Securities, at Fair Value - Composition of Agency MBS Portfolio (Details) - USD ($) $ in Thousands		3 Months Ended	12 Months Ended
		Mar. 31, 2024	Dec. 31, 2023
Debt Securities, Available-for-sale [Line Items]
Fair Value	[1]	$ 736,950	$ 746,090
$5.00% Coupon
Debt Securities, Available-for-sale [Line Items]
Coupon rate (in percent)		5.00%	5.00%
Current Face		$ 75,830	$ 76,360
Weighted Average Purchase Price (in percent)		100.20%	100.20%
Weighted Average Market Price (in percent)		97.80%	99.10%
Fair Value		$ 74,137	$ 75,650
Weighted Average Loan Age (Months)		12 months	9 months
CPR (in percent)		1.40%	2.40%
5.50% Coupon
Debt Securities, Available-for-sale [Line Items]
Coupon rate (in percent)		5.50%	5.50%
Current Face		$ 274,733	$ 277,885
Weighted Average Purchase Price (in percent)		100.40%	100.40%
Weighted Average Market Price (in percent)		99.70%	100.70%
Fair Value		$ 273,975	$ 279,851
Weighted Average Loan Age (Months)		14 months	11 months
CPR (in percent)		3.20%	5.20%
6.00% Coupon
Debt Securities, Available-for-sale [Line Items]
Coupon rate (in percent)		6.00%	6.00%
Current Face		$ 175,301	$ 177,842
Weighted Average Purchase Price (in percent)		100.00%	100.00%
Weighted Average Market Price (in percent)		101.20%	101.70%
Fair Value		$ 177,471	$ 180,841
Weighted Average Loan Age (Months)		10 months	7 months
CPR (in percent)		4.00%	4.20%
6.50% Coupon
Debt Securities, Available-for-sale [Line Items]
Coupon rate (in percent)		6.50%	6.50%
Current Face		$ 20,783	$ 22,213
Weighted Average Purchase Price (in percent)		100.10%	100.10%
Weighted Average Market Price (in percent)		102.70%	102.70%
Fair Value		$ 21,336	$ 22,802
Weighted Average Loan Age (Months)		7 months	4 months
CPR (in percent)		21.10%	1.40%
Agency MBS
Debt Securities, Available-for-sale [Line Items]
Current Face		$ 546,647	$ 554,300
Weighted Average Purchase Price (in percent)		100.30%	100.30%
Weighted Average Market Price (in percent)		100.00%	100.90%
Fair Value		$ 546,919	$ 559,144
Weighted Average Loan Age (Months)		12 months	9 months
CPR (in percent)		3.90%	4.30%

[1] See Note 6 for information regarding the Company’s pledged assets.