DERIVATIVE FINANCIAL INSTRUMENTS - Schedule of Fair Value Hedges (Details) - USD ($) $ in Millions	Mar. 31, 2024	Mar. 31, 2023
Long-term borrowings
Fair Value, Option, Quantitative Disclosures [Line Items]
Carrying Value of Hedged Items	$ 871	$ 879
Time deposits - brokered
Fair Value, Option, Quantitative Disclosures [Line Items]
Carrying Value of Hedged Items	334
Currently Designated \| Long-term borrowings
Fair Value, Option, Quantitative Disclosures [Line Items]
Cumulative Fair Value Hedging Adjustment Included in the Carrying Value of Hedged Items	0	5
Currently Designated \| Time deposits - brokered
Fair Value, Option, Quantitative Disclosures [Line Items]
Cumulative Fair Value Hedging Adjustment Included in the Carrying Value of Hedged Items	0
No Longer Designated \| Long-term borrowings
Fair Value, Option, Quantitative Disclosures [Line Items]
Cumulative Fair Value Hedging Adjustment Included in the Carrying Value of Hedged Items	0	$ 0
No Longer Designated \| Time deposits - brokered
Fair Value, Option, Quantitative Disclosures [Line Items]
Cumulative Fair Value Hedging Adjustment Included in the Carrying Value of Hedged Items	$ 0

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.

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Topic 825
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 30
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147482907/825-10-50-30

Reference 2: http://www.xbrl.org/2003/role/disclosureRef
-Topic 825
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 31
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147482907/825-10-50-31

Reference 3: http://www.xbrl.org/2003/role/disclosureRef
-Topic 825
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 32
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147482907/825-10-50-32

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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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