Investments in Unconsolidated Entities - Summary of Equity Investment In Unconsolidated Entities (Detail) (Parenthetical) - USD ($) $ in Thousands	Mar. 31, 2021	Dec. 31, 2020
Schedule Of Equity Method Investments [Line Items]
Investments in unconsolidated entities (includes $383,343 and $0 at fair value as of March 31, 2021 and December 31, 2020, respectively)	$ 1,209,809	$ 816,220
Unconsolidated Joint Ventures [Member] | Equity Method Investment [Member]
Schedule Of Equity Method Investments [Line Items]
Investments in unconsolidated entities (includes $383,343 and $0 at fair value as of March 31, 2021 and December 31, 2020, respectively)	1,209,809	816,220
Unconsolidated Joint Ventures [Member] | Equity Method Investment [Member] | Net Lease [Member] | BREIT Outside Basis [Member]
Schedule Of Equity Method Investments [Line Items]
Investments in unconsolidated entities (includes $383,343 and $0 at fair value as of March 31, 2021 and December 31, 2020, respectively)	$ 9,300	$ 9,400