Income Taxes - Reconciliation of GAAP Net Income to Estimated REIT Taxable Income (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2022	Mar. 31, 2021
Income Tax Disclosure [Abstract]
GAAP net income (loss)	$ (66,434)	$ 71,327
Book to tax differences:
TRS income	(1)	(7)
Premium amortization expense	(41)	(48)
Loss on Agency Securities, trading	254,389	62,586
U.S. Treasury Securities	78,387	28
Changes in interest rate contracts	(250,900)	(122,195)
Gain on Security Sales	0	(7,354)
Amortization of deferred hedging costs	(39,581)	(41,867)
Other	550	417
Estimated REIT taxable loss	$ (23,631)	$ (37,113)