Summary of Significant Accounting Policies - Summary of Quantitative Inputs and Assumptions Used for Items Categorized in Level 3 of Fair Value Hierarchy (Detail) - Level 3 [Member] $ in Thousands	3 Months Ended	12 Months Ended
	Mar. 31, 2021 USD ($)	Dec. 31, 2020 USD ($)
Investments in Real Estate Debt [Member] | Discounted Cash Flow [Member]
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Fair Value		$ 120,892
Unobservable Inputs		Yield
Weighted Average		10.3
Impact to Valuation from an Increase in Input		Decrease
Investments in Real Estate Debt [Member] | Discounted Cash Flow [Member] | Measurement Input, Yield [Member]
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Fair Value	$ 172,042
Unobservable Inputs	Yield
Weighted Average	9.3
Impact to Valuation from an Increase in Input	Decrease
Investments in Unconsolidated Entities [Member] | Measurement Input, Exit Capitalization Rate [Member]
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Unobservable Inputs	Exit Capitalization Rate
Weighted Average	4.8
Impact to Valuation from an Increase in Input	Decrease
Investments in Unconsolidated Entities [Member] | Measurement Input, Weighted Average Cost of Capital [Member]
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Unobservable Inputs	Weighted Average Cost of Capital
Weighted Average	12.4
Impact to Valuation from an Increase in Input	Decrease
Investments in Unconsolidated Entities [Member] | Discounted Cash Flow [Member] | Measurement Input, Discount Rate [Member]
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Fair Value	$ 383,343
Unobservable Inputs	Discount Rate
Weighted Average	6.6
Impact to Valuation from an Increase in Input	Decrease