Secured Financings on Investments in Real Estate Debt - Secured Financings on Investments in Real Estate Debt (Detail) - USD ($) $ in Thousands	3 Months Ended	12 Months Ended
Mar. 31, 2021	Dec. 31, 2020
Debt Instrument [Line Items]
Weighted Average Maturity Date	Oct. 29, 2025	Oct. 03, 2025
Collateral Assets	$ 2,238,524	$ 3,293,153
Outstanding Balance	$ 1,491,509	$ 2,140,993
Barclays [Member]
Debt Instrument [Line Items]
Weighted Average Maturity Date	Sep. 29, 2021	Sep. 29, 2021
Security Interests	CMBS	CMBS
Collateral Assets	$ 882,792	$ 1,223,580
Outstanding Balance	$ 599,940	$ 750,000
Prepayment Provisions	None	None
Royal Bank of Canada [Member]
Debt Instrument [Line Items]
Weighted Average Maturity Date	May 31, 2021	Mar. 31, 2021
Security Interests	CMBS/Corporate bonds	CMBS/Corporate bonds
Collateral Assets	$ 617,123	$ 1,295,270
Outstanding Balance	$ 414,810	$ 892,700
Prepayment Provisions	None	None
DB Secured Financing [Member]
Debt Instrument [Line Items]
Weighted Average Maturity Date	Apr. 02, 2022	Apr. 02, 2022
Security Interests	Term Loan	Term Loans
Collateral Assets	$ 399,763	$ 424,647
Outstanding Balance	$ 259,846	$ 275,319
Prepayment Provisions	None	None
Citigroup [Member]
Debt Instrument [Line Items]
Weighted Average Maturity Date		Mar. 30, 2021
Security Interests		CMBS/RMBS
Collateral Assets		$ 208,283
Outstanding Balance		$ 125,638
Prepayment Provisions		None
Morgan Stanley [Member]
Debt Instrument [Line Items]
Weighted Average Maturity Date	Dec. 19, 2021	May 20, 2021
Security Interests	CMBS	CMBS
Collateral Assets	$ 178,268	$ 113,442
Outstanding Balance	$ 118,516	$ 80,249
Prepayment Provisions	None	None
J.P. Morgan [Member]
Debt Instrument [Line Items]
Weighted Average Maturity Date	Apr. 15, 2021
Security Interests	CMBS
Collateral Assets	$ 137,222
Outstanding Balance	$ 84,691
Prepayment Provisions	None
Citi Term Loan TRS [Member]
Debt Instrument [Line Items]
Weighted Average Maturity Date	Jul. 09, 2021	Jul. 09, 2021
Security Interests	Term Loans	Term Loans
Collateral Assets	$ 23,356	$ 27,931
Outstanding Balance	$ 13,706	$ 17,087
Prepayment Provisions	None	None

Debt instrument prepayment provisions.

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- Definition

Repurchase agreements, security interests.

+ References

No definition available.

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- Definition

Weighted average maturity date.

+ References

No definition available.

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- Definition

Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table.

+ References

No definition available.

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- Definition

The fair value, as of the date of each statement of financial position presented, of securities which are owned but transferred to serve as collateral for the payment of repurchase agreements, and that are reclassified and separately reported in the statement of financial position because the transferee has the right by contract or custom to sell or re-pledge them.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 860
-SubTopic 30
-Section 45
-Paragraph 1
-URI http://asc.fasb.org/extlink&oid=66007379&loc=d3e113888-111728

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- Definition

Carrying value, as of the balance sheet date, of securities sold under agreements to repurchase where the transferor maintains effective control over the assets, accounting for them as secured debt.

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 860
-SubTopic 30
-Section 50
-Paragraph 7
-URI http://asc.fasb.org/extlink&oid=109249958&loc=SL34722452-111729

Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 235
-SubTopic 10
-Section S99
-Paragraph 1
-Subparagraph (SX 210.4-08.(m)(1)(i))
-URI http://asc.fasb.org/extlink&oid=120395691&loc=d3e23780-122690

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