Mortgage-Backed Securities - Gross Unrealized Losses (Details) $ in Thousands	Sep. 30, 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	1,716	3,926
Gross Unrealized Losses, Less than 12 Month	$ (39)	$ (149)
Number of Securities, Less than 12 Months	4	4
Fair value, 12 Months or Longer	$ 877,215	$ 932,682
Gross Unrealized Losses, 12 Months or Longer	$ (137,426)	$ (158,651)
Number of Securities, 12 Months or Longer	68	78
Non-Agency MBS
Investments [Line Items]
Fair value, Less than 12 Months	$ 562	$ 1,736
Gross Unrealized Losses, Less than 12 Month	$ (70)	$ (37)
Number of Securities, Less than 12 Months	1	8
Fair value, 12 Months or Longer	$ 7,813	$ 21,704
Gross Unrealized Losses, 12 Months or Longer	$ (267)	$ (989)
Number of Securities, 12 Months or Longer	14	41