SECURITIES - Component of Agency Mortgage-Backed Securities Portfolio by Issuing Agency Concentration (Details) - Agency Mortgage-Backed Securities - USD ($) $ in Thousands	Mar. 31, 2025	Dec. 31, 2024
Mortgage-Backed Securities Portfolio [Line Items]
Total	$ 68,329,720	$ 67,434,068
Fannie Mae
Mortgage-Backed Securities Portfolio [Line Items]
Total	63,937,187	63,211,517
Freddie Mac
Mortgage-Backed Securities Portfolio [Line Items]
Total	4,243,501	4,115,085
Ginnie Mae
Mortgage-Backed Securities Portfolio [Line Items]
Total	$ 149,032	$ 107,466

The fair value as of the balance sheet date of firm holdings in mortgages, mortgage backed securities (investment instruments that represent ownership of an undivided interest in a group of mortgages, where principal and interest from the individual mortgages are used to pay investors' principal and interest on the mortgage backed security) and asset-backed securities that are primarily paid from the cash flows of a discrete pool of receivables or other financial assets (such as credit-card receivables), either fixed or revolving, that by their terms convert into cash within a finite time period. Includes both pledged (to counterparties as collateral for financing transactions) and unpledged holdings.

Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef
-Topic 940
-SubTopic 320
-Name Accounting Standards Codification
-Section 45
-Paragraph 2
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147479035/940-320-45-2

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Balance Type:	debit
Period Type:	instant