v2.4.0.8
Summary of Changes in Financial Assets Measured at Fair Value for Which Level III Inputs Were Used (Detail) (Level 3, USD $)
In Thousands, unless otherwise specified
 3 Months Ended 9 Months Ended
Sep. 30, 2013
Sep. 30, 2012
Sep. 30, 2013
Sep. 30, 2012
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]        
Balance, Beginning of Period $ 3,045,964 $ 2,665,725 $ 3,076,466 $ 2,132,488
Transfer In Due to Consolidation and Acquisition   3,216 [1] 11,960 [1] 125,781 [1]
Transfer Out Due to Deconsolidation (96)   (152,823) (1,599)
Transfer In to Level III 235,012 [2] 436,233 [2] 693,489 [2] 575,238 [2]
Transfer Out of Level III (273,239) [2] (159,482) [2] (382,421) [2] (135,729) [2]
Purchases 499,804 216,948 1,036,328 714,390
Sales (308,421) (282,151) (1,238,281) (614,811)
Settlements 2,040 (79) 490 (46)
Realized Gains (Losses), Net 13,704 13,462 9,602 (5,342)
Changes in Unrealized Gains (Losses) Included in Earnings Related to Investments Still Held at the Reporting Date 66,691 73,992 226,649 177,494
Balance, End of Period 3,281,459 2,967,864 3,281,459 2,967,864
Investments Of Consolidated Funds
        
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]        
Balance, Beginning of Period 2,890,319 2,540,156 3,017,699 2,103,769
Transfer In Due to Consolidation and Acquisition   1,036 [1]   123,601 [1]
Transfer Out Due to Deconsolidation (96)   (152,823) (1,599)
Transfer In to Level III 226,144 [2] 436,233 [2] 684,621 [2] 575,238 [2]
Transfer Out of Level III (270,059) [2] (159,482) [2] (377,527) [2] (135,729) [2]
Purchases 349,209 209,642 673,179 564,076
Sales (154,446) (181,324) (959,115) (464,193)
Realized Gains (Losses), Net 13,861 13,671 (4,913) (5,772)
Changes in Unrealized Gains (Losses) Included in Earnings Related to Investments Still Held at the Reporting Date 67,127 76,224 240,938 176,765
Balance, End of Period 3,122,059 2,936,156 3,122,059 2,936,156
Loans And Receivables
        
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]        
Balance, Beginning of Period 107,731 104,207 30,663 8,555
Purchases 127,370 5,956 233,890 148,864
Sales (138,937) (100,728) (168,399) (149,979)
Settlements 2,293 (79) 2,312 (46)
Realized Gains (Losses), Net   (308) 43 (308)
Changes in Unrealized Gains (Losses) Included in Earnings Related to Investments Still Held at the Reporting Date (380) (1,753) (432) 209
Balance, End of Period 98,077 7,295 98,077 7,295
Other
        
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]        
Balance, Beginning of Period 47,914 [3] 21,362 [3] 28,104 [3] 20,164 [3]
Transfer In Due to Consolidation and Acquisition   2,180 [1],[3] 11,960 [1],[3] 2,180 [1],[3]
Transfer In to Level III 8,868 [2],[3]   8,868 [2],[3]  
Transfer Out of Level III (3,180) [2],[3]   (4,894) [2],[3]  
Purchases 23,225 [3] 1,350 [3] 129,259 [3] 1,450 [3]
Sales (15,038) [3] (99) [3] (110,767) [3] (639) [3]
Settlements (253) [3]   (1,822) [3]  
Realized Gains (Losses), Net (157) [3] 99 [3] 14,472 [3] 738 [3]
Changes in Unrealized Gains (Losses) Included in Earnings Related to Investments Still Held at the Reporting Date (56) [3] (479) [3] (13,857) [3] 520 [3]
Balance, End of Period $ 61,323 [3] $ 24,413 [3] $ 61,323 [3] $ 24,413 [3]
[1] Represents the transfer into Level III of financial assets and liabilities held by CLO vehicles as a result of the acquisition of management contracts and the Harbourmaster acquisition.
[2] Transfers in and out of Level III financial assets and liabilities were due to changes in the observability of inputs used in the valuation of such assets and liabilities.
[3] Represents Blackstone's Treasury Cash Management Strategies and Other Investments.