v2.4.1.9

Realized and Net Change in Unrealized Gains (Losses) on Investments Held by Blackstone's Treasury Cash Management Strategies (Detail) (Blackstone's Treasury Cash Management Strategies, USD $) In Thousands, unless otherwise specified | 3 Months Ended
--- | ---
Mar. 31, 2015 | Mar. 31, 2014
Blackstone's Treasury Cash Management Strategies |  |
Gain (Loss) on Investments [Line Items] |  |
Realized Gains (Losses) | $ (161)bx_RealizedGainsLossesOnInvestmentsHeldByTreasuryCashManagementStrategies / dei_LegalEntityAxis = bx_BlackstoneTreasuryCashManagementStrategiesMember | $ 3,094 bx_RealizedGainsLossesOnInvestmentsHeldByTreasuryCashManagementStrategies / dei_LegalEntityAxis = bx_BlackstoneTreasuryCashManagementStrategiesMember
Net Change in Unrealized Gains | 11,111 bx_NetChangesInUnrealizedGainsLossesOnInvestmentsHeldByTreasuryCashManagementStrategies / dei_LegalEntityAxis = bx_BlackstoneTreasuryCashManagementStrategiesMember | 8,970 bx_NetChangesInUnrealizedGainsLossesOnInvestmentsHeldByTreasuryCashManagementStrategies / dei_LegalEntityAxis = bx_BlackstoneTreasuryCashManagementStrategiesMember
Total realized and net change in unrealized gains (losses) | $ 10,950 bx_RealizedGainsLossesAndNetChangeInUnrealizedGainsAndLossesOnInvestmentsHeldByTreasuryCashManagementStrategies / dei_LegalEntityAxis = bx_BlackstoneTreasuryCashManagementStrategiesMember | $ 12,064 bx_RealizedGainsLossesAndNetChangeInUnrealizedGainsAndLossesOnInvestmentsHeldByTreasuryCashManagementStrategies / dei_LegalEntityAxis = bx_BlackstoneTreasuryCashManagementStrategiesMember

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