Debt and Preferred Equity Investments - Preferred Equity Investments (Details) - USD ($) $ in Thousands	12 Months Ended
Dec. 31, 2020	Dec. 31, 2019
Preferred equity investment
Mortgage loans on real estate, interest rate	5.80%
Carrying value	$ 1,076,542	$ 1,580,306
Preferred Equity June 2022
Preferred equity investment
Future Funding Obligations	0
Senior Financing	1,712,750
Carrying value	154,691	98,065
Preferred Equity, February 2027
Preferred equity investment
Future Funding Obligations	0
Senior Financing	250,000
Carrying value	105,095	0
Preferred Equity, April 2021
Preferred equity investment
Future Funding Obligations
Senior Financing	0
Carrying value	$ 0	141,171
Preferred equity investments
Preferred equity investment
Mortgage loans on real estate, interest rate	9.96%
Future Funding Obligations	$ 0
Senior Financing	1,962,750
Carrying value	259,786	239,236
Allowance for loan loss	0	(1,750)
Total after allowance for loan loss	$ 259,786	$ 240,986

Loans and Leases Receivable, Funding Obligation

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- Definition

Amount as of the balance sheet date of debt which holds a position senior to the entity's investment in a mortgage loan on real estate.

+ References

No definition available.

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- Definition

Interest rate of mortgage loan within investment in mortgage loan on real estate by entity with substantial portion of business acquiring and holding investment real estate or interest in real estate.

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Publisher SEC
-Name Regulation S-X (SX)
-Number 210
-Section 12
-Paragraph Column B
-Subsection 29

Reference 2: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 948
-SubTopic 310
-Section S99
-Paragraph 1
-Subparagraph (SX 210.12-29(Column B))
-URI http://asc.fasb.org/extlink&oid=120402547&loc=d3e617274-123014

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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

Amount of allowance for credit loss on financing receivable. Excludes allowance for financing receivable covered under loss sharing agreement.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 310
-SubTopic 10
-Section 50
-Paragraph 11B
-Subparagraph (c)(1)
-URI http://asc.fasb.org/extlink&oid=121611835&loc=SL6953423-111524

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-Publisher FASB
-Name Accounting Standards Codification
-Topic 942
-SubTopic 210
-Section S99
-Paragraph 1
-Subparagraph (SX 210.9-03(7)(2))
-URI http://asc.fasb.org/extlink&oid=120398452&loc=d3e534808-122878

Reference 3: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 326
-SubTopic 20
-Section 45
-Paragraph 1
-URI http://asc.fasb.org/extlink&oid=121599878&loc=SL82895884-210446

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-Publisher FASB
-Name Accounting Standards Codification
-Topic 326
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-Section 50
-Paragraph 13
-Subparagraph (a)
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- Definition

The balance represents the amount of loans that are secured by real estate mortgages, offset by the reserve to cover probable credit losses on the loan portfolio.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 944
-SubTopic 210
-Section S99
-Paragraph 1
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-URI http://asc.fasb.org/extlink&oid=120400017&loc=d3e572229-122910

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- Definition

Amount, after allowance for credit loss, of financing receivable. Excludes financing receivable covered under loss sharing agreement.

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 326
-SubTopic 20
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-Name Accounting Standards Codification
-Topic 210
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-Subparagraph (SX 210.5-02(3))
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-URI http://asc.fasb.org/extlink&oid=121593590&loc=d3e4428-111522

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