Fair Value of Financial Instruments (Details) - USD ($) $ in Thousands	Sep. 30, 2022	Dec. 31, 2021
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Net Amount of Assets Presented in the Balance Sheet	$ 13,865	$ 7,969
Net Amount of Liabilities Presented in the Balance Sheet	99,670	0
Fair Value, Measurements, Recurring
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
MBS	3,150,306	3,181,839
Mortgage loans held for investment, at fair value	3,073	4,268
Total assets carried at fair value	3,167,244	3,194,076
Total liabilities carried at fair value	99,670	0
Fair Value, Measurements, Recurring | Level 1
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
MBS	0	0
Mortgage loans held for investment, at fair value	0	0
Total assets carried at fair value	3,047	0
Total liabilities carried at fair value	0	0
Fair Value, Measurements, Recurring | Level 2
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
MBS	3,150,124	3,181,041
Mortgage loans held for investment, at fair value	0	0
Total assets carried at fair value	3,160,942	3,189,010
Total liabilities carried at fair value	99,670	0
Fair Value, Measurements, Recurring | Level 3
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
MBS	182	798
Mortgage loans held for investment, at fair value	3,073	4,268
Total assets carried at fair value	3,255	5,066
Total liabilities carried at fair value	0	0
Fair Value, Measurements, Recurring | Options on U.S. Treasury futures
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Net Amount of Assets Presented in the Balance Sheet	3,047	0
Fair Value, Measurements, Recurring | Options on U.S. Treasury futures | Level 1
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Net Amount of Assets Presented in the Balance Sheet	3,047	0
Fair Value, Measurements, Recurring | Options on U.S. Treasury futures | Level 2
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Net Amount of Assets Presented in the Balance Sheet	0	0
Fair Value, Measurements, Recurring | Options on U.S. Treasury futures | Level 3
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Net Amount of Assets Presented in the Balance Sheet	0	0
Fair Value, Measurements, Recurring | Interest rate swaptions
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Net Amount of Assets Presented in the Balance Sheet	0	3,202
Fair Value, Measurements, Recurring | Interest rate swaptions | Level 1
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Net Amount of Assets Presented in the Balance Sheet	0	0
Fair Value, Measurements, Recurring | Interest rate swaptions | Level 2
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Net Amount of Assets Presented in the Balance Sheet	0	3,202
Fair Value, Measurements, Recurring | Interest rate swaptions | Level 3
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Net Amount of Assets Presented in the Balance Sheet	0	0
Fair Value, Measurements, Recurring | TBA securities | Long position
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Net Amount of Assets Presented in the Balance Sheet	10,818	4,767
Net Amount of Liabilities Presented in the Balance Sheet	99,670	0
Fair Value, Measurements, Recurring | TBA securities | Level 1 | Long position
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Net Amount of Assets Presented in the Balance Sheet	0	0
Net Amount of Liabilities Presented in the Balance Sheet	0	0
Fair Value, Measurements, Recurring | TBA securities | Level 2 | Long position
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Net Amount of Assets Presented in the Balance Sheet	10,818	4,767
Net Amount of Liabilities Presented in the Balance Sheet	99,670	0
Fair Value, Measurements, Recurring | TBA securities | Level 3 | Long position
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Net Amount of Assets Presented in the Balance Sheet	0	0
Net Amount of Liabilities Presented in the Balance Sheet	$ 0	$ 0