GOODWILL AND CORE DEPOSIT INTANGIBLES - Schedule of Changes in Core Deposit Intangibles (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2025	Dec. 31, 2024	Dec. 31, 2023
Finite-lived Intangible Assets [Roll Forward]
Less: amortization for the period	$ (54)	$ (63)	$ (57)
Core Deposits
Finite-lived Intangible Assets [Roll Forward]
Balance at beginning of period, net of accumulated amortization	249	312
Less: amortization for the period	54	63
Balance at end of period, net of accumulated amortization	$ 195	$ 249	$ 312