Financings - Borrowings under Repurchase Agreements (Details) - USD ($) $ in Thousands	12 Months Ended
Dec. 31, 2021	Dec. 31, 2020
Certain characteristics of the Company's repurchase agreements
Repurchase Agreement Borrowings	$ 617,189	$ 358,846
Less unamortized debt issuance costs	0	1,923
Repurchase agreements, net	$ 617,189	$ 356,923
Weighted Average Interest Rate on Borrowings Outstanding at end of period	2.30%	3.57%
Weighted Average Remaining Maturity (days)	247 days	169 days
Repurchase Agreements
Certain characteristics of the Company's repurchase agreements
Repurchase Agreement Borrowings	$ 563,132	$ 250,248
Weighted average interest rate	2.24%	3.74%
Weighted Average Remaining Maturity (days)	270 days	225 days
Repurchase Agreements \| Non-Agency CMBS
Certain characteristics of the Company's repurchase agreements
Repurchase Agreement Borrowings	$ 59,802	$ 66,767
Weighted Average Interest Rate on Borrowings Outstanding at end of period		5.23%
Weighted average interest rate	2.14%
Weighted Average Remaining Maturity (days)	125 days	126 days
Repurchase Agreements \| Non-Agency RMBS
Certain characteristics of the Company's repurchase agreements
Repurchase Agreement Borrowings	$ 15,632	$ 14,643
Weighted Average Interest Rate on Borrowings Outstanding at end of period		5.23%
Weighted average interest rate	2.14%
Weighted Average Remaining Maturity (days)	125 days	126 days
Repurchase Agreements \| Non-Agency CMBS and Non-Agency RMBS Facility
Certain characteristics of the Company's repurchase agreements
Repurchase Agreement Borrowings	$ 102,940	$ 95,087
Weighted Average Interest Rate on Borrowings Outstanding at end of period		5.23%
Weighted average interest rate	2.16%
Weighted Average Remaining Maturity (days)	125 days	126 days
Repurchase Agreements \| Residential Whole Loans
Certain characteristics of the Company's repurchase agreements
Repurchase Agreement Borrowings	$ 396,531	$ 30,224
Weighted average interest rate	2.25%	3.00%
Weighted Average Remaining Maturity (days)	308 days	278 days
Repurchase Agreements \| Commercial Loans
Certain characteristics of the Company's repurchase agreements
Repurchase Agreement Borrowings	$ 63,661	$ 124,937
Weighted average interest rate	2.27%	2.17%
Weighted Average Remaining Maturity (days)	268 days	287 days
Repurchase Agreements \| Other securities
Certain characteristics of the Company's repurchase agreements
Repurchase Agreement Borrowings	$ 27,506	$ 13,677
Weighted Average Interest Rate on Borrowings Outstanding at end of period		5.24%
Weighted average interest rate	2.22%
Weighted Average Remaining Maturity (days)	125 days	126 days
Repurchase Agreements
Certain characteristics of the Company's repurchase agreements
Repurchase Agreement Borrowings	$ 54,057	$ 108,598
Weighted Average Interest Rate on Borrowings Outstanding at end of period	2.92%	3.19%
Weighted Average Remaining Maturity (days)	6 days	39 days
Repurchase Agreements \| Agency RMBS
Certain characteristics of the Company's repurchase agreements
Repurchase Agreement Borrowings	$ 976	$ 1,418
Weighted Average Interest Rate on Borrowings Outstanding at end of period	1.02%	1.34%
Weighted Average Remaining Maturity (days)	58 days	59 days
Repurchase Agreements \| Non-Agency CMBS
Certain characteristics of the Company's repurchase agreements
Repurchase Agreement Borrowings	$ 0	$ 10,313
Weighted Average Interest Rate on Borrowings Outstanding at end of period	0.00%	2.25%
Weighted Average Remaining Maturity (days)	0 days	14 days
Repurchase Agreements \| Non-Agency RMBS
Certain characteristics of the Company's repurchase agreements
Repurchase Agreement Borrowings	$ 38,354	$ 0
Weighted Average Interest Rate on Borrowings Outstanding at end of period	2.94%	0.00%
Weighted Average Remaining Maturity (days)	4 days	0 days
Repurchase Agreements \| Residential Whole Loans
Certain characteristics of the Company's repurchase agreements
Repurchase Agreement Borrowings	$ 1,439	$ 29,800
Weighted Average Interest Rate on Borrowings Outstanding at end of period	2.57%	3.71%
Weighted Average Remaining Maturity (days)	5 days	15 days
Repurchase Agreements \| Residential Bridge Loans
Certain characteristics of the Company's repurchase agreements
Repurchase Agreement Borrowings	$ 4,368	$ 11,254
Weighted Average Interest Rate on Borrowings Outstanding at end of period	2.61%	2.73%
Weighted Average Remaining Maturity (days)	5 days	36 days
Repurchase Agreements \| Commercial Loans
Certain characteristics of the Company's repurchase agreements
Repurchase Agreement Borrowings	$ 6,463	$ 34,375
Weighted Average Interest Rate on Borrowings Outstanding at end of period	3.20%	3.32%
Weighted Average Remaining Maturity (days)	5 days	75 days
Repurchase Agreements \| Membership Interest
Certain characteristics of the Company's repurchase agreements
Repurchase Agreement Borrowings	$ 0	$ 18,844
Weighted Average Interest Rate on Borrowings Outstanding at end of period	0.00%	2.90%
Weighted Average Remaining Maturity (days)	0 days	29 days
Repurchase Agreements \| Other securities
Certain characteristics of the Company's repurchase agreements
Repurchase Agreement Borrowings	$ 2,457	$ 2,594
Weighted Average Interest Rate on Borrowings Outstanding at end of period	3.50%	4.51%
Weighted Average Remaining Maturity (days)	18 days	19 days

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