GOODWILL AND OTHER INTANGIBLE ASSETS - Schedule of Other Intangible Assets (Details) - USD ($) $ in Millions	Dec. 31, 2025	Dec. 31, 2024
Finite-Lived Intangible Assets [Line Items]
Gross Carrying Amount	$ 539	$ 444
Accumulated Amortization	(394)	(348)
Net Carrying Value	145	96
Core deposit intangible
Finite-Lived Intangible Assets [Line Items]
Gross Carrying Amount	473	378
Accumulated Amortization	(335)	(293)
Net Carrying Value	138	85
Customer relationship
Finite-Lived Intangible Assets [Line Items]
Gross Carrying Amount	66	66
Accumulated Amortization	(59)	(55)
Net Carrying Value	$ 7	$ 11