Loans Held for Investment, net - Loan Risk Ratings Carrying Value (Details) $ in Thousands	3 Months Ended	12 Months Ended
Mar. 31, 2024 USD ($) loan	Dec. 31, 2023 USD ($) loan
SEC Schedule, 12-29, Real Estate Companies, Investment in Mortgage Loans on Real Estate [Line Items]
Number of Loans \| loan	21	24
Percentage of Portfolio	100.00%	100.00%
Year one	$ 0	$ 132,204
Year two	132,370	209,580
Year three	195,121	246,130
Year four	231,573	38,548
Prior	29,571	0
Loans held for investment	$ 588,635	$ 626,462
1
SEC Schedule, 12-29, Real Estate Companies, Investment in Mortgage Loans on Real Estate [Line Items]
Number of Loans \| loan	0	0
Percentage of Portfolio	0.00%	0.00%
Year one	$ 0	$ 0
Year two	0	0
Year three	0	0
Year four	0	0
Prior	0	0
Loans held for investment	$ 0	$ 0
2
SEC Schedule, 12-29, Real Estate Companies, Investment in Mortgage Loans on Real Estate [Line Items]
Number of Loans \| loan	3	3
Percentage of Portfolio	14.00%	15.00%
Year one	$ 0	$ 37,323
Year two	83,229	42,089
Year three	0	15,435
Year four	0	0
Prior	0	0
Loans held for investment	$ 83,229	$ 94,847
3
SEC Schedule, 12-29, Real Estate Companies, Investment in Mortgage Loans on Real Estate [Line Items]
Number of Loans \| loan	15	18
Percentage of Portfolio	71.00%	71.00%
Year one	$ 0	$ 94,881
Year two	49,141	167,491
Year three	195,121	144,456
Year four	144,692	38,548
Prior	29,571	0
Loans held for investment	$ 418,525	$ 445,376
4
SEC Schedule, 12-29, Real Estate Companies, Investment in Mortgage Loans on Real Estate [Line Items]
Number of Loans \| loan	3	3
Percentage of Portfolio	15.00%	14.00%
Year one	$ 0	$ 0
Year two	0	0
Year three	0	86,239
Year four	86,881	0
Prior	0	0
Loans held for investment	$ 86,881	$ 86,239
5
SEC Schedule, 12-29, Real Estate Companies, Investment in Mortgage Loans on Real Estate [Line Items]
Number of Loans \| loan	0	0
Percentage of Portfolio	0.00%	0.00%
Year one	$ 0	$ 0
Year two	0	0
Year three	0	0
Year four	0	0
Prior	0	0
Loans held for investment	$ 0	$ 0

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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.

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Number of mortgage loans 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.

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Amortized cost excluding accrued interest, before allowance for credit loss, of financing receivable. Excludes net investment in lease.

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-Topic 326
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Amortized cost excluding accrued interest, of financing receivable originated more than five years prior to current fiscal year. Excludes net investment in lease.

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Amortized cost excluding accrued interest, of financing receivable originated three years prior to current fiscal year. Excludes net investment in lease.

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Amortized cost excluding accrued interest, of financing receivable originated in current fiscal year. Excludes net investment in lease.

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Amortized cost excluding accrued interest, of financing receivable originated two years prior to current fiscal year. Excludes net investment in lease.

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