Real Estate Securities - Summary of Significant Valuation Assumptions for Available for Sale Securities Credit Loss (Details) - Subordinate Securities	9 Months Ended
Sep. 30, 2020
Debt Securities, Available-for-sale [Line Items]
Default rate	0.50%
Loss severity	20.00%

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.

No definition available.

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Namespace Prefix:	us-gaap_
Data Type:	xbrli:stringItemType
Balance Type:	na
Period Type:	duration