Fair Value of Financial Instruments - Summary of Assets and Liabilities Measured at Fair Value on a Recurring Basis (Details) - USD ($) $ in Thousands	Dec. 31, 2022	Dec. 31, 2021
Assets at Fair Value:
Agency Securities	$ 187,945	$ 1,387,845
U.S. Treasury Securities		4,605,354
Derivatives, at fair value	984,456	199,073
Liabilities at Fair Value:
Derivatives, at fair value	13,016	10,900
U.S. Treasury Securities
Assets at Fair Value:
U.S. Treasury Securities		198,833
Fair Value, Measurements, Recurring
Assets at Fair Value:
Agency Securities	8,198,591	4,406,521
Derivatives, at fair value	984,456	199,073
Liabilities at Fair Value:
Derivatives, at fair value	13,016	10,900
Fair Value, Measurements, Recurring | U.S. Treasury Securities
Assets at Fair Value:
U.S. Treasury Securities		198,833
Fair Value, Measurements, Recurring | Level 1
Assets at Fair Value:
Agency Securities	0	0
Derivatives, at fair value	94	0
Liabilities at Fair Value:
Derivatives, at fair value	0	0
Fair Value, Measurements, Recurring | Level 1 | U.S. Treasury Securities
Assets at Fair Value:
U.S. Treasury Securities		198,833
Fair Value, Measurements, Recurring | Level 2
Assets at Fair Value:
Agency Securities	8,198,591	4,406,521
Derivatives, at fair value	984,362	199,073
Liabilities at Fair Value:
Derivatives, at fair value	13,016	10,900
Fair Value, Measurements, Recurring | Level 2 | U.S. Treasury Securities
Assets at Fair Value:
U.S. Treasury Securities		0
Fair Value, Measurements, Recurring | Level 3
Assets at Fair Value:
Agency Securities	0	0
Derivatives, at fair value	0	0
Liabilities at Fair Value:
Derivatives, at fair value	$ 0	0
Fair Value, Measurements, Recurring | Level 3 | U.S. Treasury Securities
Assets at Fair Value:
U.S. Treasury Securities		$ 0