Mortgage-Backed Securities - Gross Unrealized Losses (Details)	Sep. 30, 2022 USD ($)	Dec. 31, 2021 USD ($)
Investments [Line Items]
Allowance for credit loss	$ 0	$ 0
Agency MBS
Investments [Line Items]
Fair value, Less than 12 Months	362,885,000	1,051,233,000
Gross Unrealized Losses, Less than 12 Month	$ (24,993,000)	$ (20,118,000)
Number of Securities, Less than 12 Months	81	23
Fair value, 12 Months or Longer	$ 705,141,000	$ 0
Gross Unrealized Losses, 12 Months or Longer	$ (169,259,000)	$ 0
Number of Securities, 12 Months or Longer	17	0
Non-Agency MBS
Investments [Line Items]
Fair value, Less than 12 Months	$ 53,113,000	$ 11,667,000
Gross Unrealized Losses, Less than 12 Month	$ (2,120,000)	$ (247,000)
Number of Securities, Less than 12 Months	59	14
Fair value, 12 Months or Longer	$ 6,207,000	$ 1,241,000
Gross Unrealized Losses, 12 Months or Longer	$ (545,000)	$ (97,000)
Number of Securities, 12 Months or Longer	13	6

Amount of allowance for credit loss on investment in debt security measured at fair value with change in fair value recognized in other comprehensive income (available-for-sale).

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Amount of investment in debt security measured at fair value with change in fair value recognized in other comprehensive income (available-for-sale), in continuous unrealized loss position for more than 12 months, without allowance for credit loss. Includes beneficial interest in securitized financial asset.

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