v2.4.0.6
Summary of Aggregate Notional Amount and Fair Value of Derivative Financial Instruments (Detail) (USD $)
In Thousands, unless otherwise specified
Jun. 30, 2012
Dec. 31, 2011
Derivatives, Fair Value [Line Items]    
Derivative Assets, Fair Value $ 98,632 $ 98,738
Derivative Liabilities, Fair Value 38,036 19,948
Derivative Assets, Notional 1,396,670 966,983
Derivative Liabilities, Notional 1,317,759 860,302
Fair Value Hedging | Interest Rate Swap
   
Derivatives, Fair Value [Line Items]    
Derivative Assets, Fair Value   67,668
Derivative Assets, Notional   450,000
Freestanding Derivatives
   
Derivatives, Fair Value [Line Items]    
Derivative Assets, Fair Value 98,632 31,070
Derivative Liabilities, Fair Value 38,036 19,948
Derivative Assets, Notional 1,396,670 516,983
Derivative Liabilities, Notional 1,317,759 860,302
Freestanding Derivatives | Interest Rate Contracts | Blackstone - Other
   
Derivatives, Fair Value [Line Items]    
Derivative Assets, Fair Value 52,009 768
Derivative Liabilities, Fair Value 2,565 1,291
Derivative Assets, Notional 905,450 221,350
Derivative Liabilities, Notional 770,950 502,200
Freestanding Derivatives | Interest Rate Contracts | Investments Of Consolidated Blackstone Funds
   
Derivatives, Fair Value [Line Items]    
Derivative Assets, Fair Value 8,203 7,270
Derivative Liabilities, Fair Value 4,103 10,867
Derivative Assets, Notional 176,495 95,482
Derivative Liabilities, Notional 176,400 191,400
Freestanding Derivatives | Foreign Currency Contracts | Blackstone - Other
   
Derivatives, Fair Value [Line Items]    
Derivative Assets, Fair Value 173 1,016
Derivative Liabilities, Fair Value 125 103
Derivative Assets, Notional 4,167 22,698
Derivative Liabilities, Notional 7,275 7,293
Freestanding Derivatives | Foreign Currency Contracts | Investments Of Consolidated Blackstone Funds
   
Derivatives, Fair Value [Line Items]    
Derivative Assets, Fair Value 38,247 22,016
Derivative Liabilities, Fair Value 31,133 7,687
Derivative Assets, Notional 310,558 177,453
Derivative Liabilities, Notional 362,534 159,409
Freestanding Derivatives | Credit Default Swap | Blackstone - Other
   
Derivatives, Fair Value [Line Items]    
Derivative Liabilities, Fair Value 110  
Derivative Liabilities, Notional $ 600