Consolidated Balance Sheets (Parenthetical) Details) - USD ($) $ in Thousands	Sep. 30, 2021	Dec. 31, 2020
Mortgage-backed securities (including pledged of $2,677,652 and $2,467,859, respectively), at fair value	$ 2,677,652	$ 2,467,859
Preferred Stock, Shares Authorized (in shares)	50,000,000	50,000,000
Preferred Stock, Shares Outstanding (in shares)	4,460,000	7,248,330
Preferred Stock, Shares Issued	4,460,000	7,248,330
Preferred Stock, Liquidation Preference, Value	$ 111,500	$ 181,208
Preferred Stock, Par or Stated Value Per Share	$ 0.01	$ 0.01
Common Stock, Shares Authorized	90,000,000	90,000,000
Common Stock, Shares, Issued	35,935,306	23,697,970
Common Stock, Shares, Outstanding	35,935,306	23,697,970
Common Stock, Par or Stated Value Per Share	$ 0.01	$ 0.01