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Debt and Preferred Equity Investments - Schedule of Roll Forward of our Total Allowance for Loan Losses (Details) $ in Thousands | 3 Months Ended | 9 Months Ended | 12 Months Ended
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Sep. 30, 2024 USD ($) loan | Sep. 30, 2023 USD ($) | Sep. 30, 2024 USD ($) loan | Sep. 30, 2023 USD ($) | Dec. 31, 2023 USD ($)
Loan loss reserve activity |  |  |  |  |
Balance at beginning of year |  |  | $ 13,520 | $ 6,630 | $ 6,630
Current period provision for loan loss | $ 0 | $ 0 | 0 | $ 6,890 | 6,890
Balance at end of period | $ 13,520 |  | $ 13,520 |  | $ 13,520
Number of financing receivables on non-accrual without allowance for loan loss | loan | 1 |  | 1 |  |
Alternative Strategy Portfolio (3) | Total floating rate |  |  |  |  |
Loan loss reserve activity |  |  |  |  |
Financing receivable on non-accrual without allowance | $ 49,800 |  | $ 49,800 |  |

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- Definition Amount excluding accrued interest, of allowance for credit loss on financing receivable. Excludes net investment in lease. + References Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef -Topic 326 -SubTopic 20 -Name Accounting Standards Codification -Section 45 -Paragraph 1 -Publisher FASB -URI https://asc.fasb.org/1943274/2147479344/326-20-45-1 + Details
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- Definition A roll forward is a reconciliation of a concept from the beginning of a period to the end of a period. + References No definition available. + Details
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- Definition Amount, excluding accrued interest, of credit loss expense (reversal of expense) on financing receivable. Excludes net investment in lease. + References Reference 1: http://www.xbrl.org/2003/role/disclosureRef -Topic 326 -SubTopic 20 -Name Accounting Standards Codification -Section 50 -Paragraph 13 -Subparagraph (b) -Publisher FASB -URI https://asc.fasb.org/1943274/2147479319/326-20-50-13 + Details
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- Definition Amortized cost of financing receivable on nonaccrual status with no allowance for credit loss. Excludes net investment in lease. + References Reference 1: http://www.xbrl.org/2003/role/disclosureRef -Topic 326 -SubTopic 20 -Name Accounting Standards Codification -Section 50 -Paragraph 16 -Subparagraph (d) -Publisher FASB -URI https://asc.fasb.org/1943274/2147479319/326-20-50-16 + Details
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- Details
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