Realized and Net Change in Unrealized Gains (Losses) on Investments Held by Blackstone's Treasury Cash Management Strategies (Detail) - USD ($) $ in Thousands	3 Months Ended	6 Months Ended
Jun. 30, 2019	Jun. 30, 2018	Jun. 30, 2019	Jun. 30, 2018
Gain (Loss) on Securities [Line Items]
Total realized and net change in unrealized gains (losses)	$ 597,947	$ 1,176,392	$ 1,746,626	$ 2,228,040
Corporate Treasury Investments
Gain (Loss) on Securities [Line Items]
Realized Gains (Losses)	22,983	4,774	23,300	7,113
Net Change in Unrealized Gains (Losses)	558	(6,702)	49,217	(14,896)
Total realized and net change in unrealized gains (losses)	$ 23,541	$ (1,928)	$ 72,517	$ (7,783)

Amount of realized and unrealized gain (loss) on investment.

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