SECURITIES - Unrealized Loss Position (Details) $ in Thousands		Dec. 31, 2024 USD ($) security	Dec. 31, 2023 USD ($) security
Unrealized Loss Position For:
Estimated Fair Value	[1]	$ 69,756,447	$ 69,613,565
Gross unrealized losses		(2,538,784)	(2,230,646)
Agency Mortgage-Backed Securities
Unrealized Loss Position For:
Estimated Fair Value		8,103,982	15,490,571
Gross unrealized losses		$ (1,021,904)	$ (1,340,450)
Number of securities | security		1,411	1,763
Agency Mortgage-Backed Securities | Less than 12 months
Unrealized Loss Position For:
Estimated Fair Value		$ 49,820	$ 35,453
Gross unrealized losses		$ (1,477)	$ (418)
Number of securities | security		34	16
Agency Mortgage-Backed Securities | 12 Months or more
Unrealized Loss Position For:
Estimated Fair Value		$ 8,054,162	$ 15,455,118
Gross unrealized losses		$ (1,020,427)	$ (1,340,032)
Number of securities | security		1,377	1,747

[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.