Consolidated Balance Sheets - USD ($) $ in Thousands	Sep. 30, 2022	Dec. 31, 2021
Assets [Abstract]
Cash and cash equivalents	$ 260,385	$ 366,023
Cash collateral posted to counterparties	246,168	55,284
Mortgage-backed securities (including pledged of $2,903,659 and $3,011,319, respectively), at fair value	3,150,306	3,181,839
Mortgage loans held for investment, at fair value	3,073	4,268
Due from counterparties	352,310	2,771
Derivative assets	13,865	7,969
Accrued interest receivable	16,090	14,184
Other assets, net	7,368	7,400
Total assets	4,049,565	3,639,738
Liabilities:
Repurchase agreements	3,009,269	2,849,916
Due to counterparties	147,925	2,471
Derivative liabilities	99,670	0
Cash collateral posted by counterparties	0	1,834
Accrued interest payable	4,909	1,365
Accrued dividends payable	8,151	6,541
Other liabilities	8,374	6,332
Total liabilities	3,278,298	2,868,459
Stockholders' Equity Attributable to Parent [Abstract]
Preferred stock, par value $0.01 per share; 50,000,000 shares authorized; 4,460,000 and 4,460,000 shares issued and outstanding, respectively ($111,500 and $111,500 aggregate liquidation preference, respectively)	107,843	107,843
Common stock, par value $0.01 per share, 90,000,000 shares authorized; 46,350,130 and 36,665,805 shares issued and outstanding, respectively	463	367
Additional paid-in capital	1,264,831	1,107,792
Accumulated other comprehensive (loss) income	(196,629)	6,729
Accumulated deficit	(405,241)	(451,452)
Total shareholders’ equity	771,267	771,279
Total liabilities and shareholders’ equity	$ 4,049,565	$ 3,639,738