Fair Value of Financial Instruments - Schedule of Fair Value, Assets and Liabilities Measured on Recurring Basis (Details) - USD ($) $ in Thousands	Jun. 30, 2026	Dec. 31, 2025
Assets at Fair Value:
Derivatives	$ 668,063	$ 611,544
Liabilities at Fair Value:
Derivatives	75,175	19,303
Agency Securities
Assets at Fair Value:
Debt securities, Available-for-sale	20,596,296	19,417,640
U.S. Treasury Securities
Assets at Fair Value:
Debt securities, Available-for-sale	587,348	598,109
Level 1
Assets at Fair Value:
Derivatives	0	17,820
Liabilities at Fair Value:
Derivatives	62,289	93
Level 1 \| Agency Securities
Assets at Fair Value:
Debt securities, Available-for-sale	0	0
Level 1 \| U.S. Treasury Securities
Assets at Fair Value:
Debt securities, Available-for-sale	587,348	598,109
Level 2
Assets at Fair Value:
Derivatives	668,063	593,724
Liabilities at Fair Value:
Derivatives	12,886	19,210
Level 2 \| Agency Securities
Assets at Fair Value:
Debt securities, Available-for-sale	20,596,296	19,417,640
Level 2 \| U.S. Treasury Securities
Assets at Fair Value:
Debt securities, Available-for-sale	0	0
Level 3
Assets at Fair Value:
Derivatives	0	0
Liabilities at Fair Value:
Derivatives	0	0
Level 3 \| Agency Securities
Assets at Fair Value:
Debt securities, Available-for-sale	0	0
Level 3 \| U.S. Treasury Securities
Assets at Fair Value:
Debt securities, Available-for-sale	$ 0	$ 0