Multi-family Loans, at Fair Value - Geographic Concentration Risk (Details) - Preferred Equity and Mezzanine Loan Investments - Geographic Concentration Risk	3 Months Ended	12 Months Ended
Mar. 31, 2022	Dec. 31, 2021
Texas
Concentration Risk [Line Items]
Geographic concentration, percent	24.50%	28.30%
Florida
Concentration Risk [Line Items]
Geographic concentration, percent	13.40%	12.20%
Tennessee
Concentration Risk [Line Items]
Geographic concentration, percent	12.10%	11.00%
Georgia
Concentration Risk [Line Items]
Geographic concentration, percent	8.10%	7.40%
Ohio
Concentration Risk [Line Items]
Geographic concentration, percent	7.80%	7.20%
Louisiana
Concentration Risk [Line Items]
Geographic concentration, percent	6.30%	5.80%
Alabama
Concentration Risk [Line Items]
Geographic concentration, percent	5.50%	5.00%

For an entity that discloses a concentration risk in relation to quantitative amount, which serves as the "benchmark" (or denominator) in the equation, this concept represents the concentration percentage derived from the division.

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 280
-SubTopic 10
-Section 50
-Paragraph 42
-URI http://asc.fasb.org/extlink&oid=123359005&loc=d3e9054-108599

Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 275
-SubTopic 10
-Section 50
-Paragraph 18
-URI http://asc.fasb.org/extlink&oid=99393423&loc=d3e6351-108592

Reference 3: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 825
-SubTopic 10
-Section 50
-Paragraph 20
-URI http://asc.fasb.org/extlink&oid=123594938&loc=d3e13531-108611

Reference 4: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 825
-SubTopic 10
-Section 50
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-Subparagraph (a)
-URI http://asc.fasb.org/extlink&oid=123594938&loc=d3e13537-108611

Reference 5: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 275
-SubTopic 10
-Section 50
-Paragraph 20
-URI http://asc.fasb.org/extlink&oid=99393423&loc=d3e6404-108592

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