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, 2014
Dec. 31, 2013
Fair Value, Option, Quantitative Disclosures [Line Items]    
Fair value assets $ 6,269,990 $ 8,895,688
Fair value liabilities 5,682,920 8,913,007
Discounted Cash Flows | Liabilities of Consolidated CLO Vehicles
   
Fair Value, Option, Quantitative Disclosures [Line Items]    
Recovery Rate 70.00%  
Recovery Lag 12 months 12 months
Pre-payment Rate 20.00%  
Discounted Cash Flows | Liabilities of Consolidated CLO Vehicles | LIBOR
   
Fair Value, Option, Quantitative Disclosures [Line Items]    
Reinvestment Rate 4.00% 4.00%
Discounted Cash Flows | Liabilities of Consolidated CLO Vehicles | Weighted Average
   
Fair Value, Option, Quantitative Disclosures [Line Items]    
Default Rate 2.10% [1] 2.10% [1]
Recovery Rate   66.00% [1]
Pre-payment Rate   18.00% [1]
Discount Rate 2.50% [1] 2.60% [1]
Discounted Cash Flows | Liabilities of Consolidated CLO Vehicles | Minimum
   
Fair Value, Option, Quantitative Disclosures [Line Items]    
Default Rate 2.00% 2.00%
Recovery Rate   30.00%
Pre-payment Rate   5.00%
Discount Rate 0.80% 0.40%
Discounted Cash Flows | Liabilities of Consolidated CLO Vehicles | Maximum
   
Fair Value, Option, Quantitative Disclosures [Line Items]    
Default Rate 3.00% 3.00%
Recovery Rate   70.00%
Pre-payment Rate   20.00%
Discount Rate 26.70% 24.20%
Level 3
   
Fair Value, Option, Quantitative Disclosures [Line Items]    
Fair value assets 3,488,628 3,555,138
Level 3 | Discounted Cash Flows | Liabilities of Consolidated CLO Vehicles
   
Fair Value, Option, Quantitative Disclosures [Line Items]    
Fair value liabilities 5,682,920 8,913,007
Blackstone's Treasury Cash Management Strategies | Discounted Cash Flows
   
Fair Value, Option, Quantitative Disclosures [Line Items]    
Default Rate 2.00% 2.00%
Recovery Rate 70.00%  
Recovery Lag 12 months 12 months
Pre-payment Rate 20.00% 20.00%
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]    
Recovery Rate   66.00% [1]
Discount Rate 6.80% [1] 6.60% [1]
Blackstone's Treasury Cash Management Strategies | Discounted Cash Flows | Minimum
   
Fair Value, Option, Quantitative Disclosures [Line Items]    
Recovery Rate   30.00%
Discount Rate 5.90% 6.00%
Blackstone's Treasury Cash Management Strategies | Discounted Cash Flows | Maximum
   
Fair Value, Option, Quantitative Disclosures [Line Items]    
Recovery Rate   70.00%
Discount Rate 9.30% 8.60%
Blackstone's Treasury Cash Management Strategies | Level 3 | Discounted Cash Flows
   
Fair Value, Option, Quantitative Disclosures [Line Items]    
Fair value assets 26,031 17,040
Blackstone's Treasury Cash Management Strategies | Level 3 | Net Asset Value Valuation Technique
   
Fair Value, Option, Quantitative Disclosures [Line Items]    
Fair value assets 9,968 10,099
Blackstone's Treasury Cash Management Strategies | Level 3 | Transaction Price Valuation Technique
   
Fair Value, Option, Quantitative Disclosures [Line Items]    
Fair value assets 981  
Blackstone's Treasury Cash Management Strategies | Level 3 | Third Party Pricing Valuation Technique
   
Fair Value, Option, Quantitative Disclosures [Line Items]    
Fair value assets 44,087 16,993
Loans And Receivables | Discounted Cash Flows | Weighted Average
   
Fair Value, Option, Quantitative Disclosures [Line Items]    
Discount Rate 10.80% [1] 12.60% [1]
Loans And Receivables | Discounted Cash Flows | Minimum
   
Fair Value, Option, Quantitative Disclosures [Line Items]    
Discount Rate 8.80% 11.00%
Loans And Receivables | Discounted Cash Flows | Maximum
   
Fair Value, Option, Quantitative Disclosures [Line Items]    
Discount Rate 12.90% 14.80%
Loans And Receivables | Level 3 | Discounted Cash Flows
   
Fair Value, Option, Quantitative Disclosures [Line Items]    
Fair value assets 69,794 137,788
Other | Discounted Cash Flows
   
Fair Value, Option, Quantitative Disclosures [Line Items]    
Default Rate 2.00%  
Recovery Rate 70.00%  
Recovery Lag 12 months  
Pre-payment Rate 20.00%  
Discount Rate   12.50%
Other | Discounted Cash Flows | LIBOR
   
Fair Value, Option, Quantitative Disclosures [Line Items]    
Reinvestment Rate 4.00%  
Other | Discounted Cash Flows | Weighted Average
   
Fair Value, Option, Quantitative Disclosures [Line Items]    
Discount Rate 3.00% [1]  
Other | Discounted Cash Flows | Minimum
   
Fair Value, Option, Quantitative Disclosures [Line Items]    
Discount Rate 1.40%  
Other | Discounted Cash Flows | Maximum
   
Fair Value, Option, Quantitative Disclosures [Line Items]    
Discount Rate 12.50%  
Other | Level 3 | Discounted Cash Flows
   
Fair Value, Option, Quantitative Disclosures [Line Items]    
Fair value assets 98,293 2,814
Other | Level 3 | Net Asset Value Valuation Technique
   
Fair Value, Option, Quantitative Disclosures [Line Items]    
Fair value assets 2,855 3,725
Other | Level 3 | Transaction Price Valuation Technique
   
Fair Value, Option, Quantitative Disclosures [Line Items]    
Fair value assets 12,986 7,927
Investments Of Consolidated Blackstone Funds | Level 3
   
Fair Value, Option, Quantitative Disclosures [Line Items]    
Fair value assets 3,223,633 3,358,752
Investments Of Consolidated Blackstone Funds | Consolidated Equity Securities | Discounted Cash Flows | Weighted Average
   
Fair Value, Option, Quantitative Disclosures [Line Items]    
Discount Rate 12.20% [1] 12.40% [1]
Revenue CAGR 6.60% [1] 6.80% [1]
Exit Multiple - EBITDA 8.0 [1] 8.9 [1]
Exit Multiple - P/E 10.7 [1] 9.8 [1]
Investments Of Consolidated Blackstone Funds | Consolidated Equity Securities | Discounted Cash Flows | Minimum
   
Fair Value, Option, Quantitative Disclosures [Line Items]    
Discount Rate 7.10% 9.20%
Revenue CAGR 1.90% 0.90%
Exit Multiple - EBITDA 5.0 5.0
Exit Multiple - P/E 9.5 8.5
Investments Of Consolidated Blackstone Funds | Consolidated Equity Securities | Discounted Cash Flows | Maximum
   
Fair Value, Option, Quantitative Disclosures [Line Items]    
Discount Rate 25.20% 26.30%
Revenue CAGR 27.60% 46.20%
Exit Multiple - EBITDA 17.0 14.0
Exit Multiple - P/E 15.0 17.0
Investments Of Consolidated Blackstone Funds | Consolidated Equity Securities | Market Comparable Companies | Weighted Average
   
Fair Value, Option, Quantitative Disclosures [Line Items]    
EBITDA Multiple 6.7 [1] 6.9 [1]
Investments Of Consolidated Blackstone Funds | Consolidated Equity Securities | Market Comparable Companies | Minimum
   
Fair Value, Option, Quantitative Disclosures [Line Items]    
EBITDA Multiple 6.5 6.3
Investments Of Consolidated Blackstone Funds | Consolidated Equity Securities | Market Comparable Companies | Maximum
   
Fair Value, Option, Quantitative Disclosures [Line Items]    
EBITDA Multiple 7.3 7.5
Investments Of Consolidated Blackstone Funds | Consolidated Equity Securities | Level 3 | Discounted Cash Flows
   
Fair Value, Option, Quantitative Disclosures [Line Items]    
Fair value assets 89,259 112,117
Investments Of Consolidated Blackstone Funds | Consolidated Equity Securities | Level 3 | Market Comparable Companies
   
Fair Value, Option, Quantitative Disclosures [Line Items]    
Fair value assets 162 275
Investments Of Consolidated Blackstone Funds | Consolidated Equity Securities | Level 3 | Transaction Price Valuation Technique
   
Fair Value, Option, Quantitative Disclosures [Line Items]    
Fair value assets 85,955 78,154
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 48 50
Investments Of Consolidated Blackstone Funds | Consolidated Equity Securities | Level 3 | Other
   
Fair Value, Option, Quantitative Disclosures [Line Items]    
Fair value assets 4,383 3,103
Investments Of Consolidated Blackstone Funds | Partnership And LLC Interests | Discounted Cash Flows | Weighted Average
   
Fair Value, Option, Quantitative Disclosures [Line Items]    
Discount Rate 9.00% [1] 9.00% [1]
Revenue CAGR 6.10% [1] 5.50% [1]
Exit Multiple - EBITDA 10.3 [1] 9.4 [1]
Exit Capitalization Rate 7.40% [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% 5.00%
Revenue CAGR (18.80%) (0.70%)
Exit Multiple - EBITDA 0.0 3.0
Exit Capitalization Rate 4.00% 4.30%
Investments Of Consolidated Blackstone Funds | Partnership And LLC Interests | Discounted Cash Flows | Maximum
   
Fair Value, Option, Quantitative Disclosures [Line Items]    
Discount Rate 21.50% 22.50%
Revenue CAGR 22.40% 17.70%
Exit Multiple - EBITDA 23.3 23.3
Exit Capitalization Rate 13.50% 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 504,092 557,534
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 740,513 687,246
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 12,967 9,181
Investments Of Consolidated Blackstone Funds | Partnership And LLC Interests | Level 3 | Other
   
Fair Value, Option, Quantitative Disclosures [Line Items]    
Fair value assets 8,368 942
Investments Of Consolidated Blackstone Funds | Debt Instruments | Discounted Cash Flows
   
Fair Value, Option, Quantitative Disclosures [Line Items]    
Default Rate 2.00% 2.00%
Recovery Rate 70.00% 67.00%
Recovery Lag 12 months 12 months
Pre-payment Rate 20.00% 20.00%
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 17.60% [1] 19.20% [1]
Revenue CAGR 5.30% [1] 4.80% [1]
Exit Multiple - EBITDA 10.2 [1] 10.8 [1]
Exit Capitalization Rate 6.60% [1] 6.70% [1]
Investments Of Consolidated Blackstone Funds | Debt Instruments | Discounted Cash Flows | Minimum
   
Fair Value, Option, Quantitative Disclosures [Line Items]    
Discount Rate 9.00% 10.70%
Revenue CAGR 5.30% 4.80%
Exit Multiple - EBITDA 5.7 5.8
Exit Capitalization Rate 1.00% 6.40%
Investments Of Consolidated Blackstone Funds | Debt Instruments | Discounted Cash Flows | Maximum
   
Fair Value, Option, Quantitative Disclosures [Line Items]    
Discount Rate 23.00% 21.00%
Revenue CAGR 6.50% 5.50%
Exit Multiple - EBITDA 10.4 11.1
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] 6.2 [1]
Investments Of Consolidated Blackstone Funds | Debt Instruments | Market Comparable Companies | Minimum
   
Fair Value, Option, Quantitative Disclosures [Line Items]    
EBITDA Multiple 6.3 6.2
Investments Of Consolidated Blackstone Funds | Debt Instruments | Market Comparable Companies | Maximum
   
Fair Value, Option, Quantitative Disclosures [Line Items]    
EBITDA Multiple 7.8 8.0
Investments Of Consolidated Blackstone Funds | Debt Instruments | Level 3 | Discounted Cash Flows
   
Fair Value, Option, Quantitative Disclosures [Line Items]    
Fair value assets 18,627 11,814
Investments Of Consolidated Blackstone Funds | Debt Instruments | Level 3 | Market Comparable Companies
   
Fair Value, Option, Quantitative Disclosures [Line Items]    
Fair value assets 189 234
Investments Of Consolidated Blackstone Funds | Debt Instruments | Level 3 | Transaction Price Valuation Technique
   
Fair Value, Option, Quantitative Disclosures [Line Items]    
Fair value assets   1,772
Investments Of Consolidated Blackstone Funds | Debt Instruments | Level 3 | Third Party Pricing Valuation Technique
   
Fair Value, Option, Quantitative Disclosures [Line Items]    
Fair value assets 103,959 31,675
Investments Of Consolidated Blackstone Funds | Assets Of Consolidated CLO Vehicles | Discounted Cash Flows
   
Fair Value, Option, Quantitative Disclosures [Line Items]    
Discount Rate 8.50%  
Revenue CAGR   4.20%
Exit Multiple - EBITDA   8.0
Investments Of Consolidated Blackstone Funds | Assets Of Consolidated CLO Vehicles | Discounted Cash Flows | Weighted Average
   
Fair Value, Option, Quantitative Disclosures [Line Items]    
Discount Rate   7.80% [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%
Investments Of Consolidated Blackstone Funds | Assets Of Consolidated CLO Vehicles | Discounted Cash Flows | Maximum
   
Fair Value, Option, Quantitative Disclosures [Line Items]    
Discount Rate   14.00%
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] 7.3 [1]
Investments Of Consolidated Blackstone Funds | Assets Of Consolidated CLO Vehicles | Market Comparable Companies | Minimum
   
Fair Value, Option, Quantitative Disclosures [Line Items]    
EBITDA Multiple 3.5 3.5
Investments Of Consolidated Blackstone Funds | Assets Of Consolidated CLO Vehicles | Market Comparable Companies | Maximum
   
Fair Value, Option, Quantitative Disclosures [Line Items]    
EBITDA Multiple 15.0 11.3
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 3,945 57,936
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 284,848 293,382
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   80
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 275,167 615,414
Investments Of Consolidated Blackstone Funds | Investment Funds | Level 3 | Net Asset Value Valuation Technique
   
Fair Value, Option, Quantitative Disclosures [Line Items]    
Fair value assets $ 1,091,151 $ 897,843
[1] Unobservable inputs were weighted based on the fair value of the investments included in the range.