Securities, at Fair Value - Interest Income (Details) - USD ($) $ in Thousands		3 Months Ended
		Mar. 31, 2023	Mar. 31, 2022
Debt Securities, Available-for-sale [Line Items]
Interest income		$ 7,308	$ 5,275
Agency MBS
Debt Securities, Available-for-sale [Line Items]
Coupon interest		2,051	0
Effective yield adjustment	[1],[2]	(31)	0
Interest income		2,020	0
Other MBS
Debt Securities, Available-for-sale [Line Items]
Coupon interest		1,912	895
Effective yield adjustment	[1],[2]	188	1,265
Interest income		2,100	2,160
Term notes backed by MSR collateral
Debt Securities, Available-for-sale [Line Items]
Coupon interest		1,963	1,157
Effective yield adjustment	[2]	1,225	1,958
Interest income		$ 3,188	$ 3,115

[1] Includes amortization of premium paid net of accretion of purchase discount.  Interest income is recorded at an effective yield, which reflects net premium amortization/accretion based on actual prepayment activity.

[2] The effective yield adjustment is the difference between the net income calculated using the net yield less the current coupon yield. The net yield may be based on management’s estimates of the amount and timing of future cash flows or in the instrument’s contractual cash flows, depending on the relevant accounting standards.