DERIVATIVES - Amounts Recorded in Balance Sheet (Details) - USD ($) $ in Millions	Mar. 31, 2026	Dec. 31, 2025
Closed Portfolios
Derivative [Line Items]
Amortized cost	$ 4,900	$ 5,100
Cumulative basis adjustment	(4)	17
Prepayable Fixed-Rate Afs Securities Portfolio
Derivative [Line Items]
Carrying amount of hedged assets	3,800	3,800
Total debt securities available for sale, at fair value
Derivative [Line Items]
Carrying amount of hedged assets	7,050	8,009
Cumulative amount of fair value hedging adjustments included in the carrying amount of the hedged items	$ 8	$ 48

Debt Securities, Available-for-Sale, Cumulative Basis Adjustment

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- Definition

Amortized cost of investment in debt security measured at fair value with change in fair value recognized in other comprehensive income (available-for-sale).

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Topic 944
-SubTopic 210
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- Definition

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/2009/role/commonPracticeRef
-Topic 815
-SubTopic 20
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- Definition

Amount of asset hedged in fair value hedging relationship.

+ References

Reference 1: http://www.xbrl.org/2003/role/exampleRef
-Topic 815
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- Definition

Amount of cumulative increase (decrease) in fair value of hedged asset in fair value hedge, attributable to hedged risk. Excludes cumulative basis adjustment related to foreign exchange risk.

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
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