Mortgage-Backed Securities - Gross Unrealized Losses (Details) $ in Thousands	Mar. 31, 2024 USD ($)	Dec. 31, 2023 USD ($)
Investments [Line Items]
Allowance for credit loss	$ 0	$ 0
Agency MBS
Investments [Line Items]
Fair value, Less than 12 Months	4,314	3,926
Gross Unrealized Losses, Less than 12 Month	$ (183)	$ (149)
Number of Securities, Less than 12 Months	4	4
Fair value, 12 Months or Longer	$ 887,563	$ 932,682
Gross Unrealized Losses, 12 Months or Longer	$ (176,389)	$ (158,651)
Number of Securities, 12 Months or Longer	71	78
Non-Agency MBS
Investments [Line Items]
Fair value, Less than 12 Months	$ 636	$ 1,736
Gross Unrealized Losses, Less than 12 Month	$ (12)	$ (37)
Number of Securities, Less than 12 Months	3	8
Fair value, 12 Months or Longer	$ 15,640	$ 21,704
Gross Unrealized Losses, 12 Months or Longer	$ (691)	$ (989)
Number of Securities, 12 Months or Longer	29	41