Residential Whole Loans and Bridge Loans - Aging of Delinquent Loans (Details) $ in Thousands	3 Months Ended	12 Months Ended
Mar. 31, 2023 USD ($) loan	Dec. 31, 2022 loan
Residential whole-loans
Variable Interest Entity [Line Items]
Number of loans \| loan	2,892
Principal	$ 1,134,794
Fair value	$ 1,074,417
Residential Bridge Loans
Variable Interest Entity [Line Items]
Number of loans \| loan	4
Principal	$ 3,091
Fair value	$ 2,782
Non-QM Loans
Variable Interest Entity [Line Items]
Number of loans in forbearance \| loan	0
Current \| Residential whole-loans
Variable Interest Entity [Line Items]
Number of loans \| loan	2,855
Principal	$ 1,113,695
Fair value	$ 1,054,337
Current \| Residential Bridge Loans
Variable Interest Entity [Line Items]
Number of loans \| loan	0
Principal	$ 0
Fair value	$ 0
1-30 days \| Residential whole-loans
Variable Interest Entity [Line Items]
Number of loans \| loan	21
Principal	$ 11,711
Fair value	$ 11,358
1-30 days \| Residential Bridge Loans
Variable Interest Entity [Line Items]
Number of loans \| loan	0
Principal	$ 0
Fair value	$ 0
31-60 days \| Residential whole-loans
Variable Interest Entity [Line Items]
Number of loans \| loan	4
Principal	$ 1,427
Fair value	$ 1,298
31-60 days \| Residential Bridge Loans
Variable Interest Entity [Line Items]
Number of loans \| loan	0
Principal	$ 0
Fair value	$ 0
61-90 days \| Residential whole-loans
Variable Interest Entity [Line Items]
Number of loans \| loan	1
Principal	$ 934
Fair value	$ 874
61-90 days \| Residential Bridge Loans
Variable Interest Entity [Line Items]
Number of loans \| loan	0
Principal	$ 0
Fair value	$ 0
90+ days \| Residential whole-loans
Variable Interest Entity [Line Items]
Number of loans \| loan	11
Principal	$ 7,027
Fair value	$ 6,550
90+ days \| Residential Bridge Loans
Variable Interest Entity [Line Items]
Number of loans \| loan	4	5
Principal	$ 3,091
Fair value	$ 2,782

Fair value portion of loan receivable, including, but not limited to, mortgage loans held for investment, finance receivables held for investment, policy loans on insurance contracts.

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