SECURITIES - Narrative (Details) - USD ($)	3 Months Ended	9 Months Ended
Sep. 30, 2024	Sep. 30, 2023	Sep. 30, 2024	Sep. 30, 2023	Dec. 31, 2023
Schedule of Available-for-sale and Held-to-maturity Securities [Line Items]
Accrued interest receivable on debt securities	$ 117,000,000		$ 117,000,000		$ 125,000,000
Taxable interest income from securities	423,000,000	$ 290,000,000	1,200,000,000	$ 823,000,000
Offsetting of short-term receivables or payables recognized	$ 0		$ 0		$ 0
Held-to-maturity, zero expected credit loss, percent of portfolio	95.00%		95.00%
Allowance for credit loss recognized	$ 0		$ 0
Mortgage-backed securities
Schedule of Available-for-sale and Held-to-maturity Securities [Line Items]
Securitizations of mortgage loans	$ 48,000,000	$ 65,000,000	$ 181,000,000	$ 65,000,000

Debt Securities, Held To Maturity, Zero Expected Credit Loss, Percent Of Portfolio

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- Definition

Debt Securities, Interest Receivable

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- Definition

[Line Items] for Schedule of Available-for-sale and Held-to-maturity Securities [Table]

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- Definition

Amount, excluding accrued interest, of allowance for credit loss on investment in debt security measured at amortized cost (held-to-maturity).

+ References

Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef
-Topic 326
-SubTopic 20
-Name Accounting Standards Codification
-Section 45
-Paragraph 1
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147479344/326-20-45-1

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- Definition

Amount of operating interest income, including amortization and accretion of premiums and discounts, on securities subject to state, federal and other income tax.

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Name Regulation S-K (SK)
-Number 229
-Section 1402
-Paragraph a
-Publisher SEC

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- Definition

The cash inflow from securitizing loans held with the intention to resell in the near future.

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Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef
-Topic 230
-SubTopic 10
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Amount, before effects of master netting arrangements, of securities loaned to entities in exchange for collateral and funds outstanding borrowed in the form of a security repurchase agreement between the entity and another party for the sale and repurchase of identical or substantially the same securities at a date certain for a specified price. Includes liabilities not subject to a master netting arrangement.

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