v2.4.0.8
Summary of Quantitative Inputs and Assumptions for Items Categorized in Level III of Fair Value Hierarchy (Detail) (USD $)
In Thousands, unless otherwise specified
9 Months Ended 12 Months Ended
Sep. 30, 2013
Dec. 31, 2012
Fair Value, Option, Quantitative Disclosures [Line Items]    
Fair value assets $ 9,124,473 $ 11,281,064
Fair value liabilities 9,246,887 11,541,607
Discounted Cash Flows | Collateralized Loan Obligations
   
Fair Value, Option, Quantitative Disclosures [Line Items]    
Recovery Lag 12 months 12 months
Discounted Cash Flows | Collateralized Loan Obligations | LIBOR
   
Fair Value, Option, Quantitative Disclosures [Line Items]    
Reinvestment Rate 4.00% 4.00%
Discounted Cash Flows | Collateralized Loan Obligations | Weighted Average
   
Fair Value, Option, Quantitative Disclosures [Line Items]    
Discount Rate 2.70% [1] 3.90% [1]
Pre-payment Rate 19.00% [1] 18.00% [1]
Recovery Rate 66.00% [1] 66.00% [1]
Default Rate 2.10% [1] 2.10% [1]
Discounted Cash Flows | Collateralized Loan Obligations | Minimum
   
Fair Value, Option, Quantitative Disclosures [Line Items]    
Discount Rate 0.20% 1.10%
Pre-payment Rate 5.00% 5.00%
Recovery Rate 30.00% 30.00%
Default Rate 2.00% 2.00%
Discounted Cash Flows | Collateralized Loan Obligations | Maximum
   
Fair Value, Option, Quantitative Disclosures [Line Items]    
Discount Rate 44.90% 50.00%
Pre-payment Rate 40.00% 20.00%
Recovery Rate 70.00% 70.00%
Default Rate 3.00% 5.00%
Level 3
   
Fair Value, Option, Quantitative Disclosures [Line Items]    
Fair value assets 3,281,459 3,076,466
Level 3 | Discounted Cash Flows | Collateralized Loan Obligations
   
Fair Value, Option, Quantitative Disclosures [Line Items]    
Fair value liabilities 9,246,887 11,541,607
Blackstone's Treasury Cash Management Strategies | Discounted Cash Flows
   
Fair Value, Option, Quantitative Disclosures [Line Items]    
Discount Rate   12.00%
Pre-payment Rate 20.00% 20.00%
Recovery Lag 12 months 12 months
Recovery Rate   70.00%
Default Rate 2.00% 2.00%
Blackstone's Treasury Cash Management Strategies | Discounted Cash Flows | LIBOR
   
Fair Value, Option, Quantitative Disclosures [Line Items]    
Reinvestment Rate 4.00% 4.00%
Blackstone's Treasury Cash Management Strategies | Discounted Cash Flows | Weighted Average
   
Fair Value, Option, Quantitative Disclosures [Line Items]    
Discount Rate 6.40% [1]  
Recovery Rate 66.00% [1]  
Blackstone's Treasury Cash Management Strategies | Discounted Cash Flows | Minimum
   
Fair Value, Option, Quantitative Disclosures [Line Items]    
Discount Rate 5.80%  
Recovery Rate 30.00%  
Blackstone's Treasury Cash Management Strategies | Discounted Cash Flows | Maximum
   
Fair Value, Option, Quantitative Disclosures [Line Items]    
Discount Rate 7.30%  
Recovery Rate 70.00%  
Blackstone's Treasury Cash Management Strategies | Level 3 | Discounted Cash Flows
   
Fair Value, Option, Quantitative Disclosures [Line Items]    
Fair value assets 16,855 1,006
Blackstone's Treasury Cash Management Strategies | Level 3 | Net Asset Value Valuation Technique
   
Fair Value, Option, Quantitative Disclosures [Line Items]    
Fair value assets 9,819  
Blackstone's Treasury Cash Management Strategies | Level 3 | Transaction Price Valuation Technique
   
Fair Value, Option, Quantitative Disclosures [Line Items]    
Fair value assets   200
Blackstone's Treasury Cash Management Strategies | Level 3 | Third Party Pricing Valuation Technique
   
Fair Value, Option, Quantitative Disclosures [Line Items]    
Fair value assets 19,386  
Loans And Receivables | Discounted Cash Flows | Weighted Average
   
Fair Value, Option, Quantitative Disclosures [Line Items]    
Discount Rate 12.40% [1] 13.70% [1]
Loans And Receivables | Discounted Cash Flows | Minimum
   
Fair Value, Option, Quantitative Disclosures [Line Items]    
Discount Rate 12.00% 11.80%
Loans And Receivables | Discounted Cash Flows | Maximum
   
Fair Value, Option, Quantitative Disclosures [Line Items]    
Discount Rate 13.00% 25.90%
Loans And Receivables | Market Comparable Companies
   
Fair Value, Option, Quantitative Disclosures [Line Items]    
EBITDA Multiple   8.7
Loans And Receivables | Level 3 | Discounted Cash Flows
   
Fair Value, Option, Quantitative Disclosures [Line Items]    
Fair value assets 98,077 30,620
Loans And Receivables | Level 3 | Market Comparable Companies
   
Fair Value, Option, Quantitative Disclosures [Line Items]    
Fair value assets   43
Other | Discounted Cash Flows
   
Fair Value, Option, Quantitative Disclosures [Line Items]    
Discount Rate 12.50% 12.50%
Other | Level 3 | Discounted Cash Flows
   
Fair Value, Option, Quantitative Disclosures [Line Items]    
Fair value assets 3,627 5,647
Other | Level 3 | Net Asset Value Valuation Technique
   
Fair Value, Option, Quantitative Disclosures [Line Items]    
Fair value assets 3,738 17,901
Other | Level 3 | Transaction Price Valuation Technique
   
Fair Value, Option, Quantitative Disclosures [Line Items]    
Fair value assets 7,898 3,350
Investments Of Consolidated Blackstone Funds | Level 3
   
Fair Value, Option, Quantitative Disclosures [Line Items]    
Fair value assets 3,122,059 3,017,699
Investments Of Consolidated Blackstone Funds | Consolidated Equity Securities | Discounted Cash Flows | Weighted Average
   
Fair Value, Option, Quantitative Disclosures [Line Items]    
Discount Rate 11.00% [1] 11.20% [1]
Revenue CAGR 6.00% [1] 5.60% [1]
Exit Multiple - EBITDA 9.6 [1] 9.2 [1]
Exit Multiple - P/E 10.1 [1] 10.1 [1]
Investments Of Consolidated Blackstone Funds | Consolidated Equity Securities | Discounted Cash Flows | Minimum
   
Fair Value, Option, Quantitative Disclosures [Line Items]    
Discount Rate 8.10% 8.40%
Revenue CAGR 0.90% 0.70%
Exit Multiple - EBITDA 5.0 5.8
Exit Multiple - P/E 8.5 8.5
Investments Of Consolidated Blackstone Funds | Consolidated Equity Securities | Discounted Cash Flows | Maximum
   
Fair Value, Option, Quantitative Disclosures [Line Items]    
Discount Rate 25.00% 25.10%
Revenue CAGR 43.40% 83.40%
Exit Multiple - EBITDA 13 11.5
Exit Multiple - P/E 19.0 17.0
Investments Of Consolidated Blackstone Funds | Consolidated Equity Securities | Market Comparable Companies
   
Fair Value, Option, Quantitative Disclosures [Line Items]    
Book Value Multiple   0.9
Investments Of Consolidated Blackstone Funds | Consolidated Equity Securities | Market Comparable Companies | Weighted Average
   
Fair Value, Option, Quantitative Disclosures [Line Items]    
EBITDA Multiple 7.3 [1] 7.8 [1]
Investments Of Consolidated Blackstone Funds | Consolidated Equity Securities | Market Comparable Companies | Minimum
   
Fair Value, Option, Quantitative Disclosures [Line Items]    
EBITDA Multiple 7.2 5.0
Investments Of Consolidated Blackstone Funds | Consolidated Equity Securities | Market Comparable Companies | Maximum
   
Fair Value, Option, Quantitative Disclosures [Line Items]    
EBITDA Multiple 7.8 8.7
Investments Of Consolidated Blackstone Funds | Consolidated Equity Securities | Level 3 | Discounted Cash Flows
   
Fair Value, Option, Quantitative Disclosures [Line Items]    
Fair value assets 166,586 151,899
Investments Of Consolidated Blackstone Funds | Consolidated Equity Securities | Level 3 | Market Comparable Companies
   
Fair Value, Option, Quantitative Disclosures [Line Items]    
Fair value assets 265 1,602
Investments Of Consolidated Blackstone Funds | Consolidated Equity Securities | Level 3 | Transaction Price Valuation Technique
   
Fair Value, Option, Quantitative Disclosures [Line Items]    
Fair value assets 76,633 61,479
Investments Of Consolidated Blackstone Funds | Consolidated Equity Securities | Level 3 | Third Party Pricing Valuation Technique
   
Fair Value, Option, Quantitative Disclosures [Line Items]    
Fair value assets 58 200
Investments Of Consolidated Blackstone Funds | Consolidated Equity Securities | Level 3 | Other
   
Fair Value, Option, Quantitative Disclosures [Line Items]    
Fair value assets 2,947 1,880
Investments Of Consolidated Blackstone Funds | Partnership And LLC Interests | Discounted Cash Flows | Weighted Average
   
Fair Value, Option, Quantitative Disclosures [Line Items]    
Discount Rate 8.90% [1] 8.90% [1]
Revenue CAGR 5.50% [1] 5.30% [1]
Exit Multiple - EBITDA 9.9 [1] 10.0 [1]
Exit Capitalization Rate 7.00% [1] 7.00% [1]
Investments Of Consolidated Blackstone Funds | Partnership And LLC Interests | Discounted Cash Flows | Minimum
   
Fair Value, Option, Quantitative Disclosures [Line Items]    
Discount Rate 5.00% 5.30%
Revenue CAGR (0.50%) (8.20%)
Exit Multiple - EBITDA 3.0 4.5
Exit Capitalization Rate 4.30% 1.00%
Investments Of Consolidated Blackstone Funds | Partnership And LLC Interests | Discounted Cash Flows | Maximum
   
Fair Value, Option, Quantitative Disclosures [Line Items]    
Discount Rate 22.50% 22.60%
Revenue CAGR 39.30% 62.00%
Exit Multiple - EBITDA 23.3 15.4
Exit Capitalization Rate 10.50% 10.50%
Investments Of Consolidated Blackstone Funds | Partnership And LLC Interests | Level 3 | Discounted Cash Flows
   
Fair Value, Option, Quantitative Disclosures [Line Items]    
Fair value assets 635,164 562,678
Investments Of Consolidated Blackstone Funds | Partnership And LLC Interests | Level 3 | Transaction Price Valuation Technique
   
Fair Value, Option, Quantitative Disclosures [Line Items]    
Fair value assets 8,419 13,316
Investments Of Consolidated Blackstone Funds | Partnership And LLC Interests | Level 3 | Third Party Pricing Valuation Technique
   
Fair Value, Option, Quantitative Disclosures [Line Items]    
Fair value assets 7,919 5,157
Investments Of Consolidated Blackstone Funds | Partnership And LLC Interests | Level 3 | Other
   
Fair Value, Option, Quantitative Disclosures [Line Items]    
Fair value assets 928  
Investments Of Consolidated Blackstone Funds | Debt Instruments | Discounted Cash Flows
   
Fair Value, Option, Quantitative Disclosures [Line Items]    
Pre-payment Rate 20.00% 20.00%
Recovery Lag 12 months 12 months
Recovery Rate 66.00% 70.00%
Default Rate 2.00% 2.00%
Exit Multiple - EBITDA   9.5
Investments Of Consolidated Blackstone Funds | Debt Instruments | Discounted Cash Flows | LIBOR
   
Fair Value, Option, Quantitative Disclosures [Line Items]    
Reinvestment Rate 4.00% 4.00%
Investments Of Consolidated Blackstone Funds | Debt Instruments | Discounted Cash Flows | Weighted Average
   
Fair Value, Option, Quantitative Disclosures [Line Items]    
Discount Rate 16.50% [1] 15.60% [1]
Revenue CAGR 2.50% [1] 3.80% [1]
Default Rate 6.90% [1]  
Exit Multiple - EBITDA 10.6 [1]  
Exit Capitalization Rate   7.10% [1]
Investments Of Consolidated Blackstone Funds | Debt Instruments | Discounted Cash Flows | Minimum
   
Fair Value, Option, Quantitative Disclosures [Line Items]    
Discount Rate 8.40% 7.80%
Revenue CAGR 1.60% 2.90%
Exit Multiple - EBITDA 5.8  
Exit Capitalization Rate 6.80% 7.00%
Investments Of Consolidated Blackstone Funds | Debt Instruments | Discounted Cash Flows | Maximum
   
Fair Value, Option, Quantitative Disclosures [Line Items]    
Discount Rate 20.00% 42.00%
Revenue CAGR 3.70% 5.10%
Exit Multiple - EBITDA 11.5  
Exit Capitalization Rate 7.50% 7.50%
Investments Of Consolidated Blackstone Funds | Debt Instruments | Market Comparable Companies | Weighted Average
   
Fair Value, Option, Quantitative Disclosures [Line Items]    
EBITDA Multiple 6.3 [1] 6.7 [1]
Investments Of Consolidated Blackstone Funds | Debt Instruments | Market Comparable Companies | Minimum
   
Fair Value, Option, Quantitative Disclosures [Line Items]    
EBITDA Multiple 6.3 6.5
Investments Of Consolidated Blackstone Funds | Debt Instruments | Market Comparable Companies | Maximum
   
Fair Value, Option, Quantitative Disclosures [Line Items]    
EBITDA Multiple 7.9 7.5
Investments Of Consolidated Blackstone Funds | Debt Instruments | Level 3 | Discounted Cash Flows
   
Fair Value, Option, Quantitative Disclosures [Line Items]    
Fair value assets 14,328 13,056
Investments Of Consolidated Blackstone Funds | Debt Instruments | Level 3 | Market Comparable Companies
   
Fair Value, Option, Quantitative Disclosures [Line Items]    
Fair value assets 278 664
Investments Of Consolidated Blackstone Funds | Debt Instruments | Level 3 | Transaction Price Valuation Technique
   
Fair Value, Option, Quantitative Disclosures [Line Items]    
Fair value assets 528  
Investments Of Consolidated Blackstone Funds | Debt Instruments | Level 3 | Third Party Pricing Valuation Technique
   
Fair Value, Option, Quantitative Disclosures [Line Items]    
Fair value assets 44,397 4,004
Investments Of Consolidated Blackstone Funds | Assets Of Consolidated CLO Vehicles | Discounted Cash Flows
   
Fair Value, Option, Quantitative Disclosures [Line Items]    
Revenue CAGR 5.60%  
Exit Multiple - EBITDA 7.0  
Investments Of Consolidated Blackstone Funds | Assets Of Consolidated CLO Vehicles | Discounted Cash Flows | Weighted Average
   
Fair Value, Option, Quantitative Disclosures [Line Items]    
Discount Rate 7.30% [1] 9.30% [1]
Investments Of Consolidated Blackstone Funds | Assets Of Consolidated CLO Vehicles | Discounted Cash Flows | Minimum
   
Fair Value, Option, Quantitative Disclosures [Line Items]    
Discount Rate 7.00% 7.00%
Investments Of Consolidated Blackstone Funds | Assets Of Consolidated CLO Vehicles | Discounted Cash Flows | Maximum
   
Fair Value, Option, Quantitative Disclosures [Line Items]    
Discount Rate 13.00% 15.70%
Investments Of Consolidated Blackstone Funds | Assets Of Consolidated CLO Vehicles | Market Comparable Companies | Weighted Average
   
Fair Value, Option, Quantitative Disclosures [Line Items]    
EBITDA Multiple 6.9 [1] 6.5 [1]
Liquidity Discount   8.40% [1]
Investments Of Consolidated Blackstone Funds | Assets Of Consolidated CLO Vehicles | Market Comparable Companies | Minimum
   
Fair Value, Option, Quantitative Disclosures [Line Items]    
EBITDA Multiple 2.0 2.0
Liquidity Discount   1.00%
Investments Of Consolidated Blackstone Funds | Assets Of Consolidated CLO Vehicles | Market Comparable Companies | Maximum
   
Fair Value, Option, Quantitative Disclosures [Line Items]    
EBITDA Multiple 11.4 13.0
Liquidity Discount   25.00%
Investments Of Consolidated Blackstone Funds | Assets Of Consolidated CLO Vehicles | Level 3 | Discounted Cash Flows
   
Fair Value, Option, Quantitative Disclosures [Line Items]    
Fair value assets 61,564 132,171
Investments Of Consolidated Blackstone Funds | Assets Of Consolidated CLO Vehicles | Level 3 | Market Comparable Companies
   
Fair Value, Option, Quantitative Disclosures [Line Items]    
Fair value assets 256,496 278,972
Investments Of Consolidated Blackstone Funds | Assets Of Consolidated CLO Vehicles | Level 3 | Transaction Price Valuation Technique
   
Fair Value, Option, Quantitative Disclosures [Line Items]    
Fair value assets 56 10
Investments Of Consolidated Blackstone Funds | Assets Of Consolidated CLO Vehicles | Level 3 | Third Party Pricing Valuation Technique
   
Fair Value, Option, Quantitative Disclosures [Line Items]    
Fair value assets 749,162 900,146
Investments Of Consolidated Blackstone Funds | Investment Funds | Level 3 | Net Asset Value Valuation Technique
   
Fair Value, Option, Quantitative Disclosures [Line Items]    
Fair value assets $ 1,096,331 $ 890,465
[1] Unobservable inputs were weighted based on the fair value of the investments included in the range.