v2.4.1.9
Financial Data of Segments (Detail) (USD $)
In Thousands, unless otherwise specified
3 Months Ended
Mar. 31, 2015
Mar. 31, 2014
Dec. 31, 2014
Segment Reporting Information [Line Items]      
Total Management and Advisory Fees, Net $ 603,498us-gaap_InvestmentAdvisoryFees $ 573,160us-gaap_InvestmentAdvisoryFees  
Performance Fees Realized - Carried Interest 1,206,425bx_PerformanceFeesRealizedCarriedInterest 333,623bx_PerformanceFeesRealizedCarriedInterest  
Performance Fees Realized - Incentive Fees 27,992bx_PerformanceFeesRealizedIncentiveFees 43,794bx_PerformanceFeesRealizedIncentiveFees  
Performance Fees Unrealized - Carried Interest 374,481bx_PerformanceFeesUnrealizedCarriedInterest 330,394bx_PerformanceFeesUnrealizedCarriedInterest  
Performance Fees Unrealized - Incentive Fees 61,860bx_PerformanceFeesUnrealizedIncentiveFees 64,233bx_PerformanceFeesUnrealizedIncentiveFees  
Total Performance Fees 1,670,758us-gaap_PerformanceFees 772,044us-gaap_PerformanceFees  
Investment Income (Loss), Realized 187,710bx_InvestmentIncomeLossRealized 153,026bx_InvestmentIncomeLossRealized  
Investment Income (Loss), Unrealized 15,771bx_InvestmentIncomeLossUnrealized 13,500bx_InvestmentIncomeLossUnrealized  
Total Investment Income 203,481us-gaap_GainLossOnInvestments 166,526us-gaap_GainLossOnInvestments  
Interest and Dividend Revenue 21,499us-gaap_InvestmentIncomeInterestAndDividend 14,069us-gaap_InvestmentIncomeInterestAndDividend  
Other (5,656)us-gaap_OtherIncome 869us-gaap_OtherIncome  
Total Revenues 2,493,580us-gaap_Revenues 1,526,668us-gaap_Revenues  
Compensation and Benefits Compensation 559,559us-gaap_SalariesAndWages 485,351us-gaap_SalariesAndWages  
Performance Fee Compensation - Realized Carried Interest 292,248bx_PerformanceFeeCompensationRealizedCarriedInterest 149,398bx_PerformanceFeeCompensationRealizedCarriedInterest  
Performance Fee Compensation - Realized Incentive Fees 12,227bx_PerformanceFeeCompensationRealizedIncentiveFees 23,635bx_PerformanceFeeCompensationRealizedIncentiveFees  
Performance Fee Compensation - Unrealized Carried Interest 74,380bx_PerformanceFeeCompensationUnrealizedCarriedInterest 40,730bx_PerformanceFeeCompensationUnrealizedCarriedInterest  
Performance Fee Compensation - Unrealized Incentive Fees 24,961bx_PerformanceFeeCompensationUnrealizedIncentiveFees 23,531bx_PerformanceFeeCompensationUnrealizedIncentiveFees  
Total Compensation and Benefits 963,375us-gaap_LaborAndRelatedExpense 722,645us-gaap_LaborAndRelatedExpense  
Total Expenses 1,148,950us-gaap_CostsAndExpenses 887,851us-gaap_CostsAndExpenses  
Economic Income (Loss) 1,583,602us-gaap_IncomeLossFromContinuingOperationsBeforeIncomeTaxesExtraordinaryItemsNoncontrollingInterest 708,972us-gaap_IncomeLossFromContinuingOperationsBeforeIncomeTaxesExtraordinaryItemsNoncontrollingInterest  
Segment Assets 32,406,601us-gaap_Assets 30,028,545us-gaap_Assets 31,510,894us-gaap_Assets
Operating Segments      
Segment Reporting Information [Line Items]      
Management and Advisory Fees, Base Management Fees 516,397us-gaap_ManagementFeesBaseRevenue
/ us-gaap_ConsolidationItemsAxis
= us-gaap_OperatingSegmentsMember
476,878us-gaap_ManagementFeesBaseRevenue
/ us-gaap_ConsolidationItemsAxis
= us-gaap_OperatingSegmentsMember
 
Management and Advisory Fees, Advisory Fees 84,238bx_AdvisoryFees
/ us-gaap_ConsolidationItemsAxis
= us-gaap_OperatingSegmentsMember
69,963bx_AdvisoryFees
/ us-gaap_ConsolidationItemsAxis
= us-gaap_OperatingSegmentsMember
 
Management and Advisory Fees, Transaction and Other Fees, Net 37,073bx_TransactionAndOtherFeesNet
/ us-gaap_ConsolidationItemsAxis
= us-gaap_OperatingSegmentsMember
59,910bx_TransactionAndOtherFeesNet
/ us-gaap_ConsolidationItemsAxis
= us-gaap_OperatingSegmentsMember
 
Management and Advisory Fees, Management Fee Offsets (17,945)bx_ManagementFeeOffsets
/ us-gaap_ConsolidationItemsAxis
= us-gaap_OperatingSegmentsMember
(16,644)bx_ManagementFeeOffsets
/ us-gaap_ConsolidationItemsAxis
= us-gaap_OperatingSegmentsMember
 
Total Management and Advisory Fees, Net 619,763us-gaap_InvestmentAdvisoryFees
/ us-gaap_ConsolidationItemsAxis
= us-gaap_OperatingSegmentsMember
590,107us-gaap_InvestmentAdvisoryFees
/ us-gaap_ConsolidationItemsAxis
= us-gaap_OperatingSegmentsMember
 
Performance Fees Realized - Carried Interest 1,207,594bx_PerformanceFeesRealizedCarriedInterest
/ us-gaap_ConsolidationItemsAxis
= us-gaap_OperatingSegmentsMember
333,623bx_PerformanceFeesRealizedCarriedInterest
/ us-gaap_ConsolidationItemsAxis
= us-gaap_OperatingSegmentsMember
 
Performance Fees Realized - Incentive Fees 29,670bx_PerformanceFeesRealizedIncentiveFees
/ us-gaap_ConsolidationItemsAxis
= us-gaap_OperatingSegmentsMember
53,837bx_PerformanceFeesRealizedIncentiveFees
/ us-gaap_ConsolidationItemsAxis
= us-gaap_OperatingSegmentsMember
 
Performance Fees Unrealized - Carried Interest 373,852bx_PerformanceFeesUnrealizedCarriedInterest
/ us-gaap_ConsolidationItemsAxis
= us-gaap_OperatingSegmentsMember
330,288bx_PerformanceFeesUnrealizedCarriedInterest
/ us-gaap_ConsolidationItemsAxis
= us-gaap_OperatingSegmentsMember
 
Performance Fees Unrealized - Incentive Fees 62,620bx_PerformanceFeesUnrealizedIncentiveFees
/ us-gaap_ConsolidationItemsAxis
= us-gaap_OperatingSegmentsMember
61,266bx_PerformanceFeesUnrealizedIncentiveFees
/ us-gaap_ConsolidationItemsAxis
= us-gaap_OperatingSegmentsMember
 
Total Performance Fees 1,673,736us-gaap_PerformanceFees
/ us-gaap_ConsolidationItemsAxis
= us-gaap_OperatingSegmentsMember
779,014us-gaap_PerformanceFees
/ us-gaap_ConsolidationItemsAxis
= us-gaap_OperatingSegmentsMember
 
Investment Income (Loss), Realized 107,792bx_InvestmentIncomeLossRealized
/ us-gaap_ConsolidationItemsAxis
= us-gaap_OperatingSegmentsMember
111,917bx_InvestmentIncomeLossRealized
/ us-gaap_ConsolidationItemsAxis
= us-gaap_OperatingSegmentsMember
 
Investment Income (Loss), Unrealized 81,849bx_InvestmentIncomeLossUnrealized
/ us-gaap_ConsolidationItemsAxis
= us-gaap_OperatingSegmentsMember
4,550bx_InvestmentIncomeLossUnrealized
/ us-gaap_ConsolidationItemsAxis
= us-gaap_OperatingSegmentsMember
 
Total Investment Income 189,641us-gaap_GainLossOnInvestments
/ us-gaap_ConsolidationItemsAxis
= us-gaap_OperatingSegmentsMember
116,467us-gaap_GainLossOnInvestments
/ us-gaap_ConsolidationItemsAxis
= us-gaap_OperatingSegmentsMember
 
Interest and Dividend Revenue 30,451us-gaap_InvestmentIncomeInterestAndDividend
/ us-gaap_ConsolidationItemsAxis
= us-gaap_OperatingSegmentsMember
22,362us-gaap_InvestmentIncomeInterestAndDividend
/ us-gaap_ConsolidationItemsAxis
= us-gaap_OperatingSegmentsMember
 
Other (4,872)us-gaap_OtherIncome
/ us-gaap_ConsolidationItemsAxis
= us-gaap_OperatingSegmentsMember
869us-gaap_OtherIncome
/ us-gaap_ConsolidationItemsAxis
= us-gaap_OperatingSegmentsMember
 
Total Revenues 2,508,719us-gaap_Revenues
/ us-gaap_ConsolidationItemsAxis
= us-gaap_OperatingSegmentsMember
1,508,819us-gaap_Revenues
/ us-gaap_ConsolidationItemsAxis
= us-gaap_OperatingSegmentsMember
 
Compensation and Benefits Compensation 329,838us-gaap_SalariesAndWages
/ us-gaap_ConsolidationItemsAxis
= us-gaap_OperatingSegmentsMember
306,545us-gaap_SalariesAndWages
/ us-gaap_ConsolidationItemsAxis
= us-gaap_OperatingSegmentsMember
 
Performance Fee Compensation - Realized Carried Interest 292,248bx_PerformanceFeeCompensationRealizedCarriedInterest
/ us-gaap_ConsolidationItemsAxis
= us-gaap_OperatingSegmentsMember
149,398bx_PerformanceFeeCompensationRealizedCarriedInterest
/ us-gaap_ConsolidationItemsAxis
= us-gaap_OperatingSegmentsMember
 
Performance Fee Compensation - Realized Incentive Fees 12,227bx_PerformanceFeeCompensationRealizedIncentiveFees
/ us-gaap_ConsolidationItemsAxis
= us-gaap_OperatingSegmentsMember
23,635bx_PerformanceFeeCompensationRealizedIncentiveFees
/ us-gaap_ConsolidationItemsAxis
= us-gaap_OperatingSegmentsMember
 
Performance Fee Compensation - Unrealized Carried Interest 74,380bx_PerformanceFeeCompensationUnrealizedCarriedInterest
/ us-gaap_ConsolidationItemsAxis
= us-gaap_OperatingSegmentsMember
40,690bx_PerformanceFeeCompensationUnrealizedCarriedInterest
/ us-gaap_ConsolidationItemsAxis
= us-gaap_OperatingSegmentsMember
 
Performance Fee Compensation - Unrealized Incentive Fees 24,961bx_PerformanceFeeCompensationUnrealizedIncentiveFees
/ us-gaap_ConsolidationItemsAxis
= us-gaap_OperatingSegmentsMember
23,531bx_PerformanceFeeCompensationUnrealizedIncentiveFees
/ us-gaap_ConsolidationItemsAxis
= us-gaap_OperatingSegmentsMember
 
Total Compensation and Benefits 733,654us-gaap_LaborAndRelatedExpense
/ us-gaap_ConsolidationItemsAxis
= us-gaap_OperatingSegmentsMember
543,799us-gaap_LaborAndRelatedExpense
/ us-gaap_ConsolidationItemsAxis
= us-gaap_OperatingSegmentsMember
 
Other Operating Expenses 143,282us-gaap_OtherCostAndExpenseOperating
/ us-gaap_ConsolidationItemsAxis
= us-gaap_OperatingSegmentsMember
139,774us-gaap_OtherCostAndExpenseOperating
/ us-gaap_ConsolidationItemsAxis
= us-gaap_OperatingSegmentsMember
 
Total Expenses 876,936us-gaap_CostsAndExpenses
/ us-gaap_ConsolidationItemsAxis
= us-gaap_OperatingSegmentsMember
683,573us-gaap_CostsAndExpenses
/ us-gaap_ConsolidationItemsAxis
= us-gaap_OperatingSegmentsMember
 
Economic Income (Loss) 1,631,783us-gaap_IncomeLossFromContinuingOperationsBeforeIncomeTaxesExtraordinaryItemsNoncontrollingInterest
/ us-gaap_ConsolidationItemsAxis
= us-gaap_OperatingSegmentsMember
825,246us-gaap_IncomeLossFromContinuingOperationsBeforeIncomeTaxesExtraordinaryItemsNoncontrollingInterest
/ us-gaap_ConsolidationItemsAxis
= us-gaap_OperatingSegmentsMember
 
Segment Assets 19,638,712us-gaap_Assets
/ us-gaap_ConsolidationItemsAxis
= us-gaap_OperatingSegmentsMember
16,458,341us-gaap_Assets
/ us-gaap_ConsolidationItemsAxis
= us-gaap_OperatingSegmentsMember
 
Operating Segments | Private Equity Segment      
Segment Reporting Information [Line Items]      
Management and Advisory Fees, Base Management Fees 108,383us-gaap_ManagementFeesBaseRevenue
/ us-gaap_ConsolidationItemsAxis
= us-gaap_OperatingSegmentsMember
/ us-gaap_StatementBusinessSegmentsAxis
= bx_PrivateEquitySegmentMember
98,584us-gaap_ManagementFeesBaseRevenue
/ us-gaap_ConsolidationItemsAxis
= us-gaap_OperatingSegmentsMember
/ us-gaap_StatementBusinessSegmentsAxis
= bx_PrivateEquitySegmentMember
 
Management and Advisory Fees, Transaction and Other Fees, Net 20,359bx_TransactionAndOtherFeesNet
/ us-gaap_ConsolidationItemsAxis
= us-gaap_OperatingSegmentsMember
/ us-gaap_StatementBusinessSegmentsAxis
= bx_PrivateEquitySegmentMember
42,847bx_TransactionAndOtherFeesNet
/ us-gaap_ConsolidationItemsAxis
= us-gaap_OperatingSegmentsMember
/ us-gaap_StatementBusinessSegmentsAxis
= bx_PrivateEquitySegmentMember
 
Management and Advisory Fees, Management Fee Offsets (4,949)bx_ManagementFeeOffsets
/ us-gaap_ConsolidationItemsAxis
= us-gaap_OperatingSegmentsMember
/ us-gaap_StatementBusinessSegmentsAxis
= bx_PrivateEquitySegmentMember
(1,713)bx_ManagementFeeOffsets
/ us-gaap_ConsolidationItemsAxis
= us-gaap_OperatingSegmentsMember
/ us-gaap_StatementBusinessSegmentsAxis
= bx_PrivateEquitySegmentMember
 
Total Management and Advisory Fees, Net 123,793us-gaap_InvestmentAdvisoryFees
/ us-gaap_ConsolidationItemsAxis
= us-gaap_OperatingSegmentsMember
/ us-gaap_StatementBusinessSegmentsAxis
= bx_PrivateEquitySegmentMember
139,718us-gaap_InvestmentAdvisoryFees
/ us-gaap_ConsolidationItemsAxis
= us-gaap_OperatingSegmentsMember
/ us-gaap_StatementBusinessSegmentsAxis
= bx_PrivateEquitySegmentMember
 
Performance Fees Realized - Carried Interest 382,978bx_PerformanceFeesRealizedCarriedInterest
/ us-gaap_ConsolidationItemsAxis
= us-gaap_OperatingSegmentsMember
/ us-gaap_StatementBusinessSegmentsAxis
= bx_PrivateEquitySegmentMember
119,805bx_PerformanceFeesRealizedCarriedInterest
/ us-gaap_ConsolidationItemsAxis
= us-gaap_OperatingSegmentsMember
/ us-gaap_StatementBusinessSegmentsAxis
= bx_PrivateEquitySegmentMember
 
Performance Fees Unrealized - Carried Interest 566,822bx_PerformanceFeesUnrealizedCarriedInterest
/ us-gaap_ConsolidationItemsAxis
= us-gaap_OperatingSegmentsMember
/ us-gaap_StatementBusinessSegmentsAxis
= bx_PrivateEquitySegmentMember
167,065bx_PerformanceFeesUnrealizedCarriedInterest
/ us-gaap_ConsolidationItemsAxis
= us-gaap_OperatingSegmentsMember
/ us-gaap_StatementBusinessSegmentsAxis
= bx_PrivateEquitySegmentMember
 
Total Performance Fees 949,800us-gaap_PerformanceFees
/ us-gaap_ConsolidationItemsAxis
= us-gaap_OperatingSegmentsMember
/ us-gaap_StatementBusinessSegmentsAxis
= bx_PrivateEquitySegmentMember
286,870us-gaap_PerformanceFees
/ us-gaap_ConsolidationItemsAxis
= us-gaap_OperatingSegmentsMember
/ us-gaap_StatementBusinessSegmentsAxis
= bx_PrivateEquitySegmentMember
 
Investment Income (Loss), Realized 44,816bx_InvestmentIncomeLossRealized
/ us-gaap_ConsolidationItemsAxis
= us-gaap_OperatingSegmentsMember
/ us-gaap_StatementBusinessSegmentsAxis
= bx_PrivateEquitySegmentMember
60,535bx_InvestmentIncomeLossRealized
/ us-gaap_ConsolidationItemsAxis
= us-gaap_OperatingSegmentsMember
/ us-gaap_StatementBusinessSegmentsAxis
= bx_PrivateEquitySegmentMember
 
Investment Income (Loss), Unrealized 31,487bx_InvestmentIncomeLossUnrealized
/ us-gaap_ConsolidationItemsAxis
= us-gaap_OperatingSegmentsMember
/ us-gaap_StatementBusinessSegmentsAxis
= bx_PrivateEquitySegmentMember
(9,033)bx_InvestmentIncomeLossUnrealized
/ us-gaap_ConsolidationItemsAxis
= us-gaap_OperatingSegmentsMember
/ us-gaap_StatementBusinessSegmentsAxis
= bx_PrivateEquitySegmentMember
 
Total Investment Income 76,303us-gaap_GainLossOnInvestments
/ us-gaap_ConsolidationItemsAxis
= us-gaap_OperatingSegmentsMember
/ us-gaap_StatementBusinessSegmentsAxis
= bx_PrivateEquitySegmentMember
51,502us-gaap_GainLossOnInvestments
/ us-gaap_ConsolidationItemsAxis
= us-gaap_OperatingSegmentsMember
/ us-gaap_StatementBusinessSegmentsAxis
= bx_PrivateEquitySegmentMember
 
Interest and Dividend Revenue 7,617us-gaap_InvestmentIncomeInterestAndDividend
/ us-gaap_ConsolidationItemsAxis
= us-gaap_OperatingSegmentsMember
/ us-gaap_StatementBusinessSegmentsAxis
= bx_PrivateEquitySegmentMember
5,228us-gaap_InvestmentIncomeInterestAndDividend
/ us-gaap_ConsolidationItemsAxis
= us-gaap_OperatingSegmentsMember
/ us-gaap_StatementBusinessSegmentsAxis
= bx_PrivateEquitySegmentMember
 
Other (1,825)us-gaap_OtherIncome
/ us-gaap_ConsolidationItemsAxis
= us-gaap_OperatingSegmentsMember
/ us-gaap_StatementBusinessSegmentsAxis
= bx_PrivateEquitySegmentMember
864us-gaap_OtherIncome
/ us-gaap_ConsolidationItemsAxis
= us-gaap_OperatingSegmentsMember
/ us-gaap_StatementBusinessSegmentsAxis
= bx_PrivateEquitySegmentMember
 
Total Revenues 1,155,688us-gaap_Revenues
/ us-gaap_ConsolidationItemsAxis
= us-gaap_OperatingSegmentsMember
/ us-gaap_StatementBusinessSegmentsAxis
= bx_PrivateEquitySegmentMember
484,182us-gaap_Revenues
/ us-gaap_ConsolidationItemsAxis
= us-gaap_OperatingSegmentsMember
/ us-gaap_StatementBusinessSegmentsAxis
= bx_PrivateEquitySegmentMember
 
Compensation and Benefits Compensation 70,089us-gaap_SalariesAndWages
/ us-gaap_ConsolidationItemsAxis
= us-gaap_OperatingSegmentsMember
/ us-gaap_StatementBusinessSegmentsAxis
= bx_PrivateEquitySegmentMember
73,307us-gaap_SalariesAndWages
/ us-gaap_ConsolidationItemsAxis
= us-gaap_OperatingSegmentsMember
/ us-gaap_StatementBusinessSegmentsAxis
= bx_PrivateEquitySegmentMember
 
Performance Fee Compensation - Realized Carried Interest 39,482bx_PerformanceFeeCompensationRealizedCarriedInterest
/ us-gaap_ConsolidationItemsAxis
= us-gaap_OperatingSegmentsMember
/ us-gaap_StatementBusinessSegmentsAxis
= bx_PrivateEquitySegmentMember
85,771bx_PerformanceFeeCompensationRealizedCarriedInterest
/ us-gaap_ConsolidationItemsAxis
= us-gaap_OperatingSegmentsMember
/ us-gaap_StatementBusinessSegmentsAxis
= bx_PrivateEquitySegmentMember
 
Performance Fee Compensation - Unrealized Carried Interest 178,120bx_PerformanceFeeCompensationUnrealizedCarriedInterest
/ us-gaap_ConsolidationItemsAxis
= us-gaap_OperatingSegmentsMember
/ us-gaap_StatementBusinessSegmentsAxis
= bx_PrivateEquitySegmentMember
(27,148)bx_PerformanceFeeCompensationUnrealizedCarriedInterest
/ us-gaap_ConsolidationItemsAxis
= us-gaap_OperatingSegmentsMember
/ us-gaap_StatementBusinessSegmentsAxis
= bx_PrivateEquitySegmentMember
 
Total Compensation and Benefits 287,691us-gaap_LaborAndRelatedExpense
/ us-gaap_ConsolidationItemsAxis
= us-gaap_OperatingSegmentsMember
/ us-gaap_StatementBusinessSegmentsAxis
= bx_PrivateEquitySegmentMember
131,930us-gaap_LaborAndRelatedExpense
/ us-gaap_ConsolidationItemsAxis
= us-gaap_OperatingSegmentsMember
/ us-gaap_StatementBusinessSegmentsAxis
= bx_PrivateEquitySegmentMember
 
Other Operating Expenses 38,755us-gaap_OtherCostAndExpenseOperating
/ us-gaap_ConsolidationItemsAxis
= us-gaap_OperatingSegmentsMember
/ us-gaap_StatementBusinessSegmentsAxis
= bx_PrivateEquitySegmentMember
33,006us-gaap_OtherCostAndExpenseOperating
/ us-gaap_ConsolidationItemsAxis
= us-gaap_OperatingSegmentsMember
/ us-gaap_StatementBusinessSegmentsAxis
= bx_PrivateEquitySegmentMember
 
Total Expenses 326,446us-gaap_CostsAndExpenses
/ us-gaap_ConsolidationItemsAxis
= us-gaap_OperatingSegmentsMember
/ us-gaap_StatementBusinessSegmentsAxis
= bx_PrivateEquitySegmentMember
164,936us-gaap_CostsAndExpenses
/ us-gaap_ConsolidationItemsAxis
= us-gaap_OperatingSegmentsMember
/ us-gaap_StatementBusinessSegmentsAxis
= bx_PrivateEquitySegmentMember
 
Economic Income (Loss) 829,242us-gaap_IncomeLossFromContinuingOperationsBeforeIncomeTaxesExtraordinaryItemsNoncontrollingInterest
/ us-gaap_ConsolidationItemsAxis
= us-gaap_OperatingSegmentsMember
/ us-gaap_StatementBusinessSegmentsAxis
= bx_PrivateEquitySegmentMember
319,246us-gaap_IncomeLossFromContinuingOperationsBeforeIncomeTaxesExtraordinaryItemsNoncontrollingInterest
/ us-gaap_ConsolidationItemsAxis
= us-gaap_OperatingSegmentsMember
/ us-gaap_StatementBusinessSegmentsAxis
= bx_PrivateEquitySegmentMember
 
Segment Assets 6,754,805us-gaap_Assets
/ us-gaap_ConsolidationItemsAxis
= us-gaap_OperatingSegmentsMember
/ us-gaap_StatementBusinessSegmentsAxis
= bx_PrivateEquitySegmentMember
   
Operating Segments | Real Estate Segment      
Segment Reporting Information [Line Items]      
Management and Advisory Fees, Base Management Fees 152,348us-gaap_ManagementFeesBaseRevenue
/ us-gaap_ConsolidationItemsAxis
= us-gaap_OperatingSegmentsMember
/ us-gaap_StatementBusinessSegmentsAxis
= bx_RealEstateSegmentMember
159,336us-gaap_ManagementFeesBaseRevenue
/ us-gaap_ConsolidationItemsAxis
= us-gaap_OperatingSegmentsMember
/ us-gaap_StatementBusinessSegmentsAxis
= bx_RealEstateSegmentMember
 
Management and Advisory Fees, Transaction and Other Fees, Net 15,216bx_TransactionAndOtherFeesNet
/ us-gaap_ConsolidationItemsAxis
= us-gaap_OperatingSegmentsMember
/ us-gaap_StatementBusinessSegmentsAxis
= bx_RealEstateSegmentMember
13,564bx_TransactionAndOtherFeesNet
/ us-gaap_ConsolidationItemsAxis
= us-gaap_OperatingSegmentsMember
/ us-gaap_StatementBusinessSegmentsAxis
= bx_RealEstateSegmentMember
 
Management and Advisory Fees, Management Fee Offsets (4,866)bx_ManagementFeeOffsets
/ us-gaap_ConsolidationItemsAxis
= us-gaap_OperatingSegmentsMember
/ us-gaap_StatementBusinessSegmentsAxis
= bx_RealEstateSegmentMember
(9,224)bx_ManagementFeeOffsets
/ us-gaap_ConsolidationItemsAxis
= us-gaap_OperatingSegmentsMember
/ us-gaap_StatementBusinessSegmentsAxis
= bx_RealEstateSegmentMember
 
Total Management and Advisory Fees, Net 162,698us-gaap_InvestmentAdvisoryFees
/ us-gaap_ConsolidationItemsAxis
= us-gaap_OperatingSegmentsMember
/ us-gaap_StatementBusinessSegmentsAxis
= bx_RealEstateSegmentMember
163,676us-gaap_InvestmentAdvisoryFees
/ us-gaap_ConsolidationItemsAxis
= us-gaap_OperatingSegmentsMember
/ us-gaap_StatementBusinessSegmentsAxis
= bx_RealEstateSegmentMember
 
Performance Fees Realized - Carried Interest 811,249bx_PerformanceFeesRealizedCarriedInterest
/ us-gaap_ConsolidationItemsAxis
= us-gaap_OperatingSegmentsMember
/ us-gaap_StatementBusinessSegmentsAxis
= bx_RealEstateSegmentMember
194,658bx_PerformanceFeesRealizedCarriedInterest
/ us-gaap_ConsolidationItemsAxis
= us-gaap_OperatingSegmentsMember
/ us-gaap_StatementBusinessSegmentsAxis
= bx_RealEstateSegmentMember
 
Performance Fees Realized - Incentive Fees 723bx_PerformanceFeesRealizedIncentiveFees
/ us-gaap_ConsolidationItemsAxis
= us-gaap_OperatingSegmentsMember
/ us-gaap_StatementBusinessSegmentsAxis
= bx_RealEstateSegmentMember
(26)bx_PerformanceFeesRealizedIncentiveFees
/ us-gaap_ConsolidationItemsAxis
= us-gaap_OperatingSegmentsMember
/ us-gaap_StatementBusinessSegmentsAxis
= bx_RealEstateSegmentMember
 
Performance Fees Unrealized - Carried Interest (181,019)bx_PerformanceFeesUnrealizedCarriedInterest
/ us-gaap_ConsolidationItemsAxis
= us-gaap_OperatingSegmentsMember
/ us-gaap_StatementBusinessSegmentsAxis
= bx_RealEstateSegmentMember
140,237bx_PerformanceFeesUnrealizedCarriedInterest
/ us-gaap_ConsolidationItemsAxis
= us-gaap_OperatingSegmentsMember
/ us-gaap_StatementBusinessSegmentsAxis
= bx_RealEstateSegmentMember
 
Performance Fees Unrealized - Incentive Fees 6,069bx_PerformanceFeesUnrealizedIncentiveFees
/ us-gaap_ConsolidationItemsAxis
= us-gaap_OperatingSegmentsMember
/ us-gaap_StatementBusinessSegmentsAxis
= bx_RealEstateSegmentMember
2,737bx_PerformanceFeesUnrealizedIncentiveFees
/ us-gaap_ConsolidationItemsAxis
= us-gaap_OperatingSegmentsMember
/ us-gaap_StatementBusinessSegmentsAxis
= bx_RealEstateSegmentMember
 
Total Performance Fees 637,022us-gaap_PerformanceFees
/ us-gaap_ConsolidationItemsAxis
= us-gaap_OperatingSegmentsMember
/ us-gaap_StatementBusinessSegmentsAxis
= bx_RealEstateSegmentMember
337,606us-gaap_PerformanceFees
/ us-gaap_ConsolidationItemsAxis
= us-gaap_OperatingSegmentsMember
/ us-gaap_StatementBusinessSegmentsAxis
= bx_RealEstateSegmentMember
 
Investment Income (Loss), Realized 71,344bx_InvestmentIncomeLossRealized
/ us-gaap_ConsolidationItemsAxis
= us-gaap_OperatingSegmentsMember
/ us-gaap_StatementBusinessSegmentsAxis
= bx_RealEstateSegmentMember
31,357bx_InvestmentIncomeLossRealized
/ us-gaap_ConsolidationItemsAxis
= us-gaap_OperatingSegmentsMember
/ us-gaap_StatementBusinessSegmentsAxis
= bx_RealEstateSegmentMember
 
Investment Income (Loss), Unrealized 37,510bx_InvestmentIncomeLossUnrealized
/ us-gaap_ConsolidationItemsAxis
= us-gaap_OperatingSegmentsMember
/ us-gaap_StatementBusinessSegmentsAxis
= bx_RealEstateSegmentMember
5,379bx_InvestmentIncomeLossUnrealized
/ us-gaap_ConsolidationItemsAxis
= us-gaap_OperatingSegmentsMember
/ us-gaap_StatementBusinessSegmentsAxis
= bx_RealEstateSegmentMember
 
Total Investment Income 108,854us-gaap_GainLossOnInvestments
/ us-gaap_ConsolidationItemsAxis
= us-gaap_OperatingSegmentsMember
/ us-gaap_StatementBusinessSegmentsAxis
= bx_RealEstateSegmentMember
36,736us-gaap_GainLossOnInvestments
/ us-gaap_ConsolidationItemsAxis
= us-gaap_OperatingSegmentsMember
/ us-gaap_StatementBusinessSegmentsAxis
= bx_RealEstateSegmentMember
 
Interest and Dividend Revenue 9,997us-gaap_InvestmentIncomeInterestAndDividend
/ us-gaap_ConsolidationItemsAxis
= us-gaap_OperatingSegmentsMember
/ us-gaap_StatementBusinessSegmentsAxis
= bx_RealEstateSegmentMember
6,110us-gaap_InvestmentIncomeInterestAndDividend
/ us-gaap_ConsolidationItemsAxis
= us-gaap_OperatingSegmentsMember
/ us-gaap_StatementBusinessSegmentsAxis
= bx_RealEstateSegmentMember
 
Other (3,977)us-gaap_OtherIncome
/ us-gaap_ConsolidationItemsAxis
= us-gaap_OperatingSegmentsMember
/ us-gaap_StatementBusinessSegmentsAxis
= bx_RealEstateSegmentMember
317us-gaap_OtherIncome
/ us-gaap_ConsolidationItemsAxis
= us-gaap_OperatingSegmentsMember
/ us-gaap_StatementBusinessSegmentsAxis
= bx_RealEstateSegmentMember
 
Total Revenues 914,594us-gaap_Revenues
/ us-gaap_ConsolidationItemsAxis
= us-gaap_OperatingSegmentsMember
/ us-gaap_StatementBusinessSegmentsAxis
= bx_RealEstateSegmentMember
544,445us-gaap_Revenues
/ us-gaap_ConsolidationItemsAxis
= us-gaap_OperatingSegmentsMember
/ us-gaap_StatementBusinessSegmentsAxis
= bx_RealEstateSegmentMember
 
Compensation and Benefits Compensation 84,834us-gaap_SalariesAndWages
/ us-gaap_ConsolidationItemsAxis
= us-gaap_OperatingSegmentsMember
/ us-gaap_StatementBusinessSegmentsAxis
= bx_RealEstateSegmentMember
80,233us-gaap_SalariesAndWages
/ us-gaap_ConsolidationItemsAxis
= us-gaap_OperatingSegmentsMember
/ us-gaap_StatementBusinessSegmentsAxis
= bx_RealEstateSegmentMember
 
Performance Fee Compensation - Realized Carried Interest 246,496bx_PerformanceFeeCompensationRealizedCarriedInterest
/ us-gaap_ConsolidationItemsAxis
= us-gaap_OperatingSegmentsMember
/ us-gaap_StatementBusinessSegmentsAxis
= bx_RealEstateSegmentMember
51,833bx_PerformanceFeeCompensationRealizedCarriedInterest
/ us-gaap_ConsolidationItemsAxis
= us-gaap_OperatingSegmentsMember
/ us-gaap_StatementBusinessSegmentsAxis
= bx_RealEstateSegmentMember
 
Performance Fee Compensation - Realized Incentive Fees 356bx_PerformanceFeeCompensationRealizedIncentiveFees
/ us-gaap_ConsolidationItemsAxis
= us-gaap_OperatingSegmentsMember
/ us-gaap_StatementBusinessSegmentsAxis
= bx_RealEstateSegmentMember
(16)bx_PerformanceFeeCompensationRealizedIncentiveFees
/ us-gaap_ConsolidationItemsAxis
= us-gaap_OperatingSegmentsMember
/ us-gaap_StatementBusinessSegmentsAxis
= bx_RealEstateSegmentMember
 
Performance Fee Compensation - Unrealized Carried Interest (98,084)bx_PerformanceFeeCompensationUnrealizedCarriedInterest
/ us-gaap_ConsolidationItemsAxis
= us-gaap_OperatingSegmentsMember
/ us-gaap_StatementBusinessSegmentsAxis
= bx_RealEstateSegmentMember
56,985bx_PerformanceFeeCompensationUnrealizedCarriedInterest
/ us-gaap_ConsolidationItemsAxis
= us-gaap_OperatingSegmentsMember
/ us-gaap_StatementBusinessSegmentsAxis
= bx_RealEstateSegmentMember
 
Performance Fee Compensation - Unrealized Incentive Fees 2,575bx_PerformanceFeeCompensationUnrealizedIncentiveFees
/ us-gaap_ConsolidationItemsAxis
= us-gaap_OperatingSegmentsMember
/ us-gaap_StatementBusinessSegmentsAxis
= bx_RealEstateSegmentMember
1,382bx_PerformanceFeeCompensationUnrealizedIncentiveFees
/ us-gaap_ConsolidationItemsAxis
= us-gaap_OperatingSegmentsMember
/ us-gaap_StatementBusinessSegmentsAxis
= bx_RealEstateSegmentMember
 
Total Compensation and Benefits 236,177us-gaap_LaborAndRelatedExpense
/ us-gaap_ConsolidationItemsAxis
= us-gaap_OperatingSegmentsMember
/ us-gaap_StatementBusinessSegmentsAxis
= bx_RealEstateSegmentMember
190,417us-gaap_LaborAndRelatedExpense
/ us-gaap_ConsolidationItemsAxis
= us-gaap_OperatingSegmentsMember
/ us-gaap_StatementBusinessSegmentsAxis
= bx_RealEstateSegmentMember
 
Other Operating Expenses 40,143us-gaap_OtherCostAndExpenseOperating
/ us-gaap_ConsolidationItemsAxis
= us-gaap_OperatingSegmentsMember
/ us-gaap_StatementBusinessSegmentsAxis
= bx_RealEstateSegmentMember
33,107us-gaap_OtherCostAndExpenseOperating
/ us-gaap_ConsolidationItemsAxis
= us-gaap_OperatingSegmentsMember
/ us-gaap_StatementBusinessSegmentsAxis
= bx_RealEstateSegmentMember
 
Total Expenses 276,320us-gaap_CostsAndExpenses
/ us-gaap_ConsolidationItemsAxis
= us-gaap_OperatingSegmentsMember
/ us-gaap_StatementBusinessSegmentsAxis
= bx_RealEstateSegmentMember
223,524us-gaap_CostsAndExpenses
/ us-gaap_ConsolidationItemsAxis
= us-gaap_OperatingSegmentsMember
/ us-gaap_StatementBusinessSegmentsAxis
= bx_RealEstateSegmentMember
 
Economic Income (Loss) 638,274us-gaap_IncomeLossFromContinuingOperationsBeforeIncomeTaxesExtraordinaryItemsNoncontrollingInterest
/ us-gaap_ConsolidationItemsAxis
= us-gaap_OperatingSegmentsMember
/ us-gaap_StatementBusinessSegmentsAxis
= bx_RealEstateSegmentMember
320,921us-gaap_IncomeLossFromContinuingOperationsBeforeIncomeTaxesExtraordinaryItemsNoncontrollingInterest
/ us-gaap_ConsolidationItemsAxis
= us-gaap_OperatingSegmentsMember
/ us-gaap_StatementBusinessSegmentsAxis
= bx_RealEstateSegmentMember
 
Segment Assets 7,916,836us-gaap_Assets
/ us-gaap_ConsolidationItemsAxis
= us-gaap_OperatingSegmentsMember
/ us-gaap_StatementBusinessSegmentsAxis
= bx_RealEstateSegmentMember
   
Operating Segments | Hedge Fund Solutions Segment      
Segment Reporting Information [Line Items]      
Management and Advisory Fees, Base Management Fees 130,637us-gaap_ManagementFeesBaseRevenue
/ us-gaap_ConsolidationItemsAxis
= us-gaap_OperatingSegmentsMember
/ us-gaap_StatementBusinessSegmentsAxis
= bx_HedgeFundSolutionsSegmentMember
113,384us-gaap_ManagementFeesBaseRevenue
/ us-gaap_ConsolidationItemsAxis
= us-gaap_OperatingSegmentsMember
/ us-gaap_StatementBusinessSegmentsAxis
= bx_HedgeFundSolutionsSegmentMember
 
Management and Advisory Fees, Transaction and Other Fees, Net 25bx_TransactionAndOtherFeesNet
/ us-gaap_ConsolidationItemsAxis
= us-gaap_OperatingSegmentsMember
/ us-gaap_StatementBusinessSegmentsAxis
= bx_HedgeFundSolutionsSegmentMember
93bx_TransactionAndOtherFeesNet
/ us-gaap_ConsolidationItemsAxis
= us-gaap_OperatingSegmentsMember
/ us-gaap_StatementBusinessSegmentsAxis
= bx_HedgeFundSolutionsSegmentMember
 
Management and Advisory Fees, Management Fee Offsets (280)bx_ManagementFeeOffsets
/ us-gaap_ConsolidationItemsAxis
= us-gaap_OperatingSegmentsMember
/ us-gaap_StatementBusinessSegmentsAxis
= bx_HedgeFundSolutionsSegmentMember
(1,455)bx_ManagementFeeOffsets
/ us-gaap_ConsolidationItemsAxis
= us-gaap_OperatingSegmentsMember
/ us-gaap_StatementBusinessSegmentsAxis
= bx_HedgeFundSolutionsSegmentMember
 
Total Management and Advisory Fees, Net 130,382us-gaap_InvestmentAdvisoryFees
/ us-gaap_ConsolidationItemsAxis
= us-gaap_OperatingSegmentsMember
/ us-gaap_StatementBusinessSegmentsAxis
= bx_HedgeFundSolutionsSegmentMember
112,022us-gaap_InvestmentAdvisoryFees
/ us-gaap_ConsolidationItemsAxis
= us-gaap_OperatingSegmentsMember
/ us-gaap_StatementBusinessSegmentsAxis
= bx_HedgeFundSolutionsSegmentMember
 
Performance Fees Realized - Incentive Fees 10,516bx_PerformanceFeesRealizedIncentiveFees
/ us-gaap_ConsolidationItemsAxis
= us-gaap_OperatingSegmentsMember
/ us-gaap_StatementBusinessSegmentsAxis
= bx_HedgeFundSolutionsSegmentMember
39,845bx_PerformanceFeesRealizedIncentiveFees
/ us-gaap_ConsolidationItemsAxis
= us-gaap_OperatingSegmentsMember
/ us-gaap_StatementBusinessSegmentsAxis
= bx_HedgeFundSolutionsSegmentMember
 
Performance Fees Unrealized - Incentive Fees 47,427bx_PerformanceFeesUnrealizedIncentiveFees
/ us-gaap_ConsolidationItemsAxis
= us-gaap_OperatingSegmentsMember
/ us-gaap_StatementBusinessSegmentsAxis
= bx_HedgeFundSolutionsSegmentMember
18,085bx_PerformanceFeesUnrealizedIncentiveFees
/ us-gaap_ConsolidationItemsAxis
= us-gaap_OperatingSegmentsMember
/ us-gaap_StatementBusinessSegmentsAxis
= bx_HedgeFundSolutionsSegmentMember
 
Total Performance Fees 57,943us-gaap_PerformanceFees
/ us-gaap_ConsolidationItemsAxis
= us-gaap_OperatingSegmentsMember
/ us-gaap_StatementBusinessSegmentsAxis
= bx_HedgeFundSolutionsSegmentMember
57,930us-gaap_PerformanceFees
/ us-gaap_ConsolidationItemsAxis
= us-gaap_OperatingSegmentsMember
/ us-gaap_StatementBusinessSegmentsAxis
= bx_HedgeFundSolutionsSegmentMember
 
Investment Income (Loss), Realized (10,375)bx_InvestmentIncomeLossRealized
/ us-gaap_ConsolidationItemsAxis
= us-gaap_OperatingSegmentsMember
/ us-gaap_StatementBusinessSegmentsAxis
= bx_HedgeFundSolutionsSegmentMember
16,820bx_InvestmentIncomeLossRealized
/ us-gaap_ConsolidationItemsAxis
= us-gaap_OperatingSegmentsMember
/ us-gaap_StatementBusinessSegmentsAxis
= bx_HedgeFundSolutionsSegmentMember
 
Investment Income (Loss), Unrealized 4,483bx_InvestmentIncomeLossUnrealized
/ us-gaap_ConsolidationItemsAxis
= us-gaap_OperatingSegmentsMember
/ us-gaap_StatementBusinessSegmentsAxis
= bx_HedgeFundSolutionsSegmentMember
4,431bx_InvestmentIncomeLossUnrealized
/ us-gaap_ConsolidationItemsAxis
= us-gaap_OperatingSegmentsMember
/ us-gaap_StatementBusinessSegmentsAxis
= bx_HedgeFundSolutionsSegmentMember
 
Total Investment Income (5,892)us-gaap_GainLossOnInvestments
/ us-gaap_ConsolidationItemsAxis
= us-gaap_OperatingSegmentsMember
/ us-gaap_StatementBusinessSegmentsAxis
= bx_HedgeFundSolutionsSegmentMember
21,251us-gaap_GainLossOnInvestments
/ us-gaap_ConsolidationItemsAxis
= us-gaap_OperatingSegmentsMember
/ us-gaap_StatementBusinessSegmentsAxis
= bx_HedgeFundSolutionsSegmentMember
 
Interest and Dividend Revenue 3,949us-gaap_InvestmentIncomeInterestAndDividend
/ us-gaap_ConsolidationItemsAxis
= us-gaap_OperatingSegmentsMember
/ us-gaap_StatementBusinessSegmentsAxis
= bx_HedgeFundSolutionsSegmentMember
2,661us-gaap_InvestmentIncomeInterestAndDividend
/ us-gaap_ConsolidationItemsAxis
= us-gaap_OperatingSegmentsMember
/ us-gaap_StatementBusinessSegmentsAxis
= bx_HedgeFundSolutionsSegmentMember
 
Other (1,607)us-gaap_OtherIncome
/ us-gaap_ConsolidationItemsAxis
= us-gaap_OperatingSegmentsMember
/ us-gaap_StatementBusinessSegmentsAxis
= bx_HedgeFundSolutionsSegmentMember
122us-gaap_OtherIncome
/ us-gaap_ConsolidationItemsAxis
= us-gaap_OperatingSegmentsMember
/ us-gaap_StatementBusinessSegmentsAxis
= bx_HedgeFundSolutionsSegmentMember
 
Total Revenues 184,775us-gaap_Revenues
/ us-gaap_ConsolidationItemsAxis
= us-gaap_OperatingSegmentsMember
/ us-gaap_StatementBusinessSegmentsAxis
= bx_HedgeFundSolutionsSegmentMember
193,986us-gaap_Revenues
/ us-gaap_ConsolidationItemsAxis
= us-gaap_OperatingSegmentsMember
/ us-gaap_StatementBusinessSegmentsAxis
= bx_HedgeFundSolutionsSegmentMember
 
Compensation and Benefits Compensation 56,104us-gaap_SalariesAndWages
/ us-gaap_ConsolidationItemsAxis
= us-gaap_OperatingSegmentsMember
/ us-gaap_StatementBusinessSegmentsAxis
= bx_HedgeFundSolutionsSegmentMember
40,571us-gaap_SalariesAndWages
/ us-gaap_ConsolidationItemsAxis
= us-gaap_OperatingSegmentsMember
/ us-gaap_StatementBusinessSegmentsAxis
= bx_HedgeFundSolutionsSegmentMember
 
Performance Fee Compensation - Realized Incentive Fees 3,470bx_PerformanceFeeCompensationRealizedIncentiveFees
/ us-gaap_ConsolidationItemsAxis
= us-gaap_OperatingSegmentsMember
/ us-gaap_StatementBusinessSegmentsAxis
= bx_HedgeFundSolutionsSegmentMember
13,271bx_PerformanceFeeCompensationRealizedIncentiveFees
/ us-gaap_ConsolidationItemsAxis
= us-gaap_OperatingSegmentsMember
/ us-gaap_StatementBusinessSegmentsAxis
= bx_HedgeFundSolutionsSegmentMember
 
Performance Fee Compensation - Unrealized Incentive Fees 15,651bx_PerformanceFeeCompensationUnrealizedIncentiveFees
/ us-gaap_ConsolidationItemsAxis
= us-gaap_OperatingSegmentsMember
/ us-gaap_StatementBusinessSegmentsAxis
= bx_HedgeFundSolutionsSegmentMember
6,761bx_PerformanceFeeCompensationUnrealizedIncentiveFees
/ us-gaap_ConsolidationItemsAxis
= us-gaap_OperatingSegmentsMember
/ us-gaap_StatementBusinessSegmentsAxis
= bx_HedgeFundSolutionsSegmentMember
 
Total Compensation and Benefits 75,225us-gaap_LaborAndRelatedExpense
/ us-gaap_ConsolidationItemsAxis
= us-gaap_OperatingSegmentsMember
/ us-gaap_StatementBusinessSegmentsAxis
= bx_HedgeFundSolutionsSegmentMember
60,603us-gaap_LaborAndRelatedExpense
/ us-gaap_ConsolidationItemsAxis
= us-gaap_OperatingSegmentsMember
/ us-gaap_StatementBusinessSegmentsAxis
= bx_HedgeFundSolutionsSegmentMember
 
Other Operating Expenses 21,206us-gaap_OtherCostAndExpenseOperating
/ us-gaap_ConsolidationItemsAxis
= us-gaap_OperatingSegmentsMember
/ us-gaap_StatementBusinessSegmentsAxis
= bx_HedgeFundSolutionsSegmentMember
19,480us-gaap_OtherCostAndExpenseOperating
/ us-gaap_ConsolidationItemsAxis
= us-gaap_OperatingSegmentsMember
/ us-gaap_StatementBusinessSegmentsAxis
= bx_HedgeFundSolutionsSegmentMember
 
Total Expenses 96,431us-gaap_CostsAndExpenses
/ us-gaap_ConsolidationItemsAxis
= us-gaap_OperatingSegmentsMember
/ us-gaap_StatementBusinessSegmentsAxis
= bx_HedgeFundSolutionsSegmentMember
80,083us-gaap_CostsAndExpenses
/ us-gaap_ConsolidationItemsAxis
= us-gaap_OperatingSegmentsMember
/ us-gaap_StatementBusinessSegmentsAxis
= bx_HedgeFundSolutionsSegmentMember
 
Economic Income (Loss) 88,344us-gaap_IncomeLossFromContinuingOperationsBeforeIncomeTaxesExtraordinaryItemsNoncontrollingInterest
/ us-gaap_ConsolidationItemsAxis
= us-gaap_OperatingSegmentsMember
/ us-gaap_StatementBusinessSegmentsAxis
= bx_HedgeFundSolutionsSegmentMember
113,903us-gaap_IncomeLossFromContinuingOperationsBeforeIncomeTaxesExtraordinaryItemsNoncontrollingInterest
/ us-gaap_ConsolidationItemsAxis
= us-gaap_OperatingSegmentsMember
/ us-gaap_StatementBusinessSegmentsAxis
= bx_HedgeFundSolutionsSegmentMember
 
Segment Assets 1,533,776us-gaap_Assets
/ us-gaap_ConsolidationItemsAxis
= us-gaap_OperatingSegmentsMember
/ us-gaap_StatementBusinessSegmentsAxis
= bx_HedgeFundSolutionsSegmentMember
   
Operating Segments | Credit Segment      
Segment Reporting Information [Line Items]      
Management and Advisory Fees, Base Management Fees 125,029us-gaap_ManagementFeesBaseRevenue
/ us-gaap_ConsolidationItemsAxis
= us-gaap_OperatingSegmentsMember
/ us-gaap_StatementBusinessSegmentsAxis
= bx_CreditSegmentMember
105,574us-gaap_ManagementFeesBaseRevenue
/ us-gaap_ConsolidationItemsAxis
= us-gaap_OperatingSegmentsMember
/ us-gaap_StatementBusinessSegmentsAxis
= bx_CreditSegmentMember
 
Management and Advisory Fees, Transaction and Other Fees, Net 1,457bx_TransactionAndOtherFeesNet
/ us-gaap_ConsolidationItemsAxis
= us-gaap_OperatingSegmentsMember
/ us-gaap_StatementBusinessSegmentsAxis
= bx_CreditSegmentMember
3,344bx_TransactionAndOtherFeesNet
/ us-gaap_ConsolidationItemsAxis
= us-gaap_OperatingSegmentsMember
/ us-gaap_StatementBusinessSegmentsAxis
= bx_CreditSegmentMember
 
Management and Advisory Fees, Management Fee Offsets (7,850)bx_ManagementFeeOffsets
/ us-gaap_ConsolidationItemsAxis
= us-gaap_OperatingSegmentsMember
/ us-gaap_StatementBusinessSegmentsAxis
= bx_CreditSegmentMember
(4,252)bx_ManagementFeeOffsets
/ us-gaap_ConsolidationItemsAxis
= us-gaap_OperatingSegmentsMember
/ us-gaap_StatementBusinessSegmentsAxis
= bx_CreditSegmentMember
 
Total Management and Advisory Fees, Net 118,636us-gaap_InvestmentAdvisoryFees
/ us-gaap_ConsolidationItemsAxis
= us-gaap_OperatingSegmentsMember
/ us-gaap_StatementBusinessSegmentsAxis
= bx_CreditSegmentMember
104,666us-gaap_InvestmentAdvisoryFees
/ us-gaap_ConsolidationItemsAxis
= us-gaap_OperatingSegmentsMember
/ us-gaap_StatementBusinessSegmentsAxis
= bx_CreditSegmentMember
 
Performance Fees Realized - Carried Interest 13,367bx_PerformanceFeesRealizedCarriedInterest
/ us-gaap_ConsolidationItemsAxis
= us-gaap_OperatingSegmentsMember
/ us-gaap_StatementBusinessSegmentsAxis
= bx_CreditSegmentMember
19,160bx_PerformanceFeesRealizedCarriedInterest
/ us-gaap_ConsolidationItemsAxis
= us-gaap_OperatingSegmentsMember
/ us-gaap_StatementBusinessSegmentsAxis
= bx_CreditSegmentMember
 
Performance Fees Realized - Incentive Fees 18,431bx_PerformanceFeesRealizedIncentiveFees
/ us-gaap_ConsolidationItemsAxis
= us-gaap_OperatingSegmentsMember
/ us-gaap_StatementBusinessSegmentsAxis
= bx_CreditSegmentMember
14,018bx_PerformanceFeesRealizedIncentiveFees
/ us-gaap_ConsolidationItemsAxis
= us-gaap_OperatingSegmentsMember
/ us-gaap_StatementBusinessSegmentsAxis
= bx_CreditSegmentMember
 
Performance Fees Unrealized - Carried Interest (11,951)bx_PerformanceFeesUnrealizedCarriedInterest
/ us-gaap_ConsolidationItemsAxis
= us-gaap_OperatingSegmentsMember
/ us-gaap_StatementBusinessSegmentsAxis
= bx_CreditSegmentMember
22,986bx_PerformanceFeesUnrealizedCarriedInterest
/ us-gaap_ConsolidationItemsAxis
= us-gaap_OperatingSegmentsMember
/ us-gaap_StatementBusinessSegmentsAxis
= bx_CreditSegmentMember
 
Performance Fees Unrealized - Incentive Fees 9,124bx_PerformanceFeesUnrealizedIncentiveFees
/ us-gaap_ConsolidationItemsAxis
= us-gaap_OperatingSegmentsMember
/ us-gaap_StatementBusinessSegmentsAxis
= bx_CreditSegmentMember
40,444bx_PerformanceFeesUnrealizedIncentiveFees
/ us-gaap_ConsolidationItemsAxis
= us-gaap_OperatingSegmentsMember
/ us-gaap_StatementBusinessSegmentsAxis
= bx_CreditSegmentMember
 
Total Performance Fees 28,971us-gaap_PerformanceFees
/ us-gaap_ConsolidationItemsAxis
= us-gaap_OperatingSegmentsMember
/ us-gaap_StatementBusinessSegmentsAxis
= bx_CreditSegmentMember
96,608us-gaap_PerformanceFees
/ us-gaap_ConsolidationItemsAxis
= us-gaap_OperatingSegmentsMember
/ us-gaap_StatementBusinessSegmentsAxis
= bx_CreditSegmentMember
 
Investment Income (Loss), Realized 2,237bx_InvestmentIncomeLossRealized
/ us-gaap_ConsolidationItemsAxis
= us-gaap_OperatingSegmentsMember
/ us-gaap_StatementBusinessSegmentsAxis
= bx_CreditSegmentMember
3,071bx_InvestmentIncomeLossRealized
/ us-gaap_ConsolidationItemsAxis
= us-gaap_OperatingSegmentsMember
/ us-gaap_StatementBusinessSegmentsAxis
= bx_CreditSegmentMember
 
Investment Income (Loss), Unrealized 6,887bx_InvestmentIncomeLossUnrealized
/ us-gaap_ConsolidationItemsAxis
= us-gaap_OperatingSegmentsMember
/ us-gaap_StatementBusinessSegmentsAxis
= bx_CreditSegmentMember
3,079bx_InvestmentIncomeLossUnrealized
/ us-gaap_ConsolidationItemsAxis
= us-gaap_OperatingSegmentsMember
/ us-gaap_StatementBusinessSegmentsAxis
= bx_CreditSegmentMember
 
Total Investment Income 9,124us-gaap_GainLossOnInvestments
/ us-gaap_ConsolidationItemsAxis
= us-gaap_OperatingSegmentsMember
/ us-gaap_StatementBusinessSegmentsAxis
= bx_CreditSegmentMember
6,150us-gaap_GainLossOnInvestments
/ us-gaap_ConsolidationItemsAxis
= us-gaap_OperatingSegmentsMember
/ us-gaap_StatementBusinessSegmentsAxis
= bx_CreditSegmentMember
 
Interest and Dividend Revenue 5,651us-gaap_InvestmentIncomeInterestAndDividend
/ us-gaap_ConsolidationItemsAxis
= us-gaap_OperatingSegmentsMember
/ us-gaap_StatementBusinessSegmentsAxis
= bx_CreditSegmentMember
5,861us-gaap_InvestmentIncomeInterestAndDividend
/ us-gaap_ConsolidationItemsAxis
= us-gaap_OperatingSegmentsMember
/ us-gaap_StatementBusinessSegmentsAxis
= bx_CreditSegmentMember
 
Other 3,493us-gaap_OtherIncome
/ us-gaap_ConsolidationItemsAxis
= us-gaap_OperatingSegmentsMember
/ us-gaap_StatementBusinessSegmentsAxis
= bx_CreditSegmentMember
(259)us-gaap_OtherIncome
/ us-gaap_ConsolidationItemsAxis
= us-gaap_OperatingSegmentsMember
/ us-gaap_StatementBusinessSegmentsAxis
= bx_CreditSegmentMember
 
Total Revenues 165,875us-gaap_Revenues
/ us-gaap_ConsolidationItemsAxis
= us-gaap_OperatingSegmentsMember
/ us-gaap_StatementBusinessSegmentsAxis
= bx_CreditSegmentMember
213,026us-gaap_Revenues
/ us-gaap_ConsolidationItemsAxis
= us-gaap_OperatingSegmentsMember
/ us-gaap_StatementBusinessSegmentsAxis
= bx_CreditSegmentMember
 
Compensation and Benefits Compensation 49,877us-gaap_SalariesAndWages
/ us-gaap_ConsolidationItemsAxis
= us-gaap_OperatingSegmentsMember
/ us-gaap_StatementBusinessSegmentsAxis
= bx_CreditSegmentMember
50,752us-gaap_SalariesAndWages
/ us-gaap_ConsolidationItemsAxis
= us-gaap_OperatingSegmentsMember
/ us-gaap_StatementBusinessSegmentsAxis
= bx_CreditSegmentMember
 
Performance Fee Compensation - Realized Carried Interest 6,270bx_PerformanceFeeCompensationRealizedCarriedInterest
/ us-gaap_ConsolidationItemsAxis
= us-gaap_OperatingSegmentsMember
/ us-gaap_StatementBusinessSegmentsAxis
= bx_CreditSegmentMember
11,794bx_PerformanceFeeCompensationRealizedCarriedInterest
/ us-gaap_ConsolidationItemsAxis
= us-gaap_OperatingSegmentsMember
/ us-gaap_StatementBusinessSegmentsAxis
= bx_CreditSegmentMember
 
Performance Fee Compensation - Realized Incentive Fees 8,401bx_PerformanceFeeCompensationRealizedIncentiveFees
/ us-gaap_ConsolidationItemsAxis
= us-gaap_OperatingSegmentsMember
/ us-gaap_StatementBusinessSegmentsAxis
= bx_CreditSegmentMember
10,380bx_PerformanceFeeCompensationRealizedIncentiveFees
/ us-gaap_ConsolidationItemsAxis
= us-gaap_OperatingSegmentsMember
/ us-gaap_StatementBusinessSegmentsAxis
= bx_CreditSegmentMember
 
Performance Fee Compensation - Unrealized Carried Interest (5,656)bx_PerformanceFeeCompensationUnrealizedCarriedInterest
/ us-gaap_ConsolidationItemsAxis
= us-gaap_OperatingSegmentsMember
/ us-gaap_StatementBusinessSegmentsAxis
= bx_CreditSegmentMember
10,853bx_PerformanceFeeCompensationUnrealizedCarriedInterest
/ us-gaap_ConsolidationItemsAxis
= us-gaap_OperatingSegmentsMember
/ us-gaap_StatementBusinessSegmentsAxis
= bx_CreditSegmentMember
 
Performance Fee Compensation - Unrealized Incentive Fees 6,735bx_PerformanceFeeCompensationUnrealizedIncentiveFees
/ us-gaap_ConsolidationItemsAxis
= us-gaap_OperatingSegmentsMember
/ us-gaap_StatementBusinessSegmentsAxis
= bx_CreditSegmentMember
15,388bx_PerformanceFeeCompensationUnrealizedIncentiveFees
/ us-gaap_ConsolidationItemsAxis
= us-gaap_OperatingSegmentsMember
/ us-gaap_StatementBusinessSegmentsAxis
= bx_CreditSegmentMember
 
Total Compensation and Benefits 65,627us-gaap_LaborAndRelatedExpense
/ us-gaap_ConsolidationItemsAxis
= us-gaap_OperatingSegmentsMember
/ us-gaap_StatementBusinessSegmentsAxis
= bx_CreditSegmentMember
99,167us-gaap_LaborAndRelatedExpense
/ us-gaap_ConsolidationItemsAxis
= us-gaap_OperatingSegmentsMember
/ us-gaap_StatementBusinessSegmentsAxis
= bx_CreditSegmentMember
 
Other Operating Expenses 21,836us-gaap_OtherCostAndExpenseOperating
/ us-gaap_ConsolidationItemsAxis
= us-gaap_OperatingSegmentsMember
/ us-gaap_StatementBusinessSegmentsAxis
= bx_CreditSegmentMember
32,839us-gaap_OtherCostAndExpenseOperating
/ us-gaap_ConsolidationItemsAxis
= us-gaap_OperatingSegmentsMember
/ us-gaap_StatementBusinessSegmentsAxis
= bx_CreditSegmentMember
 
Total Expenses 87,463us-gaap_CostsAndExpenses
/ us-gaap_ConsolidationItemsAxis
= us-gaap_OperatingSegmentsMember
/ us-gaap_StatementBusinessSegmentsAxis
= bx_CreditSegmentMember
132,006us-gaap_CostsAndExpenses
/ us-gaap_ConsolidationItemsAxis
= us-gaap_OperatingSegmentsMember
/ us-gaap_StatementBusinessSegmentsAxis
= bx_CreditSegmentMember
 
Economic Income (Loss) 78,412us-gaap_IncomeLossFromContinuingOperationsBeforeIncomeTaxesExtraordinaryItemsNoncontrollingInterest
/ us-gaap_ConsolidationItemsAxis
= us-gaap_OperatingSegmentsMember
/ us-gaap_StatementBusinessSegmentsAxis
= bx_CreditSegmentMember
81,020us-gaap_IncomeLossFromContinuingOperationsBeforeIncomeTaxesExtraordinaryItemsNoncontrollingInterest
/ us-gaap_ConsolidationItemsAxis
= us-gaap_OperatingSegmentsMember
/ us-gaap_StatementBusinessSegmentsAxis
= bx_CreditSegmentMember
 
Segment Assets 2,563,449us-gaap_Assets
/ us-gaap_ConsolidationItemsAxis
= us-gaap_OperatingSegmentsMember
/ us-gaap_StatementBusinessSegmentsAxis
= bx_CreditSegmentMember
   
Operating Segments | Financial Advisory Segment      
Segment Reporting Information [Line Items]      
Management and Advisory Fees, Advisory Fees 84,238bx_AdvisoryFees
/ us-gaap_ConsolidationItemsAxis
= us-gaap_OperatingSegmentsMember
/ us-gaap_StatementBusinessSegmentsAxis
= bx_FinancialAdvisorySegmentMember
69,963bx_AdvisoryFees
/ us-gaap_ConsolidationItemsAxis
= us-gaap_OperatingSegmentsMember
/ us-gaap_StatementBusinessSegmentsAxis
= bx_FinancialAdvisorySegmentMember
 
Management and Advisory Fees, Transaction and Other Fees, Net 16bx_TransactionAndOtherFeesNet
/ us-gaap_ConsolidationItemsAxis
= us-gaap_OperatingSegmentsMember
/ us-gaap_StatementBusinessSegmentsAxis
= bx_FinancialAdvisorySegmentMember
62bx_TransactionAndOtherFeesNet
/ us-gaap_ConsolidationItemsAxis
= us-gaap_OperatingSegmentsMember
/ us-gaap_StatementBusinessSegmentsAxis
= bx_FinancialAdvisorySegmentMember
 
Total Management and Advisory Fees, Net 84,254us-gaap_InvestmentAdvisoryFees
/ us-gaap_ConsolidationItemsAxis
= us-gaap_OperatingSegmentsMember
/ us-gaap_StatementBusinessSegmentsAxis
= bx_FinancialAdvisorySegmentMember
70,025us-gaap_InvestmentAdvisoryFees
/ us-gaap_ConsolidationItemsAxis
= us-gaap_OperatingSegmentsMember
/ us-gaap_StatementBusinessSegmentsAxis
= bx_FinancialAdvisorySegmentMember
 
Investment Income (Loss), Realized (230)bx_InvestmentIncomeLossRealized
/ us-gaap_ConsolidationItemsAxis
= us-gaap_OperatingSegmentsMember
/ us-gaap_StatementBusinessSegmentsAxis
= bx_FinancialAdvisorySegmentMember
134bx_InvestmentIncomeLossRealized
/ us-gaap_ConsolidationItemsAxis
= us-gaap_OperatingSegmentsMember
/ us-gaap_StatementBusinessSegmentsAxis
= bx_FinancialAdvisorySegmentMember
 
Investment Income (Loss), Unrealized 1,482bx_InvestmentIncomeLossUnrealized
/ us-gaap_ConsolidationItemsAxis
= us-gaap_OperatingSegmentsMember
/ us-gaap_StatementBusinessSegmentsAxis
= bx_FinancialAdvisorySegmentMember
694bx_InvestmentIncomeLossUnrealized
/ us-gaap_ConsolidationItemsAxis
= us-gaap_OperatingSegmentsMember
/ us-gaap_StatementBusinessSegmentsAxis
= bx_FinancialAdvisorySegmentMember
 
Total Investment Income 1,252us-gaap_GainLossOnInvestments
/ us-gaap_ConsolidationItemsAxis
= us-gaap_OperatingSegmentsMember
/ us-gaap_StatementBusinessSegmentsAxis
= bx_FinancialAdvisorySegmentMember
828us-gaap_GainLossOnInvestments
/ us-gaap_ConsolidationItemsAxis
= us-gaap_OperatingSegmentsMember
/ us-gaap_StatementBusinessSegmentsAxis
= bx_FinancialAdvisorySegmentMember
 
Interest and Dividend Revenue 3,237us-gaap_InvestmentIncomeInterestAndDividend
/ us-gaap_ConsolidationItemsAxis
= us-gaap_OperatingSegmentsMember
/ us-gaap_StatementBusinessSegmentsAxis
= bx_FinancialAdvisorySegmentMember
2,502us-gaap_InvestmentIncomeInterestAndDividend
/ us-gaap_ConsolidationItemsAxis
= us-gaap_OperatingSegmentsMember
/ us-gaap_StatementBusinessSegmentsAxis
= bx_FinancialAdvisorySegmentMember
 
Other (956)us-gaap_OtherIncome
/ us-gaap_ConsolidationItemsAxis
= us-gaap_OperatingSegmentsMember
/ us-gaap_StatementBusinessSegmentsAxis
= bx_FinancialAdvisorySegmentMember
(175)us-gaap_OtherIncome
/ us-gaap_ConsolidationItemsAxis
= us-gaap_OperatingSegmentsMember
/ us-gaap_StatementBusinessSegmentsAxis
= bx_FinancialAdvisorySegmentMember
 
Total Revenues 87,787us-gaap_Revenues
/ us-gaap_ConsolidationItemsAxis
= us-gaap_OperatingSegmentsMember
/ us-gaap_StatementBusinessSegmentsAxis
= bx_FinancialAdvisorySegmentMember
73,180us-gaap_Revenues
/ us-gaap_ConsolidationItemsAxis
= us-gaap_OperatingSegmentsMember
/ us-gaap_StatementBusinessSegmentsAxis
= bx_FinancialAdvisorySegmentMember
 
Compensation and Benefits Compensation 68,934us-gaap_SalariesAndWages
/ us-gaap_ConsolidationItemsAxis
= us-gaap_OperatingSegmentsMember
/ us-gaap_StatementBusinessSegmentsAxis
= bx_FinancialAdvisorySegmentMember
61,682us-gaap_SalariesAndWages
/ us-gaap_ConsolidationItemsAxis
= us-gaap_OperatingSegmentsMember
/ us-gaap_StatementBusinessSegmentsAxis
= bx_FinancialAdvisorySegmentMember
 
Total Compensation and Benefits 68,934us-gaap_LaborAndRelatedExpense
/ us-gaap_ConsolidationItemsAxis
= us-gaap_OperatingSegmentsMember
/ us-gaap_StatementBusinessSegmentsAxis
= bx_FinancialAdvisorySegmentMember
61,682us-gaap_LaborAndRelatedExpense
/ us-gaap_ConsolidationItemsAxis
= us-gaap_OperatingSegmentsMember
/ us-gaap_StatementBusinessSegmentsAxis
= bx_FinancialAdvisorySegmentMember
 
Other Operating Expenses 21,342us-gaap_OtherCostAndExpenseOperating
/ us-gaap_ConsolidationItemsAxis
= us-gaap_OperatingSegmentsMember
/ us-gaap_StatementBusinessSegmentsAxis
= bx_FinancialAdvisorySegmentMember
21,342us-gaap_OtherCostAndExpenseOperating
/ us-gaap_ConsolidationItemsAxis
= us-gaap_OperatingSegmentsMember
/ us-gaap_StatementBusinessSegmentsAxis
= bx_FinancialAdvisorySegmentMember
 
Total Expenses 90,276us-gaap_CostsAndExpenses
/ us-gaap_ConsolidationItemsAxis
= us-gaap_OperatingSegmentsMember
/ us-gaap_StatementBusinessSegmentsAxis
= bx_FinancialAdvisorySegmentMember
83,024us-gaap_CostsAndExpenses
/ us-gaap_ConsolidationItemsAxis
= us-gaap_OperatingSegmentsMember
/ us-gaap_StatementBusinessSegmentsAxis
= bx_FinancialAdvisorySegmentMember
 
Economic Income (Loss) (2,489)us-gaap_IncomeLossFromContinuingOperationsBeforeIncomeTaxesExtraordinaryItemsNoncontrollingInterest
/ us-gaap_ConsolidationItemsAxis
= us-gaap_OperatingSegmentsMember
/ us-gaap_StatementBusinessSegmentsAxis
= bx_FinancialAdvisorySegmentMember
(9,844)us-gaap_IncomeLossFromContinuingOperationsBeforeIncomeTaxesExtraordinaryItemsNoncontrollingInterest
/ us-gaap_ConsolidationItemsAxis
= us-gaap_OperatingSegmentsMember
/ us-gaap_StatementBusinessSegmentsAxis
= bx_FinancialAdvisorySegmentMember
 
Segment Assets $ 869,846us-gaap_Assets
/ us-gaap_ConsolidationItemsAxis
= us-gaap_OperatingSegmentsMember
/ us-gaap_StatementBusinessSegmentsAxis
= bx_FinancialAdvisorySegmentMember