SECURITIES - Unrealized Loss Position (Details) $ in Thousands		Mar. 31, 2025 USD ($) security	Dec. 31, 2024 USD ($) security
Unrealized Loss Position For:
Estimated Fair Value	[1]	$ 70,361,364	$ 69,756,447	[2]
Gross Unrealized Losses		(1,619,480)	(2,538,784)
Agency Mortgage-Backed Securities
Unrealized Loss Position For:
Estimated Fair Value		7,530,425	8,103,982
Gross Unrealized Losses		$ (792,229)	$ (1,021,904)
Number of Securities | security		1,320	1,411
Agency Mortgage-Backed Securities | Less than 12 months
Unrealized Loss Position For:
Estimated Fair Value		$ 28,285	$ 49,820
Gross Unrealized Losses		$ (547)	$ (1,477)
Number of Securities | security		9	34
Agency Mortgage-Backed Securities | 12 Months or more
Unrealized Loss Position For:
Estimated Fair Value		$ 7,502,140	$ 8,054,162
Gross Unrealized Losses		$ (791,682)	$ (1,020,427)
Number of Securities | security		1,311	1,377

[1] (3)Excludes $2.3 billion and $2.2 billion at March 31, 2025 and December 31, 2024, respectively, of non-Agency mortgage-backed securities in consolidated VIEs pledged as collateral and eliminated from the Company’s Consolidated Statements of Financial Condition. 

[2] (1)Derived from the audited consolidated financial statements at December 31, 2024.