 10

-Article 5

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Amount of Net Income (Loss) attributable to noncontrolling interest.

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Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 810

-SubTopic 10

-Section 50

-Paragraph 1A

-URI http://asc.fasb.org/extlink&oid=18733093&loc=SL4573702-111684



Reference 2: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 810

-SubTopic 10

-Section 55

-Paragraph 4J

-URI http://asc.fasb.org/extlink&oid=35736750&loc=SL4591551-111686

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The net amount of other income and expense amounts, the components of which are not separately disclosed on the income statement, resulting from ancillary business-related activities (that is, excluding major activities considered part of the normal operations of the business) also known as other nonoperating income (expense) recognized for the period. Such amounts may include: (a) dividends, (b) interest on securities, (c) net gains or losses on securities, (d) unusual costs, (e) gains or losses on foreign exchange transactions, and (f) miscellaneous other income and expense items.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher SEC

-Name Regulation S-X (SX)

-Number 210

-Section 03

-Paragraph 9

-Article 5



Reference 2: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 225

-SubTopic 10

-Section S99

-Paragraph 2

-Subparagraph (SX 210.5-03.9)

-URI http://asc.fasb.org/extlink&oid=26872669&loc=d3e20235-122688

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