SECURITIES - Summary of Residential Securities and CMBS (Details) $ in Thousands	12 Months Ended
	Dec. 31, 2024 USD ($)
Debt Securities, Available-For-Sale [Roll Forward]
Beginning balance January 1, 2024	$ 69,613,565	[1]
Purchases	29,266,556
Sales	(21,505,898)
Principal paydowns	(6,834,284)
(Amortization) / accretion	(98,172)
Fair value adjustment	(685,320)
Ending balance December 31, 2024	69,756,447	[1]
Agency Securities
Debt Securities, Available-For-Sale [Roll Forward]
Beginning balance January 1, 2024	66,308,788
Purchases	28,692,300
Sales	(20,566,652)
Principal paydowns	(6,114,284)
(Amortization) / accretion	(100,506)
Fair value adjustment	(785,578)
Ending balance December 31, 2024	67,434,068
Residential Credit Securities
Debt Securities, Available-For-Sale [Roll Forward]
Beginning balance January 1, 2024	3,082,333
Purchases	574,256
Sales	(802,933)
Principal paydowns	(706,226)
(Amortization) / accretion	1,692
Fair value adjustment	98,979
Ending balance December 31, 2024	2,248,101
Commercial securities
Debt Securities, Available-For-Sale [Roll Forward]
Beginning balance January 1, 2024	222,444
Purchases	0
Sales	(136,313)
Principal paydowns	(13,774)
(Amortization) / accretion	642
Fair value adjustment	1,279
Ending balance December 31, 2024	$ 74,278

[1] (2) Excludes $2.2 billion and $1.5 billion at December 31, 2024 and 2023, respectively, of non-Agency mortgage-backed securities in consolidated VIEs pledged as collateral and eliminated from the Company’s Consolidated Statements of Financial Condition.