Other Assets - Impact of Derivative Instruments on Earnings (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2023	Sep. 30, 2022	Sep. 30, 2023	Sep. 30, 2022
Deferred Costs, Capitalized, Prepaid, and Other Assets Disclosure [Abstract]
Income on swap variable receive leg	$ 41,427	$ 17,273	$ 113,062	$ 22,580
Expense on swap fixed pay leg	(12,563)	(13,623)	(36,416)	(28,730)
Unrealized mark-to-market gain	9,433	108,918	5,704	221,437
Net price alignment expense on margin collateral received	(3,437)	(752)	(8,247)	(752)
Net gain on TBA short positions	0	0	0	39,186
Total Net gain on derivatives used for risk management purposes	$ 34,860	$ 111,816	$ 74,103	$ 253,721