v2.4.0.8

Reconciliation of Total Segments to Income (Loss) Before Provision (Benefit) for Taxes and Total Assets (Parenthetical) (Detail) (USD $) In Thousands, unless otherwise specified | 3 Months Ended | 9 Months Ended
--- | --- | ---
Sep. 30, 2013 | Sep. 30, 2012 | Sep. 30, 2013 | Sep. 30, 2012
Segment Reporting Information [Line Items] |  |  |  |
Fund Management Fees and Performance Fees Eliminated in Consolidation and Transactional Investment Loss | $ 6,321 | $ (4,273) | $ 11,455 | $ 32,217
Fund Expenses Added in Consolidation | 7,679 | (8,837) | 21,703 | 31,040
Non-Controlling Interests in Income (Loss) of Consolidated Entities | 81,419 | (115,753) | 184,593 | 358,417
Transaction-Related Other Income | (7,467) | (7,097) | (21,623) | (21,262)
Total Consolidation Adjustments and Reconciling Items | 87,952 | (135,960) | 196,128 | 400,412
Economic Income | 655,023 | 633,009 | 2,012,752 | 1,354,994
Amortization of Intangibles | (27,525) | (33,338) | (77,504) | (123,661)
IPO and Acquisition-Related Charges | (190,525) | (248,179) | (556,193) | (762,012)
Non-Controlling Interests in Income (Loss) of Consolidated Entities | 81,419 | (115,753) | 184,593 | 358,417
Total Consolidation Adjustments and Reconciling Items | (136,631) | (397,270) | (449,104) | (527,256)
Income Before Provision for Taxes | $ 518,392 | $ 235,739 | $ 1,563,648 | $ 827,738

X
- Definition Economic Income + References No definition available. + Details
Name: | bx_EconomicIncome
Namespace Prefix: | bx_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | duration

X
- Definition Fund Expenses Added in Consolidation + References No definition available. + Details
Name: | bx_FundExpensesAddedInConsolidation
Namespace Prefix: | bx_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | duration

X
- Definition Fund Management Fees And Performance Fees Eliminated In Consolidation + References No definition available. + Details
Name: | bx_FundManagementFeesAndPerformanceFeesEliminatedInConsolidation
Namespace Prefix: | bx_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | duration

X
- Definition IPO And Acquisition Related Charges + References No definition available. + Details
Name: | bx_IpoAndAcquisitionRelatedCharges
Namespace Prefix: | bx_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | duration

X
- Definition Segment Reconciliation Amortization Of Intangible Assets + References No definition available. + Details
Name: | bx_SegmentReconciliationAmortizationOfIntangibleAssets
Namespace Prefix: | bx_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | duration

X
- Definition Total Consolidation Adjustments and Reconciling Items + References No definition available. + Details
Name: | bx_TotalConsolidationAdjustmentsAndReconcilingItems
Namespace Prefix: | bx_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | duration

X
- Definition Total Consolidation Adjustments And Reconciling Items For Economic Net Income To Income Loss Before Provision For Taxes. + References No definition available. + Details
Name: | bx_TotalConsolidationAdjustmentsAndReconcilingItemsForEconomicNetIncomeToIncomeLossBeforeProvisionForTaxes
Namespace Prefix: | bx_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | duration

X
- Definition Transaction Related Other Income + References No definition available. + Details
Name: | bx_TransactionRelatedOtherIncome
Namespace Prefix: | bx_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | duration

X
- Definition Sum of operating profit and nonoperating income or expense before Income or Loss from equity method investments, income taxes, extraordinary items, and noncontrolling interest. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 235 -SubTopic 10 -Section S99 -Paragraph 1 -Subparagraph (SX 210.4-08.(h)(1)(i)) -URI http://asc.fasb.org/extlink&oid=26873400&loc=d3e23780-122690 + Details
Name: | us-gaap_IncomeLossFromContinuingOperationsBeforeIncomeTaxesMinorityInterestAndIncomeLossFromEquityMethodInvestments
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | duration

X
- Definition Amount of Net Income (Loss) attributable to noncontrolling interest. + References 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=31814832&loc=SL4591551-111686 + Details
Name: | us-gaap_NetIncomeLossAttributableToNoncontrollingInterest
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | duration

X
- Details
Name: | us-gaap_SegmentReportingInformationLineItems
Namespace Prefix: | us-gaap_
Data Type: | xbrli:stringItemType
Balance Type: | na
Period Type: | duration