DERIVATIVES - Amounts Recorded in Balance Sheet (Details) - USD ($) $ in Millions	Dec. 31, 2023	Dec. 31, 2022
Derivative [Line Items]
Cumulative amount of fair value hedging adjustments included in the carrying amount of the hedged items	$ (17)	$ (27)
Debt Securities
Derivative [Line Items]
Carrying amount of hedged assets	7,253	0
Cumulative amount of fair value hedging adjustments included in the carrying amount of the hedged items	60	0
Debt Securities \| Closed Portfolios
Derivative [Line Items]
Carrying amount of hedged assets	5,900
Cumulative amount of fair value hedging adjustments included in the carrying amount of the hedged items	39
Amount of hedged item	4,000
Long-term borrowed funds
Derivative [Line Items]
Carrying amount of hedged liabilities	483	972
Cumulative amount of fair value hedging adjustments included in the carrying amount of the hedged items	$ (17)	$ (27)

Amount of hedged item in hedging relationship. Excludes hedged asset or liability.

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Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table.

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Topic 815
-SubTopic 40
-Name Accounting Standards Codification
-Section 50
-Paragraph 5
-Subparagraph (f)
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147480237/815-40-50-5

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Amount of asset hedged in fair value hedging relationship.

+ References

Reference 1: http://www.xbrl.org/2003/role/exampleRef
-Topic 815
-SubTopic 10
-Name Accounting Standards Codification
-Section 55
-Paragraph 181
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147480401/815-10-55-181

Reference 2: http://www.xbrl.org/2003/role/disclosureRef
-Topic 815
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-Name Accounting Standards Codification
-Section 50
-Paragraph 4EE
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Amount of cumulative increase (decrease) in fair value of hedged asset in fair value hedge, attributable to hedged risk.

+ References

Reference 1: http://www.xbrl.org/2003/role/exampleRef
-Topic 815
-SubTopic 10
-Name Accounting Standards Codification
-Section 55
-Paragraph 181
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147480401/815-10-55-181

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-Topic 815
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 4EE
-Subparagraph (b)
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147480434/815-10-50-4EE

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Amount of liability hedged in fair value hedging relationship.

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Topic 815
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 4EE
-Subparagraph (a)
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147480434/815-10-50-4EE

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Amount of cumulative increase (decrease) in fair value of hedged liability in fair value hedge, attributable to hedged risk.

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Topic 815
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 4EE
-Subparagraph (b)
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147480434/815-10-50-4EE

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