Investments in RMBS, Assets by Maturity (Details) $ in Thousands		9 Months Ended	12 Months Ended
		Sep. 30, 2024 USD ($) Security	Dec. 31, 2023 USD ($) Security
RMBS, Assets by Maturity [Abstract]
Carrying value		$ 1,214,123	$ 1,012,130
Carrying value of collateral for repurchase agreements		1,153,213	973,221
RMBS [Member]
RMBS, Assets by Maturity [Abstract]
Original face value		1,332,600	1,097,720
Book value		1,188,458	1,004,803
Gross unrealized gains		28,140	16,166
Gross unrealized losses		(2,475)	(8,839)
Carrying value	[1]	$ 1,214,123	$ 1,012,130
Number of securities | Security		98	80
Weighted average coupon		4.81%	4.64%
Weighted average yield	[2]	4.93%	4.77%
Weighted average maturity		28 years	28 years
Carrying value of collateral for repurchase agreements		$ 1,200,000	$ 973,200
RMBS [Member] | Fair Value through OCI [Member] | Over 10 Years [Member]
RMBS, Assets by Maturity [Abstract]
Original face value		381,975	474,467
Book value		319,399	423,006
Gross unrealized gains		5,604	4,045
Gross unrealized losses		(1,961)	(6,472)
Carrying value	[1],[3]	$ 323,042	$ 420,579
Number of securities | Security		28	34
Weighted average coupon		4.50%	4.49%
Weighted average yield	[2]	4.62%	4.59%
Weighted average maturity		27 years	28 years
RMBS [Member] | Fair Value through Earnings [Member] | Over 10 Years [Member]
RMBS, Assets by Maturity [Abstract]
Original face value		$ 950,625	$ 623,253
Book value		869,059	581,797
Gross unrealized gains		22,536	12,121
Gross unrealized losses		(514)	(2,367)
Carrying value	[1],[3]	$ 891,081	$ 591,551
Number of securities | Security		70	46
Weighted average coupon		4.93%	4.74%
Weighted average yield	[2]	5.04%	4.90%
Weighted average maturity		28 years	28 years

[1] See Note 9 regarding the estimation of fair value, which approximates carrying value for all securities.

[2] The weighted average yield is based on the most recent gross monthly interest income, which is then annualized and divided by the book value of settled securities.

[3] The Company used an implied AAA rating for the Agency RMBS.