Investments (Detail) - USD ($) $ in Thousands	Jun. 30, 2018	Dec. 31, 2017
Schedule of Investments [Line Items]
Investments	$ 22,008,182	$ 24,434,049
Partnership Investments
Schedule of Investments [Line Items]
Investments	3,589,234	3,263,131
Accrued Performance Allocations
Schedule of Investments [Line Items]
Investments	6,354,179	5,328,280
Other Investments
Schedule of Investments [Line Items]
Investments	368,203	322,474
Consolidated Blackstone Funds
Schedule of Investments [Line Items]
Investments	8,608,565	12,954,121
Corporate Treasury Investments
Schedule of Investments [Line Items]
Investments	$ 3,088,001	$ 2,566,043