Mortgage-Backed Securities - Gross Unrealized Losses (Details) $ in Thousands	Sep. 30, 2025 USD ($)	Dec. 31, 2024 USD ($)
Investments [Line Items]
Allowance for credit loss	$ 0	$ 0
Agency MBS
Investments [Line Items]
Fair value, Less than 12 Months	0	920
Gross Unrealized Losses, Less than 12 Month	$ 0	$ (3)
Number of Securities, Less than 12 Months	0	3
Fair value, 12 Months or Longer	$ 736,741	$ 814,443
Gross Unrealized Losses, 12 Months or Longer	$ (135,988)	$ (175,497)
Number of Securities, 12 Months or Longer	57	65
Non-Agency MBS
Investments [Line Items]
Fair value, Less than 12 Months	$ 298	$ 823
Gross Unrealized Losses, Less than 12 Month	$ (12)	$ (73)
Number of Securities, Less than 12 Months	2	2
Fair value, 12 Months or Longer	$ 1,677	$ 6,097
Gross Unrealized Losses, 12 Months or Longer	$ (42)	$ (200)
Number of Securities, 12 Months or Longer	5	10