v2.4.1.9

Scheduled Principal Payments for Borrowings (Detail) (USD $) In Thousands, unless otherwise specified	Mar. 31, 2015
Debt Instrument [Line Items]
2015	$ 4,483us-gaap_LongTermDebtMaturitiesRepaymentsOfPrincipalInNextTwelveMonths
2016	0us-gaap_LongTermDebtMaturitiesRepaymentsOfPrincipalInYearTwo
2017	476,498us-gaap_LongTermDebtMaturitiesRepaymentsOfPrincipalInYearThree
2018	0us-gaap_LongTermDebtMaturitiesRepaymentsOfPrincipalInYearFour
2019	585,000us-gaap_LongTermDebtMaturitiesRepaymentsOfPrincipalInYearFive
Thereafter	8,503,562us-gaap_LongTermDebtMaturitiesRepaymentsOfPrincipalAfterYearFive
Total	9,569,543us-gaap_LongTermDebt
Operating Borrowings
Debt Instrument [Line Items]
2016	0us-gaap_LongTermDebtMaturitiesRepaymentsOfPrincipalInYearTwo / us-gaap_DebtInstrumentAxis = bx_OperatingBorrowingsMember
2018	0us-gaap_LongTermDebtMaturitiesRepaymentsOfPrincipalInYearFour / us-gaap_DebtInstrumentAxis = bx_OperatingBorrowingsMember
2019	585,000us-gaap_LongTermDebtMaturitiesRepaymentsOfPrincipalInYearFive / us-gaap_DebtInstrumentAxis = bx_OperatingBorrowingsMember
Thereafter	1,550,000us-gaap_LongTermDebtMaturitiesRepaymentsOfPrincipalAfterYearFive / us-gaap_DebtInstrumentAxis = bx_OperatingBorrowingsMember
Total	2,135,000us-gaap_LongTermDebt / us-gaap_DebtInstrumentAxis = bx_OperatingBorrowingsMember
Blackstone Fund Facilities Clo Vehicles
Debt Instrument [Line Items]
2015	4,483us-gaap_LongTermDebtMaturitiesRepaymentsOfPrincipalInNextTwelveMonths / us-gaap_DebtInstrumentAxis = bx_BlackstoneFundFacilitiesCloVehiclesMember
2016	0us-gaap_LongTermDebtMaturitiesRepaymentsOfPrincipalInYearTwo / us-gaap_DebtInstrumentAxis = bx_BlackstoneFundFacilitiesCloVehiclesMember
2017	476,498us-gaap_LongTermDebtMaturitiesRepaymentsOfPrincipalInYearThree / us-gaap_DebtInstrumentAxis = bx_BlackstoneFundFacilitiesCloVehiclesMember
2018	0us-gaap_LongTermDebtMaturitiesRepaymentsOfPrincipalInYearFour / us-gaap_DebtInstrumentAxis = bx_BlackstoneFundFacilitiesCloVehiclesMember
Thereafter	6,953,562us-gaap_LongTermDebtMaturitiesRepaymentsOfPrincipalAfterYearFive / us-gaap_DebtInstrumentAxis = bx_BlackstoneFundFacilitiesCloVehiclesMember
Total	$ 7,434,543us-gaap_LongTermDebt / us-gaap_DebtInstrumentAxis = bx_BlackstoneFundFacilitiesCloVehiclesMember

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Carrying amount of long-term debt, net of unamortized discount or premium, including current and noncurrent amounts. Includes, but not limited to, notes payable, bonds payable, debentures, mortgage loans and commercial paper. Excludes capital lease obligations.

+ References

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-Publisher SEC

-Name Regulation S-X (SX)

-Number 210

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Amount of long-term debt payable, sinking fund requirements, and other securities issued that are redeemable by holder at fixed or determinable prices and dates maturing after the fifth fiscal year following the latest fiscal year. Excludes interim and annual periods when interim periods are reported on a rolling approach, from latest balance sheet date.

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Amount of long-term debt payable, sinking fund requirements, and other securities issued that are redeemable by holder at fixed or determinable prices and dates maturing in the fourth fiscal year following the latest fiscal year. Excludes interim and annual periods when interim periods are reported on a rolling approach, from latest balance sheet date.

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