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Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef
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Reference 2: http://www.xbrl.org/2003/role/disclosureRef
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Reference 1: http://www.xbrl.org/2003/role/exampleRef
-Topic 815
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Reference 2: http://www.xbrl.org/2009/role/commonPracticeRef
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Reference 3: http://www.xbrl.org/2009/role/commonPracticeRef
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Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef
-Topic 815
-SubTopic 30
-Name Accounting Standards Codification
-Section 50
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DERIVATIVES - Narrative (Details) - USD ($) $ in Millions	Sep. 30, 2025	Mar. 31, 2025	Dec. 31, 2024
Derivative [Line Items]
Notional amount	$ 305,510		$ 279,484
Net loss (pre-tax) on derivatives expected to be reclassified in next 12 months	396
Prepayable Fixed-Rate Afs Securities Portfolio
Derivative [Line Items]
Carrying amount of hedged assets	4,700		4,700
Nonprepayable Fixed-Rate Afs Securities Portfolio
Derivative [Line Items]
Carrying amount of hedged assets	3,600		$ 3,100
Interest rate contracts \| Cash Flow Hedging
Derivative [Line Items]
Notional amount	$ 466	$ 1,500