Clawback Obligations by Segment (Detail) - USD ($) $ in Thousands	Sep. 30, 2015	Dec. 31, 2014
Product Liability Contingency [Line Items]
Clawback obligations	$ 1,177	$ 3,889
Real Estate Segment
Product Liability Contingency [Line Items]
Clawback obligations		1,777
Credit Segment
Product Liability Contingency [Line Items]
Clawback obligations	1,177	2,112
Blackstone Holdings Finance Co. L.L.C.
Product Liability Contingency [Line Items]
Clawback obligations partnerships	682	1,371
Blackstone Holdings Finance Co. L.L.C. | Real Estate Segment
Product Liability Contingency [Line Items]
Clawback obligations partnerships		130
Blackstone Holdings Finance Co. L.L.C. | Credit Segment
Product Liability Contingency [Line Items]
Clawback obligations partnerships	682	1,241
Current And Former Blackstone Personnel
Product Liability Contingency [Line Items]
Clawback obligations Current and Former Personnel	495	2,518
Current And Former Blackstone Personnel | Real Estate Segment
Product Liability Contingency [Line Items]
Clawback obligations Current and Former Personnel		1,647
Current And Former Blackstone Personnel | Credit Segment
Product Liability Contingency [Line Items]
Clawback obligations Current and Former Personnel	$ 495	$ 871