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PREMISES AND EQUIPMENT - Narrative (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2025	Dec. 31, 2024	Dec. 31, 2023
Property, Plant and Equipment [Line Items]
Depreciation and amortization expense	$ 314	$ 276	$ 225
Software and related projects
Property, Plant and Equipment [Line Items]
Impairment charges	$ 6	22
Software and related projects | Acquisition-related expenses
Property, Plant and Equipment [Line Items]
Impairment charges		$ 9

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Amount of write-down of assets recognized in the income statement. Includes, but is not limited to, losses from tangible assets, intangible assets and goodwill.

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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.

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